0001564590-21-052630 | 10-Q | XBRL Viewer

Net periodic benefit of defined benefit pension plans

286

348

Non-cash lease expense

108

110

(125)

(142)

Provision for doubtful receivables from clients

Provision for deferred income taxes

Share-based compensation

Net gain on disposal of operations

(380)

(83)

Non-cash foreign exchange gain

(5)

(10)

Other, net

(21)

Changes in operating assets and liabilities, net of effects from purchase of subsidiaries:

Accounts receivable

175

359

Fiduciary assets

(715)

(2,453)

Fiduciary liabilities

715

2,453

Other assets

(135)

(78)

Other liabilities

(199)

(217)

Provisions

Net cash from operating activities

1,877

1,206

CASH FLOWS FROM/(USED IN) INVESTING ACTIVITIES

Additions to fixed assets and software for internal use

(109)

(183)

Capitalized software costs

(40)

(49)

Acquisitions of operations, net of cash acquired

(66)

Net proceeds from sale of operations

726

212

Other, net

(22)

Net cash from/(used in) investing activities

577

(108)

CASH FLOWS USED IN FINANCING ACTIVITIES

Senior notes issued

282

Debt issuance costs

(2)

Repayments of debt

(970)

(319)

Repurchase of shares

(1,000)

Proceeds from issuance of shares

Payments of deferred and contingent consideration related to acquisitions

(19)

Cash paid for employee taxes on withholding shares

(8)

(14)

Dividends paid

(275)

(259)

Acquisitions of and dividends paid to non-controlling interests

(35)

(27)

Other, net

(3)

Net cash used in financing activities

(2,305)

(334)

INCREASE IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH

149

764

Effect of exchange rate changes on cash, cash equivalents and restricted cash

(24)

(5)

CASH, CASH EQUIVALENTS AND RESTRICTED CASH, BEGINNING OF PERIOD

^[1]

2,096

895

CASH, CASH EQUIVALENTS AND RESTRICTED CASH, END OF PERIOD

^[1]

$ 2,221

$ 1,654

[1]

Cash, cash equivalents and restricted cash included $6 million, $7 million, $7 million and $8 million of restricted cash at September 30, 2021, December 31, 2020, September 30, 2020 and December 31, 2019, respectively, which is included within prepaid and other current assets on our condensed consolidated balance sheets. Additionally, cash, cash equivalents and restricted cash included $53 million, $50 million, $56 million and $56 million of cash attributable to discontinued operations at September 30, 2021, December 31, 2020, September 30, 2020 and December 31, 2019, respectively, which is included within assets held for sale on our condensed consolidated balance sheets.

Condensed Consolidated Statements of Cash Flows (Unaudited) (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2019
Prepaid Expenses and Other Current Assets [Member]
Restricted cash	$ 6	$ 7	$ 7	$ 8
Assets Held for Sale [Member]
Cash attributable to discontinued operations	$ 53	$ 50	$ 56	$ 56

Condensed Consolidated Statements of Changes in Equity (Unaudited) - USD ($)
shares in Thousands, $ in Millions

Total

Shares outstanding [Member]

Ordinary shares and APIC [Member]

Retained earnings [Member]

Treasury shares [Member]

AOCL [Member]

^[1]

Total WTW shareholders' equity [Member]

Non-controlling interests [Member]

Equity, beginning balance at Dec. 31, 2019

$ 10,369

$ 10,687

$ 1,792

$ (3)

$ (2,227)

$ 10,249

$ 120

Equity, beginning balance (in shares) at Dec. 31, 2019

128,690

Increase (Decrease) in Stockholders' Equity [Roll Forward]

313

305

Dividends attributable to non-controlling interests

(88)

(1)

Issuance of shares under employee stock compensation plans

(220)

(219)

(1)

Issuance of shares under employee stock compensation plans (in shares)

Equity, ending balance at Mar. 31, 2020

10,389

10,703

2,009

(3)

(2,446)

10,263

126

Equity, ending balance (in shares) at Mar. 31, 2020

128,726

Increase (Decrease) in Stockholders' Equity [Roll Forward]

102

Dividends attributable to non-controlling interests

(88)

(12)

Issuance of shares under employee stock compensation plans

Issuance of shares under employee stock compensation plans (in shares)

Other

(3)

^[2]

(1)

Equity, ending balance at Jun. 30, 2020

(1)

10,456

10,713

2,015

(3)

(2,390)

10,335

121

Equity, ending balance (in shares) at Jun. 30, 2020

128,763

Increase (Decrease) in Stockholders' Equity [Roll Forward]

122

121

Dividends attributable to non-controlling interests

(89)

(9)

Issuance of shares under employee stock compensation plans

138

137

Issuance of shares under employee stock compensation plans (in shares)

108

^[2]

(2)

(9)

Equity, ending balance at Sep. 30, 2020

(5)

10,620

10,724

2,047

(3)

(2,253)

10,515

105

Equity, ending balance (in shares) at Sep. 30, 2020

128,871

Equity, beginning balance at Dec. 31, 2020

10,932

10,748

2,434

(3)

(2,359)

10,820

112

Equity, beginning balance (in shares) at Dec. 31, 2020

128,965

Increase (Decrease) in Stockholders' Equity [Roll Forward]

736

733

Dividends attributable to non-controlling interests

(92)

(17)

Issuance of shares under employee stock compensation plans

Issuance of shares under employee stock compensation plans (in shares)

^[2]

(52)

Equity, ending balance at Mar. 31, 2021

11,574

10,765

3,075

(3)

(2,311)

11,526

Equity, ending balance (in shares) at Mar. 31, 2021

128,974

Increase (Decrease) in Stockholders' Equity [Roll Forward]

186

184

Dividends attributable to non-controlling interests

(93)

(4)

Issuance of shares under employee stock compensation plans

Issuance of shares under employee stock compensation plans (in shares)

^[2]

(1)

Equity, ending balance at Jun. 30, 2021

(1)

11,715

10,785

3,166

(3)

(2,278)

11,670

Equity, ending balance (in shares) at Jun. 30, 2021

128,988

Increase (Decrease) in Stockholders' Equity [Roll Forward]

Shares repurchased

(1,000)

Shares repurchased (in shares)

(4,456)

907

903

Dividends attributable to non-controlling interests

(100)

(6)

Issuance of shares under employee stock compensation plans (in shares)

(81)

^[2]

(11)

(8)

(3)

Equity, ending balance at Sep. 30, 2021

$ 11,433

$ 10,786

$ 2,969

$ (3)

$ (2,359)

$ 11,393

$ 40

Equity, ending balance (in shares) at Sep. 30, 2021

124,596

[1]	Accumulated other comprehensive loss, net of tax (‘AOCL’).
[2]	Attributable to the divestiture of businesses that are less than wholly-owned or the acquisition of shares previously owned by minority interest holders.

Condensed Consolidated Statements of Changes in Equity (Unaudited) (Parenthetical) - $ / shares	3 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020
Statement Of Stockholders Equity [Abstract]
Dividends declared per share	$ 0.80	$ 0.71	$ 0.71	$ 0.68	$ 0.68	$ 0.68

Nature of Operations

9 Months Ended

Sep. 30, 2021

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Nature of Operations

Note 1 — Nature of Operations

Willis Towers Watson plc is a leading global advisory, broking and solutions company that helps clients around the world turn risk into a path for growth. The Company has more than 46,000 employees and services clients in more than 140 countries.

We design and deliver solutions that manage risk, optimize benefits, cultivate talent, and expand the power of capital to protect and strengthen institutions and individuals.

Our risk management services include strategic risk consulting (including providing actuarial analysis), a variety of due diligence services, the provision of practical on-site risk control services (such as health and safety and property loss control consulting), and analytical and advisory services (such as hazard modeling and reinsurance optimization studies). We also assist our clients with planning for addressing incidents or crises when they occur. These services include contingency planning, security audits and product tampering plans.

We help our clients enhance business performance by delivering consulting services, technology and solutions that optimize benefits and cultivate talent. Our services and solutions encompass such areas as employee benefits, total rewards, talent and benefits outsourcing. In addition, we provide investment advice to help our clients develop disciplined and efficient strategies to meet their investment goals and expand the power of capital.

As an insurance broker, we act as an intermediary between our clients and insurance carriers by advising on their risk management requirements, helping them to determine the best means of managing risk and negotiating and placing insurance with insurance carriers through our global distribution network.

We operate a private Medicare marketplace in the U.S. through which, along with our active employee marketplace, we help our clients move to a more sustainable economic model by capping and controlling the costs associated with healthcare benefits. We also provide direct-to-consumer sales of Medicare coverage.

We are not an insurance company, and therefore we do not underwrite insurable risks for our own account. We believe our broad perspective allows us to see the critical intersections between talent, assets and ideas - the dynamic formula that drives business performance.

Termination of Proposed Combination with Aon plc

On March 9, 2020, WTW and Aon plc (‘Aon’) issued an announcement disclosing that the respective boards of directors of WTW and Aon had reached agreement on the terms of a recommended acquisition of WTW by Aon. Under the terms of the agreement each WTW shareholder would receive 1.08 Aon ordinary shares for each WTW ordinary share. At the time of the announcement, it was estimated that upon completion of the combination, existing Aon shareholders would own approximately 63% and existing WTW shareholders would own approximately 37% of the combined company on a fully diluted basis.

The transaction was approved by the shareholders of both WTW and Aon during meetings of the respective shareholders held on August 26, 2020. On June 16, 2021, the U.S. Department of Justice filed suit in U.S. District Court in the District of Columbia against WTW and Aon, seeking to enjoin the proposed business combination between the two companies (among other relief). On July 26, 2021, WTW and Aon announced they had terminated the business combination agreement and that Aon had agreed to pay WTW $1 billion in connection with such termination, which was received by WTW on July 27, 2021 (the ‘Termination’ or the ‘Termination Agreement’). The $1 billion income receipt has been included in transaction and integration, net in the condensed consolidated statements of operations. Under the Termination Agreement, WTW and Aon on behalf of themselves and certain other related and affiliated parties, each agreed to release the other from all claims and actions arising out of or related to the business combination agreement and the transactions contemplated thereby, subject to certain exceptions.

Basis of Presentation and Recent Accounting Pronouncements

9 Months Ended

Sep. 30, 2021

Accounting Policies [Abstract]

Basis of Presentation and Recent Accounting Pronouncements

Note 2 — Basis of Presentation and Recent Accounting Pronouncements

Basis of Presentation

The accompanying unaudited quarterly condensed consolidated financial statements of Willis Towers Watson and our subsidiaries are presented in accordance with the rules and regulations of the SEC for quarterly reports on Form 10-Q and therefore do not include all of the information and footnotes required by U.S. GAAP. We have reclassified certain prior period amounts to conform to the current period presentation due to the recognition of discontinued operations and assets and liabilities as held-for-sale (see below for further discussion). In the opinion of management, these condensed consolidated financial statements reflect all adjustments, consisting of normal recurring adjustments, which are necessary for a fair presentation of the condensed consolidated financial statements and results for the interim periods. All intercompany accounts and transactions have been eliminated in consolidation. The condensed

consolidated financial statements should be read together with the Company’s Annual Report on Form 10-K, filed with the SEC on February 23, 2021, and may be accessed via EDGAR on the SEC’s web site at www.sec.gov.

The results of operations for the three and nine months ended September 30, 2021 are not necessarily indicative of the results that can be expected for the entire year. The Company experiences seasonal fluctuations of its revenue. Revenue is typically higher during the Company’s first and fourth quarters due primarily to the timing of broking-related activities. The results reflect certain estimates and assumptions made by management, including those estimates used in calculating acquisition consideration and fair value of tangible and intangible assets and liabilities, professional liability claims, estimated bonuses, valuation of billed and unbilled receivables, and anticipated tax liabilities that affect the amounts reported in the condensed consolidated financial statements and related notes.

Risks and Uncertainties Related to the COVID-19 Pandemic and the Related Economic Environment

The COVID-19 pandemic has had an adverse impact on global commercial activity, particularly on the global supply chain and workforce availability, and has contributed to significant volatility in the global financial markets including, among other effects, occasional declines in the equity markets, changes in interest rates and reduced liquidity on a global basis. With regard to the effects on our own business operations and those of our clients, suppliers and other third parties with whom we interact, the Company has regularly considered the impact of COVID-19 and the wider economic results on our business, taking into account our business resilience and continuity plans, financial modeling and stress testing of liquidity and financial resources.

Generally, the COVID-19 pandemic did not have a material adverse impact on our overall financial results during 2020 or on our results through the third quarter of 2021; however, during 2020 and through the first quarter of 2021, the COVID-19 pandemic had a negative impact on our revenue growth, primarily in our businesses that are discretionary in nature. We saw an increased demand for these services, which improved revenue growth, in the second and third quarters of 2021. We believe this positive trend could continue for the remainder of the year with some variability based on further disruptions to the supply chain, workforce availability, vaccination rates and further social-distancing orders in jurisdictions where we do business.

We have considered this outlook as part of the significant estimates and assumptions that are inherent in our financial statements, including the collectability of billed and unbilled receivables, the estimation of revenue, and the fair value of our reporting units, tangible and intangible assets and contingent consideration. Although the primary revenue impact of the pandemic has been on certain discretionary lines of business, non-discretionary lines of business have also been, to some extent, adversely affected and may be adversely affected in the future. Further, reduced economic activity or disruption in insurance markets could reduce the demand for or the extent of insurance coverage. Also, the increased frequency and severity of coverage disputes between our clients and (re)insurers arising out of the pandemic could increase our professional liability risk. In 2021, global labor market shifts have become more pronounced, having a negative effect on workforce availability, which could hamper our ability to grow our capacity on pace with increasing demand for our services. We expect the market for talent to remain highly competitive for at least the next several months. We will continue to monitor the situation and assess any implications to our business and our stakeholders.

The extent to which COVID-19 impacts our business and financial position will depend on future developments, which are difficult to predict. These future developments may include the severity and scope of the COVID-19 outbreak, which may unexpectedly change or worsen, and the types and duration of measures imposed by governmental authorities to contain the virus or address its impact. We continue to expect that the COVID-19 pandemic and the related impacts on the wider economic environment will negatively impact our revenue and operating results in fiscal 2021. We believe that these trends and uncertainties are similar to those faced by other comparable registrants as a result of the pandemic.

Recent Accounting Pronouncements

Not Yet Adopted

There are no pending accounting pronouncements that are expected to have a significant impact on our condensed consolidated financial statements.

Adopted

In December 2019, the FASB issued ASU No. 2019-12, Simplifying the Accounting for Income Taxes, which clarifies and amends existing guidance, including removing certain exceptions to the general principles of accounting for income taxes. Some of the changes must be applied on a retrospective or modified retrospective basis while others must be applied on a prospective basis. The Company adopted this guidance as it became effective on January 1, 2021 without any impact to our condensed consolidated financial statements.

Divestitures

9 Months Ended

Sep. 30, 2021

Dispositions [Abstract]

Divestitures

Note 3 — Divestitures

Willis Re Divestiture

As part of the potential combination with Aon, the Company entered into an agreement with Arthur J. Gallagher & Co. (‘Gallagher’), a leading global provider of insurance, risk management and consulting services, to sell its treaty-reinsurance business (‘Willis Re’)

and certain of the Company’s corporate risk and broking and health and benefit businesses. Upon termination of the Aon combination, the definitive agreement with Gallagher automatically terminated in accordance with its terms.

On August 13, 2021, the Company entered into a new definitive agreement to sell Willis Re to Gallagher for total upfront cash consideration of $3.25 billion plus an earnout payable in 2025 of up to $750 million in cash, subject to certain adjustments. The completion of the deal is subject to required regulatory approvals and clearances, as well as other customary closing conditions, and is expected to be completed no later than the end of the first quarter of 2022. The Company will account for the earnout as a gain contingency and therefore will not record any receivables upon close. Rather, the earnout will be recognized in the Company’s condensed consolidated financial statements, if it is received, in 2025.

After the divestiture is complete, upon satisfaction or waiver of the closing conditions, a number of services are expected to continue under a Transition Services Agreement.

In connection with the pending transaction, the Company has reclassified the results of its Willis Re operations as discontinued operations on its condensed consolidated statements of comprehensive income and has reclassified Willis Re assets and liabilities as held for sale on its condensed consolidated balance sheets. Willis Re was previously included in the Investment, Risk and Reinsurance segment.

