Marsh & McLennan Companies (MMC) 10-Q 21 Apr 22 2022 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2022	Apr. 18, 2022
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2022
Document Transition Report	false
Entity Registrant Name	Marsh & McLennan Companies, Inc.
Entity Address, Address Line One	1166 Avenue of the Americas
Entity Address, City or Town	New York
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10036
City Area Code	212
Local Phone Number	345-5000
Entity File Number	1-5998
Entity Address, State or Province	DE
Entity Tax Identification Number	36-2668272
Title of 12(b) Security	Common Stock, par value $1.00 per share
Trading Symbol	MMC
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		501,913,724
Entity Central Index Key	0000062709
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q1
Amendment Flag	false
New York Stock Exchange
Entity Information [Line Items]
Security Exchange Name	NYSE
Chicago Stock Exchange
Entity Information [Line Items]
Security Exchange Name	CHX

Consolidated Statements of Inco

Consolidated Statements of Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Income Statement [Abstract]
Revenue	$ 5,549	$ 5,083
Expense:
Compensation and benefits	3,100	2,807
Other operating expenses	1,004	918
Operating expenses	4,104	3,725
Operating income	1,445	1,358
Other net benefit credits	62	71
Interest income	1	0
Interest expense	(110)	(118)
Investment income	26	11
Income before income taxes	1,424	1,322
Income tax expense	338	324
Net income before non-controlling interests	1,086	998
Less: Net income attributable to non-controlling interests	15	15
Net income attributable to the Company	$ 1,071	$ 983
Net income per share attributable to the Company:
Basic (usd per share)	$ 2.13	$ 1.93
Diluted (usd per share)	$ 2.10	$ 1.91
Average number of shares outstanding:
Basic (in shares)	503	509
Diluted (in shares)	509	514
Shares outstanding (in shares)	502	509

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Statement of Comprehensive Income [Abstract]
Net income before non-controlling interests	$ 1,086	$ 998
Other comprehensive (loss) income, before tax:
Foreign currency translation adjustments	(169)	(91)
Gain related to pension/post-retirement plans	86	6
Other comprehensive loss, before tax	(83)	(85)
Income tax expense on other comprehensive income	21	2
Other comprehensive loss, net of tax	(104)	(87)
Comprehensive income	982	911
Less: comprehensive income attributable to non-controlling interest	15	15
Comprehensive income attributable to the Company	$ 967	$ 896

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 772	$ 1,752
Receivables
Commissions and fees	5,503	5,093
Advanced premiums and claims	139	136
Other	494	523
Gross receivables	6,136	5,752
Less-allowance for credit losses	(173)	(166)
Net receivables	5,963	5,586
Other current assets	1,053	926
Total current assets	7,788	8,264
Goodwill	16,254	16,317
Other intangible assets	2,720	2,810
Fixed assets (net of accumulated depreciation and amortization of $1,679 at March 31, 2022 and $1,589 at December 31, 2021)	865	847
Pension related assets	2,246	2,270
Right of use assets	1,825	1,868
Deferred tax assets	530	551
Other assets	1,460	1,461
Total assets	33,688	34,388
Current liabilities:
Short-term debt	1,191	17
Accounts payable and accrued liabilities	3,084	3,165
Accrued compensation and employee benefits	1,400	2,942
Current lease liabilities	331	332
Accrued income taxes	308	198
Dividends payable	273	0
Total current liabilities	6,587	6,654
Fiduciary liabilities	10,461	9,622
Less – cash and cash equivalents held in a fiduciary capacity	(10,461)	(9,622)
Net fiduciary liabilities	0	0
Long-term debt	10,552	10,933
Pension, post-retirement and post-employment benefits	1,515	1,632
Long-term lease liabilities	1,831	1,880
Liabilities for errors and omissions	352	355
Other liabilities	1,695	1,712
Commitments and contingencies	0	0
Equity:
Preferred stock, $1 par value, authorized 6,000,000 shares, none issued	0	0
Common stock, $1 par value, authorized 1,600,000,000 shares, issued 560,641,640 shares at March 31, 2022 and December 31, 2021	561	561
Additional paid-in capital	1,026	1,112
Retained earnings	18,916	18,389
Accumulated other comprehensive loss	(4,679)	(4,575)
Non-controlling interests	219	213
Stockholders' equity before treasury stock	16,043	15,700
Less – treasury shares, at cost, 58,524,983 shares at March 31, 2022 and 57,105,619 shares at December 31, 2021	(4,887)	(4,478)
Total equity	11,156	11,222
Total liabilities and stockholders' equity	$ 33,688	$ 34,388

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Fixed assets, accumulated depreciation and amortization	$ 1,679	$ 1,589
Preferred stock, par value (usd per share)	$ 1	$ 1
Preferred stock, shares authorized	6,000,000	6,000,000
Preferred stock, shares issued	0	0
Common stock, par value (usd per share)	$ 1	$ 1
Common stock, shares authorized	1,600,000,000	1,600,000,000
Common stock, shares issued	560,641,640	560,641,640
Treasury shares, shares	58,524,983	57,105,619

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating cash flows:
Net income before non-controlling interests	$ 1,086	$ 998
Adjustments to reconcile net income used for operations:
Depreciation and amortization of fixed assets and capitalized software	89	97
Amortization of intangible assets	91	100
Non cash lease expense	77	79
Adjustments and payments related to contingent consideration assets and liabilities	10	(1)
Deconsolidation of Russian businesses	39	0
Net gain on investments	(26)	(11)
Net (gain) loss on disposition of assets	(1)	3
Share-based compensation expense	105	78
Changes in assets and liabilities:
Net receivables	(429)	(404)
Other assets	(117)	(116)
Accrued compensation and employee benefits	(1,528)	(1,167)
Provision for taxes, net of payments and refunds	144	198
Contributions to pension and other benefit plans in excess of current year credit	(125)	(102)
Other liabilities	(33)	(78)
Operating lease liabilities	(84)	(82)
Net cash used for operations	(702)	(408)
Financing cash flows:
Purchase of treasury shares	(500)	(112)
Net proceeds from issuance of commercial paper	825	0
Repayments of debt	(4)	(4)
Shares withheld for taxes on vested units – treasury shares	(134)	(93)
Issuance of common stock from treasury shares	34	35
Payments of deferred and contingent consideration for acquisitions	(16)	(32)
Receipts of contingent consideration for dispositions	3	0
Distributions of non-controlling interests	(7)	(8)
Dividends paid	(272)	(237)
Change in fiduciary liabilities	926	190
Net cash provided by (used for) financing activities	855	(261)
Investing cash flows:
Capital expenditures	(122)	(69)
Net (purchases) sale of long term investments	(8)	4
Dispositions	(4)	0
Acquisitions	(24)	0
Other, net	(1)	(2)
Net cash used for investing activities	(159)	(67)
Effect of exchange rate changes on cash, cash equivalents, and cash and cash equivalents held in a fiduciary capacity	(136)	(36)
Decrease in cash, cash equivalents, and cash and cash equivalents held in a fiduciary capacity	(142)	(772)
Cash, cash equivalents, and cash and cash equivalents held in a fiduciary capacity at beginning of period	11,375	10,674
Cash, cash equivalents, and cash and cash equivalents held in a fiduciary capacity at end of period	11,233	9,902
Cash and cash equivalents	772	1,120
Cash and cash equivalents held in a fiduciary capacity	10,461	8,782
Total cash, cash equivalents, and cash and cash equivalents held in a fiduciary capacity	$ 11,233	$ 9,902

Consolidated Statements of Equi

Consolidated Statements of Equity (Unaudited) - USD ($) $ in Millions	Total	COMMON STOCK	ADDITIONAL PAID-IN CAPITAL	RETAINED EARNINGS	ACCUMULATED OTHER COMPREHENSIVE (LOSS) INCOME	TREASURY SHARES	NON-CONTROLLING INTERESTS
Balance, beginning of period at Dec. 31, 2020		$ 561	$ 943	$ 16,272	$ (5,110)	$ (3,562)	$ 156
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Change in accrued stock compensation costs			(133)
Issuance of shares under stock compensation plans and employee stock purchase plans			41			113
Net income attributable to the Company	$ 998			983			15
Dividend equivalents declared				(3)
Dividends declared				(472)
Other comprehensive (loss) income, net of tax	(87)				(87)
Purchase of treasury shares	(119)					(112)
Distributions and other changes							(9)
Balance, end of period at Mar. 31, 2021	$ 9,596	561	851	16,780	(5,197)	(3,561)	162
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends declared per share (in dollars per share)	$ 0.93
Balance, beginning of period at Dec. 31, 2021	$ 11,222	561	1,112	18,389	(4,575)	(4,478)	213
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Change in accrued stock compensation costs			(145)
Issuance of shares under stock compensation plans and employee stock purchase plans			59			91
Net income attributable to the Company	1,086			1,071			15
Dividend equivalents declared				(4)
Dividends declared				(540)
Other comprehensive (loss) income, net of tax	(104)				(104)
Purchase of treasury shares	(500)					(500)
Distributions and other changes							(9)
Balance, end of period at Mar. 31, 2022	$ 11,156	$ 561	$ 1,026	$ 18,916	$ (4,679)	$ (4,887)	$ 219
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends declared per share (in dollars per share)	$ 1.07

Nature of Operations

Nature of Operations	3 Months Ended
	Mar. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Operations	Nature of Operations Marsh & McLennan Companies, Inc. (the "Company"), a global professional services firm, is organized based on the different services that it offers. Under this structure, the Company’s two business segments are Risk and Insurance Services and Consulting. The Risk and Insurance Services segment ("RIS") provides risk management solutions (risk advice, risk transfer and risk control and mitigation) as well as insurance and reinsurance broking and services for businesses, public entities, insurance companies, associations, professional services organizations, and private clients. The Company conducts business in this segment through Marsh and Guy Carpenter. Marsh provides data-driven risk advisory services and solutions to commercial and consumer clients. Guy Carpenter develops advanced risk, reinsurance and capital strategies that help clients grow profitably and identify and capitalize on emerging opportunities. The Company conducts business in its Consulting segment through Mercer and Oliver Wyman Group. Mercer delivers advice and solutions that help organizations create a dynamic world of work, shape retirement and investment outcomes, and unlock health and well being for a changing workforce. Oliver Wyman Group serves as critical strategic, economic and brand advisor to private sector and governmental clients. Deconsolidation of Russia On February 24, 2022, Russian forces launched a military invasion of Ukraine. In response, the United States, the European Union, United Kingdom and other governments have imposed significant economic sanctions on Russia, and Russia has responded with counter-sanctions. The war in Ukraine has disrupted international commerce and the global economy. On March 10, 2022, the Company announced it would exit its businesses in Russia and transfer ownership of its Russian businesses to local management who will operate independently in the Russian market. In the first quarter of 2022, the Company concluded that it does not meet the accounting criteria for control over its wholly-owned Russian businesses due to the evolving trade and economic sanctions against Russia and related Russian counter-sanctions. These sanctions include restrictions on payments to and from Russian companies and reduced currency access through official exchange markets that have significantly impacted the Company's ability to effectively manage and operate its Russian businesses. For the three months ended March 31, 2022, the Company recorded a loss of $52 million on the deconsolidation of the Russian businesses and other related charges. Refer to Note 8, Acquisitions and Dispositions, for additional information on the deconsolidation of the Russian businesses. The Company continues to monitor the ongoing situation and its potential impact on our business, financial condition, results of operations and cash flows. Business Update Related To COVID-19 For over two years, the COVID-19 pandemic has impacted businesses globally including in every geography in which the Company operates. Our businesses have remained resilient throughout the pandemic and demand for our advice and services remains strong.