The following selected financial information relates to the operations of Willis Re for the periods presented:

	Three Months Ended September 30,					Nine Months Ended September 30,
	2021			2020		2021		2020
Revenue from discontinued operations	$	111		$	112	$	668	$	642
Costs of providing services
Salaries and benefits		97			93		291		281
Other operating expenses		29			12		60		43
Depreciation and amortization		—			—		1		2
Total costs of providing services		126			105		352		326
Other income, net		—			—		1		3
(Loss)/income from discontinued operations before income taxes	$	(15	)	$	7	$	317	$	319

The expense amounts reflected above represent only the direct costs attributable to the Willis Re business and exclude allocations of corporate costs that will be retained following the sale. Neither the discontinued operations presented above, nor the unallocated corporate costs, reflect the impact of any cost reimbursement that will be received under a Transition Services Agreement following the closing of the transaction upon the satisfaction or waiver of closing conditions.

The following table summarizes the total assets and liabilities of Willis Re classified as held for sale within our condensed consolidated balance sheets at the balance sheet dates presented:

	September 30, 2021		December 31, 2020
Assets held for sale:
Cash and cash equivalents	$	53	$	50
Fiduciary assets		3,853		3,157
Accounts receivable, net		199		147
Fixed assets, net		1		1
Goodwill		812		812
Other intangible assets, net		8		8
Right-of-use assets		1		1
Other assets		34		40
Total assets held for sale	$	4,961	$	4,216
Liabilities held for sale:
Fiduciary liabilities	$	3,853	$	3,157
Deferred revenue and accrued expenses		101		118
Liability for pension benefits		1		2
Lease liabilities		1		1
Provision for liabilities		1		1
Other liabilities		163		126
Total liabilities held for sale	$	4,120	$	3,405

Certain amounts included in the condensed consolidated balance sheets have been excluded from the held-for-sale balances disclosed since the assets are not transferring under the terms of the sale agreement, and instead will be settled by the Company. At September 30, 2021 and December 31, 2020, these excluded amounts are comprised of fiduciary assets of $3.8 billion and $3.0 billion, respectively, and their corresponding equal fiduciary liabilities, and accounts receivable, net balances of $155 million and $100 million, respectively.

Miller Divestiture

On March 1, 2021, the Company completed the transaction to sell its U.K.-based, majority-owned wholesale subsidiary Miller for final total consideration of GBP 623 million ($818 million), which includes amounts paid to the minority shareholder. The $356 million net tax-exempt gain on the sale was included in Other income, net in the condensed consolidated statement of comprehensive income for the nine months ended September 30, 2021. Prior to disposal, Miller was included within the Investment, Risk and Reinsurance segment.

Max Matthiessen Divestiture

In September 2020, the Company completed the transaction to sell its Swedish majority-owned subsidiary MM Holding AB (‘Max Matthiessen’) for total consideration of SEK 2.3 billion ($262 million) plus certain other adjustments, resulting in a tax-exempt gain on the sale of $86 million, which was included in Other income, net in the consolidated statement of comprehensive income during the year ended December 31, 2020. Of the total consideration, the Company financed a SEK 600 million ($68 million) note repayable by the purchaser. The note has no fixed term but is repayable subject to certain terms and conditions and bears an interest rate that could range from 5% to 10%, increasing the longer the note remains outstanding. This note receivable is included in Other non-current assets in the condensed consolidated balance sheet. Prior to disposal, Max Matthiessen was included within the Investment, Risk and Reinsurance segment.

Revenue

9 Months Ended

Sep. 30, 2021

Revenue From Contract With Customer [Abstract]

Note 4 — Revenue

All periods presented have been recast to exclude the revenue and receivables of Willis Re, which have been reclassified as discontinued operations and assets held for sale, respectively, on the Company’s condensed consolidated financial statements (see Note 3 – Divestitures).

Disaggregation of Revenue

The Company reports revenue by segment in Note 5 — Segment Information. The following tables present revenue by service offering and segment, as well as reconciliations to total revenue for the three and nine months ended September 30, 2021 and 2020. Along with reimbursable expenses and other, total revenue by service offering represents our revenue from customer contracts.

	Three Months Ended September 30,
	HCB				CRB				IRR				BDA				Corporate ⁽ⁱ⁾						Total
	2021		2020		2021		2020		2021		2020		2021		2020		2021			2020			2021		2020
Broking	$	68	$	62	$	621	$	592	$	11	$	71	$	119	$	100	$	—		$	—		$	819	$	825
Consulting		561		529		39		31		111		97		—		—		2			1			713		658
Outsourced administration		122		126		17		16		4		4		123		126		—			—			266		272
Other		97		77		4		4		46		48		—		—		1			1			148		130
Total revenue by service offering		848		794		681		643		172		220		242		226		3			2			1,946		1,885
Reimbursable expenses and other ⁽ⁱ⁾		10		10		—		—		2		1		2		2		(9	)		(10	)		5		3
Total revenue from customer contracts	$	858	$	804	$	681	$	643	$	174	$	221	$	244	$	228	$	(6	)	$	(8	)	$	1,951	$	1,888
Interest and other income ⁽ⁱⁱ⁾		4		2		16		6		—		—		—		—		2			1			22		9
Total revenue	$	862	$	806	$	697	$	649	$	174	$	221	$	244	$	228	$	(4	)	$	(7	)	$	1,973	$	1,897

	Nine Months Ended September 30,
	HCB				CRB				IRR				BDA				Corporate ⁽ⁱ⁾					Total
	2021		2020		2021		2020		2021		2020		2021		2020		2021			2020		2021		2020
Broking	$	248	$	216	$	2,026	$	1,877	$	67	$	238	$	391	$	288	$	—		$	—	$	2,732	$	2,619
Consulting		1,732		1,642		128		118		348		282		—		—		6			4		2,214		2,046
Outsourced administration		377		376		58		57		12		11		377		378		—			—		824		822
Other		196		165		12		6		188		185		—		—		3			3		399		359
Total revenue by service offering		2,553		2,399		2,224		2,058		615		716		768		666		9			7		6,169		5,846
Reimbursable expenses and other ⁽ⁱ⁾		33		36		1		1		4		6		6		7		(9	)		2		35		52
Total revenue from customer contracts	$	2,586	$	2,435	$	2,225	$	2,059	$	619	$	722	$	774	$	673	$	—		$	9	$	6,204	$	5,898
Interest and other income ⁽ⁱⁱ⁾		10		14		71		31		—		—		3		—		4			3		88		48
Total revenue	$	2,596	$	2,449	$	2,296	$	2,090	$	619	$	722	$	777	$	673	$	4		$	12	$	6,292	$	5,946

______________

(i)

Reimbursable expenses and other, as well as Corporate revenue, are excluded from segment revenue, but included in total revenue on the condensed consolidated statements of comprehensive income. Amounts included in Corporate revenue may include eliminations, adjustments to reserves and impacts from hedged revenue transactions.

(ii)

Interest and other income is included in segment revenue and total revenue. However, it has been presented separately in the above tables because it does not arise directly from contracts with customers. The significant increase in CRB’s interest and other income resulted from book-of-business settlements.

The following tables present revenue by the geography where our work is performed for the three and nine months ended September 30, 2021 and 2020. Reconciliations to total revenue on our condensed consolidated statements of comprehensive income and to segment revenue are shown in the tables above.

	Three Months Ended September 30,
	HCB				CRB				IRR				BDA				Corporate				Total
	2021		2020		2021		2020		2021		2020		2021		2020		2021		2020		2021		2020
North America	$	485	$	465	$	310	$	287	$	45	$	39	$	239	$	224	$	2	$	1	$	1,081	$	1,016
Great Britain		137		120		143		138		86		117		—		—		—		—		366		375
Western Europe		135		129		116		112		18		44		—		—		1		1		270		286
International		91		80		112		106		23		20		3		2		—		—		229		208
Total revenue by geography	$	848	$	794	$	681	$	643	$	172	$	220	$	242	$	226	$	3	$	2	$	1,946	$	1,885

	Nine Months Ended September 30,
	HCB				CRB				IRR				BDA				Corporate				Total
	2021		2020		2021		2020		2021		2020		2021		2020		2021		2020		2021		2020
North America	$	1,430	$	1,403	$	865	$	816	$	136	$	117	$	760	$	660	$	7	$	5	$	3,198	$	3,001
Great Britain		427		363		471		435		343		401		—		—		—		—		1,241		1,199
Western Europe		444		404		521		483		69		139		—		—		2		2		1,036		1,028
International		252		229		367		324		67		59		8		6		—		—		694		618
Total revenue by geography	$	2,553	$	2,399	$	2,224	$	2,058	$	615	$	716	$	768	$	666	$	9	$	7	$	6,169	$	5,846

Contract Balances

The Company reports accounts receivable, net on the condensed consolidated balance sheet, which includes billed and unbilled receivables and current contract assets. In addition to accounts receivable, net, the Company had the following non-current contract assets and deferred revenue balances at September 30, 2021 and December 31, 2020:

	September 30, 2021		December 31, 2020
Billed receivables, net of allowance for doubtful accounts of $44 million and $40 million	$	1,360	$	1,589
Unbilled receivables		511		445
Current contract assets		194		374
Accounts receivable, net	$	2,065	$	2,408
Non-current accounts receivable, net	$	23	$	34
Non-current contract assets	$	431	$	327
Deferred revenue	$	636	$	547

During the three and nine months ended September 30, 2021, revenue of $39 million and $408 million, respectively, was recognized that was reflected as deferred revenue at December 31, 2020. During the three months ended September 30, 2021, revenue of $262 million was recognized that was reflected as deferred revenue at June 30, 2021.

During the three and nine months ended September 30, 2021, the Company recognized revenue of $16 million and $62 million, respectively, related to performance obligations satisfied prior to 2021.

Performance Obligations

The Company has contracts for which performance obligations have not been satisfied as of September 30, 2021 or have been partially satisfied as of this date. The following table shows the expected timing for the satisfaction of the remaining performance obligations. This table does not include contract renewals or variable consideration, which was excluded from the transaction prices in accordance with the guidance on constraining estimates of variable consideration.

In addition, in accordance with ASC 606, Revenue From Contracts With Customers (‘ASC 606’), the Company has elected not to disclose the remaining performance obligations when one or both of the following circumstances apply:

•

Performance obligations which are part of a contract that has an original expected duration of less than one year, and

•

Performance obligations satisfied in accordance with ASC 606-10-55-18 (‘right to invoice’).

		Remainder of 2021				2022				2023 onward				Total
Revenue expected to be recognized on contracts as of September 30, 2021		$	174			$	546			$	788			$	1,508

Since most of the Company’s contracts are cancellable with less than one year’s notice and have no substantive penalty for cancellation, the majority of the Company’s remaining performance obligations as of September 30, 2021 have been excluded from the table above.

The entire disclosure of revenue from contract with customer to transfer good or service and to transfer nonfinancial asset. Includes, but is not limited to, disaggregation of revenue, credit loss recognized from contract with customer, judgment and change in judgment related to contract with customer, and asset recognized from cost incurred to obtain or fulfill contract with customer. Excludes insurance and lease contracts.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Topic 606
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Segment Information

9 Months Ended

Sep. 30, 2021

Segment Reporting [Abstract]

Segment Information

Note 5 — Segment Information

Willis Towers Watson has four reportable operating segments or business areas:

•

Human Capital and Benefits (‘HCB’)

•

Corporate Risk and Broking (‘CRB’)

•

Investment, Risk and Reinsurance (‘IRR’)

•

Benefits Delivery and Administration (‘BDA’)

Willis Towers Watson’s chief operating decision maker is its chief executive officer. We determined that the operational data used by the chief operating decision maker is at the segment level. Management bases strategic goals and decisions on these segments and the data presented below is used to assess the adequacy of strategic decisions and the methods of achieving these strategies and related financial results. Management evaluates the performance of its segments and allocates resources to them based on net operating income on a pre-tax basis.

The Company experiences seasonal fluctuations of its revenue. Revenue is typically higher during the Company’s first and fourth quarters due primarily to the timing of broking-related activities.

All periods presented have been recast to exclude the operating results of Willis Re, which was included within IRR and has been reclassified to discontinued operations (see Note 3 – Divestitures).

The following table presents segment revenue and segment operating income for our reportable segments for the three months ended September 30, 2021 and 2020.

	Three Months Ended September 30,
	HCB				CRB				IRR				BDA						Total
	2021		2020		2021		2020		2021		2020		2021			2020			2021		2020
Segment revenue	$	852	$	796	$	697	$	649	$	172	$	220	$	242		$	226		$	1,963	$	1,891

Segment operating income/(loss)	$	242	$	209	$	114	$	81	$	22	$	20	$	(19	)	$	(11	)	$	359	$	299

The following table presents segment revenue and segment operating income for our reportable segments for the nine months ended September 30, 2021 and 2020.

	Nine Months Ended September 30,
	HCB				CRB				IRR				BDA						Total
	2021		2020		2021		2020		2021		2020		2021			2020			2021		2020
Segment revenue	$	2,563	$	2,413	$	2,295	$	2,089	$	615	$	716	$	771		$	666		$	6,244	$	5,884

Segment operating income/(loss)	$	654	$	582	$	457	$	343	$	108	$	108	$	(22	)	$	(31	)	$	1,197	$	1,002

The following table presents reconciliations of the information reported by segment to the Company’s condensed consolidated statements of comprehensive income for the three and nine months ended September 30, 2021 and 2020.

	Three Months Ended September 30,						Nine Months Ended September 30,
	2021			2020			2021			2020
Revenue:
Total segment revenue	$	1,963		$	1,891		$	6,244		$	5,884
Reimbursable expenses and other		10			6			48			62
Revenue	$	1,973		$	1,897		$	6,292		$	5,946

Total segment operating income	$	359		$	299		$	1,197		$	1,002
Amortization		(85	)		(108	)		(285	)		(347	)
Transaction and integration, net ⁽ⁱ⁾		952			(42	)		877			(65	)
Unallocated, net ⁽ⁱⁱ⁾		(95	)		(83	)		(277	)		(310	)
Income from operations		1,131			66			1,512			280
Interest expense		(50	)		(61	)		(161	)		(184	)
Other income, net		105			156			617			321
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	$	1,186		$	161		$	1,968		$	417

(i)	Includes mainly transaction costs related to the proposed Aon combination prior to its termination. For the three and nine months ended September 30, 2021, includes the $1 billion income receipt related to the termination of the proposed Aon transaction.

(ii)

Includes certain costs, primarily related to corporate functions which are not directly related to the segments, and certain differences between budgeted expenses determined at the beginning of the year and actual expenses that we report for U.S. GAAP purposes. Additionally, these costs also include corporate costs that had previously been allocated to Willis Re, due to the reclassification of the Willis Re results as discontinued operations.

The Company does not currently provide asset information by reportable segment as it does not routinely evaluate the total asset position by segment.

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Income Taxes

9 Months Ended

Sep. 30, 2021

Income Tax Disclosure [Abstract]

Income Taxes

Note 6 — Income Taxes

Provision for income taxes on continuing operations for the three and nine months ended September 30, 2021 was $267 million and $386 million, respectively, compared to $42 million and $133 million for the three and nine months ended September 30, 2020, respectively. The effective tax rates were 22.5% and 19.6% for the three and nine months ended September 30, 2021, respectively, and 26.6% and 31.9% for the three and nine months ended September 30, 2020, respectively. These effective tax rates are calculated using extended values from our condensed consolidated statements of comprehensive income and are therefore more precise tax rates than can be calculated from rounded values. The current-quarter effective tax rate includes a $250 million estimated tax expense related to the income receipt of the termination payment, however the prior-year effective tax rate for the three months ended September 30, 2020 was higher due to an additional deferred tax expense related to the enacted U.K. statutory tax rate change. The prior-year effective tax rate for the nine months ended September 30, 2020 was higher due to additional tax expense recognized in connection with the temporary provisions of the Coronavirus Aid, Relief, and Economic Security (‘CARES’) Act.

The amounts above exclude the benefit from income tax attributable to discontinued operations of $3 million and the provision for income tax expense of $70 million for the three and nine months ended September 30, 2021, respectively, as well as the provisions for income tax expense of $4 million and $66 million for the three and nine months ended September 30, 2020, respectively.

The Company recognizes deferred tax balances related to the undistributed earnings of subsidiaries when it expects that it will recover those undistributed earnings in a taxable manner, such as through receipt of dividends or sale of the investments. Historically, we have not provided taxes on cumulative earnings of our subsidiaries that have been reinvested indefinitely. As a result of our plans to restructure or distribute accumulated earnings of certain foreign operations, we have recorded an estimate of foreign withholding and

state income taxes. In addition, in connection with the Willis Re divestiture, we have recorded an estimated deferred tax expense for certain Willis Re subsidiaries whose outside basis differences are no longer considered indefinitely reinvested. However, we assert that the historical cumulative earnings of our other subsidiaries are reinvested indefinitely, and therefore do not provide deferred tax liabilities on these amounts.

The Company records valuation allowances against net deferred tax assets based on whether it is more likely than not that the deferred tax assets will be realized. We have liabilities for uncertain tax positions under ASC 740 of $45 million, excluding interest and penalties. The Company believes the outcomes that are reasonably possible within the next 12 months may result in a reduction in the liability for uncertain tax positions of approximately $5 million to $9 million, excluding interest and penalties.

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Goodwill And Intangible Assets Disclosure [Abstract]

Goodwill and Other Intangible Assets

9 Months Ended

Sep. 30, 2021

Goodwill and Other Intangible Assets

Note 7 — Goodwill and Other Intangible Assets

The components of goodwill are outlined below for the nine months ended September 30, 2021:

	HCB			CRB			IRR			BDA		Total
Balance at December 31, 2020:
Goodwill, gross ⁽ⁱ⁾	$	4,346		$	2,378		$	882		$	3,278	$	10,884
Accumulated impairment losses		(130	)		(362	)		—			—		(492	)
Goodwill, net - December 31, 2020		4,216			2,016			882			3,278		10,392
Goodwill disposals		—			(7	)		(188	)		—		(195	)
Foreign exchange		(28	)		(25	)		2			—		(51	)
Balance at September 30, 2021:
Goodwill, gross		4,318			2,346			696			3,278		10,638
Accumulated impairment losses		(130	)		(362	)		—			—		(492	)
Goodwill, net - September 30, 2021	$	4,188		$	1,984		$	696		$	3,278	$	10,146

(i)	Excludes $812 million of goodwill associated with our IRR segment, which has been reclassified as assets held for sale on our condensed consolidated balance sheets at both September 30, 2021 and December 31, 2020 in conjunction with the pending divestiture of our Willis Re business.

Other Intangible Assets

The following table reflects changes in the net carrying amounts of the components of finite-lived intangible assets for the nine months ended September 30, 2021:

	Client relationships			Software			Trademark and trade name			Other			Total
Balance at December 31, 2020:
Intangible assets, gross	$	4,058		$	761		$	1,054		$	103		$	5,976
Accumulated amortization		(2,028	)		(659	)		(220	)		(34	)		(2,941	)
Intangible assets, net - December 31, 2020 ⁽ⁱ⁾		2,030			102			834			69			3,035
Intangible asset disposals		(47	)		—			(8	)		—			(55	)
Amortization		(193	)		(49	)		(32	)		(11	)		(285	)
Foreign exchange		(14	)		—			(1	)		1			(14	)
Balance at September 30, 2021:
Intangible assets, gross		3,837			742			1,040			104			5,723
Accumulated amortization		(2,061	)		(689	)		(247	)		(45	)		(3,042	)
Intangible assets, net - September 30, 2021	$	1,776		$	53		$	793		$	59		$	2,681

(i)	Excludes $8 million of intangible assets, net, which have been reclassified as assets held for sale on our condensed consolidated balance sheets at both September 30, 2021 and December 31, 2020 in conjunction with the pending divestiture of our Willis Re business.

The weighted-average remaining life of amortizable intangible assets at September 30, 2021 was 13.1 years.

The table below reflects the future estimated amortization expense for amortizable intangible assets for the remainder of 2021 and for subsequent years:

	Amortization
Remainder of 2021	$	84
2022		307
2023		254
2024		223
2025		203
Thereafter		1,610
Total	$	2,681

Derivative Financial Instruments

9 Months Ended

Sep. 30, 2021

Derivative Instruments And Hedging Activities Disclosure [Abstract]

Derivative Financial Instruments

Note 8 — Derivative Financial Instruments

We are exposed to certain foreign currency risks. Where possible, we identify exposures in our business that can be offset internally. Where no natural offset is identified, we may choose to enter into various derivative transactions. These instruments have the effect of reducing our exposure to unfavorable changes in foreign currency rates. The Company’s board of directors reviews and approves policies for managing this risk as summarized below. Additional information regarding our derivative financial instruments can be found in Note 10 — Fair Value Measurements and Note 16 — Accumulated Other Comprehensive Loss.

Foreign Currency Risk

Certain non-U.S. subsidiaries receive revenue and incur expenses in currencies other than their functional currency, and as a result, the foreign subsidiary’s functional currency revenue and/or expenses will fluctuate as the currency rates change. Additionally, the forecast Pounds sterling expenses of our London brokerage market operations may exceed their Pounds sterling revenue, and the entity with such operations may also hold significant foreign currency asset or liability positions in the condensed consolidated balance sheet. To reduce such variability, we use foreign exchange contracts to hedge against this currency risk.

These derivatives were designated as hedging instruments and at September 30, 2021 and December 31, 2020 had total notional amounts of $129 million and $340 million, respectively, and had net asset fair values of $3 million and $5 million, respectively. As part of and prior to our disposal of Miller (see Note 3 – Divestitures), and prior to their contract expiration, we closed derivatives designated as hedging instruments with notional values of $27 million that were outstanding at December 31, 2020.

At September 30, 2021, the Company estimates, based on current exchange rates, there will be $2 million of net derivative gains on forward exchange rates reclassified from accumulated other comprehensive loss into earnings within the next twelve months as the forecast transactions affect earnings. At September 30, 2021, our longest outstanding maturity was 1.6 years.

The effects of the material derivative instruments that are designated as hedging instruments on the condensed consolidated statements of comprehensive income for the three and nine months ended September 30, 2021 and 2020 are below. Amounts pertaining to the ineffective portion of hedging instruments and those excluded from effectiveness testing were immaterial for the three and nine months ended September 30, 2021 and 2020.

	(Loss)/gain recognized in OCL (effective element)
	Three months ended September 30,					Nine months ended September 30,
	2021			2020		2021		2020
Forward exchange contracts	$	(2	)	$	6	$	3	$	(21	)

Location of (loss)/gain reclassified from Accumulated OCL into income (effective element)	(Loss)/gain reclassified from Accumulated OCL into income (effective element)
	Three months ended September 30,						Nine months ended September 30,
	2021			2020			2021			2020
Revenue	$	(1	)	$	(2	)	$	(3	)	$	(4	)
Salaries and benefits		2			(2	)		5			(3	)
Discontinued operations		—			—			3			(1	)
	$	1		$	(4	)	$	5		$	(8	)

We also enter into foreign currency transactions, primarily to hedge certain intercompany loans and other balance sheet exposures in currencies other than the functional currency of a given entity. These derivatives are not generally designated as hedging instruments, and at September 30, 2021 and December 31, 2020, we had notional amounts of $1.9 billion and $1.5 billion, respectively, and had a net liability fair value of $21 million and a net asset fair value of $15 million, respectively.

The effects of derivatives that have not been designated as hedging instruments on the condensed consolidated statements of comprehensive income for the three and nine months ended September 30, 2021 and 2020 are as follows:

		(Loss)/gain recognized in income
		Three Months Ended September 30,					Nine Months Ended September 30,
Derivatives not designated as hedging instruments:	Location of (loss)/gain recognized in income	2021			2020		2021			2020
Forward exchange contracts	Other income, net	$	(7	)	$	5	$	(36	)	$	(15	)

Debt

9 Months Ended

Sep. 30, 2021

Debt Disclosure [Abstract]

Debt

Note 9 — Debt

Current debt consists of the following:

	September 30, 2021		December 31, 2020
Revolving $1.25 billion credit facility ⁽ⁱ⁾	$	—	$	—
5.750% senior notes due 2021		—		500
3.500% senior notes due 2021		—		449
2.125% senior notes due 2022⁽ⁱⁱ⁾		625		—
Current portion of collateralized facility		19		22
	$	644	$	971

Long-term debt consists of the following:

	September 30, 2021		December 31, 2020
Revolving $1.25 billion credit facility	$	—	$	—
Collateralized facility ⁽ⁱⁱⁱ⁾		19		33
2.125% senior notes due 2022⁽ⁱⁱ⁾		—		659
4.625% senior notes due 2023		249		249
3.600% senior notes due 2024		648		647
4.400% senior notes due 2026		546		546
4.500% senior notes due 2028		596		596
2.950% senior notes due 2029		727		726
6.125% senior notes due 2043		271		271
5.050% senior notes due 2048		395		395
3.875% senior notes due 2049		542		542
	$	3,993	$	4,664

(i)	The $1.25 billion revolving credit facility expires on March 7, 2022 (see Note 18 – Subsequent Event for additional information).

(ii)	Notes issued in Euro (€540 million).

(iii)

At September 30, 2021 and December 31, 2020, the Company had $82 million and $98 million, respectively, of renewal commissions receivables pledged as collateral for this facility.

Payments of 3.500% Senior Notes due 2021 and 5.750% Senior Notes due 2021

In August 2021, the Company called the $450 million 3.500% senior notes due to mature in September 2021. The Company repaid the principal and interest in August 2021 using cash on-hand.

In March 2021, the $500 million 5.750% senior notes matured. The principal and interest were repaid by the Company using cash on-hand.

At September 30, 2021 and December 31, 2020 we were in compliance with all financial covenants.

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

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Fair Value Measurements

9 Months Ended

Sep. 30, 2021

Fair Value Disclosures [Abstract]

Fair Value Measurements

Note 10 — Fair Value Measurements

The Company has categorized its assets and liabilities that are measured at fair value on a recurring and non-recurring basis into a three-level fair value hierarchy, based on the reliability of the inputs used to determine fair value as follows:

•

Level 1: refers to fair values determined based on quoted market prices in active markets for identical assets;

•

Level 2: refers to fair values estimated using observable market-based inputs or unobservable inputs that are corroborated by market data; and

•

Level 3: includes fair values estimated using unobservable inputs that are not corroborated by market data.

The following methods and assumptions were used by the Company in estimating its fair value disclosure for financial instruments:

•

Available-for-sale securities are classified as Level 1 because we use quoted market prices in determining the fair value of these securities.

•

Market values for our derivative instruments have been used to determine the fair value of forward foreign exchange contracts based on estimated amounts the Company would receive or have to pay to terminate the agreements, taking into account observable information about the current foreign currency forward rates. Such financial instruments are classified as Level 2 in the fair value hierarchy.

•

Contingent consideration payable is classified as Level 3, and we estimate fair value based on the likelihood and timing of achieving the relevant milestones of each arrangement, applying a probability assessment to each of the potential outcomes, which at times includes the use of a Monte Carlo simulation, and discounting the probability-weighted payout. Typically, milestones are based on revenue or earnings growth for the acquired business.

The following tables present our assets and liabilities measured at fair value on a recurring basis at September 30, 2021 and December 31, 2020:

		Fair Value Measurements on a Recurring Basis at September 30, 2021
	Balance Sheet Location	Level 1		Level 2		Level 3		Total
Assets:
Available-for-sale securities:
Mutual funds / exchange traded funds	Prepaid and other current assets and other non-current assets	$	9	$	—	$	—	$	9
Derivatives:
Derivative financial instruments ⁽ⁱ⁾	Prepaid and other current assets and other non-current assets	$	—	$	4	$	—	$	4
Liabilities:
Contingent consideration:
Contingent consideration ⁽ⁱⁱ⁾	Other current liabilities and other non-current liabilities	$	—	$	—	$	30	$	30
Derivatives:
Derivative financial instruments ⁽ⁱ⁾	Other current liabilities and other non-current liabilities	$	—	$	22	$	—	$	22

		Fair Value Measurements on a Recurring Basis at December 31, 2020
	Balance Sheet Location	Level 1		Level 2		Level 3		Total
Assets:
Available-for-sale securities:
Mutual funds / exchange traded funds	Prepaid and other current assets and other non-current assets	$	8	$	—	$	—	$	8
Derivatives:
Derivative financial instruments ⁽ⁱ⁾	Prepaid and other current assets and other non-current assets	$	—	$	27	$	—	$	27
Liabilities:
Contingent consideration:
Contingent consideration ⁽ⁱⁱ⁾	Other current liabilities and other non-current liabilities	$	—	$	—	$	45	$	45
Derivatives:
Derivative financial instruments ⁽ⁱ⁾	Other current liabilities and other non-current liabilities	$	—	$	7	$	—	$	7

(i)	See Note 8 — Derivative Financial Instruments for further information on our derivative investments.

(ii)

Probability weightings are based on our knowledge of the past and planned performance of the acquired entity to which the contingent consideration applies. The fair value weighted-average discount rates used in our material contingent consideration calculations were 11.01% and 9.46% at September 30, 2021 and December 31, 2020, respectively. The range of these discount rates was 3.53% - 13.00% at September 30, 2021. Using different probability weightings and discount rates could result in an increase or decrease of the contingent consideration payable.

The following table summarizes the change in fair value of the Level 3 liabilities:

Fair Value Measurements Using Significant Unobservable Inputs (Level 3)	September 30, 2021
Balance at December 31, 2020	$	45
Obligations assumed		—
Payments		(19	)
Realized and unrealized gains		5
Foreign exchange		(1	)
Balance at September 30, 2021	$	30

There were no significant transfers to or from Level 3 in the nine months ended September 30, 2021.

The following tables present our assets and liabilities not measured at fair value on a recurring basis at September 30, 2021 and December 31, 2020:

	September 30, 2021				December 31, 2020
	Carrying Value		Fair Value		Carrying Value		Fair Value
Assets:
Long-term note receivable	$	70	$	72	$	71	$	73
Liabilities:
Current debt	$	644	$	651	$	971	$	985
Long-term debt	$	3,993	$	4,560	$	4,664	$	5,488

The carrying values of our revolving credit facility and collateralized facility approximate their fair values. The fair values above, which exclude accrued interest, are not necessarily indicative of the amounts that the Company would realize upon disposition, nor do they indicate the Company’s intent or ability to dispose of the financial instruments. The fair values of our respective senior notes and long-term note receivable are considered Level 2 financial instruments as they are corroborated by observable market data.

Compensation And Retirement Disclosure [Abstract]

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Retirement Benefits

9 Months Ended

Sep. 30, 2021

Retirement Benefits

Note 11 — Retirement Benefits

Defined Benefit Plans and Post-retirement Welfare Plans

Willis Towers Watson sponsors both qualified and non-qualified defined benefit pension plans and other post-retirement welfare (‘PRW’) plans throughout the world. The majority of our plan assets and obligations are in the U.S. and the U.K. We have also included disclosures related to defined benefit plans in certain other countries, including Canada, France, Germany and Ireland. Together, these disclosed funded and unfunded plans represent 99% of Willis Towers Watson’s pension and PRW obligations and are disclosed herein.

Components of Net Periodic Benefit (Income)/Cost for Defined Benefit Pension and Post-retirement Welfare Plans

The following tables set forth the components of net periodic benefit (income)/cost for the Company’s defined benefit pension and PRW plans for the three and nine months ended September 30, 2021 and 2020:

	Three Months Ended September 30,
	2021												2020
	U.S.			U.K.			Other			PRW			U.S.			U.K.			Other			PRW
Service cost	$	19		$	4		$	6		$	—		$	18		$	4		$	5		$	—
Interest cost		24			14			3			—			32			18			4			1
Expected return on plan assets		(79	)		(42	)		(9	)		—			(73	)		(63	)		(8	)		—
Settlement		—			1			2			—			—			—			—			—
Amortization of net loss		8			7			1			1			9			6			—			—
Amortization of prior service credit		—			(4	)		1			(1	)		—			(4	)		—			(1	)
Net periodic benefit (income)/cost	$	(28	)	$	(20	)	$	4		$	—		$	(14	)	$	(39	)	$	1		$	—

	Nine Months Ended September 30,
	2021												2020
	U.S.			U.K.			Other			PRW			U.S.			U.K.			Other			PRW
Service cost	$	59		$	13		$	18		$	—		$	54		$	11		$	15		$	—
Interest cost		71			42			9			1			98			54			11			2
Expected return on plan assets		(233	)		(128	)		(28	)		—			(218	)		(184	)		(25	)		—
Settlement		1			2			2			—			2			1			—			—
Amortization of net loss		30			21			4			2			26			17			2			1
Amortization of prior service credit		—			(13	)		1			(3	)		—			(12	)		—			(3	)
Net periodic benefit (income)/cost	$	(72	)	$	(63	)	$	6		$	—		$	(38	)	$	(113	)	$	3		$	—

Amounts related to discontinued operations in the tables above were not material during the three and nine months ended September 30, 2021 and 2020.

Employer Contributions to Defined Benefit Pension Plans

The Company made $60 million of contributions to its U.S. plans for the nine months ended September 30, 2021 and does not anticipate making any additional contributions over the remainder of the fiscal year. The Company made contributions of $28 million to its U.K. plans for the nine months ended September 30, 2021 and anticipates making additional contributions of $14 million for the remainder of the fiscal year. The Company made contributions of $22 million to its other plans for the nine months ended September 30, 2021 and anticipates making additional contributions of $3 million for the remainder of the fiscal year.