Principles of Consolidation and

Principles of Consolidation and Other Matters	3 Months Ended
	Mar. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Principles of Consolidation and Other Matters	Principles of Consolidation and Other MattersThe Company prepared the consolidated financial statements included herein pursuant to the rules and regulations of the Securities and Exchange Commission. For interim filings, certain information and disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America have been omitted pursuant to such rules and regulations. The Company believes that the information and disclosures presented are adequate to make such information and disclosures not misleading. These consolidated financial statements should be read in conjunction with the consolidated financial statements and the notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021 (the "2021 Form 10-K"). The financial information contained herein reflects all normal recurring adjustments which are, in the opinion of management, necessary for a fair presentation of the Company’s consolidated financial statements as of and for the three months ended March 31, 2022 and 2021. Estimates: The preparation of the consolidated financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of assets and liabilities at the date of the financial statements, and the reported amounts of revenue and expense during the reporting period. On an ongoing basis, the Company evaluates its estimates, judgments and methodologies. The estimates are based on historical experience and on various other assumptions that the Company believes are reasonable. Such matters include: • estimates of revenue; • impairment assessments and charges; • recoverability of long-lived assets; • liabilities for errors and omissions; • deferred tax assets, uncertain tax positions and income tax expense; • share-based and incentive compensation expense; • the allowance for current expected credit losses on receivables; • useful lives assigned to long-lived assets, and depreciation and amortization; and • fair value estimates of contingent consideration receivable or payable related to acquisitions or dispositions. The Company believes these estimates are reasonable based on information currently available at the time they are made. The Company also considered the potential impact of COVID-19 and the war in Ukraine to its customer base in various industries and geographies. Insurance exposures subject to variable factors are subject to mid-term and end of term adjustments, as well as policy audits, which may reduce premiums and corresponding commissions. Estimates were updated based on internal and industry specific economic data. The ultimate extent to which COVID-19 will directly or indirectly impact the Company’s businesses, results of operations and financial condition will depend on numerous evolving factors and future developments that it is not able to predict. Actual results may differ from these estimates. Cash and Cash Equivalents Cash and cash equivalents primarily consist of certificates of deposit and time deposits, with original maturities of three months or less, and money market funds. The estimated fair value of the Company's cash and cash equivalents approximates their carrying value. The Company is required to maintain operating funds primarily related to regulatory requirements outside of the United States or as collateral under captive insurance arrangements. At March 31, 2022, the Company maintained $304 million compared to $303 million at December 31, 2021 related to these regulatory requirements. Allowance for Credit Losses on Accounts Receivable The Company’s policy for providing an allowance for credit losses on its accounts receivable is based on a combination of factors, including historical write-offs, aging of balances, and other qualitative and quantitative analyses. The charge related to expected credit losses was immaterial to the consolidated statements of income for the three months ended March 31, 2022 and 2021,respectively. Investments The caption "Investment income" in the consolidated statements of income comprises realized and unrealized gains and losses from investments recognized in earnings. It includes, when applicable, other than temporary declines in the value of securities, mark-to-market increases or decreases in equity investments with readily determinable fair values and equity method gains or losses on the Company's investments in private equity funds. The Company holds investments in certain private equity funds. Investments in private equity funds are accounted for in accordance with the equity method of accounting using a consistently applied three-month lag period adjusted for any known significant changes from the lag period to the reporting date of the Company. The underlying private equity funds follow investment company accounting, where investments within the fund are carried at fair value. Investment gains or losses for its proportionate share of the change in fair value of the funds are recorded in earnings. Investments using the equity method of accounting are included in "other assets" in the consolidated balance sheets. The Company recorded investment income of $26 million for the three months ended March 31, 2022 compared to investment income of $11 million for the same period last year. The increase in 2022 is primarily driven by higher mark to market gains in the Company's private equity investments and its investment in Alexander Forbes ("AF"). Income Taxes The Company's effective tax rate in the first quarter of 2022 was 23.7% compared with 24.5% in the first quarter of 2021. The tax rates in both periods reflect the impact of discrete tax matters such as excess tax benefits related to share-based compensation, enacted tax legislation, changes in uncertain tax positions, deferred tax adjustments and nontaxable adjustments to contingent acquisition consideration. The excess tax benefit related to share-based payments is the most significant discrete item, as it normally is in the first quarter because that is when most share-based compensation vests, reducing the effective tax rate by 1.8% and 1.1% in the first quarters of 2022 and 2021, respectively. The rate in the first quarter of 2022 also reflects tax benefits from planning implemented in the period that postponed the utilization of current year losses in the U.K. to a future year when the tax rate will be 25%. The Company's tax rate reflects its income, statutory tax rates, and tax planning in the various jurisdictions in which it operates. Significant judgment is required in determining the annual effective tax rate and in evaluating uncertain tax positions. Losses in one jurisdiction, generally, cannot offset earnings in another, and within certain jurisdictions profits and losses may not offset between entities. Consequently, losses in certain jurisdictions may require valuation allowances affecting the effective tax rate, depending on estimates of the realizability of associated deferred tax assets. The tax rate is also sensitive to changes in unrecognized tax benefits, including the impact of settled tax audits and expired statutes of limitation. Changes in tax laws or tax rulings may have a significant impact on our effective tax rate. The Company reports a liability for unrecognized tax benefits resulting from uncertain tax positions taken or expected to be taken in tax returns. The Company's gross unrecognized tax benefits was $94 million at March 31, 2022 and December 31, 2021. It is reasonably possible that the total amount of unrecognized tax benefits will decrease between zero and approximately $49 million within the next twelve months due to settlements of audits and expirations of statutes of limitation. Integration and Restructuring Charges Severance and related costs are recognized based on amounts due under established severance plans or estimates of one-time benefits that will be provided. Typically, severance benefits are recognized when the impacted colleagues are notified of their expected termination and such termination is expected to occur within the legally required notification period. These costs are included in compensation and benefits in the consolidated statements of income. Costs for real estate consolidation are recognized based on the type of cost, and the expected future use of the facility. For locations where the Company does not expect to sub-lease the property, the amortization of any Right-of-use ("ROU") asset is accelerated from the decision date to the cease use date. For locations where the Company expects to sub-lease the properties subsequent to its vacating the property, the ROU asset is reviewed for potential impairment at the earlier of the cease use date or the date a sub-lease is signed. To determine the amount of impairment, the fair value of the ROU asset is determined based on the present value of the estimated net cash flows related to the property. Contractual costs outside of the ROU asset are recognized based on the net present value of expected future cash outflows for which the Company will not receive any benefit. Such amounts are reliant on estimates of future sub-lease income to be received and future contractual costs to be incurred. These costs are included in other operating expenses in the consolidated statements of income. Other costs related to integration and restructuring, such as moving, legal or consulting costs are recognized as incurred. These costs are included in other operating expenses in the consolidated statements of income.

Revenue

Revenue	3 Months Ended
	Mar. 31, 2022
Revenue from Contract with Customer [Abstract]
Revenue	RevenueThe core principle of the revenue recognition guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. To achieve this principle, the entity applies the following steps: identify the contract(s) with the customer, identify the performance obligations in the contract(s), determine the transaction price, allocate the transaction price to the performance obligations in the contract and recognize revenue when (or as) the entity satisfies a performance obligation. In accordance with accounting guidance, a performance obligation is satisfied either at a “point in time” or “over time” depending on the nature of the product or service provided, and the specific terms of the contract with customers. Other revenue included in the consolidated statements of income that is not from contracts with customers is less than 2% of total revenue, and therefore, is not presented as a separate line item. The Company's revenue recognition guidance is provided in more detail in Note 2, Revenue, in the Form 10-K for the year ended December 31, 2021. The following table disaggregates components of the Company's revenue: Three Months Ended (In millions) 2022 2021 Marsh: EMEA $ 842 $ 837 Asia Pacific 321 274 Latin America 104 90 Total International 1,267 1,201 U.S./Canada 1,279 1,124 Total Marsh 2,546 2,325 Guy Carpenter 999 895 Subtotal 3,545 3,220 Fiduciary interest income 4 5 Total Risk and Insurance Services $ 3,549 $ 3,225 Mercer: Wealth $ 617 $ 623 Health 524 487 Career 202 178 Total Mercer 1,343 1,288 Oliver Wyman Group 667 585 Total Consulting $ 2,010 $ 1,873 The Company recognizes commission revenue for a significant portion of its brokerage arrangements at a point in time on the effective date of the underlying policy. Commission revenue is estimated using historical information about the risks to be covered over the policy period, some of which are dependent on variable factors such as number of employees covered, covered payroll, airline passenger miles flown, shipped tonnage of marine cargo and others. The following table provides contract assets and contract liabilities information from contracts with customers: (In millions) March 31, 2022 December 31, 2021 Contract assets $ 357 $ 290 Contract liabilities $ 824 $ 776 The Company records accounts receivable when the right to consideration is unconditional, subject only to the passage of time. Contract assets primarily relate to quota share reinsurance brokerage and contingent insurer revenue. The Company does not have the right to bill and collect revenue for quota share brokerage until the underlying policies written by the ceding insurer attach to the treaty. Estimated revenue related to achievement of volume or loss ratio metrics cannot be billed or collected until all related policy placements are completed and the contingency is resolved. Contract assets are included in other current assets in the Company's consolidated balance sheets. Contract liabilities primarily relate to the advance consideration received from customers. Contract liabilities are included in current liabilities in the Company's consolidated balance sheets. Revenue recognized in the first three months of 2022 and 2021 that was included in the contract liability balance at the beginning of each of those years was $280 million and $238 million, respectively. The amount of revenue recognized in the first three months of 2022 and 2021 from performance obligations satisfied in previous periods, mainly due to variable consideration from contracts with insurers, quota share business and consulting contracts previously considered constrained was $24 million and $34 million, respectively. The Company applies the practical expedient and does not disclose the value of unsatisfied performance obligations for (1) contracts with original contract terms of one year or less and (2) contracts where the Company has the right to invoice for services performed. The revenue expected to be recognized in future periods during the non-cancellable term of existing contracts greater than one year that is related to performance obligations that are unsatisfied or partially satisfied at the end of the reporting period is approximately $187 million, primarily related to Mercer. The Company expects revenue in 2023, 2024, 2025, 2026 and 2027 and beyond of $78 million, $61 million, $28 million, $12 million and $8 million, respectively, related to these performance obligations.

Fiduciary Assets and Liabilitie

Fiduciary Assets and Liabilities	3 Months Ended
	Mar. 31, 2022
Fiduciary Assets And Liabilities [Abstract]
Fiduciary Assets and Liabilities	Fiduciary Assets and Liabilities In its capacity as an insurance broker or agent, generally the Company collects premiums from insureds and after deducting its commissions, remits the premiums to the respective insurance underwriters. The Company also collects claims or refunds from underwriters on behalf of insureds. Un-remitted insurance premiums and claims proceeds are held by the Company in a fiduciary capacity. The Company's fiduciary assets primarily include bank or short term time deposits and liquid money market funds, and are classified as cash and cash equivalents. Risk and Insurance Services revenue includes interest on fiduciary funds of $4 million and $5 million for the three months ended March 31, 2022 and 2021, respectively. Since cash and cash equivalents held in a fiduciary capacity are not available for corporate use, they are shown in the consolidated balance sheets as an offset to fiduciary liabilities. Net uncollected premiums and claims and the related payables amounted to $13.0 billion at March 31, 2022 and at December 31, 2021 respectively. The Company is not a principal to the contracts under which the right to receive premiums or the right to receive reimbursement of insured losses arises. Accordingly, net uncollected premiums and claims and the related payables are not assets and liabilities of the Company and are not included in the accompanying consolidated balance sheets. In certain instances, the Company advances premiums, refunds or claims to insurance underwriters or insureds prior to collection. These advances are made from corporate funds and are reflected in the accompanying consolidated balance sheets as receivables. The Company, through its Mercer subsidiary, manages assets in trusts or funds for which Mercer’s management or trustee fee is not considered a variable interest, since the fees are commensurate with the level of effort required to provide those services. Mercer is not the primary beneficiary of these trusts or funds. Mercer’s maximum exposure to loss of its interests is, therefore, limited to collection of its fees.

Per Share Data

Per Share Data	3 Months Ended
	Mar. 31, 2022
Earnings Per Share [Abstract]
Per Share Data	Per Share Data Basic net income per share attributable to the Company is calculated by dividing the after-tax income attributable to the Company by the weighted average number of outstanding shares of the Company’s common stock. Diluted net income per share attributable to the Company is calculated by dividing the after-tax income attributable to the Company by the weighted average number of outstanding shares of the Company’s common stock, which have been adjusted for the dilutive effect of potentially issuable common shares. Basic and Diluted EPS Calculation Three Months Ended (In millions, except per share data) 2022 2021 Net income before non-controlling interests $ 1,086 $ 998 Less: Net income attributable to non-controlling interests 15 15 Net income attributable to the Company $ 1,071 $ 983 Basic weighted average common shares outstanding 503 509 Dilutive effect of potentially issuable common shares 6 5 Diluted weighted average common shares outstanding 509 514 Average stock price used to calculate common stock equivalents $ 157.49 $ 114.96

Supplemental Disclosures to the

Supplemental Disclosures to the Consolidated Statements of Cash Flows	3 Months Ended
	Mar. 31, 2022
Supplemental Cash Flow Information [Abstract]
Supplemental Disclosures to the Consolidated Statements of Cash Flows	Supplemental Disclosures to the Consolidated Statements of Cash Flows The following table provides additional information concerning acquisitions, interest and income taxes paid for the three month periods ended March 31, 2022 and 2021. (In millions) 2022 2021 Assets acquired, excluding cash $ 30 $ — Liabilities assumed (2) — Contingent/deferred purchase consideration (4) — Net cash outflow for current year acquisitions $ 24 $ — (In millions) 2022 2021 Interest paid $ 171 $ 191 Income taxes paid, net of refunds $ 201 $ 122 The classification of contingent consideration payments in the consolidated statements of cash flows is dependent upon whether receipt, payment or adjustment was part of the initial liability established on the acquisition date (financing) or an adjustment to the acquisition date liability (operating). The following amounts are included in the consolidated statements of cash flows as operating and financing activities: For the Three Months Ended March 31, (In millions) 2022 2021 Operating: Contingent consideration payments $ — $ (1) Acquisition/disposition related net charges for adjustments 10 — Adjustments and payments related to contingent consideration $ 10 $ (1) Financing: Contingent purchase consideration $ (4) $ (10) Deferred purchase consideration related to prior years' acquisitions (12) (27) Payments of deferred and contingent consideration for acquisitions $ (16) $ (37) Receipt of contingent consideration related to prior year dispositions $ 3 $ 5 The Company had non-cash issuances of common stock under its share-based payment plan of $250 million and $212 million for the three months ended March 31, 2022 and 2021, respectively. The Company recorded share-based compensation expense related to restricted stock units, performance stock units and stock options of $105 million and $78 million for the three months ended March 31, 2022 and 2021, respectively. Statement of Cash Flows Reclassifications

Other Comprehensive Income (Los

Other Comprehensive Income (Loss)	3 Months Ended
	Mar. 31, 2022
Equity [Abstract]
Other Comprehensive Income (Loss)	Other Comprehensive Income (Loss) The changes, net of tax, in the balances of each component of Accumulated Other Comprehensive Income ("AOCI") for the three months ended March 31, 2022 and 2021, including amounts reclassified out of AOCI, are as follows: (In millions) Pension/Post-Retirement Plans Gains (Losses) Foreign Currency Translation Gains (Losses) Total Gains (Losses) Balance as of December 31, 2021 $ (3,202) $ (1,373) $ (4,575) Other comprehensive income (loss) before reclassifications 35 (169) (134) Amounts reclassified from accumulated other comprehensive income 30 — 30 Net current period other comprehensive income (loss) 65 (169) (104) Balance as of March 31, 2022 $ (3,137) $ (1,542) $ (4,679) (In millions) Pension/Post-Retirement Plans Gains (Losses) Foreign Currency Translation Gains (Losses) Total Gains (Losses) Balance as of December 31, 2020 $ (4,126) $ (984) $ (5,110) Other comprehensive income (loss) before reclassifications (36) (91) (127) Amounts reclassified from accumulated other comprehensive income 40 — 40 Net current period other comprehensive income (loss) 4 (91) (87) Balance as of March 31, 2021 $ (4,122) $ (1,075) $ (5,197) The components of other comprehensive income (loss) for the three month periods ended March 31, 2022 and 2021 are as follows: Three Months Ended March 31, 2022 2021 (In millions) Pre-Tax Tax (Credit) Net of Tax Pre-Tax Tax (Credit) Net of Tax Foreign currency translation adjustments $ (169) $ — $ (169) $ (91) $ — $ (91) Pension/post-retirement plans: Amortization of gains included in net periodic pension cost: Net actuarial losses (a) 39 9 30 52 12 40 Subtotal 39 9 30 52 12 40 Foreign currency translation adjustments 65 16 49 (37) (8) (29) Other adjustments (18) (4) (14) (7) (2) (5) Effect of re-measurement — — — (2) — (2) Pension/post-retirement plans gains 86 21 65 6 2 4 Other comprehensive (loss) income $ (83) $ 21 $ (104) $ (85) $ 2 $ (87) (a) Components of net periodic pension cost are included in other net benefit credits in the consolidated statements of income. Income tax expense on net actuarial losses are included in income tax expense.