Defined Contribution Plans

The Company made contributions to its defined contribution plans of $36 million and $118 million during the three and nine months ended September 30, 2021, respectively, and $39 million and $122 million during the three and nine months ended September 30, 2020, respectively.

The entire disclosure for retirement benefits.

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Commitments And Contingencies Disclosure [Abstract]

Leases

9 Months Ended

Sep. 30, 2021

Leases [Abstract]

Leases

Note 12 — Leases

The following tables present lease costs recorded on our condensed consolidated statements of comprehensive income for the three and nine months ended September 30, 2021 and 2020.

	Three Months Ended September 30,						Nine Months Ended September 30,
	2021			2020			2021			2020
Finance lease cost:
Amortization of right-of-use assets	$	—		$	1		$	1		$	2
Interest on lease liabilities		1			—			2			2
Operating lease cost		43			45			134			138
Short-term lease cost		—			1			1			1
Variable lease cost		13			14			39			37
Sublease income		(6	)		(6	)		(16	)		(16	)
Total lease cost, net	$	51		$	55		$	161		$	164

Amounts related to discontinued operations in the tables above were not material during the three and nine months ended September 30, 2021 and 2020.

The total lease cost is recognized in different locations in our condensed consolidated statements of comprehensive income. Amortization of the finance lease ROU assets is included in depreciation, while the interest cost component of these finance leases is included in interest expense. All other costs are included in other operating expenses.

Commitments and Contingencies

9 Months Ended

Sep. 30, 2021

Commitments and Contingencies

Note 13 — Commitments and Contingencies

Indemnification Agreements

Willis Towers Watson has various agreements which provide that it may be obligated to indemnify the other party to the agreement with respect to certain matters. Generally, these indemnification provisions are included in contracts arising in the normal course of business and in connection with the purchase and sale of certain businesses. It is not possible to predict the maximum potential amount of future payments that may become due under these indemnification agreements because of the conditional nature of the Company’s obligations and the unique facts of each particular agreement. However, we do not believe that any potential liability that may arise from such indemnity provisions is probable or material.

Legal Proceedings

In the ordinary course of business, the Company is subject to various actual and potential claims, lawsuits and other proceedings. Some of the claims, lawsuits and other proceedings seek damages in amounts which could, if assessed, be significant. We expect the impact of claims or demands not described below to be immaterial to the Company’s condensed consolidated financial statements. The Company also receives subpoenas in the ordinary course of business and, from time to time, receives requests for information in connection with governmental investigations.

Errors and omissions claims, lawsuits, and other proceedings arising in the ordinary course of business are covered in part by professional indemnity or other appropriate insurance. The terms of this insurance vary by policy year. Regarding self-insured risks, the Company has established provisions which are believed to be adequate in light of current information and legal advice, or, in

certain cases, where a range of loss exists, the Company accrues the minimum amount in the range if no amount within the range is a better estimate than any other amount. The Company adjusts such provisions from time to time according to developments. See Note 14 — Supplementary Information for Certain Balance Sheet Accounts for the amounts accrued at September 30, 2021 and December 31, 2020 in the condensed consolidated balance sheets.

On the basis of current information, the Company does not expect that the actual claims, lawsuits and other proceedings to which it is subject, or potential claims, lawsuits, and other proceedings relating to matters of which it is aware, will ultimately have a material adverse effect on its financial condition, results of operations or liquidity. Nonetheless, given the large or indeterminate amounts sought in certain of these actions, and the inherent unpredictability of litigation and disputes with insurance companies, it is possible that an adverse outcome or settlement in certain matters could, from time to time, have a material adverse effect on the Company’s results of operations or cash flows in particular quarterly or annual periods. In addition, given the early stages of some litigation or regulatory proceedings described below, it may not be possible to predict their outcomes or resolutions, and it is possible that any one or more of these events may have a material adverse effect on the Company.

The Company provides for contingent liabilities based on ASC 450, Contingencies, when it is determined that a liability, inclusive of defense costs, is probable and reasonably estimable. The contingent liabilities recorded are primarily developed actuarially. Litigation is subject to many factors which are difficult to predict so there can be no assurance that in the event of a material unfavorable result in one or more claims, we will not incur material costs.

Willis Towers Watson Merger-Related Securities Litigation

The Company was named as a defendant in two consolidated actions arising out of the 2016 ‘merger of equals’ between Towers Watson and Willis (the ‘Merger’), consisting of a consolidated shareholder class action pending in the United States District Court for the Eastern District of Virginia, captioned ‘In re Willis Towers Watson plc Proxy Litigation,’ Master File No. 1:17-cv-1338-AJT-JFA (the ‘Federal Action’), and a consolidated putative shareholder class action pending in the Delaware Court of Chancery, captioned ‘In re Towers Watson & Co. Stockholders Litigation,’ C.A. No. 2018-0132-KSJM (the ‘Delaware Action’). The complaints in these actions generally allege that the defendants omitted material information from the proxy disclosures relating to the Merger, including with respect to potential conflicts of interest, and, as a result, that Towers Watson’s stockholders approved the Merger based on inadequate information. Based on these allegations, among others, the complaint in the Federal Action asserts claims under Sections 14(a) and 20(a) of the Securities Exchange Act of 1934, and the complaint in the Delaware Action asserts claims under Delaware state law for breach of fiduciary duty and aiding and abetting breach of fiduciary duty.

On or about November 19, 2020, the parties to the Federal Action and the Delaware Action reached an agreement in principle to resolve the Federal Action and the Delaware Action for $75 million and $15 million, respectively. The Company agreed to the settlement and the payment of the settlement amounts to eliminate the distraction, burden, expense and uncertainty of further litigation. Further, in reaching the settlement, the parties understood and agreed that there is no admission of liability or wrongdoing by the Company or any of the other defendants in either the Federal Action or the Delaware Action. The Company and the other defendants expressly deny any liability or wrongdoing with respect to the matters alleged in the Federal Action and the Delaware Action.

On January 15, 2021, the parties to the Federal Action and the Delaware Action signed formal stipulations of settlement, which memorialized the terms of the agreement in principle, and which the plaintiffs in the Federal Action and the Delaware Action then filed with each of the respective courts. Also on January 15, 2021, the plaintiff in the Federal Action filed a motion to preliminarily approve the settlement. On January 21, 2021 the court in the Federal Action preliminarily approved the settlement, approved the form of notice to be disseminated to class members, and scheduled a final fairness hearing on the settlement for May 21, 2021. On May 21, 2021, following the final fairness hearing, the court in the Federal Action finally approved the settlement. On January 25, 2021 the court in the Delaware Action approved the form of notice to be disseminated to class members and scheduled a final fairness hearing on the settlement for May 25, 2021. On May 25, 2021, following the final fairness hearing, the court in the Delaware Action finally approved the settlement. The Company made the $90 million aggregate settlement payment in escrow in February 2021.

During 2020 the Company recognized $65 million of expense, net of $25 million of insurance and other recoveries. Additional insurance recoveries are possible.

Supplementary Information for Certain Balance Sheet Accounts

9 Months Ended

Sep. 30, 2021

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Supplementary Information for Certain Balance Sheet Accounts

Note 14 — Supplementary Information for Certain Balance Sheet Accounts

Additional details of specific balance sheet accounts are detailed below. The information at both dates presented excludes the assets and liabilities of Willis Re, which have been reclassified to held for sale as appropriate on the condensed consolidated balance sheets.

Deferred revenue and accrued expenses consist of the following:

	September 30, 2021		December 31, 2020
Accounts payable, accrued liabilities and deferred income	$	911	$	854
Accrued discretionary and incentive compensation		674		749
Litigation settlements		—		210
Accrued vacation		170		155
Other employee-related liabilities		74		75
Total deferred revenue and accrued expenses	$	1,829	$	2,043

Other current liabilities consist of the following:

	September 30, 2021		December 31, 2020
Dividends payable	$	114	$	103
Income and other taxes payable		333		96
Interest payable		22		68
Deferred compensation plan liabilities		39		51
Contingent and deferred consideration on acquisitions		17		39
Payroll-related liabilities		263		264
Derivatives		22		5
Third-party commissions		87		95
Other current liabilities		53		72
Total other current liabilities	$	950	$	793

Provision for liabilities consists of the following:

	September 30, 2021		December 31, 2020
Claims, lawsuits and other proceedings	$	335	$	325
Other provisions		66		81
Total provision for liabilities	$	401	$	406

Other non-current liabilities consist of the following:

	September 30, 2021		December 31, 2020
Deferred compensation plan liability	$	100	$	103
Contingent and deferred consideration on acquisitions		13		16
Liabilities for uncertain tax positions		45		49
Derivatives		—		2
Finance leases		17		19
Other non-current liabilities		64		92
Total other non-current liabilities	$	239	$	281

Other Income, Net

9 Months Ended

Sep. 30, 2021

Other Income And Expenses [Abstract]

Other Income, Net

Note 15 — Other Income, Net

Other income, net consists of the following:

	Three Months Ended September 30,					Nine Months Ended September 30,
	2021		2020			2021		2020
Gain on disposal of operations	$	23	$	85		$	380	$	83
Net periodic pension and postretirement benefit credits		79		76			227		227
Interest in earnings of associates and other investments		1		(1	)		5		4
Foreign exchange gain/(loss)		1		(2	)		4		7
Other		1		(2	)		1		—
Other income, net	$	105	$	156		$	617	$	321

Certain prior period amounts within the tables above have been reclassified to discontinued operations within the condensed consolidated statements of income.

Accumulated Other Comprehensive Loss

9 Months Ended

Sep. 30, 2021

Equity [Abstract]

Accumulated Other Comprehensive Loss

Note 16 — Accumulated Other Comprehensive Loss

Changes in accumulated other comprehensive loss, net of non-controlling interests, and net of tax are provided in the following tables for the three and nine months ended September 30, 2021 and 2020. These tables exclude amounts attributable to non-controlling interests, which are not material for further disclosure.

	Foreign currency translation ⁽ⁱ⁾						Derivative instruments⁽ⁱ⁾						Defined pension and post-retirement benefit costs ⁽ⁱⁱ⁾						Total
	2021			2020			2021			2020			2021			2020			2021			2020
Quarter-to-date activity:
Balance at June 30, 2021 and 2020, respectively	$	(376	)	$	(698	)	$	13		$	(6	)	$	(1,915	)	$	(1,686	)	$	(2,278	)	$	(2,390	)
Other comprehensive (loss)/income before reclassifications		(81	)		119			(1	)		5			2			—			(80	)		124
(Gain)/loss reclassified from accumulated other comprehensive loss (net of income tax benefit of $8 and $2, respectively)		—			—			(1	)		4			—			9			(1	)		13
Net current-period other comprehensive (loss)/income		(81	)		119			(2	)		9			2			9			(81	)		137
Balance at September 30, 2021 and 2020, respectively	$	(457	)	$	(579	)	$	11		$	3		$	(1,913	)	$	(1,677	)	$	(2,359	)	$	(2,253	)

Year-to-date activity:
Balance at December 31, 2020 and 2019, respectively	$	(400	)	$	(538	)	$	9		$	13		$	(1,968	)	$	(1,702	)	$	(2,359	)	$	(2,227	)
Other comprehensive (loss)/income before reclassifications		(101	)		(41	)		7			(17	)		2			2			(92	)		(56	)
Loss/(gain) reclassified from accumulated other comprehensive loss (net of income tax benefit of $15 and $9, respectively) ⁽ⁱⁱⁱ⁾		44			—			(5	)		7			53			23			92			30
Net current-period other comprehensive (loss)/income		(57	)		(41	)		2			(10	)		55			25			—			(26	)
Balance at September 30, 2021 and 2020, respectively	$	(457	)	$	(579	)	$	11		$	3		$	(1,913	)	$	(1,677	)	$	(2,359	)	$	(2,253	)

(i)

Reclassification adjustments from accumulated other comprehensive loss related to derivative instruments are included in Revenue and Salaries and benefits in the accompanying condensed consolidated statements of comprehensive income. See Note 8 — Derivative Financial Instruments for additional details regarding the reclassification adjustments for the derivative settlements.

(ii)	Reclassification adjustments from accumulated other comprehensive loss are included in the computation of net periodic pension cost (see Note 11 — Retirement Benefits). These components are included in Other income, net in the accompanying condensed consolidated statements of comprehensive income.

(iii)

Includes reclassifications of $44 million and $31 million of foreign currency translation and defined pension and post-retirement benefit costs, respectively, attributable to the gain on disposal of our Miller business (see Note 3 — Divestitures). The net gain on disposal is included in Other income, net in the accompanying condensed consolidated statements of comprehensive income.

Earnings Per Share

9 Months Ended

Sep. 30, 2021

Earnings Per Share [Abstract]

Earnings Per Share

Note 17 — Earnings Per Share

Basic and diluted earnings per share from continuing operations attributable to Willis Towers Watson and discontinued operations, net of tax are calculated by dividing net income from continuing operations attributable to Willis Towers Watson and discontinued operations, net of tax, respectively, by the average number of ordinary shares outstanding during each period. The computation of diluted earnings per share reflects the potential dilution that could occur if dilutive securities and other contracts to issue shares were exercised or converted into shares or resulted in the issuance of shares that then shared in the net income of the Company.

At September 30, 2021 and 2020, there were 0.6 million and 0.4 million restricted performance-based stock units outstanding, respectively, and 0.1 million and 0.3 million time-based share options outstanding, respectively. Additionally, at September 30, 2021 and 2020, there were 0.3 million performance-based options outstanding, and the Company’s restricted time-based stock units were immaterial.

Basic and diluted earnings per share from continuing operations attributable to Willis Towers Watson and discontinued operations are as follows:

	Three Months Ended September 30,						Nine Months Ended September 30,
	2021			2020			2021			2020
Income from continuing operations	$	919		$	119		$	1,582		$	284
Less: Income attributable to non-controlling interests		(4	)		(1	)		(9	)		(17	)
Income from continuing operations attributable to Willis Towers Watson	$	915		$	118		$	1,573		$	267

(Loss)/income from discontinued operations, net of tax	$	(12	)	$	3		$	247		$	253

Basic average number of shares outstanding		129			130			130			130
Dilutive effect of potentially issuable shares		—			—			—			—
Diluted average number of shares outstanding		129			130			130			130

Basic earnings per share from continuing operations attributable to Willis Towers Watson	$	7.10		$	0.91		$	12.14		$	2.06
Dilutive effect of potentially issuable shares		(0.02	)		—			(0.04	)		(0.01	)
Diluted earnings per share from continuing operations attributable to Willis Towers Watson	$	7.08		$	0.91		$	12.10		$	2.05

Basic (loss)/earnings per share from discontinued operations, net of tax	$	(0.09	)	$	0.02		$	1.90		$	1.95
Dilutive effect of potentially issuable shares		—			—			—			(0.01	)
Diluted (loss)/earnings per share from discontinued operations, net of tax	$	(0.09	)	$	0.02		$	1.90		$	1.94

For the three and nine months ended September 30, 2021, 0.4 million and 0.3 million restricted stock units, respectively, were not included in the computation of the dilutive effect of potentially issuable shares because their effect was anti-dilutive; there were no anti-dilutive restricted stock units for the three and nine months ended September 30, 2020. There were no anti-dilutive options for the three and nine months ended September 30, 2021 and 2020.

Subsequent Event

9 Months Ended

Sep. 30, 2021

Subsequent Events [Abstract]

Subsequent Event

Note 18 — Subsequent Event

On October 6, 2021, Trinity Acquisition plc entered into a second amended and restated revolving credit facility (the ‘new RCF’) for $1.5 billion that will mature on October 6, 2026. This new RCF replaces the previous $1.25 billion revolving credit facility which was due to expire in March of 2022.

Borrowing costs under the $1.5 billion facility differ if the borrowing is a ‘base rate’ borrowing or a ‘Eurocurrency’ borrowing, both as defined by the new RCF, and equal the sum of the relevant benchmark plus a margin based on the Company’s senior unsecured long-term debt rating:

•

For base rate borrowings, the benchmark rate will be the greatest of (a) the Prime Rate in effect on such day, (b) the Federal Funds Effective Rate in effect on such day plus 0.50%, and (c) the one-month LIBOR rate plus 1.0%. The margin on the base rate benchmark is 0.00% to 0.75% depending on the Company’s senior unsecured long-term debt rating.

•

For Eurocurrency or Sterling Overnight Interbank Average Rate (‘SONIA’) borrowings, the rate will be the applicable LIBOR rate or SONIA (as applicable based on the currency of the borrower) plus a margin of 1.0% to 1.75% depending on the Company’s guaranteed unsecured long-term debt rating. In anticipation of the cessation of LIBOR, the new RCF provides for a benchmark rate adjustment that will be added to the replacement benchmark rate to reflect the differential between LIBOR and the replacement benchmark (e.g., the Secured Overnight Financing Rate). This adjustment amount will be a function of both the currency and borrowing tenor.

The new RCF also carries a commitment (unused) fees of 0.09% to 0.25%, which is also based on the Company’s senior unsecured long-term debt rating.

Basis of Presentation and Recent Accounting Pronouncements (Policies)

9 Months Ended

Sep. 30, 2021

Accounting Policies [Abstract]

Basis of Presentation

Risks and Uncertainties Related to the COVID-19 Pandemic and the Related Economic Environment

Recent Accounting Pronouncements

Not Yet Adopted

There are no pending accounting pronouncements that are expected to have a significant impact on our condensed consolidated financial statements.

Adopted

Fair Value of Financial Instruments

•

Level 1: refers to fair values determined based on quoted market prices in active markets for identical assets;

•

Level 2: refers to fair values estimated using observable market-based inputs or unobservable inputs that are corroborated by market data; and

•

Level 3: includes fair values estimated using unobservable inputs that are not corroborated by market data.

The following methods and assumptions were used by the Company in estimating its fair value disclosure for financial instruments:

•

Available-for-sale securities are classified as Level 1 because we use quoted market prices in determining the fair value of these securities.

•

Divestitures (Tables)

9 Months Ended

Sep. 30, 2021

Business Combinations [Abstract]

Schedule of Selected Financial Information and Summary of Total Assets and Liabilities Relates to the Operations of Willis Re

The following selected financial information relates to the operations of Willis Re for the periods presented:

	Three Months Ended September 30,					Nine Months Ended September 30,
	2021			2020		2021		2020
Revenue from discontinued operations	$	111		$	112	$	668	$	642
Costs of providing services
Salaries and benefits		97			93		291		281
Other operating expenses		29			12		60		43
Depreciation and amortization		—			—		1		2
Total costs of providing services		126			105		352		326
Other income, net		—			—		1		3
(Loss)/income from discontinued operations before income taxes	$	(15	)	$	7	$	317	$	319

The following table summarizes the total assets and liabilities of Willis Re classified as held for sale within our condensed consolidated balance sheets at the balance sheet dates presented:

	September 30, 2021		December 31, 2020
Assets held for sale:
Cash and cash equivalents	$	53	$	50
Fiduciary assets		3,853		3,157
Accounts receivable, net		199		147
Fixed assets, net		1		1
Goodwill		812		812
Other intangible assets, net		8		8
Right-of-use assets		1		1
Other assets		34		40
Total assets held for sale	$	4,961	$	4,216
Liabilities held for sale:
Fiduciary liabilities	$	3,853	$	3,157
Deferred revenue and accrued expenses		101		118
Liability for pension benefits		1		2
Lease liabilities		1		1
Provision for liabilities		1		1
Other liabilities		163		126
Total liabilities held for sale	$	4,120	$	3,405

Tabular disclosure of information related to a disposal group. Includes, but is not limited to, a discontinued operation, disposal classified as held-for-sale or disposed of by means other than sale or disposal of an individually significant component.

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Revenue From Contract With Customer [Abstract]

Revenue (Tables)

9 Months Ended

Sep. 30, 2021

Disaggregation of Revenue

The following tables present revenue by service offering and segment, as well as reconciliations to total revenue for the three and nine months ended September 30, 2021 and 2020. Along with reimbursable expenses and other, total revenue by service offering represents our revenue from customer contracts.

	Three Months Ended September 30,
	HCB				CRB				IRR				BDA				Corporate ⁽ⁱ⁾						Total
	2021		2020		2021		2020		2021		2020		2021		2020		2021			2020			2021		2020
Broking	$	68	$	62	$	621	$	592	$	11	$	71	$	119	$	100	$	—		$	—		$	819	$	825
Consulting		561		529		39		31		111		97		—		—		2			1			713		658
Outsourced administration		122		126		17		16		4		4		123		126		—			—			266		272
Other		97		77		4		4		46		48		—		—		1			1			148		130
Total revenue by service offering		848		794		681		643		172		220		242		226		3			2			1,946		1,885
Reimbursable expenses and other ⁽ⁱ⁾		10		10		—		—		2		1		2		2		(9	)		(10	)		5		3
Total revenue from customer contracts	$	858	$	804	$	681	$	643	$	174	$	221	$	244	$	228	$	(6	)	$	(8	)	$	1,951	$	1,888
Interest and other income ⁽ⁱⁱ⁾		4		2		16		6		—		—		—		—		2			1			22		9
Total revenue	$	862	$	806	$	697	$	649	$	174	$	221	$	244	$	228	$	(4	)	$	(7	)	$	1,973	$	1,897

	Nine Months Ended September 30,
	HCB				CRB				IRR				BDA				Corporate ⁽ⁱ⁾					Total
	2021		2020		2021		2020		2021		2020		2021		2020		2021			2020		2021		2020
Broking	$	248	$	216	$	2,026	$	1,877	$	67	$	238	$	391	$	288	$	—		$	—	$	2,732	$	2,619
Consulting		1,732		1,642		128		118		348		282		—		—		6			4		2,214		2,046
Outsourced administration		377		376		58		57		12		11		377		378		—			—		824		822
Other		196		165		12		6		188		185		—		—		3			3		399		359
Total revenue by service offering		2,553		2,399		2,224		2,058		615		716		768		666		9			7		6,169		5,846
Reimbursable expenses and other ⁽ⁱ⁾		33		36		1		1		4		6		6		7		(9	)		2		35		52
Total revenue from customer contracts	$	2,586	$	2,435	$	2,225	$	2,059	$	619	$	722	$	774	$	673	$	—		$	9	$	6,204	$	5,898
Interest and other income ⁽ⁱⁱ⁾		10		14		71		31		—		—		3		—		4			3		88		48
Total revenue	$	2,596	$	2,449	$	2,296	$	2,090	$	619	$	722	$	777	$	673	$	4		$	12	$	6,292	$	5,946

______________

(i)

(ii)

	Three Months Ended September 30,
	HCB				CRB				IRR				BDA				Corporate				Total
	2021		2020		2021		2020		2021		2020		2021		2020		2021		2020		2021		2020
North America	$	485	$	465	$	310	$	287	$	45	$	39	$	239	$	224	$	2	$	1	$	1,081	$	1,016
Great Britain		137		120		143		138		86		117		—		—		—		—		366		375
Western Europe		135		129		116		112		18		44		—		—		1		1		270		286
International		91		80		112		106		23		20		3		2		—		—		229		208
Total revenue by geography	$	848	$	794	$	681	$	643	$	172	$	220	$	242	$	226	$	3	$	2	$	1,946	$	1,885

	Nine Months Ended September 30,
	HCB				CRB				IRR				BDA				Corporate				Total
	2021		2020		2021		2020		2021		2020		2021		2020		2021		2020		2021		2020
North America	$	1,430	$	1,403	$	865	$	816	$	136	$	117	$	760	$	660	$	7	$	5	$	3,198	$	3,001
Great Britain		427		363		471		435		343		401		—		—		—		—		1,241		1,199
Western Europe		444		404		521		483		69		139		—		—		2		2		1,036		1,028
International		252		229		367		324		67		59		8		6		—		—		694		618
Total revenue by geography	$	2,553	$	2,399	$	2,224	$	2,058	$	615	$	716	$	768	$	666	$	9	$	7	$	6,169	$	5,846

Contract with Customer, Asset and Liability

	September 30, 2021		December 31, 2020
Billed receivables, net of allowance for doubtful accounts of $44 million and $40 million	$	1,360	$	1,589
Unbilled receivables		511		445
Current contract assets		194		374
Accounts receivable, net	$	2,065	$	2,408
Non-current accounts receivable, net	$	23	$	34
Non-current contract assets	$	431	$	327
Deferred revenue	$	636	$	547

Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction

•

Performance obligations which are part of a contract that has an original expected duration of less than one year, and

•

Performance obligations satisfied in accordance with ASC 606-10-55-18 (‘right to invoice’).

		Remainder of 2021				2022				2023 onward				Total
Revenue expected to be recognized on contracts as of September 30, 2021		$	174			$	546			$	788			$	1,508

Segment Information (Tables)

9 Months Ended

Sep. 30, 2021

Segment Reporting [Abstract]

Schedule of Segment Reporting Information, by Segment

The following table presents segment revenue and segment operating income for our reportable segments for the three months ended September 30, 2021 and 2020.

	Three Months Ended September 30,
	HCB				CRB				IRR				BDA						Total
	2021		2020		2021		2020		2021		2020		2021			2020			2021		2020
Segment revenue	$	852	$	796	$	697	$	649	$	172	$	220	$	242		$	226		$	1,963	$	1,891

Segment operating income/(loss)	$	242	$	209	$	114	$	81	$	22	$	20	$	(19	)	$	(11	)	$	359	$	299

The following table presents segment revenue and segment operating income for our reportable segments for the nine months ended September 30, 2021 and 2020.

	Nine Months Ended September 30,
	HCB				CRB				IRR				BDA						Total
	2021		2020		2021		2020		2021		2020		2021			2020			2021		2020
Segment revenue	$	2,563	$	2,413	$	2,295	$	2,089	$	615	$	716	$	771		$	666		$	6,244	$	5,884

Segment operating income/(loss)	$	654	$	582	$	457	$	343	$	108	$	108	$	(22	)	$	(31	)	$	1,197	$	1,002

Net Operating Income of the Reported Segments

	Three Months Ended September 30,						Nine Months Ended September 30,
	2021			2020			2021			2020
Revenue:
Total segment revenue	$	1,963		$	1,891		$	6,244		$	5,884
Reimbursable expenses and other		10			6			48			62
Revenue	$	1,973		$	1,897		$	6,292		$	5,946

Total segment operating income	$	359		$	299		$	1,197		$	1,002
Amortization		(85	)		(108	)		(285	)		(347	)
Transaction and integration, net ⁽ⁱ⁾		952			(42	)		877			(65	)
Unallocated, net ⁽ⁱⁱ⁾		(95	)		(83	)		(277	)		(310	)
Income from operations		1,131			66			1,512			280
Interest expense		(50	)		(61	)		(161	)		(184	)
Other income, net		105			156			617			321
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	$	1,186		$	161		$	1,968		$	417

(i)	Includes mainly transaction costs related to the proposed Aon combination prior to its termination. For the three and nine months ended September 30, 2021, includes the $1 billion income receipt related to the termination of the proposed Aon transaction.

(ii)

Goodwill and Other Intangible Assets (Tables)

9 Months Ended

Sep. 30, 2021

Goodwill And Intangible Assets Disclosure [Abstract]

Components of Goodwill

The components of goodwill are outlined below for the nine months ended September 30, 2021:

	HCB			CRB			IRR			BDA		Total
Balance at December 31, 2020:
Goodwill, gross ⁽ⁱ⁾	$	4,346		$	2,378		$	882		$	3,278	$	10,884
Accumulated impairment losses		(130	)		(362	)		—			—		(492	)
Goodwill, net - December 31, 2020		4,216			2,016			882			3,278		10,392
Goodwill disposals		—			(7	)		(188	)		—		(195	)
Foreign exchange		(28	)		(25	)		2			—		(51	)
Balance at September 30, 2021:
Goodwill, gross		4,318			2,346			696			3,278		10,638
Accumulated impairment losses		(130	)		(362	)		—			—		(492	)
Goodwill, net - September 30, 2021	$	4,188		$	1,984		$	696		$	3,278	$	10,146

(i)	Excludes $812 million of goodwill associated with our IRR segment, which has been reclassified as assets held for sale on our condensed consolidated balance sheets at both September 30, 2021 and December 31, 2020 in conjunction with the pending divestiture of our Willis Re business.

Changes in the Net Carrying Amount of the Components of Finite-Lived Intangible Assets

The following table reflects changes in the net carrying amounts of the components of finite-lived intangible assets for the nine months ended September 30, 2021:

	Client relationships			Software			Trademark and trade name			Other			Total
Balance at December 31, 2020:
Intangible assets, gross	$	4,058		$	761		$	1,054		$	103		$	5,976
Accumulated amortization		(2,028	)		(659	)		(220	)		(34	)		(2,941	)
Intangible assets, net - December 31, 2020 ⁽ⁱ⁾		2,030			102			834			69			3,035
Intangible asset disposals		(47	)		—			(8	)		—			(55	)
Amortization		(193	)		(49	)		(32	)		(11	)		(285	)
Foreign exchange		(14	)		—			(1	)		1			(14	)
Balance at September 30, 2021:
Intangible assets, gross		3,837			742			1,040			104			5,723
Accumulated amortization		(2,061	)		(689	)		(247	)		(45	)		(3,042	)
Intangible assets, net - September 30, 2021	$	1,776		$	53		$	793		$	59		$	2,681

(i)	Excludes $8 million of intangible assets, net, which have been reclassified as assets held for sale on our condensed consolidated balance sheets at both September 30, 2021 and December 31, 2020 in conjunction with the pending divestiture of our Willis Re business.

Schedule of Future Estimated Amortization Expense for Amortizable Intangible Assets

The table below reflects the future estimated amortization expense for amortizable intangible assets for the remainder of 2021 and for subsequent years:

	Amortization
Remainder of 2021	$	84
2022		307
2023		254
2024		223
2025		203
Thereafter		1,610
Total	$	2,681

Derivative Financial Instruments (Tables)

9 Months Ended

Sep. 30, 2021

Designated [Member]

Schedule of Derivative Instruments Designated/Nondesignated As Hedging Instrument Effect on Condensed Consolidated Statements of Comprehensive Income

	(Loss)/gain recognized in OCL (effective element)
	Three months ended September 30,					Nine months ended September 30,
	2021			2020		2021		2020
Forward exchange contracts	$	(2	)	$	6	$	3	$	(21	)

Location of (loss)/gain reclassified from Accumulated OCL into income (effective element)	(Loss)/gain reclassified from Accumulated OCL into income (effective element)
	Three months ended September 30,						Nine months ended September 30,
	2021			2020			2021			2020
Revenue	$	(1	)	$	(2	)	$	(3	)	$	(4	)
Salaries and benefits		2			(2	)		5			(3	)
Discontinued operations		—			—			3			(1	)
	$	1		$	(4	)	$	5		$	(8	)

Nondesignated [Member]

Schedule of Derivative Instruments Designated/Nondesignated As Hedging Instrument Effect on Condensed Consolidated Statements of Comprehensive Income

		(Loss)/gain recognized in income
		Three Months Ended September 30,					Nine Months Ended September 30,
Derivatives not designated as hedging instruments:	Location of (loss)/gain recognized in income	2021			2020		2021			2020
Forward exchange contracts	Other income, net	$	(7	)	$	5	$	(36	)	$	(15	)

Debt (Tables)

9 Months Ended

Sep. 30, 2021

Debt Disclosure [Abstract]

Schedule of Current and Long-term Debt

Current debt consists of the following:

	September 30, 2021		December 31, 2020
Revolving $1.25 billion credit facility ⁽ⁱ⁾	$	—	$	—
5.750% senior notes due 2021		—		500
3.500% senior notes due 2021		—		449
2.125% senior notes due 2022⁽ⁱⁱ⁾		625		—
Current portion of collateralized facility		19		22
	$	644	$	971

Long-term debt consists of the following:

	September 30, 2021		December 31, 2020
Revolving $1.25 billion credit facility	$	—	$	—
Collateralized facility ⁽ⁱⁱⁱ⁾		19		33
2.125% senior notes due 2022⁽ⁱⁱ⁾		—		659
4.625% senior notes due 2023		249		249
3.600% senior notes due 2024		648		647
4.400% senior notes due 2026		546		546
4.500% senior notes due 2028		596		596
2.950% senior notes due 2029		727		726
6.125% senior notes due 2043		271		271
5.050% senior notes due 2048		395		395
3.875% senior notes due 2049		542		542
	$	3,993	$	4,664

(i)	The $1.25 billion revolving credit facility expires on March 7, 2022 (see Note 18 – Subsequent Event for additional information).

(ii)	Notes issued in Euro (€540 million).

(iii)

At September 30, 2021 and December 31, 2020, the Company had $82 million and $98 million, respectively, of renewal commissions receivables pledged as collateral for this facility.

Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2021

Fair Value Disclosures [Abstract]

Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis

The following tables present our assets and liabilities measured at fair value on a recurring basis at September 30, 2021 and December 31, 2020:

		Fair Value Measurements on a Recurring Basis at September 30, 2021
	Balance Sheet Location	Level 1		Level 2		Level 3		Total
Assets:
Available-for-sale securities:
Mutual funds / exchange traded funds	Prepaid and other current assets and other non-current assets	$	9	$	—	$	—	$	9
Derivatives:
Derivative financial instruments ⁽ⁱ⁾	Prepaid and other current assets and other non-current assets	$	—	$	4	$	—	$	4
Liabilities:
Contingent consideration:
Contingent consideration ⁽ⁱⁱ⁾	Other current liabilities and other non-current liabilities	$	—	$	—	$	30	$	30
Derivatives:
Derivative financial instruments ⁽ⁱ⁾	Other current liabilities and other non-current liabilities	$	—	$	22	$	—	$	22

		Fair Value Measurements on a Recurring Basis at December 31, 2020
	Balance Sheet Location	Level 1		Level 2		Level 3		Total
Assets:
Available-for-sale securities:
Mutual funds / exchange traded funds	Prepaid and other current assets and other non-current assets	$	8	$	—	$	—	$	8
Derivatives:
Derivative financial instruments ⁽ⁱ⁾	Prepaid and other current assets and other non-current assets	$	—	$	27	$	—	$	27
Liabilities:
Contingent consideration:
Contingent consideration ⁽ⁱⁱ⁾	Other current liabilities and other non-current liabilities	$	—	$	—	$	45	$	45
Derivatives:
Derivative financial instruments ⁽ⁱ⁾	Other current liabilities and other non-current liabilities	$	—	$	7	$	—	$	7

(i)	See Note 8 — Derivative Financial Instruments for further information on our derivative investments.

(ii)

Schedule of Change in Fair Value of Level 3 Liabilities

The following table summarizes the change in fair value of the Level 3 liabilities:

Fair Value Measurements Using Significant Unobservable Inputs (Level 3)	September 30, 2021
Balance at December 31, 2020	$	45
Obligations assumed		—
Payments		(19	)
Realized and unrealized gains		5
Foreign exchange		(1	)
Balance at September 30, 2021	$	30

Schedule of Assets and Liabilities Whose Carrying Values Differ From the Fair Value and are Not Measured on a Recurring Basis

The following tables present our assets and liabilities not measured at fair value on a recurring basis at September 30, 2021 and December 31, 2020:

	September 30, 2021				December 31, 2020
	Carrying Value		Fair Value		Carrying Value		Fair Value
Assets:
Long-term note receivable	$	70	$	72	$	71	$	73
Liabilities:
Current debt	$	644	$	651	$	971	$	985
Long-term debt	$	3,993	$	4,560	$	4,664	$	5,488

Retirement Benefits (Tables)

9 Months Ended

Sep. 30, 2021

Compensation And Retirement Disclosure [Abstract]

Schedule of Net Periodic Benefit Cost

	Three Months Ended September 30,
	2021												2020
	U.S.			U.K.			Other			PRW			U.S.			U.K.			Other			PRW
Service cost	$	19		$	4		$	6		$	—		$	18		$	4		$	5		$	—
Interest cost		24			14			3			—			32			18			4			1
Expected return on plan assets		(79	)		(42	)		(9	)		—			(73	)		(63	)		(8	)		—
Settlement		—			1			2			—			—			—			—			—
Amortization of net loss		8			7			1			1			9			6			—			—
Amortization of prior service credit		—			(4	)		1			(1	)		—			(4	)		—			(1	)
Net periodic benefit (income)/cost	$	(28	)	$	(20	)	$	4		$	—		$	(14	)	$	(39	)	$	1		$	—

	Nine Months Ended September 30,
	2021												2020
	U.S.			U.K.			Other			PRW			U.S.			U.K.			Other			PRW
Service cost	$	59		$	13		$	18		$	—		$	54		$	11		$	15		$	—
Interest cost		71			42			9			1			98			54			11			2
Expected return on plan assets		(233	)		(128	)		(28	)		—			(218	)		(184	)		(25	)		—
Settlement		1			2			2			—			2			1			—			—
Amortization of net loss		30			21			4			2			26			17			2			1
Amortization of prior service credit		—			(13	)		1			(3	)		—			(12	)		—			(3	)
Net periodic benefit (income)/cost	$	(72	)	$	(63	)	$	6		$	—		$	(38	)	$	(113	)	$	3		$	—

Leases (Tables)

9 Months Ended

Sep. 30, 2021

Leases [Abstract]

Schedule of Lease Costs Recorded in Condensed Consolidated Statements of Comprehensive Income

The following tables present lease costs recorded on our condensed consolidated statements of comprehensive income for the three and nine months ended September 30, 2021 and 2020.

	Three Months Ended September 30,						Nine Months Ended September 30,
	2021			2020			2021			2020
Finance lease cost:
Amortization of right-of-use assets	$	—		$	1		$	1		$	2
Interest on lease liabilities		1			—			2			2
Operating lease cost		43			45			134			138
Short-term lease cost		—			1			1			1
Variable lease cost		13			14			39			37
Sublease income		(6	)		(6	)		(16	)		(16	)
Total lease cost, net	$	51		$	55		$	161		$	164

Supplementary Information for Certain Balance Sheet Accounts (Tables)

9 Months Ended

Sep. 30, 2021

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Deferred Revenue and Accrued Expenses

Deferred revenue and accrued expenses consist of the following:

	September 30, 2021		December 31, 2020
Accounts payable, accrued liabilities and deferred income	$	911	$	854
Accrued discretionary and incentive compensation		674		749
Litigation settlements		—		210
Accrued vacation		170		155
Other employee-related liabilities		74		75
Total deferred revenue and accrued expenses	$	1,829	$	2,043

Schedule of Other Current Liabilities

Other current liabilities consist of the following:

	September 30, 2021		December 31, 2020
Dividends payable	$	114	$	103
Income and other taxes payable		333		96
Interest payable		22		68
Deferred compensation plan liabilities		39		51
Contingent and deferred consideration on acquisitions		17		39
Payroll-related liabilities		263		264
Derivatives		22		5
Third-party commissions		87		95
Other current liabilities		53		72
Total other current liabilities	$	950	$	793

Provisions for Liabilities

Provision for liabilities consists of the following:

	September 30, 2021		December 31, 2020
Claims, lawsuits and other proceedings	$	335	$	325
Other provisions		66		81
Total provision for liabilities	$	401	$	406

Schedule of Other Non-current Liabilities

Other non-current liabilities consist of the following:

	September 30, 2021		December 31, 2020
Deferred compensation plan liability	$	100	$	103
Contingent and deferred consideration on acquisitions		13		16
Liabilities for uncertain tax positions		45		49
Derivatives		—		2
Finance leases		17		19
Other non-current liabilities		64		92
Total other non-current liabilities	$	239	$	281

Other Income, Net (Tables)

9 Months Ended

Sep. 30, 2021

Other Income And Expenses [Abstract]

Schedule of Other Nonoperating Income

Other income, net consists of the following:

	Three Months Ended September 30,					Nine Months Ended September 30,
	2021		2020			2021		2020
Gain on disposal of operations	$	23	$	85		$	380	$	83
Net periodic pension and postretirement benefit credits		79		76			227		227
Interest in earnings of associates and other investments		1		(1	)		5		4
Foreign exchange gain/(loss)		1		(2	)		4		7
Other		1		(2	)		1		—
Other income, net	$	105	$	156		$	617	$	321

Accumulated Other Comprehensive Loss (Tables)

9 Months Ended

Sep. 30, 2021

Equity [Abstract]

Schedule of Accumulated Other Comprehensive Income (Loss)

	Foreign currency translation ⁽ⁱ⁾						Derivative instruments⁽ⁱ⁾						Defined pension and post-retirement benefit costs ⁽ⁱⁱ⁾						Total
	2021			2020			2021			2020			2021			2020			2021			2020
Quarter-to-date activity:
Balance at June 30, 2021 and 2020, respectively	$	(376	)	$	(698	)	$	13		$	(6	)	$	(1,915	)	$	(1,686	)	$	(2,278	)	$	(2,390	)
Other comprehensive (loss)/income before reclassifications		(81	)		119			(1	)		5			2			—			(80	)		124
(Gain)/loss reclassified from accumulated other comprehensive loss (net of income tax benefit of $8 and $2, respectively)		—			—			(1	)		4			—			9			(1	)		13
Net current-period other comprehensive (loss)/income		(81	)		119			(2	)		9			2			9			(81	)		137
Balance at September 30, 2021 and 2020, respectively	$	(457	)	$	(579	)	$	11		$	3		$	(1,913	)	$	(1,677	)	$	(2,359	)	$	(2,253	)

Year-to-date activity:
Balance at December 31, 2020 and 2019, respectively	$	(400	)	$	(538	)	$	9		$	13		$	(1,968	)	$	(1,702	)	$	(2,359	)	$	(2,227	)
Other comprehensive (loss)/income before reclassifications		(101	)		(41	)		7			(17	)		2			2			(92	)		(56	)
Loss/(gain) reclassified from accumulated other comprehensive loss (net of income tax benefit of $15 and $9, respectively) ⁽ⁱⁱⁱ⁾		44			—			(5	)		7			53			23			92			30
Net current-period other comprehensive (loss)/income		(57	)		(41	)		2			(10	)		55			25			—			(26	)
Balance at September 30, 2021 and 2020, respectively	$	(457	)	$	(579	)	$	11		$	3		$	(1,913	)	$	(1,677	)	$	(2,359	)	$	(2,253	)

(i)

(ii)	Reclassification adjustments from accumulated other comprehensive loss are included in the computation of net periodic pension cost (see Note 11 — Retirement Benefits). These components are included in Other income, net in the accompanying condensed consolidated statements of comprehensive income.

(iii)

Earnings Per Share (Tables)

9 Months Ended

Sep. 30, 2021

Earnings Per Share [Abstract]

Schedule of Basic and Diluted Earnings Per Share from Continuing Operations Attributable to Willis Towers Watson and Discontinued Operations

Basic and diluted earnings per share from continuing operations attributable to Willis Towers Watson and discontinued operations are as follows:

	Three Months Ended September 30,						Nine Months Ended September 30,
	2021			2020			2021			2020
Income from continuing operations	$	919		$	119		$	1,582		$	284
Less: Income attributable to non-controlling interests		(4	)		(1	)		(9	)		(17	)
Income from continuing operations attributable to Willis Towers Watson	$	915		$	118		$	1,573		$	267

(Loss)/income from discontinued operations, net of tax	$	(12	)	$	3		$	247		$	253

Basic average number of shares outstanding		129			130			130			130
Dilutive effect of potentially issuable shares		—			—			—			—
Diluted average number of shares outstanding		129			130			130			130

Basic earnings per share from continuing operations attributable to Willis Towers Watson	$	7.10		$	0.91		$	12.14		$	2.06
Dilutive effect of potentially issuable shares		(0.02	)		—			(0.04	)		(0.01	)
Diluted earnings per share from continuing operations attributable to Willis Towers Watson	$	7.08		$	0.91		$	12.10		$	2.05

Basic (loss)/earnings per share from discontinued operations, net of tax	$	(0.09	)	$	0.02		$	1.90		$	1.95
Dilutive effect of potentially issuable shares		—			—			—			(0.01	)
Diluted (loss)/earnings per share from discontinued operations, net of tax	$	(0.09	)	$	0.02		$	1.90		$	1.94

Nature of Operations (Details) $ in Billions		3 Months Ended	9 Months Ended
Nature of Operations (Details) $ in Billions	Jul. 26, 2021 USD ($)	Sep. 30, 2021 USD ($) Employee Country	Sep. 30, 2021 USD ($) Employee Country
Minority Interest [Line Items]
Number of employees employed (more than 00,000) \| Employee		46,000	46,000
Number of countries in which entity operates (more than 140) \| Country		140	140
Termination of Proposed Combination with AON Plc [Member]
Minority Interest [Line Items]
Number of shares receivable upon acquisition		1.08	1.08
Termination of Proposed Combination with AON Plc [Member] \| Termination Agreement
Minority Interest [Line Items]
Termination payment \| $	$ 1	$ 1	$ 1
Termination of Proposed Combination with AON Plc [Member] \| Aon Plc [Member]
Minority Interest [Line Items]
Percentage of ownership by parent		63.00%	63.00%
Termination of Proposed Combination with AON Plc [Member] \| Willis Towers Watson Public Limited Company [Member]
Minority Interest [Line Items]
Percentage of ownership by non-controlling owner		37.00%	37.00%

Divestitures - Willis Re Divestiture (Details) - USD ($)	Sep. 30, 2021	Aug. 13, 2021	Dec. 31, 2020
Willis Re [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Fiduciary assets excluded from held-for-sale	$ 3,800,000,000		$ 3,000,000,000.0
Accounts receivable, net balances excluded from held-for-sale	$ 155,000,000		$ 100,000,000
Gallagher [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Total upfront cash consideration received from sale of subsidiary		$ 3,250,000,000
Gallagher [Member] \| Maximum [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Earnout receivable in cash in 2025		$ 750,000,000

Divestitures - Schedule of Selected Financial Information Relates to the Operations of Willis Re (Details) - Willis Re [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Revenue from discontinued operations	$ 111	$ 112	$ 668	$ 642
Costs of providing services
Salaries and benefits	97	93	291	281
Other operating expenses	29	12	60	43
Depreciation and amortization			1	2
Total costs of providing services	126	105	352	326
Other income, net			1	3
(Loss)/income from discontinued operations before income taxes	$ (15)	$ 7	$ 317	$ 319

Divestitures - Summary of Total Assets and Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Assets held for sale:
Total assets held for sale	$ 4,961	$ 3,376
Liabilities held for sale:
Total liabilities held for sale	4,120	3,370
Willis Re [Member]
Assets held for sale:
Cash and cash equivalents	53	50
Fiduciary assets	3,853	3,157
Accounts receivable, net	199	147
Fixed assets, net	1	1
Goodwill	812	812
Other intangible assets, net	8	8
Right-of-use assets	1	1
Other assets	34	40
Total assets held for sale	4,961	4,216
Liabilities held for sale:
Fiduciary liabilities	3,853	3,157
Deferred revenue and accrued expenses	101	118
Liability for pension benefits	1	2
Lease liabilities	1	1
Provision for liabilities	1	1
Other liabilities	163	126
Total liabilities held for sale	$ 4,120	$ 3,405

Divestitures - Miller Divestiture (Details) £ in Millions, $ in Millions	9 Months Ended
	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Mar. 01, 2021 USD ($)	Mar. 01, 2021 GBP (£)
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Tax exempt gain on sale	$ 380	$ 83
Miller [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Final total consideration received from sale of subsidiary			$ 818	£ 623
Miller [Member] \| Other Income, Net [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Tax exempt gain on sale	$ 356

Divestitures - Max Matthiessen Divestiture (Details) kr in Millions, $ in Millions	1 Months Ended	9 Months Ended
	Sep. 30, 2020 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2020 SEK (kr)
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Tax exempt gain on sale		$ 380	$ 83
Max Matthiessen [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Total consideration received from sale of subsidiary	$ 262		262	kr 2,300
Notes receivable repayable by purchaser	68		$ 68	kr 600
Max Matthiessen [Member] \| Other Income, Net [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Tax exempt gain on sale	$ 86
Max Matthiessen [Member] \| Minimum [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Disposal group including discontinued operation notes payable interest rate	5.00%
Max Matthiessen [Member] \| Maximum [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Disposal group including discontinued operation notes payable interest rate	10.00%

Revenue - Schedule of Disaggregation of Revenue (Details) - USD ($)
$ in Millions

3 Months Ended

9 Months Ended

Sep. 30, 2021

Sep. 30, 2020

Sep. 30, 2021

Sep. 30, 2020

Revenue from Contract with Customer, Excluding Assessed Tax

$ 1,951

$ 1,888

$ 6,204

$ 5,898

^[1]

^[2]

1,973

1,897

6,292

5,946

HCB [Member]

Revenue from Contract with Customer, Excluding Assessed Tax

858

804

2,586

2,435

^[1]

^[2]

862

806

2,596

2,449

CRB [Member]

Revenue from Contract with Customer, Excluding Assessed Tax

681

643

2,225

2,059

^[1]

^[2]

697

649

2,296

2,090

IRR [Member]

Revenue from Contract with Customer, Excluding Assessed Tax

174

221

619

722

^[1]

174

221

619

722

BDA [Member]

Revenue from Contract with Customer, Excluding Assessed Tax

244

228

774

673

^[1]

^[2]

244

228

777

673

Corporate, Non-Segment

Revenue from Contract with Customer, Excluding Assessed Tax

^[1]

(6)

(8)

^[1]

(9)

(10)

(9)

^[1],[2]

^[1]

(4)

(7)

Broking [Member]

Revenue from Contract with Customer, Excluding Assessed Tax

819

825

2,732

2,619

Broking [Member] | HCB [Member]

Revenue from Contract with Customer, Excluding Assessed Tax

248

216

Broking [Member] | CRB [Member]