Acquisitions and Dispositions

Acquisitions and Dispositions	3 Months Ended
	Mar. 31, 2022
Business Combination and Asset Acquisition [Abstract]
Acquisitions and Dispositions	Acquisitions and Dispositions The Company’s acquisitions have been accounted for as business combinations. Net assets and results of operations are included in the Company’s consolidated financial statements commencing at the respective purchase closing dates. In connection with acquisitions, the Company records the estimated values of the net tangible assets and the identifiable intangible assets purchased, which typically consist of customer relationships, developed technology, trademarks and non-compete agreements. The valuation of purchased intangible assets involves significant estimates and assumptions. The Company estimates the fair value of purchased intangible assets, primarily using the income approach, by determining the present value of future cash flows over the remaining economic life of the respective assets. The significant estimates and assumptions used in this approach include the determination of the discount rate, economic life, future revenue growth rates, expected account attrition rates and earnings margins. Refinement and completion of final valuation of net assets acquired could affect the carrying value of tangible assets, goodwill and identifiable intangible assets. The Risk and Insurance Services segment completed one acquisition during the three months ended March 31, 2022: • January – Marsh McLennan Agency ("MMA") acquired Heil & Kay Insurance Agency Inc., an Illinois-based full-service independent insurance agency providing business insurance, employee health benefits services and personal lines insurance. The Consulting segment completed two acquisitions during the three months ended March 31, 2022: • February – Oliver Wyman acquired Azure Consulting, an Australia-based management consulting firm with expertise in strategy development, organizational design and operations in the industrials, energy and natural resources sectors. • March – Mercer acquired GeFi Assurances, a France-based brokerage and consulting firm specializing in collective corporate social protection. Total purchase consideration for acquisitions made during the three months ended March 31, 2022 was $28 million, which consisted of cash paid of $24 million and deferred purchase consideration and estimated contingent consideration of $4 million. Contingent consideration arrangements are based primarily on earnings before interest, tax, depreciation and amortization ("EBITDA") or revenue targets over a period of two The following table presents the preliminary allocation of purchase consideration to the assets acquired and liabilities assumed during 2022 based on the estimated fair values for the acquisitions as of their respective acquisition dates: Acquisitions through March 31, 2022 (In millions) Cash $ 24 Estimated fair value of deferred/contingent consideration 4 Total consideration $ 28 Allocation of purchase price: Net receivables 1 Other current assets 2 Goodwill 17 Other intangible assets 10 Total assets acquired 30 Current liabilities 1 Other liabilities 1 Total liabilities assumed 2 Net assets acquired $ 28 The purchase price allocation for assets acquired and liabilities assumed is based on estimates that are preliminary in nature and subject to adjustments, which could be material. Any necessary adjustments must be finalized during the measurement period, which for a particular asset, liability, or non-controlling interest ends once the acquirer determines that either (1) the necessary information has been obtained or (2) the information is not available. However, the measurement period for all items is limited to one year from the acquisition date. Items subject to change include: • amounts of intangible assets, fixed assets, capitalized software assets and right-of-use assets, subject to finalization of valuation efforts; • amounts for contingencies, pending the finalization of the Company’s assessment of the portfolio of contingencies; • amounts for deferred tax assets and liabilities, pending the finalization of valuations of the assets acquired, liabilities assumed and associated goodwill discussed below; and • amounts for income tax assets, receivables and liabilities, pending the filing of the acquired companies' pre-acquisition income tax returns and receipt of information from taxing authorities which may change certain estimates and assumptions used. The estimation of fair value requires numerous judgments, assumptions and estimates about future events and uncertainties, which could materially impact these values, and the related amortization, where applicable, in the Company’s results of operations. The following table provides information about intangible assets acquired during 2022: Intangible assets through March 31, 2022 (In millions) Amount Weighted Average Amortization Period Client relationships $ 10 10.4 years The consolidated statements of income include the results of operations of acquired companies since their respective acquisition dates. The Company had no acquisitions during the first three months of 2021. Dispositions During the first three months of 2022, Mercer sold its retirement plan administration and call center operations in Brazil for cash proceeds of approximately $4 million. Prior-Year Acquisitions The Risk and Insurance Services segment completed eight acquisitions during 2021: • April – MMA acq uired PayneWest Insurance, Inc., a Montana-based full-service broker providing business insurance, surety, employee benefits and personal insurance services to companies and individuals, and The Pryor Group, LLC, a Texas-based full-service broker providing business insurance with a specialty in quick service restaurants and the personal lines of franchise owners. • September – MMA acquired Vaaler Insurance, Inc., a North Dakota-based insurance broker providing business insurance, employee health and benefits, and personal lines solutions, with specialized expertise in the construction, education, and healthcare industries. • November – MMA acquired Pelnik Insurance, a North Carolina-based full-service broker providing business insurance, employee health and benefits, and private client services to midsize businesses and individuals throughout the Mid-Atlantic, Southwest Truck Insurance Agency, Inc., a Texas-based broker providing business insurance for the trucking industry, serving clients in the U.S., and Mexico and InSource Insurance Group LLC, a Texas-based full-service broker providing business insurance, employee health and benefits, private client and surety services to the oil and gas, construction, manufacturing, and transportation industries. • December – Marsh acquired Services Assurance Monétique (SAM), a France-based affinity insurance broker specializing in bank and retail insurance markets and increased its ownership interest in Marsh India Insurance Broker Private Limited ("Marsh India") from 49% to 92%. The Consulting segment completed one acquisition during 2021: • November – Oliver Wyman Group acquired Huron Consulting Group’s life sciences strategy consulting practice in the U.S. and the U.K., which assists clients in addressing their most important commercial strategy, marketing, pricing, market access and research and development challenges. Prior year dispositions There were no dispositions during the first three months of 2021. Deconsolidation of Russia In the first quarter of 2022, the Company concluded that it does not meet the accounting criteria for control over its wholly-owned Russian subsidiaries, and therefore, deconsolidated the businesses effective as of the end of the first quarter. For the three months ended March 31, 2022, the Company recorded a loss of $39 million on the deconsolidation of the Russian businesses included in revenue in the consolidated statements of income. The loss consisted of the reclassification of cumulative translation losses from accumulated other comprehensive income and a charge for the write-off of the Russia businesses' net assets. On March 10, 2022, the Company announced it would exit its businesses in Russia and transfer ownership of its Russian entities to local management who will operate independently in the Russian market. The closing of the transaction is subject to approval from the Russian regulators. Subsequent event On April 1, 2022, Mercer sold its U.S. affinity business that provides insurance marketing, brokerage and administration to association and affinity groups for cash proceeds of approximately $145 million and a net gain of approximately $110 million. Pro-Forma Information The following unaudited pro-forma financial data gives effect to the acquisitions made by the Company during 2022 and 2021. In accordance with accounting guidance related to pro-forma disclosures, the information presented for acquisitions made in 2022 is as if they occurred on January 1, 2021 and reflects acquisitions made in 2021 as if they occurred on January 1, 2020. The unaudited pro-forma information includes the effects of amortization of acquired intangibles. The unaudited pro-forma financial data is presented for illustrative purposes only and is not necessarily indicative of the operating results that would have been achieved if such acquisitions had occurred on the dates indicated, nor is it necessarily indicative of future consolidated results. Three Months Ended (In millions, except per share data) 2022 2021 Revenue $ 5,550 $ 5,156 Net income attributable to the Company $ 1,071 $ 987 Basic net income per share attributable to the Company $ 2.13 $ 1.94 Diluted net income per share attributable to the Company $ 2.10 $ 1.92

Goodwill and Other Intangibles

Goodwill and Other Intangibles	3 Months Ended
	Mar. 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangibles	Goodwill and Other Intangibles The Company is required to assess goodwill and any indefinite-lived intangible assets for impairment annually, or more frequently if circumstances indicate impairment may have occurred. The Company performs the annual impairment assessment for each of its reporting units during the third quarter of each year. In accordance with applicable accounting guidance, a company can assess qualitative factors to determine whether it is necessary to perform a quantitative goodwill impairment test. Alternatively, the Company may elect to proceed directly to the quantitative goodwill impairment test. In 2021, the Company elected to perform a qualitative impairment assessment. As part of its assessment, the Company considered numerous factors, including: • that the fair value of each reporting unit exceeds its carrying value by a substantial margin based on its most recent quantitative assessment in 2019; • whether significant acquisitions or dispositions occurred which might alter the fair value of its reporting units; • macroeconomic conditions and their potential impact on reporting unit fair values; • actual performance compared with budget and prior projections used in its estimation of reporting unit fair values; • industry and market conditions; and • the year-over-year change in the Company’s share price. The Company completed its qualitative assessment in the third quarter of 2021 and concluded that goodwill was not impaired. Other intangible assets that are not deemed to have an indefinite life are amortized over their estimated lives and assessed for impairment upon the occurrence of certain triggering events in accordance with applicable accounting literature. Based on its assessment, the Company concluded that other intangible assets were not impaired. The Company does not have any indefinite lived intangible assets. Changes in the carrying amount of goodwill are as follows: March 31, (In millions) 2022 2021 Balance as of January 1, $ 16,317 $ 15,517 Goodwill acquired 17 — Other adjustments (a) (80) (59) Balance at March 31, $ 16,254 $ 15,458 (a) Primarily reflects the impact of foreign exchange. The goodwill arising from the acquisitions in 2022 and 2021 consists largely of the synergies and economies of scale expected from combining the operations of the Company and the acquired entities and the trained and assembled workforce acquired. The goodwill acquired in 2022 was $17 million, of which approximately $1.6 million is deductible for tax purposes, and is primarily related to the Risk and Insurance Services segment. Goodwill allocable to the Company’s reportable segments at March 31, 2022 is as follows: Risk and Insurance Services, $12.5 billion and Consulting, $3.8 billion. The gross cost and accumulated amortization of identified intangible assets at March 31, 2022 and December 31, 2021 are as follows: March 31, 2022 December 31, 2021 (In millions) Gross Accumulated Net Gross Accumulated Net Client relationships $ 4,041 $ 1,389 $ 2,652 $ 4,066 $ 1,334 $ 2,732 Other (a) 362 294 68 365 287 78 Amortized intangibles $ 4,403 $ 1,683 $ 2,720 $ 4,431 $ 1,621 $ 2,810 (a) Primarily non-compete agreements, trade names and developed technology. Aggregate amortization expense for the three months ended March 31, 2022 and 2021 was $91 million and $100 million, respectively. The estimated future aggregate amortization expense is as follows: For the Years Ending December 31, (In millions) Estimated Expense 2022 (excludes amortization through March 31, 2022) $ 261 2023 328 2024 308 2025 269 2026 248 Subsequent years 1,306 Total future amortization $ 2,720

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2022
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Fair Value Hierarchy The Company has categorized its assets and liabilities that are valued at fair value on a recurring basis into a three-level fair value hierarchy as defined by the FASB. The fair value hierarchy gives the highest priority to quoted prices in active markets for identical assets and liabilities (Level 1) and lowest priority to unobservable inputs (Level 3). In some cases, the inputs used to measure fair value might fall into different levels of the fair value hierarchy. In such cases, the level in the fair value hierarchy, for disclosure purposes, is determined based on the lowest level input that is significant to the fair value measurement. Assets and liabilities recorded in the consolidated balance sheets at fair value are categorized based on the inputs in the valuation techniques as follows: Level 1. Assets and liabilities whose values are based on unadjusted quoted prices for identical assets or liabilities in an active market (examples include active exchange-traded equity securities and exchange-traded money market mutual funds). Assets and liabilities measured using Level 1 inputs include exchange-traded equity securities, exchange-traded mutual funds and money market funds. Level 2. Assets and liabilities whose values are based on the following: a) Quoted prices for similar assets or liabilities in active markets; b) Quoted prices for identical or similar assets or liabilities in non-active markets (examples include corporate and municipal bonds, which trade infrequently); c) Pricing models whose inputs are observable for substantially the full term of the asset or liability (examples include most over-the-counter derivatives, including interest rate and currency swaps); and d) Pricing models whose inputs are derived principally from or corroborated by observable market data through correlation or other means for substantially the full asset or liability (for example, certain mortgage loans). Assets and liabilities using Level 2 inputs are related to an equity security. Level 3. Assets and liabilities whose values are based on prices, or valuation techniques that require inputs that are both unobservable and significant to the overall fair value measurement. These inputs reflect management’s own assumptions about the assumptions a market participant would use in pricing the asset or liability. Assets and liabilities measured using Level 3 inputs relate to assets and liabilities for contingent purchase consideration. Valuation Techniques Equity Securities, Money Market Mutual Funds and Mutual Funds – Level 1 Investments for which market quotations are readily available are valued at the sale price on their principal exchange or, for certain markets, official closing bid price. Money market mutual funds are valued using a valuation technique that results in price per share at $1.00. Contingent Purchase Consideration Assets and Liabilities – Level 3 Purchase consideration for some acquisitions and dispositions made by the Company include contingent consideration arrangements. Contingent consideration arrangements are based primarily on EBITDA or revenue targets over a period of two The following fair value hierarchy table presents information about the Company’s assets and liabilities measured at fair value on a recurring basis as of March 31, 2022 and December 31, 2021: Identical Assets Observable Inputs Unobservable Total (In millions) 03/31/22 12/31/21 03/31/22 12/31/21 03/31/22 12/31/21 03/31/22 12/31/21 Assets: Financial instruments owned: Exchange traded equity securities (a) $ 69 $ 61 $ — $ — $ — $ — $ 69 $ 61 Mutual funds (a) 179 192 — — — — 179 192 Money market funds (b) 82 425 — — — — 82 425 Other equity investment (a) — — 8 8 — — 8 8 Contingent purchase consideration assets (c) — — — — 2 5 2 5 Total assets measured at fair value $ 330 $ 678 $ 8 $ 8 $ 2 $ 5 $ 340 $ 691 Fiduciary Assets: U.S. treasury bills (e) $ 30 $ 55 $ — $ — $ — $ — $ 30 $ 55 Money market funds 205 527 — — — — 205 527 Total fiduciary assets measured $ 235 $ 582 $ — $ — $ — $ — $ 235 $ 582 Liabilities: Contingent purchase consideration liability (d) $ — $ — $ — $ — $ 358 $ 352 $ 358 $ 352 Total liabilities measured at fair value $ — $ — $ — $ — $ 358 $ 352 $ 358 $ 352 (a) Included in other assets in the consolidated balance sheets. (b) Included in cash and cash equivalents in the consolidated balance sheets. (c) Included in other receivables in the consolidated balance sheets. (d) Included in accounts payable and accrued liabilities and other liabilities in the consolidated balance sheets. (e) Maturity dates of three months or less. The Level 3 assets in the table reflect contingent purchase consideration from the sale of businesses. The change in the contingent purchase consideration assets from December 31, 2021 is driven primarily by cash receipts. During the three months ended March 31, 2022, there were no assets or liabilities that were transferred between levels. The following table sets forth a summary of the changes in fair value of the Company’s Level 3 liabilities for the three month periods ended March 31, 2022 and 2021: Three Months Ended (In millions) 2022 2021 Balance at beginning of period $ 352 $ 243 Payments (4) (11) Revaluation impact 10 1 Balance at March 31, $ 358 $ 233 Long-Term Investments The Company holds investments in public and private companies as well as certain private equity investments that are accounted for using the equity method of accounting. The carrying value of these investments was $224 million and $207 million at March 31, 2022 and December 31, 2021, respectively. Investments in Public and Private Companies The Company has investments in private insurance and consulting companies with a carrying value of $51 million and $58 million at March 31, 2022 and December 31, 2021, respectively. These investments are accounted for using the equity method of accounting, the results of which are included in revenue in the consolidated statements of income and the carrying value of which is included in other assets in the consolidated balance sheets. The Company records its share of income or loss on its equity method investments, some of which are on a one quarter lag basis. Private Equity Investments The Company's investments in private equity funds were $173 million and $149 million at March 31, 2022 and December 31, 2021, respectively. The carrying values of these private equity investments approximate fair value. The underlying private equity funds follow investment company accounting, where investments within the fund are carried at fair value. The Company records in earnings its proportionate share of the change in fair value of the funds on the investment income (loss) line in the consolidated statements of income. These investments are included in other assets in the consolidated balance sheets. The Company recorded net investment gains of $17 million for the three month period ended March 31, 2022, and gains of $10 million from these investments for the same period in 2021. Other Investments

Derivatives

Derivatives	3 Months Ended
	Mar. 31, 2022
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives	Derivatives Net Investment Hedge The Company has investments in various subsidiaries with Euro functional currencies. As a result, the Company is exposed to the risk of fluctuations between the Euro and U.S. dollar exchange rates. The Company designated its €1.1 billion senior note debt instruments ("euro notes") as a net investment hedge (the "hedge") of its Euro denominated subsidiaries. The hedge effectiveness is re-assessed each quarter to confirm that the designated equity balance at the beginning of each period continues to equal or exceed 80% of the outstanding balance of the Euro debt instrument and that all the critical terms of the hedging instrument and the hedged net investment continue to match. If the Company concludes that the hedge is highly effective, the change in the debt balance related to foreign exchange fluctuations is recorded in foreign currency translation gains (losses) in the consolidated balance sheets. The Company concluded that the hedge continues to be highly effective as of March 31, 2022. The U.S. dollar value of the euro notes decreased $29 million through March 31, 2022 due to the impact of foreign exchange rates, with a corresponding decrease to accumulated other comprehensive loss.

Leases

Leases	3 Months Ended
	Mar. 31, 2022
Leases [Abstract]
Leases	Leases The Company leases office facilities under non-cancelable operating leases with terms generally ranging between 10 and 25 years. The Company utilizes these leased office facilities for use by its employees in countries in which the Company conducts its business. None of the Company’s leases restrict the payment of dividends or the incurrence of debt or additional lease obligations, or contain significant purchase options. Operating leases are recognized on the balance sheet as ROU assets and operating lease liabilities based on the present value of the remaining future minimum payments over the lease term at commencement date of the lease. The following table provides additional information about the Company’s property leases: Three Months Ended (In millions) 2022 2021 Lease Cost: Operating lease cost (a) $ 90 $ 94 Short-term lease cost 1 1 Variable lease cost 34 37 Sublease income (5) (8) Net lease cost $ 120 $ 124 Other information: Operating cash outflows from operating leases $ 99 $ 99 Right of use assets obtained in exchange for new operating lease liabilities $ 51 $ 22 Weighted-average remaining lease term – real estate 8.7 years 8.3 years Weighted-average discount rate – real estate leases 2.75% 2.93% (a) Excludes ROU asset impairment charges. Future minimum lease payments for the Company’s operating leases as of March 31, 2022 are as follows: Payment Dates (In millions) Real Estate Leases Remainder of 2022 $ 290 2023 356 2024 314 2025 282 2026 258 2027 223 Subsequent years 710 Total future lease payments 2,433 Less: Imputed interest (271) Total $ 2,162 Current lease liabilities $ 331 Long-term lease liabilities 1,831 Total lease liabilities $ 2,162 Note: Table excludes obligations for leases with original terms of 12 months or less which have not been recognized as a ROU asset or liability in the consolidated balance sheets . As of March 31, 2022, the Company had additional operating real estate leases that had not yet commenced of $41 million. These operating leases will commence over the next 12 months .

Retirement Benefits

Retirement Benefits	3 Months Ended
	Mar. 31, 2022
Retirement Benefits [Abstract]
Retirement Benefits	Retirement Benefits The Company maintains qualified and non-qualified defined benefit pension plans for some of its U.S. and non-U.S. eligible employees. The Company’s policy for funding its tax-qualified defined benefit pension plans is to contribute amounts at least sufficient to meet the funding requirements set forth in accordance with applicable law. The target asset allocation for the Company's U.S. plans is 60% equities and equity alternatives and 40% fixed income. At March 31, 2022 the actual allocation for the Company's U.S. Plan was 62% equities and equity alternatives and 38% fixed income. The target allocation for the U.K. Plans at March 31, 2022 is 22% equities and equity alternatives and 78% fixed income. At March 31, 2022, the actual allocation for the U.K. Plans was 24% equities and equity alternatives and 76% fixed income. The Company's U.K. Plans comprised approximately 81% of non-U.S. plan assets at December 31, 2021. The assets of the Company's defined benefit plans are diversified and are managed in accordance with applicable laws and with the goal of maximizing the plans' real return within acceptable risk parameters. The Company generally uses threshold-based portfolio re-balancing to ensure the actual portfolio remains consistent with target asset allocation ranges. The components of the net periodic benefit cost for defined benefit plans are as follows: Combined U.S. and significant non-U.S. Plans Pension For the Three Months Ended March 31, (In millions) 2022 2021 Service cost $ 8 $ 10 Interest cost 100 85 Expected return on plan assets (202) (208) Recognized actuarial loss 39 52 Net periodic credit $ (55) $ (61) Amounts Recorded in the Consolidated Statement of Income Combined U.S. and significant non-U.S. Plans Pension For the Three Months Ended March 31, (In millions) 2022 2021 Compensation and benefits expense $ 8 $ 10 Other net benefit credit (63) (71) Total credit $ (55) $ (61) U.S. Plans only Pension For the Three Months Ended March 31, (In millions) 2022 2021 Interest cost $ 48 $ 46 Expected return on plan assets (84) (82) Recognized actuarial loss 19 23 Net periodic credit $ (17) $ (13) Significant non-U.S. Plans only Pension For the Three Months Ended March 31, (In millions) 2022 2021 Service cost $ 8 $ 10 Interest cost 52 39 Expected return on plan assets (118) (126) Recognized actuarial loss 20 29 Net periodic credit $ (38) $ (48) The weighted average actuarial assumptions utilized to calculate the net periodic benefit costs for the U.S. and significant non-U.S. defined benefit plans are as follows: Combined U.S. and significant non-U.S. Plans Pension For the Three Months Ended March 31, 2022 2021 Weighted average assumptions: Expected return on plan assets 4.56 % 4.72 % Discount rate 2.28 % 1.92 % Rate of compensation increase 2.16 % 1.85 % The Company made approximately $68 million of contributions to its U.S. and non-U.S. defined benefit pension plans for the three months ended March 31, 2022. The Company expects to contribute approximately $110 million to its U.S. and non-U.S. defined benefit pension plans during the remainder of 2022. Defined Contribution Plans The Company maintains certain defined contribution plans ("DC Plans") for its employees, the most significant being in the U.S. and the U.K. The cost of the U.S. DC Plans was $43 million and $39 million for the three months ended March 31, 2022 and 2021, respectively. The cost of the U.K. DC Plans was $44 million and $39 million for the three months ended March 31, 2022 and 2021, respectively.

Debt

Debt	3 Months Ended
	Mar. 31, 2022
Debt Disclosure [Abstract]
Debt	Debt The Company’s outstanding debt is as follows: (In millions) March 31, December 31, Short-term: Commercial paper $ 825 $ — Current portion of long-term debt 366 17 1,191 17 Long-term: Senior notes – 3.30% due 2023 350 349 Senior notes – 4.05% due 2023 250 249 Senior notes – 3.50% due 2024 599 599 Senior notes – 3.875% due 2024 997 997 Senior notes – 3.50% due 2025 498 498 Senior notes – 1.349% due 2026 615 629 Senior notes – 3.75% due 2026 598 598 Senior notes – 4.375% due 2029 1,499 1,499 Senior notes – 1.979% due 2030 600 614 Senior notes – 2.250% due 2030 739 739 Senior notes – 2.375% due 2031 396 397 Senior notes – 5.875% due 2033 298 298 Senior notes – 4.75% due 2039 495 495 Senior notes – 4.35% due 2047 493 493 Senior notes – 4.20% due 2048 593 593 Senior notes – 4.90% due 2049 1,238 1,238 Senior notes – 2.90% due 2051 346 346 Mortgage – 5.70% due 2035 312 316 Other 2 3 10,918 10,950 Less current portion 366 17 $ 10,552 $ 10,933 The senior notes in the table above are registered by the Company with the Securities and Exchange Commission and are not guaranteed. On April 9, 2021, the Company increased its short-term commercial paper financing program to $2.0 billion from $1.5 billion. The Company had $825 million of commercial paper outstanding at March 31, 2022 at an average effective interest rate of 0.91%. Credit Facilities On April 2, 2021, the Company entered into an amended and restated multi-currency unsecured $2.8 billion five In connection with the New Facility, the Company terminated its previous multi-currency unsecured $1.8 billion five-year revolving credit facility and its unsecured $1 billion 364-days unsecured revolving credit facility ("364-day Facility"). Additional credit facilities, guarantees and letters of credit are maintained with various banks agg regating $483 million at March 31 , 2022 and $508 million at December 31, 2021. There were no outstanding borrowings under these facilities at March 31, 2022 and December 31, 2021. Senior Notes In December 2021, the Company issued $400 million of 2.375% senior notes due 2031 and $350 million of 2.90% senior notes due 2051. The Company used the net proceeds from these issuances for general corporate purposes, and repaid $500 million of 2.75% senior notes with an original maturity date of January 2022 in December 2021. On April 15, 2021, the Company repaid $500 million of senior notes maturing in July 2021. Fair Value of Short-term and Long-term Debt The estimated fair value of the Company's short-term and long-term debt is provided below. Certain estimates and judgments were required to develop the fair value amounts. The fair value amounts are not necessarily indicative of the amounts that the Company would realize upon disposition, nor do they indicate the Company’s intent or need to dispose of the financial instrument. March 31, 2022 December 31, 2021 (In millions) Carrying Fair Carrying Fair Short-term debt $ 1,191 $ 1,195 $ 17 $ 17 Long-term debt $ 10,552 $ 11,004 $ 10,933 $ 12,466 The fair value of the Company's short-term debt consists primarily of commercial paper and term debt maturing within the next year and its fair value approximates its carrying value. The estimated fair value of a primary portion of the Company's long-term debt is based on discounted future cash flows using current interest rates available for debt with similar terms and remaining maturities. Short-term and long-term debt would be classified as Level 2 in the fair value hierarchy.