Revenue from Contract with Customer, Excluding Assessed Tax

621

592

2,026

1,877

Broking [Member] | IRR [Member]

Revenue from Contract with Customer, Excluding Assessed Tax

238

Broking [Member] | BDA [Member]

Revenue from Contract with Customer, Excluding Assessed Tax

119

100

391

288

Consulting [Member]

Revenue from Contract with Customer, Excluding Assessed Tax

713

658

2,214

2,046

Consulting [Member] | HCB [Member]

Revenue from Contract with Customer, Excluding Assessed Tax

561

529

1,732

1,642

Consulting [Member] | CRB [Member]

Revenue from Contract with Customer, Excluding Assessed Tax

128

118

Consulting [Member] | IRR [Member]

Revenue from Contract with Customer, Excluding Assessed Tax

111

348

282

Consulting [Member] | Corporate, Non-Segment

Revenue from Contract with Customer, Excluding Assessed Tax

^[1]

Outsourced administration [Member]

Revenue from Contract with Customer, Excluding Assessed Tax

266

272

824

822

Outsourced administration [Member] | HCB [Member]

Revenue from Contract with Customer, Excluding Assessed Tax

122

126

377

376

Outsourced administration [Member] | CRB [Member]

Revenue from Contract with Customer, Excluding Assessed Tax

Outsourced administration [Member] | IRR [Member]

Revenue from Contract with Customer, Excluding Assessed Tax

Outsourced administration [Member] | BDA [Member]

Revenue from Contract with Customer, Excluding Assessed Tax

123

126

377

378

Other [Member]

Revenue from Contract with Customer, Excluding Assessed Tax

148

130

399

359

Other [Member] | HCB [Member]

Revenue from Contract with Customer, Excluding Assessed Tax

196

165

Other [Member] | CRB [Member]

Revenue from Contract with Customer, Excluding Assessed Tax

Other [Member] | IRR [Member]

Revenue from Contract with Customer, Excluding Assessed Tax

188

185

Other [Member] | Corporate, Non-Segment

Revenue from Contract with Customer, Excluding Assessed Tax

^[1]

Service

Revenue from Contract with Customer, Excluding Assessed Tax

1,946

1,885

6,169

5,846

Service | HCB [Member]

Revenue from Contract with Customer, Excluding Assessed Tax

848

794

2,553

2,399

Service | CRB [Member]

Revenue from Contract with Customer, Excluding Assessed Tax

681

643

2,224

2,058

Service | IRR [Member]

Revenue from Contract with Customer, Excluding Assessed Tax

172

220

615

716

Service | BDA [Member]

Revenue from Contract with Customer, Excluding Assessed Tax

242

226

768

666

Service | Corporate, Non-Segment

Revenue from Contract with Customer, Excluding Assessed Tax

^[1]

$ 3

$ 2

$ 9

$ 7

[1]	Reimbursable expenses and other, as well as Corporate revenue, are excluded from segment revenue, but included in total revenue on the condensed consolidated statements of comprehensive income. Amounts included in Corporate revenue may include eliminations, adjustments to reserves and impacts from hedged revenue transactions.
[2]	Interest and other income is included in segment revenue and total revenue. However, it has been presented separately in the above tables because it does not arise directly from contracts with customers. The significant increase in CRB’s interest and other income resulted from book-of-business settlements.

Revenue - Schedule of Revenue by Geography (Detail) - USD ($)
$ in Millions

3 Months Ended

9 Months Ended

Sep. 30, 2021

Sep. 30, 2020

Sep. 30, 2021

Sep. 30, 2020

Revenue from Contract with Customer, Excluding Assessed Tax

$ 1,951

$ 1,888

$ 6,204

$ 5,898

Service

Revenue from Contract with Customer, Excluding Assessed Tax

1,946

1,885

6,169

5,846

Operating Segments [Member] | Service

Revenue from Contract with Customer, Excluding Assessed Tax

1,946

1,885

6,169

5,846

Corporate, Non-Segment

Revenue from Contract with Customer, Excluding Assessed Tax

^[1]

(6)

(8)

Corporate, Non-Segment | Service

Revenue from Contract with Customer, Excluding Assessed Tax

^[1]

HCB [Member]

Revenue from Contract with Customer, Excluding Assessed Tax

858

804

2,586

2,435

HCB [Member] | Service

Revenue from Contract with Customer, Excluding Assessed Tax

848

794

2,553

2,399

HCB [Member] | Operating Segments [Member] | Service

Revenue from Contract with Customer, Excluding Assessed Tax

848

794

2,553

2,399

CRB [Member]

Revenue from Contract with Customer, Excluding Assessed Tax

681

643

2,225

2,059

CRB [Member] | Service

Revenue from Contract with Customer, Excluding Assessed Tax

681

643

2,224

2,058

CRB [Member] | Operating Segments [Member] | Service

Revenue from Contract with Customer, Excluding Assessed Tax

681

643

2,224

2,058

IRR [Member]

Revenue from Contract with Customer, Excluding Assessed Tax

174

221

619

722

IRR [Member] | Service

Revenue from Contract with Customer, Excluding Assessed Tax

172

220

615

716

IRR [Member] | Operating Segments [Member] | Service

Revenue from Contract with Customer, Excluding Assessed Tax

172

220

615

716

BDA [Member]

Revenue from Contract with Customer, Excluding Assessed Tax

244

228

774

673

BDA [Member] | Service

Revenue from Contract with Customer, Excluding Assessed Tax

242

226

768

666

BDA [Member] | Operating Segments [Member] | Service

Revenue from Contract with Customer, Excluding Assessed Tax

242

226

768

666

North America [Member] | Operating Segments [Member] | Service

Revenue from Contract with Customer, Excluding Assessed Tax

1,081

1,016

3,198

3,001

North America [Member] | Corporate, Non-Segment | Service

Revenue from Contract with Customer, Excluding Assessed Tax

North America [Member] | HCB [Member] | Operating Segments [Member] | Service

Revenue from Contract with Customer, Excluding Assessed Tax

485

465

1,430

1,403

North America [Member] | CRB [Member] | Operating Segments [Member] | Service

Revenue from Contract with Customer, Excluding Assessed Tax

310

287

865

816

North America [Member] | IRR [Member] | Operating Segments [Member] | Service

Revenue from Contract with Customer, Excluding Assessed Tax

136

117

North America [Member] | BDA [Member] | Operating Segments [Member] | Service

Revenue from Contract with Customer, Excluding Assessed Tax

239

224

760

660

Great Britain [Member] | Operating Segments [Member] | Service

Revenue from Contract with Customer, Excluding Assessed Tax

366

375

1,241

1,199

Great Britain [Member] | HCB [Member] | Operating Segments [Member] | Service

Revenue from Contract with Customer, Excluding Assessed Tax

137

120

427

363

Great Britain [Member] | CRB [Member] | Operating Segments [Member] | Service

Revenue from Contract with Customer, Excluding Assessed Tax

143

138

471

435

Great Britain [Member] | IRR [Member] | Operating Segments [Member] | Service

Revenue from Contract with Customer, Excluding Assessed Tax

117

343

401

Western Europe [Member] | Operating Segments [Member] | Service

Revenue from Contract with Customer, Excluding Assessed Tax

270

286

1,036

1,028

Western Europe [Member] | Corporate, Non-Segment | Service

Revenue from Contract with Customer, Excluding Assessed Tax

Western Europe [Member] | HCB [Member] | Operating Segments [Member] | Service

Revenue from Contract with Customer, Excluding Assessed Tax

135

129

444

404

Western Europe [Member] | CRB [Member] | Operating Segments [Member] | Service

Revenue from Contract with Customer, Excluding Assessed Tax

116

112

521

483

Western Europe [Member] | IRR [Member] | Operating Segments [Member] | Service

Revenue from Contract with Customer, Excluding Assessed Tax

139

International [Member] | Operating Segments [Member] | Service

Revenue from Contract with Customer, Excluding Assessed Tax

229

208

694

618

International [Member] | HCB [Member] | Operating Segments [Member] | Service

Revenue from Contract with Customer, Excluding Assessed Tax

252

229

International [Member] | CRB [Member] | Operating Segments [Member] | Service

Revenue from Contract with Customer, Excluding Assessed Tax

112

106

367

324

International [Member] | IRR [Member] | Operating Segments [Member] | Service

Revenue from Contract with Customer, Excluding Assessed Tax

International [Member] | BDA [Member] | Operating Segments [Member] | Service

Revenue from Contract with Customer, Excluding Assessed Tax

$ 3

$ 2

$ 8

$ 6

[1]

Revenue - Schedule of Contract Balances (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Revenue From Contract With Customer [Abstract]
Billed Receivable, Current	$ 1,360	$ 1,589
Unbilled Receivable, Current	511	445
Contract asset, Current	194	374
Accounts receivable, net	2,065	2,408
Non-current accounts receivable, net	23	34
Contract asset, Noncurrent	431	327
Deferred revenue	$ 636	$ 547

Revenue - Schedule of Contract Balances (Parenthetical) (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Revenue From Contract With Customer [Abstract]
Allowance for doubtful debts	$ 44	$ 40

Revenue - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Revenue - Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2021	Sep. 30, 2021
Disaggregation Of Revenue [Line Items]
Contract with Customer, Performance Obligation Satisfied in Previous Period	$ 16	$ 62
December 31 2020 [Member]
Disaggregation Of Revenue [Line Items]
Contract with Customer, Liability, Revenue Recognized	39	$ 408
June 30 2021 [Member]
Disaggregation Of Revenue [Line Items]
Contract with Customer, Liability, Revenue Recognized	$ 262

Revenue - Schedule of Remaining Performance Obligations (Details) $ in Millions	Sep. 30, 2021 USD ($)
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 1,508
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2021-10-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 174
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	3 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2022-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 546
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2023-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 788
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period

Revenue - Schedule of Remaining Performance Obligations (Details1) $ in Millions	Sep. 30, 2021 USD ($)
Revenue From Contract With Customer [Abstract]
Revenue, Remaining Performance Obligation	$ 1,508

Segment Information - Narrative (Details)	9 Months Ended
Segment Information - Narrative (Details)	Sep. 30, 2021 segment
Segment Reporting [Abstract]
Number of operating segments	4
Number of reportable segments	4

Segment Information - Revenue (Net of Reimbursable Expenses) of the Reported Segments (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting Information [Line Items]
Revenues	$ 1,973	$ 1,897	$ 6,292	$ 5,946
Income from operations	1,131	66	1,512	280
HCB [Member]
Segment Reporting Information [Line Items]
Revenues	862	806	2,596	2,449
CRB [Member]
Segment Reporting Information [Line Items]
Revenues	697	649	2,296	2,090
IRR [Member]
Segment Reporting Information [Line Items]
Revenues	174	221	619	722
BDA [Member]
Segment Reporting Information [Line Items]
Revenues	244	228	777	673
Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues	1,963	1,891	6,244	5,884
Income from operations	359	299	1,197	1,002
Operating Segments [Member] \| HCB [Member]
Segment Reporting Information [Line Items]
Revenues	852	796	2,563	2,413
Income from operations	242	209	654	582
Operating Segments [Member] \| CRB [Member]
Segment Reporting Information [Line Items]
Revenues	697	649	2,295	2,089
Income from operations	114	81	457	343
Operating Segments [Member] \| IRR [Member]
Segment Reporting Information [Line Items]
Revenues	172	220	615	716
Income from operations	22	20	108	108
Operating Segments [Member] \| BDA [Member]
Segment Reporting Information [Line Items]
Revenues	242	226	771	666
Income from operations	$ (19)	$ (11)	$ (22)	$ (31)

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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Segment Information - Reconciliation of Information Reported by Segment to Condensed Consolidated Statement of Comprehensive Income Amounts (Details) - USD ($)
$ in Millions

3 Months Ended

9 Months Ended

Sep. 30, 2021

Sep. 30, 2020

Sep. 30, 2021

Sep. 30, 2020

Revenue:

Income/(loss) from operations

$ 1,973

$ 1,897

$ 6,292

$ 5,946

1,131

1,512

280

INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES

(85)

(108)

(285)

(347)

Interest expense

(50)

(61)

(161)

(184)

Other income, net

105

156

617

321

1,186

161

1,968

417

Operating Segments [Member]

Revenue:

Income/(loss) from operations

1,963

1,891

6,244

5,884

359

299

1,197

1,002

Segment Reconciling Items [Member]

Revenue:

Transaction and integration, net

(85)

(108)

(285)

(347)

^[1]

952

(42)

877

(65)

Unallocated, net

^[2]

(95)

(83)

(277)

(310)

Interest expense

(50)

(61)

(161)

(184)

Other income, net

$ 105

$ 156

$ 617

$ 321

[1]

Includes mainly transaction costs related to the proposed Aon combination prior to its termination. For the three and nine months ended September 30, 2021, includes the $1 billion income receipt related to the termination of the proposed Aon transaction.

[2]

Segment Information - Reconciliation of Information Reported by Segment to Condensed Consolidated Statement of Comprehensive Income Amounts (Parenthetical) (Details) - USD ($) $ in Billions		3 Months Ended	9 Months Ended
	Jul. 26, 2021	Sep. 30, 2021	Sep. 30, 2021
Termination of Proposed Combination with AON Plc [Member] \| Termination Agreement [Member]
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Termination payment	$ 1	$ 1	$ 1

Income Taxes - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
Income Taxes - Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Operating Loss Carryforwards [Line Items]
Provision for income taxes	$ 267	$ 42	$ 386	$ 133
Effective tax rate	22.50%	26.60%	19.60%	31.90%
Estimated tax expense related to income receipt of termination payment	$ 250
Income taxes on discontinued operations	(3)	$ 4	$ 70	$ 66
Liabilities for uncertain tax positions	45		45
Minimum [Member]
Operating Loss Carryforwards [Line Items]
Expected decrease in liability for uncertain tax position	5		5
Maximum [Member]
Operating Loss Carryforwards [Line Items]
Expected decrease in liability for uncertain tax position	$ 9		$ 9

Amount of tax expense (benefit) related to a discontinued operation. Includes, but is not limited to, tax expense (benefit) related to income (loss) from operations during the phase-out period, tax expense (benefit) related to gain (loss) on disposal, tax expense (benefit) related to gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and tax expense (benefit) related to adjustments of a prior period gain (loss) on disposal.

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-Topic 205
-SubTopic 20
-Section 50
-Paragraph 5C
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=109222650&loc=SL51721675-107760

Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 5B
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109222650&loc=SL51721673-107760

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32672-109319

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References + Details

Goodwill and Other Intangible Assets - Components of Goodwill (Details)
$ in Millions

9 Months Ended

Sep. 30, 2021

USD ($)

$ 10,884

^[1]

(492)

10,392

(195)

(51)

10,638

(492)

10,146

HCB [Member]

4,346

^[1]

(130)

4,216

(28)

4,318

(130)

4,188

CRB [Member]

2,378

^[1]

(362)

2,016

(7)

(25)

2,346

(362)

1,984

IRR [Member]

882

^[1]

882

(188)

696

696

BDA [Member]

3,278

^[1]

3,278

3,278

$ 3,278

[1]	Excludes $812 million of goodwill associated with our IRR segment, which has been reclassified as assets held for sale on our condensed consolidated balance sheets at both September 30, 2021 and December 31, 2020 in conjunction with the pending divestiture of our Willis Re business.

Goodwill and Other Intangible Assets - Components of Goodwill (Parenthetical) (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
IRR [Member]
Goodwill [Line Items]
Goodwill reclassified as assets held for sale	$ 812	$ 812

Goodwill and Other Intangible Assets - Changes in the Net Carrying Amount of the Components of Finite-Lived Intangible Assets (Details) - USD ($)
$ in Millions

3 Months Ended

9 Months Ended

Sep. 30, 2021

Sep. 30, 2020

Sep. 30, 2021

Sep. 30, 2020

Dec. 31, 2020

Finite-lived intangible assets, gross carrying amount

$ 5,723

$ 5,976

Finite-lived intangible assets, accumulated amortization

(3,042)

(2,941)

2,681

3,035

^[1]

(55)

(85)

$ (108)

(285)

$ (347)

Client relationships [Member]

(14)

Finite-lived intangible assets, gross carrying amount

3,837

4,058

Finite-lived intangible assets, accumulated amortization

(2,061)

(2,028)

1,776

2,030

^[1]

(47)

(193)

(14)

Software [Member]

Finite-lived intangible assets, gross carrying amount

742

761

Finite-lived intangible assets, accumulated amortization

(689)

(659)

102

^[1]

(49)

Trademark and trade name [Member]

Finite-lived intangible assets, gross carrying amount

1,040

1,054

Finite-lived intangible assets, accumulated amortization

(247)

(220)

793

834

^[1]

(8)

(32)

(1)

Other [Member]

Finite-lived intangible assets, gross carrying amount

104

103

Finite-lived intangible assets, accumulated amortization

(45)

(34)

$ 59

$ 69

^[1]

(11)

Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]

$ 1

[1]	Excludes $8 million of intangible assets, net, which have been reclassified as assets held for sale on our condensed consolidated balance sheets at both September 30, 2021 and December 31, 2020 in conjunction with the pending divestiture of our Willis Re business.