Restructuring Costs

Restructuring Costs	3 Months Ended
	Mar. 31, 2022
Restructuring and Related Activities [Abstract]
Restructuring Costs	Restructuring Costs Restructuring costs include Company initiated actions related to improving and streamlining the Company's global information technology and HR functions, JLT integration costs, improving efficiencies and client services related to Marsh's operational excellence program, and real estate related costs for exiting leased facilities. For the three months ended March 31, 2022, the Company incurred costs of $30 million, reflecting $16 million in RIS, $6 million in Consulting, and $8 million in Corporate related to these initiatives. Details of the restructuring activity from January 1, 2021 through March 31, 2022, are as follows: (In millions) Severance Real Estate Related Costs (a) Information Technology Consulting and Other Outside Services Total Liability at 1/1/21 $ 52 $ 51 $ 2 $ 1 $ 106 2021 charges 38 31 23 71 163 Cash payments (55) (26) (25) (72) (178) Non-cash charges — (22) — — (22) Liability at 12/31/21 $ 35 $ 34 $ — $ — $ 69 2022 charges 3 6 5 16 30 Cash payments (16) (4) (3) (16) (39) Non-cash charges — (4) (2) — (6) Liability at 3/31/22 $ 22 $ 32 $ — $ — $ 54 (a) Includes ROU and fixed asset impairments and other real estate related costs.

Common Stock

Common Stock	3 Months Ended
	Mar. 31, 2022
Equity [Abstract]
Common Stock	Common Stock On March 23, 2022, the Board of Directors of the Company authorized an additional $5 billion in share repurchases. This is in addition to the Company's existing share repurchase program, which had approximately $1.3 billion of remaining authorization as of December 31, 2021. During the first three months of 2022, the Company repurchased 3.2 million shares of its common stock for $500 million. As of March 31, 2022, the Company remained authorized to repurchase up to approximately $5.8 billion in shares of its common stock. There is no time limit on the authorization. During the first three months of 2021, the Company repurchased 1.0 million shares of its common stock for $119 million, of which approximately $112 million was paid in the first quarter of 2021. The Company issued approximately 1.8 million and 2.0 million shares related to stock compensation and employee stock purchase plans during the first three months of 2022 and 2021, respectively.

Claims, Lawsuits And Other Cont

Claims, Lawsuits And Other Contingencies	3 Months Ended
	Mar. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Claims, Lawsuits and Other Contingencies	Claims, Lawsuits and Other Contingencies Acquisition of Jardine Lloyd Thompson Group plc On April 1, 2019, the Company completed its previously announced acquisition of all of the outstanding shares of JLT. Upon the consummation of the acquisition of JLT, the Company assumed the legal liabilities and became responsible for JLT’s litigation and regulatory exposures as of April 1, 2019. Nature of Contingencies The Company and its subsidiaries are subject to a significant number of claims, lawsuits and proceedings in the course of our business. Such claims and lawsuits consist principally of alleged errors and omissions in connection with the performance of professional services, including the placement of insurance, the provision of actuarial services for corporate and public sector clients, the provision of investment advice and investment management services to pension plans, the provision of advice relating to pension buy-out transactions and the provision of consulting services relating to the drafting and interpretation of trust deeds and other documentation governing pension plans. These claims often seek damages, including punitive and treble damages, in amounts that could be significant. In establishing liabilities for errors and omissions claims in accordance with FASB guidance on Contingencies - Loss Contingencies, the Company uses case level reviews by inside and outside counsel, and internal actuarial analysis by Oliver Wyman, a subsidiary of the Company, and other methods to estimate potential losses. A liability is established when a loss is both probable and reasonably estimable. The liability is reviewed quarterly and adjusted as developments warrant. In many cases, the Company has not recorded a liability, other than for legal fees to defend the claim, because we are unable, at the present time, to make a determination that a loss is both probable and reasonably estimable. To the extent that expected losses exceed our deductible in any policy year, the Company also records an asset for the amount that we expect to recover under any available third-party insurance programs. The Company has varying levels of third-party insurance coverage, with policy limits and coverage terms varying significantly by policy year. Our activities are regulated under the laws of the United States and its various states, United Kingdom, the European Union and its member states, and the many other jurisdictions in which the Company operates. The Company also receives subpoenas in the ordinary course of business, and, from time to time, requests for information in connection with government investigations. Current Matters Risk and Insurance Services Segment • In January 2019, the Company received a notice that the Administrative Council for Economic Defense anti-trust agency in Brazil had commenced an administrative proceeding against a number of insurance brokers, including both Marsh and JLT, and insurers “to investigate an alleged sharing of sensitive commercial and competitive confidential information" in the aviation insurance and reinsurance sector. • In 2017, JLT identified payments to a third-party introducer that had been directed to unapproved bank accounts. These payments related to reinsurance placements made on behalf of an Ecuadorian state-owned insurer between 2014 and 2017. In early 2018, JLT voluntarily reported this matter to law enforcement authorities. In February and March 2020, money laundering charges were filed in the United States against a former employee of JLT, the principals of the third-party introducer and a former official of the state-owned insurer. These individuals, including the former JLT employee, have since pleaded guilty to criminal charge s. In March 2022, the U.S. Department of Justice (DOJ) issued a declination letter, declining to pursue any charges against any JLT entity and seeking disgorgement of $29 million in alleged gross profits on this account. As previously disclosed, the Company recorded a charge for this amount in the fourth quarter 2021. In addition, in March 2022, the Colombian Superintendecia de Sociedades (SS) concluded its investigation of this matter and notified JLT of its intention to seek $2 million in civil penalties. We are cooperating with ongoing investigations by the U.K. authorities related to this matter. • From 2014, Marsh Ltd. was engaged by Greensill Capital (UK) Limited as its insurance broker. Marsh Ltd. placed a number of trade credit insurance policies for Greensill. On March 1, 2021, Greensill filed an action against certain of its trade credit insurers in Australia seeking a mandatory injunction compelling these insurers to renew coverage under expiring policies. Later that day, the Australian court denied Greensill’s application. Since then, a number of Greensill entities have filed for, or been subject to, insolve ncy proceedings, and several litigations and investigations have been commenced in the U.K., Australia, Germany, Switzerland and the U.S. Consulting Segment • In 2014, the FCA conducted an industry-wide review of the suitability of financial advice provided to individuals by a number of companies, including JLT, relating to enhanced transfer value ("ETV") defined benefit pension transfers. In January 2015, the FCA notified JLT that it was commissioning a Skilled Person review of ETV pension transfer advice given by JLT and a business acquired by JLT in 2012. Following the Skilled Person review which took place between 2015 and 2018, JLT engaged a compliance consulting firm to conduct an analysis of approximately 14,000 individual files to assess the suitability of the advice provided and, where appropriate, the amount of redress to be paid. In February 2019, prior to the completion of its acquisition by the Company, JLT recorded a gross liability of £59 million (or $77 million). This preliminary estimate by JLT, reflected projected redress amounts based on the limited number of files examined as part of the Skilled person review and report. Thereafter, the FCA expanded the scope of the review. As of December 31, 2020, the updated redress liability, including the projected costs of completing the review, increased to £155 million (or $210 million) resulting from the expansion in the scope of the review, and the significant progress made in completing the individual suitability reviews. Payments of redress and expenses during 2021 and the first quarter of 2022, together with a reduction of the actuarial estimates of future redress payments, reduced the recorded liability to £10 million (or $13 million) as of March 31, 2022. The suitability review is substantially complete and we expect to finalize the remaining redress calculations and to make substantially all redress payments by the end of the second quarter 2022. This gross liability has been, and we anticipate will continue to be, partially offset by a contractual indemnity obligation and insurance recoveries from third-party E&O insurers. At this time, we are unable to predict the likely timing, outcome or ultimate impact of the foregoing matters. Adverse determinations in one or more of these matters could have a material impact on the Company's consolidated results of operations, financial condition or cash flows in a future period. Other Contingencies-Guarantees In connection with its acquisition of U.K.-based Sedgwick Group in 1998, the Company acquired several insurance underwriting businesses that were already in run-off, including River Thames Insurance Company Limited ("River Thames"), which the Company sold in 2001. Sedgwick guaranteed payment of claims on certain policies underwritten through the Institute of London Underwriters (the "ILU") by River Thames. The policies covered by this guarantee are partly reinsured by a related party of River Thames. Payment of claims under the reinsurance agreement is collateralized by funds withheld by River Thames from the reinsurer. To the extent River Thames or the reinsurer is unable to meet its obligations under those policies, a claimant may seek to recover from the Company under the guarantee. From 1980 to 1983, the Company owned indirectly the English & American Insurance Company ("E&A"), which was a member of the ILU. The ILU required the Company to guarantee a portion of E&A's obligations. After E&A became insolvent in 1993, the ILU agreed to discharge the guarantee in exchange for the Company's agreement to post an evergreen letter of credit that is available to pay claims by policyholders on certain E&A policies issued through the ILU and incepting between July 3, 1980 and October 6, 1983. Certain claims have been paid under the letter of credit and the Company anticipates that additional claimants may seek to recover against the letter of credit. * * * * The pending proceedings describ ed above and other matters not explicitly described in this Note 17 on Claims, Lawsuits and Other Contingencies may expose the Company or its subsidiaries to liability for significant monetary damages, fines, penalties or other forms of relief. Where a loss is both probable and reasonably estimable, the Company establishes liabilities in accordance with FASB guidance on Contingencies - Loss Contingencies. Except as described above, the Company is not able at this time to provide a reasonable estimate of the range of possible loss attributable to these matters or the impact they may have on the Company's consolidated results of operations, financial position or cash flows. This is primarily because these matters are still developing and involve complex issues subject to inherent uncertainty. Adverse determinations in one or more of these matters could have a material impact on the Company's consolidated results of operations, financial condition or cash flows in a future period.

Segment Information

Segment Information	3 Months Ended
	Mar. 31, 2022
Segment Reporting [Abstract]
Segment Information	Segment Information The Company is organized based on the types of services provided. Under this structure, the Company’s segments are: • Risk and Insurance Services , comprising insurance services (Marsh) and reinsurance services (Guy Carpenter); and • Consulting , comprising Mercer and Oliver Wyman Group. The accounting policies of the segments are the same as those used for the consolidated financial statements described in Note 1, Summary of Significant Accounting Policies, in the Company’s 2021 Form 10-K. Segment performance is evaluated based on segment operating income, which includes directly related expenses, and charges or credits related to integration and restructuring but not the Company’s corporate-level expenses. Revenues are attributed to geographic areas on the basis of where the services are performed. Selected information about the Company’s operating segments for the three month period ended March 31, 2022 and 2021 is as follows: Three Months Ended (In millions) Revenue Operating Income (Loss) 2022– Risk and Insurance Services $ 3,549 (a) $ 1,121 Consulting 2,010 (b) 392 Total Operating Segments 5,559 1,513 Corporate/Eliminations (10) (68) Total Consolidated $ 5,549 $ 1,445 2021– Risk and Insurance Services $ 3,225 (a) $ 1,060 Consulting 1,873 (b) 361 Total Operating Segments 5,098 1,421 Corporate/Eliminations (15) (63) Total Consolidated $ 5,083 $ 1,358 (a) Includes interest income on fiduciary funds of $4 million and $5 million in 2022 and 2021. Revenue for 2022 also includes the loss on deconsolidation of the Russian businesses of $27 million. (b) Includes inter-segment revenue of $10 million and $15 million in 2022 and 2021. Revenue for 2022 also includes the loss on deconsolidation of the Russian businesses of $12 million. Details of operating segment revenue for the three month periods ended March 31, 2022 and 2021 are as follows: Three Months Ended (In millions) 2022 2021 Risk and Insurance Services Marsh $ 2,549 $ 2,329 Guy Carpenter 1,000 896 Total Risk and Insurance Services 3,549 3,225 Consulting Mercer 1,343 1,288 Oliver Wyman Group 667 585 Total Consulting 2,010 1,873 Total Operating Segments 5,559 5,098 Corporate Eliminations (10) (15) Total $ 5,549 $ 5,083

New Accounting Guidance

New Accounting Guidance	3 Months Ended
	Mar. 31, 2022
Accounting Standards Update and Change in Accounting Principle [Abstract]
New Accounting Guidance	New Accounting Guidance New Accounting Pronouncement Adopted Effective January 1, 2022: In October, 2021, the FASB issued new guidance for measuring contract assets and contract liabilities acquired in a business combination. In accordance with the new guidance, contract assets and contract liabilities should be measured in accordance with the guidance for revenue from contracts with customers as opposed to the guidance for business combinations. The guidance must be applied on a prospective basis, and is effective for fiscal years beginning after December 15, 2022, including interim periods therein. Early adoption is permitted. The Company elected to adopt this new standard effective January 1, 2022. Adoption of this guidance did not have a material impact on the Company's financial position or results of operations. New Accounting Pronouncements Adopted Effective January 1, 2021: In January 2020, the FASB issued guidance that addresses accounting for the transition into and out of the equity method and measuring certain purchased options and forward contracts to acquire investments. The standard takes effect for public business entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2020. The adoption of this standard did not have a material impact on the Company’s financial position or its results of operations. In December 2019, the FASB issued guidance related to the accounting for income taxes. The standard removes specific exceptions in the current rules and eliminates the need for an organization to analyze whether the following apply in a given period: (a) exception to the incremental approach for intraperiod tax allocation; (b) exceptions to accounting for basis differences when there are ownership changes in foreign investments and (c) exception in interim period income tax accounting for year-to-date losses that exceed anticipated losses. The standard also is designed to improve financial statement preparers’ application of income tax-related guidance and simplify GAAP for (a) franchise taxes that are partially based on income; (b) transactions with a government that result in a step-up in the tax basis of goodwill; (c) separate financial statements of legal entities that are not subject to tax and (d) enacted changes in tax laws in interim periods. The standard takes effect for public business entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2020. The adoption of this standard did not have a material impact on the Company’s financial position or its results of operations.

Principles of Consolidation a_2

Principles of Consolidation and Other Matters (Policies)	3 Months Ended
	Mar. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash and Cash Equivalents	Cash and cash equivalents primarily consist of certificates of deposit and time deposits, with original maturities of three months or less, and money market funds. The estimated fair value of the Company's cash and cash equivalents approximates their carrying value. The Company is required to maintain operating funds primarily related to regulatory requirements outside of the United States or as collateral under captive insurance arrangements.
Allowance for Credit Losses on Accounts Receivable	The Company’s policy for providing an allowance for credit losses on its accounts receivable is based on a combination of factors, including historical write-offs, aging of balances, and other qualitative and quantitative analyses.
Investments	The caption "Investment income" in the consolidated statements of income comprises realized and unrealized gains and losses from investments recognized in earnings. It includes, when applicable, other than temporary declines in the value of securities, mark-to-market increases or decreases in equity investments with readily determinable fair values and equity method gains or losses on the Company's investments in private equity funds.The Company holds investments in certain private equity funds. Investments in private equity funds are accounted for in accordance with the equity method of accounting using a consistently applied three-month lag period adjusted for any known significant changes from the lag period to the reporting date of the Company. The underlying private equity funds follow investment company accounting, where investments within the fund are carried at fair value. Investment gains or losses for its proportionate share of the change in fair value of the funds are recorded in earnings. Investments using the equity method of accounting are included in "other assets" in the consolidated balance sheets.
Income Taxes	The Company's effective tax rate in the first quarter of 2022 was 23.7% compared with 24.5% in the first quarter of 2021. The tax rates in both periods reflect the impact of discrete tax matters such as excess tax benefits related to share-based compensation, enacted tax legislation, changes in uncertain tax positions, deferred tax adjustments and nontaxable adjustments to contingent acquisition consideration. The excess tax benefit related to share-based payments is the most significant discrete item, as it normally is in the first quarter because that is when most share-based compensation vests, reducing the effective tax rate by 1.8% and 1.1% in the first quarters of 2022 and 2021, respectively. The rate in the first quarter of 2022 also reflects tax benefits from planning implemented in the period that postponed the utilization of current year losses in the U.K. to a future year when the tax rate will be 25%. The Company's tax rate reflects its income, statutory tax rates, and tax planning in the various jurisdictions in which it operates. Significant judgment is required in determining the annual effective tax rate and in evaluating uncertain tax positions. Losses in one jurisdiction, generally, cannot offset earnings in another, and within certain jurisdictions profits and losses may not offset between entities. Consequently, losses in certain jurisdictions may require valuation allowances affecting the effective tax rate, depending on estimates of the realizability of associated deferred tax assets. The tax rate is also sensitive to changes in unrecognized tax benefits, including the impact of settled tax audits and expired statutes of limitation. Changes in tax laws or tax rulings may have a significant impact on our effective tax rate. The Company reports a liability for unrecognized tax benefits resulting from uncertain tax positions taken or expected to be taken in tax returns. The Company's gross unrecognized tax benefits was $94 million at March 31, 2022 and December 31, 2021. It is reasonably possible that the total amount of unrecognized tax benefits will decrease between zero and approximately $49 million within the next twelve months due to settlements of audits and expirations of statutes of limitation.
Integration and Restructuring Charges	Severance and related costs are recognized based on amounts due under established severance plans or estimates of one-time benefits that will be provided. Typically, severance benefits are recognized when the impacted colleagues are notified of their expected termination and such termination is expected to occur within the legally required notification period. These costs are included in compensation and benefits in the consolidated statements of income. Costs for real estate consolidation are recognized based on the type of cost, and the expected future use of the facility. For locations where the Company does not expect to sub-lease the property, the amortization of any Right-of-use ("ROU") asset is accelerated from the decision date to the cease use date. For locations where the Company expects to sub-lease the properties subsequent to its vacating the property, the ROU asset is reviewed for potential impairment at the earlier of the cease use date or the date a sub-lease is signed. To determine the amount of impairment, the fair value of the ROU asset is determined based on the present value of the estimated net cash flows related to the property. Contractual costs outside of the ROU asset are recognized based on the net present value of expected future cash outflows for which the Company will not receive any benefit. Such amounts are reliant on estimates of future sub-lease income to be received and future contractual costs to be incurred. These costs are included in other operating expenses in the consolidated statements of income. Other costs related to integration and restructuring, such as moving, legal or consulting costs are recognized as incurred. These costs are included in other operating expenses in the consolidated statements of income.
Fair Value Measurement	Fair Value Hierarchy The Company has categorized its assets and liabilities that are valued at fair value on a recurring basis into a three-level fair value hierarchy as defined by the FASB. The fair value hierarchy gives the highest priority to quoted prices in active markets for identical assets and liabilities (Level 1) and lowest priority to unobservable inputs (Level 3). In some cases, the inputs used to measure fair value might fall into different levels of the fair value hierarchy. In such cases, the level in the fair value hierarchy, for disclosure purposes, is determined based on the lowest level input that is significant to the fair value measurement. Assets and liabilities recorded in the consolidated balance sheets at fair value are categorized based on the inputs in the valuation techniques as follows: Level 1. Assets and liabilities whose values are based on unadjusted quoted prices for identical assets or liabilities in an active market (examples include active exchange-traded equity securities and exchange-traded money market mutual funds). Assets and liabilities measured using Level 1 inputs include exchange-traded equity securities, exchange-traded mutual funds and money market funds. Level 2. Assets and liabilities whose values are based on the following: a) Quoted prices for similar assets or liabilities in active markets; b) Quoted prices for identical or similar assets or liabilities in non-active markets (examples include corporate and municipal bonds, which trade infrequently); c) Pricing models whose inputs are observable for substantially the full term of the asset or liability (examples include most over-the-counter derivatives, including interest rate and currency swaps); and d) Pricing models whose inputs are derived principally from or corroborated by observable market data through correlation or other means for substantially the full asset or liability (for example, certain mortgage loans). Assets and liabilities using Level 2 inputs are related to an equity security. Level 3. Assets and liabilities whose values are based on prices, or valuation techniques that require inputs that are both unobservable and significant to the overall fair value measurement. These inputs reflect management’s own assumptions about the assumptions a market participant would use in pricing the asset or liability. Assets and liabilities measured using Level 3 inputs relate to assets and liabilities for contingent purchase consideration. Valuation Techniques Equity Securities, Money Market Mutual Funds and Mutual Funds – Level 1 Investments for which market quotations are readily available are valued at the sale price on their principal exchange or, for certain markets, official closing bid price. Money market mutual funds are valued using a valuation technique that results in price per share at $1.00. Contingent Purchase Consideration Assets and Liabilities – Level 3 Purchase consideration for some acquisitions and dispositions made by the Company include contingent consideration arrangements. Contingent consideration arrangements are based primarily on EBITDA or revenue targets over a period of two
New Accounting Pronouncements	New Accounting Guidance New Accounting Pronouncement Adopted Effective January 1, 2022: In October, 2021, the FASB issued new guidance for measuring contract assets and contract liabilities acquired in a business combination. In accordance with the new guidance, contract assets and contract liabilities should be measured in accordance with the guidance for revenue from contracts with customers as opposed to the guidance for business combinations. The guidance must be applied on a prospective basis, and is effective for fiscal years beginning after December 15, 2022, including interim periods therein. Early adoption is permitted. The Company elected to adopt this new standard effective January 1, 2022. Adoption of this guidance did not have a material impact on the Company's financial position or results of operations. New Accounting Pronouncements Adopted Effective January 1, 2021: In January 2020, the FASB issued guidance that addresses accounting for the transition into and out of the equity method and measuring certain purchased options and forward contracts to acquire investments. The standard takes effect for public business entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2020. The adoption of this standard did not have a material impact on the Company’s financial position or its results of operations. In December 2019, the FASB issued guidance related to the accounting for income taxes. The standard removes specific exceptions in the current rules and eliminates the need for an organization to analyze whether the following apply in a given period: (a) exception to the incremental approach for intraperiod tax allocation; (b) exceptions to accounting for basis differences when there are ownership changes in foreign investments and (c) exception in interim period income tax accounting for year-to-date losses that exceed anticipated losses. The standard also is designed to improve financial statement preparers’ application of income tax-related guidance and simplify GAAP for (a) franchise taxes that are partially based on income; (b) transactions with a government that result in a step-up in the tax basis of goodwill; (c) separate financial statements of legal entities that are not subject to tax and (d) enacted changes in tax laws in interim periods. The standard takes effect for public business entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2020. The adoption of this standard did not have a material impact on the Company’s financial position or its results of operations.

Revenue (Tables)

Revenue (Tables)	3 Months Ended
	Mar. 31, 2022
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following table disaggregates components of the Company's revenue: Three Months Ended (In millions) 2022 2021 Marsh: EMEA $ 842 $ 837 Asia Pacific 321 274 Latin America 104 90 Total International 1,267 1,201 U.S./Canada 1,279 1,124 Total Marsh 2,546 2,325 Guy Carpenter 999 895 Subtotal 3,545 3,220 Fiduciary interest income 4 5 Total Risk and Insurance Services $ 3,549 $ 3,225 Mercer: Wealth $ 617 $ 623 Health 524 487 Career 202 178 Total Mercer 1,343 1,288 Oliver Wyman Group 667 585 Total Consulting $ 2,010 $ 1,873
Contract with Customer, Asset and Liability	The following table provides contract assets and contract liabilities information from contracts with customers: (In millions) March 31, 2022 December 31, 2021 Contract assets $ 357 $ 290 Contract liabilities $ 824 $ 776

Per Share Data (Tables)

Per Share Data (Tables)	3 Months Ended
	Mar. 31, 2022
Earnings Per Share [Abstract]
Basic and Diluted EPS Calculation	Basic and Diluted EPS Calculation Three Months Ended (In millions, except per share data) 2022 2021 Net income before non-controlling interests $ 1,086 $ 998 Less: Net income attributable to non-controlling interests 15 15 Net income attributable to the Company $ 1,071 $ 983 Basic weighted average common shares outstanding 503 509 Dilutive effect of potentially issuable common shares 6 5 Diluted weighted average common shares outstanding 509 514 Average stock price used to calculate common stock equivalents $ 157.49 $ 114.96

Supplemental Disclosures to t_2

Supplemental Disclosures to the Consolidated Statements of Cash Flows (Tables)	3 Months Ended
	Mar. 31, 2022
Supplemental Cash Flow Information [Abstract]
Additional Information Concerning Acquisitions, Interest and Income Taxes Paid	The following table provides additional information concerning acquisitions, interest and income taxes paid for the three month periods ended March 31, 2022 and 2021. (In millions) 2022 2021 Assets acquired, excluding cash $ 30 $ — Liabilities assumed (2) — Contingent/deferred purchase consideration (4) — Net cash outflow for current year acquisitions $ 24 $ — (In millions) 2022 2021 Interest paid $ 171 $ 191 Income taxes paid, net of refunds $ 201 $ 122 For the Three Months Ended March 31, (In millions) 2022 2021 Operating: Contingent consideration payments $ — $ (1) Acquisition/disposition related net charges for adjustments 10 — Adjustments and payments related to contingent consideration $ 10 $ (1) Financing: Contingent purchase consideration $ (4) $ (10) Deferred purchase consideration related to prior years' acquisitions (12) (27) Payments of deferred and contingent consideration for acquisitions $ (16) $ (37) Receipt of contingent consideration related to prior year dispositions $ 3 $ 5

Other Comprehensive Income (L_2

Other Comprehensive Income (Loss) (Tables)	3 Months Ended
	Mar. 31, 2022
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)	The changes, net of tax, in the balances of each component of Accumulated Other Comprehensive Income ("AOCI") for the three months ended March 31, 2022 and 2021, including amounts reclassified out of AOCI, are as follows: (In millions) Pension/Post-Retirement Plans Gains (Losses) Foreign Currency Translation Gains (Losses) Total Gains (Losses) Balance as of December 31, 2021 $ (3,202) $ (1,373) $ (4,575) Other comprehensive income (loss) before reclassifications 35 (169) (134) Amounts reclassified from accumulated other comprehensive income 30 — 30 Net current period other comprehensive income (loss) 65 (169) (104) Balance as of March 31, 2022 $ (3,137) $ (1,542) $ (4,679) (In millions) Pension/Post-Retirement Plans Gains (Losses) Foreign Currency Translation Gains (Losses) Total Gains (Losses) Balance as of December 31, 2020 $ (4,126) $ (984) $ (5,110) Other comprehensive income (loss) before reclassifications (36) (91) (127) Amounts reclassified from accumulated other comprehensive income 40 — 40 Net current period other comprehensive income (loss) 4 (91) (87) Balance as of March 31, 2021 $ (4,122) $ (1,075) $ (5,197)
Schedule of Components of Comprehensive Income (Loss)	The components of other comprehensive income (loss) for the three month periods ended March 31, 2022 and 2021 are as follows: Three Months Ended March 31, 2022 2021 (In millions) Pre-Tax Tax (Credit) Net of Tax Pre-Tax Tax (Credit) Net of Tax Foreign currency translation adjustments $ (169) $ — $ (169) $ (91) $ — $ (91) Pension/post-retirement plans: Amortization of gains included in net periodic pension cost: Net actuarial losses (a) 39 9 30 52 12 40 Subtotal 39 9 30 52 12 40 Foreign currency translation adjustments 65 16 49 (37) (8) (29) Other adjustments (18) (4) (14) (7) (2) (5) Effect of re-measurement — — — (2) — (2) Pension/post-retirement plans gains 86 21 65 6 2 4 Other comprehensive (loss) income $ (83) $ 21 $ (104) $ (85) $ 2 $ (87) (a) Components of net periodic pension cost are included in other net benefit credits in the consolidated statements of income. Income tax expense on net actuarial losses are included in income tax expense.