Goodwill and Other Intangible Assets - Changes in the Net Carrying Amount of the Components of Finite-Lived Intangible Assets (Parenthetical) (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Willis Re [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets, net	$ 8	$ 8

Goodwill and Other Intangible Assets - Narrative (Details)	9 Months Ended
	Sep. 30, 2021
Finite-lived Intangible Assets [Roll Forward]
Weighted average remaining life of amortizable intangible assets	13 years 1 month 6 days

Goodwill and Other Intangible Assets - Schedule of Future Estimated Amortization Expense for Amortizable Intangible Assets (Details) - USD ($)
$ in Millions

Sep. 30, 2021

Dec. 31, 2020

^[1]

$ 84

307

254

223

203

1,610

$ 2,681

$ 3,035

[1]	Excludes $8 million of intangible assets, net, which have been reclassified as assets held for sale on our condensed consolidated balance sheets at both September 30, 2021 and December 31, 2020 in conjunction with the pending divestiture of our Willis Re business.

Derivative Financial Instruments - Narrative (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Derivative [Line Items]
Gains on derivatives to be reclassified within the next twelve months	$ 2
Maximum [Member]
Derivative [Line Items]
Longest outstanding maturity	1 year 7 months 6 days
Not Designated as Hedging Instrument [Member] \| Foreign exchange contracts [Member]
Derivative [Line Items]
Derivative, notional amount	$ 1,900	$ 1,500
Derivative asset, fair values		15
Derivative liability, fair value	21
Cash Flow Hedging [Member] \| Designated as Hedging Instrument [Member] \| Miller [Member]
Derivative [Line Items]
Derivative, notional amount		27
Cash Flow Hedging [Member] \| Designated as Hedging Instrument [Member] \| Foreign exchange contracts [Member]
Derivative [Line Items]
Derivative, notional amount	129	340
Derivative asset, fair values	$ 3	$ 5

Derivative Financial Instruments - Schedule of Derivative Instruments Designated As Hedging Instrument Effect on Condensed Consolidated Statements of Comprehensive Income (Details) - Cash Flow Hedging [Member] - Designated as Hedging Instrument [Member] - Foreign exchange contracts [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Derivative [Line Items]
(Loss)/gain recognized in OCL (effective element)	$ (2)	$ 6	$ 3	$ (21)
(Loss)/gain reclassified from Accumulated OCL into income (effective element)	1	(4)	5	(8)
Revenue [Member]
Derivative [Line Items]
(Loss)/gain reclassified from Accumulated OCL into income (effective element)	(1)	(2)	(3)	(4)
Salaries and Benefits [Member]
Derivative [Line Items]
(Loss)/gain reclassified from Accumulated OCL into income (effective element)	$ 2	$ (2)	5	(3)
Discontinued Operations [Member]
Derivative [Line Items]
(Loss)/gain reclassified from Accumulated OCL into income (effective element)			$ 3	$ (1)

Derivative Financial Instruments - Schedule Of Derivative Instruments, Effect on Condensed Consolidated Statements of Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Other income, net [Member] \| Not Designated as Hedging Instrument [Member] \| Foreign exchange contracts [Member]
Derivative [Line Items]
(Loss)/gain recognized in income	$ (7)	$ 5	$ (36)	$ (15)

Debt - Schedule of Current and Long-term Debt (Details)
€ in Millions

9 Months Ended

12 Months Ended

Sep. 30, 2021

USD ($)

Dec. 31, 2020

USD ($)

Sep. 30, 2021

EUR (€)

Aug. 31, 2021

Mar. 31, 2021

$ 644,000,000

$ 971,000,000

Revolving 1.25 Billion Dollar Credit Facility [Member] | Revolving Credit Facility [Member]

3,993,000,000

4,664,000,000

Maximum borrowing capacity

^[1]

$ 1,250,000,000

Line of credit maturity date

Mar. 07, 2022

5.750% senior notes due 2021 [Member]

$ 500,000,000

5.75%

3.500% senior notes due 2021 [Member]

2021

$ 449,000,000

3.50%

Collateralized Facility [Member]

2021

Current portion of long term debt

$ 19,000,000

$ 22,000,000

Renewal commissions receivables pledged as collateral

^[2]

19,000,000

33,000,000

82,000,000

$ 98,000,000

2.125% senior notes due 2022 [Member]

^[3]

$ 625,000,000

^[3]

2.125%

^[3]

2022

4.625% senior notes due 2023 [Member]

$ 659,000,000

^[3]

€ 540

4.625%

2023

3.600% senior notes due 2024 [Member]

$ 249,000,000

3.60%

2024

4.400% senior notes due 2026 [Member]

$ 648,000,000

$ 647,000,000

4.40%

2026

4.500% senior notes due 2028 [Member]

$ 546,000,000

4.50%

2028

2.950% senior notes due 2029 [Member]

$ 596,000,000

2.95%

2029

6.125% senior notes due 2043 [Member]

$ 727,000,000

$ 726,000,000

6.125%

2043

5.050% senior notes due 2048 [Member]

$ 271,000,000

5.05%

2048

3.875% senior notes due 2049 [Member]

$ 395,000,000

3.875%

2049

Contingent consideration [Member] | Fair Value Inputs, Discount Rate [Member]

$ 542,000,000

[1]	The $1.25 billion revolving credit facility expires on March 7, 2022 (see Note 18 – Subsequent Event for additional information).
[2]	At September 30, 2021 and December 31, 2020, the Company had $82 million and $98 million, respectively, of renewal commissions receivables pledged as collateral for this facility.
[3]	Notes issued in Euro (€540 million).

Debt - Narrative (Details) - USD ($) $ in Millions	Aug. 31, 2021	Sep. 30, 2021	Mar. 31, 2021	Dec. 31, 2020
3.500% senior notes due 2021 [Member]
Debt Instrument [Line Items]
Debt instrument principal and interest payment	$ 450
Debt instrument, maturity date	September 2021
Stated interest rate	3.50%	3.50%		3.50%
5.750% senior notes due 2021 [Member]
Debt Instrument [Line Items]
Debt instrument principal and interest payment			$ 500
Stated interest rate		5.75%	5.75%	5.75%

Fair Value Measurements - Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis (Details)
$ in Millions

Sep. 30, 2021

USD ($)

Dec. 31, 2020

USD ($)

Fair value inputs, weighted-average discount rate

0.1101

0.0946

Contingent consideration [Member] | Fair Value Inputs, Discount Rate [Member] | Minimum [Member]

Fair value inputs, weighted-average discount rate

0.0353

Contingent consideration [Member] | Fair Value Inputs, Discount Rate [Member] | Maximum [Member]

Fair value inputs, weighted-average discount rate

0.1300

Recurring [Member]

Assets:

$ 9

$ 8

^[1]

^[2]

Recurring [Member] | Level 1 [Member]

^[1]

Assets:

^[1]

^[2]

Recurring [Member] | Level 2 [Member]

^[1]

Assets:

^[1]

^[2]

Recurring [Member] | Level 3 [Member]

^[1]

Assets:

^[1]

^[2]

^[1]

$ 0

[1]

See Note 8 — Derivative Financial Instruments for further information on our derivative investments.

[2]

Fair Value Measurements - Fair Value Liabilities Measured Using Significant Unobservable Inputs Level 3 (Details) $ in Millions	9 Months Ended
	Sep. 30, 2021 USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance as of beginning of period	$ 45
Obligations assumed	0
Payments	(19)
Realized and unrealized gains	5
Foreign exchange	(1)
Balance as of end of period	$ 30

Fair Value Measurements - Narrative (Details)	9 Months Ended
Fair Value Measurements - Narrative (Details)	Sep. 30, 2021 USD ($)
Fair Value Disclosures [Abstract]
Fair value significant transfers to or from Level 3	$ 0

Fair Value Measurements - Schedule of Assets and Liabilities Whose Carrying Values Differ From the Fair Value and are Not Measured on a Recurring Basis (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Current debt	$ 644	$ 971
Long-term debt	3,993	4,664
Carrying Value [Member] \| Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term note receivable	70	71
Current debt	644	971
Long-term debt	3,993	4,664
Fair Value [Member] \| Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term note receivable	72	73
Current debt	651	985
Long-term debt	$ 4,560	$ 5,488

Retirement Benefits - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
Retirement Benefits - Narrative (Details) - USD ($)	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Compensation and Retirement Disclosure [Line Items]
Portion of pension and OPEB obligation attributed to disclosed plans (as a percent)			99.00%
Defined contribution plan, employer contribution	$ 36,000,000	$ 39,000,000	$ 118,000,000	$ 122,000,000
Pension Plan [Member] \| United States [Member]
Compensation and Retirement Disclosure [Line Items]
Defined benefit pension plans, employer contributions			60,000,000
Defined benefit plan, estimated future employer additional contributions, remainder of fiscal year	0		0
Pension Plan [Member] \| United Kingdom [Member]
Compensation and Retirement Disclosure [Line Items]
Defined benefit pension plans, employer contributions			28,000,000
Defined benefit plan, estimated future employer additional contributions, remainder of fiscal year	14,000,000		14,000,000
Pension Plan [Member] \| Other Foreign Plans [Member]
Compensation and Retirement Disclosure [Line Items]
Defined benefit pension plans, employer contributions			22,000,000
Defined benefit plan, estimated future employer additional contributions, remainder of fiscal year	$ 3,000,000		$ 3,000,000

Amount of contribution received by defined benefit plan from employer which increases plan assets.

+ References + Details

Retirement Benefits - Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Pension Plan [Member] \| United States [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 19	$ 18	$ 59	$ 54
Interest cost	24	32	71	98
Expected return on plan assets	(79)	(73)	(233)	(218)
Settlement	0	0	1	2
Amortization of net loss	8	9	30	26
Amortization of prior service credit	0	0	0	0
Net periodic benefit (income)/cost	(28)	(14)	(72)	(38)
Pension Plan [Member] \| United Kingdom [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	4	4	13	11
Interest cost	14	18	42	54
Expected return on plan assets	(42)	(63)	(128)	(184)
Settlement	1	0	2	1
Amortization of net loss	7	6	21	17
Amortization of prior service credit	(4)	(4)	(13)	(12)
Net periodic benefit (income)/cost	(20)	(39)	(63)	(113)
Pension Plan [Member] \| Other Foreign Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	6	5	18	15
Interest cost	3	4	9	11
Expected return on plan assets	(9)	(8)	(28)	(25)
Settlement	2	0	2	0
Amortization of net loss	1	0	4	2
Amortization of prior service credit	1	0	1	0
Net periodic benefit (income)/cost	4	1	6	3
PRW [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0	0
Interest cost	0	1	1	2
Expected return on plan assets	0	0	0	0
Settlement	0	0	0	0
Amortization of net loss	1	0	2	1
Amortization of prior service credit	(1)	(1)	(3)	(3)
Net periodic benefit (income)/cost	$ 0	$ 0	$ 0	$ 0

Leases - Schedule of Lease Costs Recorded in Condensed Consolidated Statements of Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Finance lease cost:
Amortization of right-of-use assets		$ 1	$ 1	$ 2
Interest on lease liabilities	$ 1		2	2
Operating lease cost	43	45	134	138
Short-term lease cost		1	1	1
Variable lease cost	13	14	39	37
Sublease income	(6)	(6)	(16)	(16)
Total lease cost, net	$ 51	$ 55	$ 161	$ 164

Commitments and Contingencies - Narrative (Details) - Settled Litigation [Member] - Merger-Related Securities Litigation [Member] - USD ($) $ in Millions		1 Months Ended	12 Months Ended
	Nov. 19, 2020	Feb. 28, 2021	Dec. 31, 2020
Loss Contingencies [Line Items]
Provision for litigation losses			$ 65
Litigation settlement amount		$ 90
Insurance recovery receivables			$ 25
Federal Action [Member]
Loss Contingencies [Line Items]
Litigation settlement amount	$ 75
Delaware Action [Member]
Loss Contingencies [Line Items]
Litigation settlement amount	$ 15

Supplementary Information for Certain Balance Sheet Accounts - Deferred Revenue and Accrued Expenses (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Accounts payable, accrued liabilities and deferred income	$ 911	$ 854
Accrued discretionary and incentive compensation	674	749
Litigation settlements		210
Accrued vacation	170	155
Other employee-related liabilities	74	75
Total deferred revenue and accrued expenses	$ 1,829	$ 2,043

Supplementary Information for Certain Balance Sheet Accounts - Other Current Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Dividends payable	$ 114	$ 103
Income and other taxes payable	333	96
Interest payable	22	68
Deferred compensation plan liabilities	39	51
Contingent and deferred consideration on acquisitions	17	39
Payroll-related liabilities	263	264
Derivatives	22	5
Third-party commissions	87	95
Other current liabilities	53	72
Total other current liabilities	$ 950	$ 793

Supplementary Information for Certain Balance Sheet Accounts - Provision For Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Claims, lawsuits and other proceedings	$ 335	$ 325
Other provisions	66	81
Total provision for liabilities	$ 401	$ 406

Supplementary Information for Certain Balance Sheet Accounts - Other Non-current Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Deferred compensation plan liability	$ 100	$ 103
Contingent and deferred consideration on acquisitions	13	16
Liabilities for uncertain tax positions	45	49
Derivatives		2
Finance leases	17	19
Other non-current liabilities	64	92
Total other non-current liabilities	$ 239	$ 281

Other Income, Net (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
Other Income, Net (Details) - USD ($) $ in Millions	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Other Income And Expenses [Abstract]
Gain on disposal of operations	$ 23	$ 85	$ 380	$ 83
Net periodic pension and postretirement benefit credits	79	76	227	227
Interest in earnings of associates and other investments	1	(1)	5	4
Foreign exchange gain/(loss)	1	(2)	4	7
Other	1	(2)	1
Other income, net	$ 105	$ 156	$ 617	$ 321

Accumulated Other Comprehensive Loss - Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Stockholders' equity attributable to parent, beginning balance			$ 10,820
Stockholders' equity attributable to parent, ending balance	$ 11,393		11,393
Foreign currency translation [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Stockholders' equity attributable to parent, beginning balance	(376)	$ (698)	(400)	$ (538)
Other comprehensive (loss)/income before reclassifications	(81)	119	(101)	(41)
Amounts reclassified from accumulated other comprehensive income/(loss) (net of income tax)	0	0	44	0
Net current-period other comprehensive (loss)/income	(81)	119	(57)	(41)
Stockholders' equity attributable to parent, ending balance	(457)	(579)	(457)	(579)
Derivative instruments [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Stockholders' equity attributable to parent, beginning balance	13	(6)	9	13
Other comprehensive (loss)/income before reclassifications	(1)	5	7	(17)
Amounts reclassified from accumulated other comprehensive income/(loss) (net of income tax)	(1)	4	(5)	7
Net current-period other comprehensive (loss)/income	(2)	9	2	(10)
Stockholders' equity attributable to parent, ending balance	11	3	11	3
Defined pension and post-retirement benefit costs [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Stockholders' equity attributable to parent, beginning balance	(1,915)	(1,686)	(1,968)	(1,702)
Other comprehensive (loss)/income before reclassifications	2	0	2	2
Amounts reclassified from accumulated other comprehensive income/(loss) (net of income tax)	0	9	53	23
Net current-period other comprehensive (loss)/income	2	9	55	25
Stockholders' equity attributable to parent, ending balance	(1,913)	(1,677)	(1,913)	(1,677)
Total [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Stockholders' equity attributable to parent, beginning balance	(2,278)	(2,390)	(2,359)	(2,227)
Other comprehensive (loss)/income before reclassifications	(80)	124	(92)	(56)
Amounts reclassified from accumulated other comprehensive income/(loss) (net of income tax)	(1)	13	92	30
Net current-period other comprehensive (loss)/income	(81)	137	0	(26)
Stockholders' equity attributable to parent, ending balance	$ (2,359)	$ (2,253)	$ (2,359)	$ (2,253)

Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g)(1)(ii))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 852
-SubTopic 10
-Section 55
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=84165509&loc=d3e56426-112766

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 4.E)
-URI http://asc.fasb.org/extlink&oid=122038336&loc=d3e74512-122707

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(31))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(30))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 28
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=123596393&loc=d3e14064-108612

Reference 8: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571