Acquisitions and Dispositions (

Acquisitions and Dispositions (Tables)	3 Months Ended
	Mar. 31, 2022
Business Combination and Asset Acquisition [Abstract]
Schedule For Allocation of Acquisition Costs	The following table presents the preliminary allocation of purchase consideration to the assets acquired and liabilities assumed during 2022 based on the estimated fair values for the acquisitions as of their respective acquisition dates: Acquisitions through March 31, 2022 (In millions) Cash $ 24 Estimated fair value of deferred/contingent consideration 4 Total consideration $ 28 Allocation of purchase price: Net receivables 1 Other current assets 2 Goodwill 17 Other intangible assets 10 Total assets acquired 30 Current liabilities 1 Other liabilities 1 Total liabilities assumed 2 Net assets acquired $ 28
Schedule of Acquired Finite-Lived Intangible Assets by Major Class	The following table provides information about intangible assets acquired during 2022: Intangible assets through March 31, 2022 (In millions) Amount Weighted Average Amortization Period Client relationships $ 10 10.4 years
Pro-Forma Information	The following unaudited pro-forma financial data gives effect to the acquisitions made by the Company during 2022 and 2021. In accordance with accounting guidance related to pro-forma disclosures, the information presented for acquisitions made in 2022 is as if they occurred on January 1, 2021 and reflects acquisitions made in 2021 as if they occurred on January 1, 2020. The unaudited pro-forma information includes the effects of amortization of acquired intangibles. The unaudited pro-forma financial data is presented for illustrative purposes only and is not necessarily indicative of the operating results that would have been achieved if such acquisitions had occurred on the dates indicated, nor is it necessarily indicative of future consolidated results. Three Months Ended (In millions, except per share data) 2022 2021 Revenue $ 5,550 $ 5,156 Net income attributable to the Company $ 1,071 $ 987 Basic net income per share attributable to the Company $ 2.13 $ 1.94 Diluted net income per share attributable to the Company $ 2.10 $ 1.92

Goodwill and Other Intangibles

Goodwill and Other Intangibles (Tables)	3 Months Ended
	Mar. 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Changes in the Carrying Amount of Goodwill	Changes in the carrying amount of goodwill are as follows: March 31, (In millions) 2022 2021 Balance as of January 1, $ 16,317 $ 15,517 Goodwill acquired 17 — Other adjustments (a) (80) (59) Balance at March 31, $ 16,254 $ 15,458
Amortized Intangible Assets	The gross cost and accumulated amortization of identified intangible assets at March 31, 2022 and December 31, 2021 are as follows: March 31, 2022 December 31, 2021 (In millions) Gross Accumulated Net Gross Accumulated Net Client relationships $ 4,041 $ 1,389 $ 2,652 $ 4,066 $ 1,334 $ 2,732 Other (a) 362 294 68 365 287 78 Amortized intangibles $ 4,403 $ 1,683 $ 2,720 $ 4,431 $ 1,621 $ 2,810 (a) Primarily non-compete agreements, trade names and developed technology.
Estimated Future Aggregate Amortization Expense	The estimated future aggregate amortization expense is as follows: For the Years Ending December 31, (In millions) Estimated Expense 2022 (excludes amortization through March 31, 2022) $ 261 2023 328 2024 308 2025 269 2026 248 Subsequent years 1,306 Total future amortization $ 2,720

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2022
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value on a Recurring Basis	The following fair value hierarchy table presents information about the Company’s assets and liabilities measured at fair value on a recurring basis as of March 31, 2022 and December 31, 2021: Identical Assets Observable Inputs Unobservable Total (In millions) 03/31/22 12/31/21 03/31/22 12/31/21 03/31/22 12/31/21 03/31/22 12/31/21 Assets: Financial instruments owned: Exchange traded equity securities (a) $ 69 $ 61 $ — $ — $ — $ — $ 69 $ 61 Mutual funds (a) 179 192 — — — — 179 192 Money market funds (b) 82 425 — — — — 82 425 Other equity investment (a) — — 8 8 — — 8 8 Contingent purchase consideration assets (c) — — — — 2 5 2 5 Total assets measured at fair value $ 330 $ 678 $ 8 $ 8 $ 2 $ 5 $ 340 $ 691 Fiduciary Assets: U.S. treasury bills (e) $ 30 $ 55 $ — $ — $ — $ — $ 30 $ 55 Money market funds 205 527 — — — — 205 527 Total fiduciary assets measured $ 235 $ 582 $ — $ — $ — $ — $ 235 $ 582 Liabilities: Contingent purchase consideration liability (d) $ — $ — $ — $ — $ 358 $ 352 $ 358 $ 352 Total liabilities measured at fair value $ — $ — $ — $ — $ 358 $ 352 $ 358 $ 352 (a) Included in other assets in the consolidated balance sheets. (b) Included in cash and cash equivalents in the consolidated balance sheets. (c) Included in other receivables in the consolidated balance sheets. (d) Included in accounts payable and accrued liabilities and other liabilities in the consolidated balance sheets. (e) Maturity dates of three months or less.
Changes in Fair Value of Level 3 Liabilities Representing Acquisition Related Contingent Consideration	The following table sets forth a summary of the changes in fair value of the Company’s Level 3 liabilities for the three month periods ended March 31, 2022 and 2021: Three Months Ended (In millions) 2022 2021 Balance at beginning of period $ 352 $ 243 Payments (4) (11) Revaluation impact 10 1 Balance at March 31, $ 358 $ 233

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2022
Leases [Abstract]
Lease Cost and Additional Information	The following table provides additional information about the Company’s property leases: Three Months Ended (In millions) 2022 2021 Lease Cost: Operating lease cost (a) $ 90 $ 94 Short-term lease cost 1 1 Variable lease cost 34 37 Sublease income (5) (8) Net lease cost $ 120 $ 124 Other information: Operating cash outflows from operating leases $ 99 $ 99 Right of use assets obtained in exchange for new operating lease liabilities $ 51 $ 22 Weighted-average remaining lease term – real estate 8.7 years 8.3 years Weighted-average discount rate – real estate leases 2.75% 2.93% (a) Excludes ROU asset impairment charges.
Future Minimum Lease Payments for Operating Leases	Future minimum lease payments for the Company’s operating leases as of March 31, 2022 are as follows: Payment Dates (In millions) Real Estate Leases Remainder of 2022 $ 290 2023 356 2024 314 2025 282 2026 258 2027 223 Subsequent years 710 Total future lease payments 2,433 Less: Imputed interest (271) Total $ 2,162 Current lease liabilities $ 331 Long-term lease liabilities 1,831 Total lease liabilities $ 2,162 Note: Table excludes obligations for leases with original terms of 12 months or less which have not been recognized as a ROU asset or liability in the consolidated balance sheets .

Retirement Benefits (Tables)

Retirement Benefits (Tables)	3 Months Ended
	Mar. 31, 2022
Retirement Benefits [Abstract]
Schedule of Net Benefit Costs	The components of the net periodic benefit cost for defined benefit plans are as follows: Combined U.S. and significant non-U.S. Plans Pension For the Three Months Ended March 31, (In millions) 2022 2021 Service cost $ 8 $ 10 Interest cost 100 85 Expected return on plan assets (202) (208) Recognized actuarial loss 39 52 Net periodic credit $ (55) $ (61) Amounts Recorded in the Consolidated Statement of Income Combined U.S. and significant non-U.S. Plans Pension For the Three Months Ended March 31, (In millions) 2022 2021 Compensation and benefits expense $ 8 $ 10 Other net benefit credit (63) (71) Total credit $ (55) $ (61) U.S. Plans only Pension For the Three Months Ended March 31, (In millions) 2022 2021 Interest cost $ 48 $ 46 Expected return on plan assets (84) (82) Recognized actuarial loss 19 23 Net periodic credit $ (17) $ (13) Significant non-U.S. Plans only Pension For the Three Months Ended March 31, (In millions) 2022 2021 Service cost $ 8 $ 10 Interest cost 52 39 Expected return on plan assets (118) (126) Recognized actuarial loss 20 29 Net periodic credit $ (38) $ (48)
Schedule of Assumptions Used	The weighted average actuarial assumptions utilized to calculate the net periodic benefit costs for the U.S. and significant non-U.S. defined benefit plans are as follows: Combined U.S. and significant non-U.S. Plans Pension For the Three Months Ended March 31, 2022 2021 Weighted average assumptions: Expected return on plan assets 4.56 % 4.72 % Discount rate 2.28 % 1.92 % Rate of compensation increase 2.16 % 1.85 %

Debt (Tables)

Debt (Tables)	3 Months Ended
	Mar. 31, 2022
Debt Disclosure [Abstract]
Schedule of Outstanding Debt	The Company’s outstanding debt is as follows: (In millions) March 31, December 31, Short-term: Commercial paper $ 825 $ — Current portion of long-term debt 366 17 1,191 17 Long-term: Senior notes – 3.30% due 2023 350 349 Senior notes – 4.05% due 2023 250 249 Senior notes – 3.50% due 2024 599 599 Senior notes – 3.875% due 2024 997 997 Senior notes – 3.50% due 2025 498 498 Senior notes – 1.349% due 2026 615 629 Senior notes – 3.75% due 2026 598 598 Senior notes – 4.375% due 2029 1,499 1,499 Senior notes – 1.979% due 2030 600 614 Senior notes – 2.250% due 2030 739 739 Senior notes – 2.375% due 2031 396 397 Senior notes – 5.875% due 2033 298 298 Senior notes – 4.75% due 2039 495 495 Senior notes – 4.35% due 2047 493 493 Senior notes – 4.20% due 2048 593 593 Senior notes – 4.90% due 2049 1,238 1,238 Senior notes – 2.90% due 2051 346 346 Mortgage – 5.70% due 2035 312 316 Other 2 3 10,918 10,950 Less current portion 366 17 $ 10,552 $ 10,933
Estimated Fair Value Of Significant Financial Instruments	Certain estimates and judgments were required to develop the fair value amounts. The fair value amounts are not necessarily indicative of the amounts that the Company would realize upon disposition, nor do they indicate the Company’s intent or need to dispose of the financial instrument. March 31, 2022 December 31, 2021 (In millions) Carrying Fair Carrying Fair Short-term debt $ 1,191 $ 1,195 $ 17 $ 17 Long-term debt $ 10,552 $ 11,004 $ 10,933 $ 12,466

Restructuring Costs (Tables)

Restructuring Costs (Tables)	3 Months Ended
	Mar. 31, 2022
Restructuring and Related Activities [Abstract]
Restructuring Activities	Details of the restructuring activity from January 1, 2021 through March 31, 2022, are as follows: (In millions) Severance Real Estate Related Costs (a) Information Technology Consulting and Other Outside Services Total Liability at 1/1/21 $ 52 $ 51 $ 2 $ 1 $ 106 2021 charges 38 31 23 71 163 Cash payments (55) (26) (25) (72) (178) Non-cash charges — (22) — — (22) Liability at 12/31/21 $ 35 $ 34 $ — $ — $ 69 2022 charges 3 6 5 16 30 Cash payments (16) (4) (3) (16) (39) Non-cash charges — (4) (2) — (6) Liability at 3/31/22 $ 22 $ 32 $ — $ — $ 54 (a) Includes ROU and fixed asset impairments and other real estate related costs.

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
	Mar. 31, 2022
Segment Reporting [Abstract]
Selected Information And Details For MMC's Operating Segments	Selected information about the Company’s operating segments for the three month period ended March 31, 2022 and 2021 is as follows: Three Months Ended (In millions) Revenue Operating Income (Loss) 2022– Risk and Insurance Services $ 3,549 (a) $ 1,121 Consulting 2,010 (b) 392 Total Operating Segments 5,559 1,513 Corporate/Eliminations (10) (68) Total Consolidated $ 5,549 $ 1,445 2021– Risk and Insurance Services $ 3,225 (a) $ 1,060 Consulting 1,873 (b) 361 Total Operating Segments 5,098 1,421 Corporate/Eliminations (15) (63) Total Consolidated $ 5,083 $ 1,358 (a) Includes interest income on fiduciary funds of $4 million and $5 million in 2022 and 2021. Revenue for 2022 also includes the loss on deconsolidation of the Russian businesses of $27 million. (b) Includes inter-segment revenue of $10 million and $15 million in 2022 and 2021. Revenue for 2022 also includes the loss on deconsolidation of the Russian businesses of $12 million.
Details of Operating Segment Revenue	Details of operating segment revenue for the three month periods ended March 31, 2022 and 2021 are as follows: Three Months Ended (In millions) 2022 2021 Risk and Insurance Services Marsh $ 2,549 $ 2,329 Guy Carpenter 1,000 896 Total Risk and Insurance Services 3,549 3,225 Consulting Mercer 1,343 1,288 Oliver Wyman Group 667 585 Total Consulting 2,010 1,873 Total Operating Segments 5,559 5,098 Corporate Eliminations (10) (15) Total $ 5,549 $ 5,083

Nature of Operations (Details)

Nature of Operations (Details) $ in Millions	3 Months Ended
	Mar. 31, 2022USD ($)segment
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of business segments (segment) | segment	2
Loss on deconsolidation of Russian entities and other charges | $	$ 52

Principles of Consolidation A_3

Principles of Consolidation And Other Matters (Details) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Operating funds related to regulatory requirements or as collateral under captive insurance arrangements	$ 304,000,000		$ 303,000,000
Equity method investments lag period	3 months
Gain on investment income, net	$ 26,000,000	$ 11,000,000
Effective tax rate (as a percent)	23.70%	24.50%
Excess tax benefit related to share-based payments, percent	1.80%	1.10%
Unrecognized tax benefits	$ 94,000,000
Minimum
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Reasonably possible decrease in unrecognized tax benefits	0
Maximum
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Reasonably possible decrease in unrecognized tax benefits	$ 49,000,000

Revenue - Narrative (Details)

Revenue - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Disaggregation of Revenue [Line Items]
Threshold percentage of total revenue	2.00%
Revenue recognized that was included in the contract liability balance at the beginning of the period	$ 280	$ 238
Performance obligation satisfied in previous period	24	$ 34
Mercer Consulting Group
Disaggregation of Revenue [Line Items]
Revenue, remaining performance obligation	$ 187

Revenue - Disaggregation of Rev

Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Disaggregation of Revenue [Line Items]
Revenue	$ 5,549	$ 5,083
Risk and Insurance Services Segment
Disaggregation of Revenue [Line Items]
Revenue	3,549	3,225
Fiduciary interest income	4	5
Risk and Insurance Services Segment | Total International
Disaggregation of Revenue [Line Items]
Revenue	1,267	1,201
Risk and Insurance Services Segment | EMEA
Disaggregation of Revenue [Line Items]
Revenue	842	837
Risk and Insurance Services Segment | Asia Pacific
Disaggregation of Revenue [Line Items]
Revenue	321	274
Risk and Insurance Services Segment | Latin America
Disaggregation of Revenue [Line Items]
Revenue	104	90
Risk and Insurance Services Segment | U.S./Canada
Disaggregation of Revenue [Line Items]
Revenue	1,279	1,124
Consulting Segment
Disaggregation of Revenue [Line Items]
Revenue	2,010	1,873
Consulting Segment | Wealth
Disaggregation of Revenue [Line Items]
Revenue	617	623
Consulting Segment | Health
Disaggregation of Revenue [Line Items]
Revenue	524	487
Consulting Segment | Career
Disaggregation of Revenue [Line Items]
Revenue	202	178
Marsh & Guy Carpenter | Risk and Insurance Services Segment
Disaggregation of Revenue [Line Items]
Revenue	3,545	3,220
Marsh Insurance Group | Risk and Insurance Services Segment
Disaggregation of Revenue [Line Items]
Revenue	2,546	2,325
Guy Carpenter Reinsurance Group | Risk and Insurance Services Segment
Disaggregation of Revenue [Line Items]
Revenue	999	895
Mercer Consulting Group | Consulting Segment
Disaggregation of Revenue [Line Items]
Revenue	1,343	1,288
Oliver Wyman Group Consulting Group | Consulting Segment
Disaggregation of Revenue [Line Items]
Revenue	$ 667	$ 585

Revenue - Contract Assets and C

Revenue - Contract Assets and Contract Liabilities (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Revenue from Contract with Customer [Abstract]
Contract assets	$ 357	$ 290
Contract liabilities	$ 824	$ 776

Revenue - Estimated Revenue Exp

Revenue - Estimated Revenue Expected to Be Recognized Related to Performance Obligations (Details) $ in Millions	Mar. 31, 2022USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 78
Revenue, remaining performance obligation, expected timing of satisfaction, period (in years)	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 61
Revenue, remaining performance obligation, expected timing of satisfaction, period (in years)	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 28
Revenue, remaining performance obligation, expected timing of satisfaction, period (in years)	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 12
Revenue, remaining performance obligation, expected timing of satisfaction, period (in years)	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 8
Revenue, remaining performance obligation, expected timing of satisfaction, period (in years)

Fiduciary Assets and Liabilit_2

Fiduciary Assets and Liabilities (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Fiduciary Assets and Liabilities [Line Items]
Net uncollected premiums and claims receivable and payable	$ 13,000		$ 13,000
Risk and Insurance Services Segment
Fiduciary Assets and Liabilities [Line Items]
Interest on fiduciary funds	4	$ 5
Operating Segments | Risk and Insurance Services Segment
Fiduciary Assets and Liabilities [Line Items]
Interest on fiduciary funds	$ 4	$ 5

Per Share Data (Basic and Dilut

Per Share Data (Basic and Diluted EPS Calculation Continuing Operations) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Earnings Per Share [Abstract]
Net income before non-controlling interests	$ 1,086	$ 998
Less: Net income attributable to non-controlling interests	15	15
Net income attributable to the Company	$ 1,071	$ 983
Basic weighted average common shares outstanding (in shares)	503	509
Dilutive effect of potentially issuable common shares (in shares)	6	5
Diluted weighted average common shares outstanding (in shares)	509	514
Average stock price used to calculate common stock equivalents (in dollars per share)	$ 157.49	$ 114.96

Supplemental Disclosures to t_3

Supplemental Disclosures to the Consolidated Statements of Cash Flows (Additional Information Concerning Acquisitions, Interest And Income Taxes Paid) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Supplemental Cash Flow Information [Abstract]
Assets acquired, excluding cash	$ 30	$ 0
Liabilities assumed	(2)	0
Contingent/deferred purchase consideration	(4)	0
Net cash outflow for current year acquisitions	24	0
Interest paid	171	191
Income taxes paid, net of refunds	$ 201	$ 122

Supplemental Disclosures (Suppl

Supplemental Disclosures (Supplemental Operating and Financing Cash Flow Items) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating:
Contingent consideration payments	$ 0	$ (1)
Acquisition/disposition related net charges for adjustments	10	0
Adjustments and payments related to contingent consideration	10	(1)
Financing:
Contingent purchase consideration	(4)	(10)
Deferred purchase consideration related to prior years' acquisitions	(12)	(27)
Payments of deferred and contingent consideration for acquisitions	(16)	(37)
Receipt of contingent consideration related to prior year dispositions	$ 3	$ 5

Supplemental Disclosures to t_4

Supplemental Disclosures to the Consolidated Statements of Cash Flows (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Supplemental Cash Flow Information [Abstract]
Non-cash issuance of common stock	$ 250	$ 212
Stock-based compensation expense, equity awards	$ 105	$ 78

Other Comprehensive Income (L_3

Other Comprehensive Income (Loss) (Schedule of Components of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of period	$ 11,222
Other comprehensive loss, net of tax	(104)	$ (87)
Balance, end of period	11,156	9,596
AOCI Attributable to Parent
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of period	(4,575)	(5,110)
Other comprehensive income (loss), before reclassification, net of tax	(134)	(127)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	30	40
Other comprehensive loss, net of tax	(104)	(87)
Balance, end of period	(4,679)	(5,197)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of period	(3,202)	(4,126)
Other comprehensive income (loss), before reclassification, net of tax	35	(36)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	30	40
Other comprehensive loss, net of tax	65	4
Balance, end of period	(3,137)	(4,122)
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of period	(1,373)	(984)
Other comprehensive income (loss), before reclassification, net of tax	(169)	(91)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	0
Other comprehensive loss, net of tax	(169)	(91)
Balance, end of period	$ (1,542)	$ (1,075)

Other Comprehensive Income (L_4

Other Comprehensive Income (Loss) (Schedule Of Components Of Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss), before tax	$ (83)	$ (85)
Other comprehensive income (loss), tax	21	2
Other comprehensive loss, net of tax	(104)	(87)
Foreign currency translation adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss), before reclassification, before tax	(169)	(91)
Other comprehensive income (loss), before reclassification, tax	0	0
Other comprehensive income (loss), before reclassification, net of tax	(169)	(91)
Reclassification from AOCI, net of tax	0	0
Other comprehensive loss, net of tax	(169)	(91)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss), before reclassification, net of tax	35	(36)
Reclassification from AOCI, before Tax	39	52
Reclassification from AOCI, tax	9	12
Reclassification from AOCI, net of tax	30	40
Other comprehensive income (loss), before tax	86	6
Other comprehensive income (loss), tax	21	2
Other comprehensive loss, net of tax	65	4
Net actuarial losses
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from AOCI, before Tax	39	52
Reclassification from AOCI, tax	9	12
Reclassification from AOCI, net of tax	30	40
Foreign currency translation adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss), before reclassification, before tax	65	(37)
Other comprehensive income (loss), before reclassification, tax	16	(8)
Other comprehensive income (loss), before reclassification, net of tax	49	(29)
Other adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss), before reclassification, before tax	(18)	(7)
Other comprehensive income (loss), before reclassification, tax	(4)	(2)
Other comprehensive income (loss), before reclassification, net of tax	(14)	(5)
Effect of re-measurement
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss), before reclassification, before tax	0	(2)
Other comprehensive income (loss), before reclassification, tax	0	0
Other comprehensive income (loss), before reclassification, net of tax	$ 0	$ (2)

Acquisitions and Dispositions_2

Acquisitions and Dispositions (Narrative) (Details) $ in Millions	Apr. 01, 2022USD ($)	Mar. 31, 2022USD ($)acquisition	Mar. 31, 2021USD ($)dispositionacquisition	Dec. 31, 2021acquisition	Nov. 30, 2021
Business Acquisition [Line Items]
Number of acquisitions made (in acquisitions) | acquisition			0
Total consideration		$ 28
Cash paid		24
Estimated fair value of deferred/contingent consideration		4	$ 0
Deferred purchase consideration from prior years' acquisitions		12	27
Deconsolidation of Russian businesses		(39)	$ 0
Number of dispositions | disposition			0
Certain Businesses Primarily in Brazil
Business Acquisition [Line Items]
Disposal group, consideration		4
U.S. Affinity Business | Subsequent Event
Business Acquisition [Line Items]
Disposal group, consideration	$ 145
Gain on disposal	$ 110
Marsh India Insurance Brokers Limited
Business Acquisition [Line Items]
Percentage of ownership in equity investment				92.00%	49.00%
Prior Fiscal Periods Acquisitions
Business Acquisition [Line Items]
Estimated fair value of deferred/contingent consideration		4
Current Fiscal Period Acquisitions
Business Acquisition [Line Items]
Total consideration		28
Cash paid		24
Estimated fair value of deferred/contingent consideration		$ 4
Risk and Insurance Services Segment
Business Acquisition [Line Items]
Number of acquisitions made (in acquisitions) | acquisition		1		8
Consulting Segment
Business Acquisition [Line Items]
Number of acquisitions made (in acquisitions) | acquisition		2		1
Minimum
Business Acquisition [Line Items]
Revenue target period (in years)		2 years
Maximum
Business Acquisition [Line Items]
Revenue target period (in years)		4 years

Acquisitions and Dispositions_3

Acquisitions and Dispositions (Allocation Of Acquisition Costs) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Dec. 31, 2020
Business Acquisition [Line Items]
Cash	$ 24
Estimated fair value of deferred/contingent consideration	4	$ 0
Total consideration	28
Allocation of purchase price:
Goodwill	16,254	$ 15,458	$ 16,317	$ 15,517
Current Fiscal Period Acquisitions
Business Acquisition [Line Items]
Cash	24
Estimated fair value of deferred/contingent consideration	4
Total consideration	28
Allocation of purchase price:
Net receivables	1
Other current assets	2
Goodwill	17
Other intangible assets	10
Total assets acquired	30
Current liabilities	1
Other liabilities	1
Total liabilities assumed	2
Net assets acquired	$ 28

Acquisitions and Dispositions_4

Acquisitions and Dispositions (Acquired Finite-Lived Intangible Assets) (Details) - Client relationships $ in Millions	3 Months Ended
	Mar. 31, 2022USD ($)
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired	$ 10
Finite-lived intangible assets, remaining amortization period	10 years 4 months 24 days

Acquisitions and Dispositions_5

Acquisitions and Dispositions (Pro-Forma Information) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Business Combination and Asset Acquisition [Abstract]
Revenue	$ 5,550	$ 5,156
Net income attributable to the Company	$ 1,071	$ 987
Basic net income per share attributable to the Company (in dollars per share)	$ 2.13	$ 1.94
Diluted net income per share attributable to the Company (in dollars per share)	$ 2.10	$ 1.92

Goodwill and Other Intangible_2

Goodwill and Other Intangibles (Changes in the Carrying Amount of Goodwill) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Goodwill [Roll Forward]
Balance as of January 1,	$ 16,317	$ 15,517
Goodwill acquired	17	0
Other adjustments	(80)	(59)
Balance at March 31,	$ 16,254	$ 15,458

Goodwill and Other Intangible_3

Goodwill and Other Intangibles (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
Goodwill acquired	$ 17	$ 0
Goodwill	16,254	15,458	$ 16,317	$ 15,517
Aggregate amortization expense	91	$ 100
Risk and Insurance Services Segment
Segment Reporting Information [Line Items]
Goodwill acquired	17
Goodwill, expected tax deductible amount	1.6
Goodwill	12,500
Consulting Segment
Segment Reporting Information [Line Items]
Goodwill	$ 3,800

Goodwill and Other Intangible_4

Goodwill and Other Intangibles (Amortized Intangible Assets) (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Finite-Lived Intangible Assets [Line Items]
Gross Cost	$ 4,403	$ 4,431
Accumulated Amortization	1,683	1,621
Net Carrying Amount	2,720	2,810
Client relationships
Finite-Lived Intangible Assets [Line Items]
Gross Cost	4,041	4,066
Accumulated Amortization	1,389	1,334
Net Carrying Amount	2,652	2,732
Other
Finite-Lived Intangible Assets [Line Items]
Gross Cost	362	365
Accumulated Amortization	294	287
Net Carrying Amount	$ 68	$ 78

Goodwill And Other Intangible_5

Goodwill And Other Intangibles (Estimated Future Aggregate Amortization Expense) (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
2022 (excludes amortization through March 31, 2022)	$ 261
2023	328
2024	308
2025	269
2026	248
Subsequent years	1,306
Net Carrying Amount	$ 2,720	$ 2,810

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying value of investment	$ 224		$ 207
Equity securities	82		75
Gain on equity securities	9		5
Equity investments without readily determinable market value	$ 39		36
Minimum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Revenue target period (in years)	2 years
Maximum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Revenue target period (in years)	4 years
Private Insurance and Consulting
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying value of investment	$ 51		58
Private Equity Funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying value of investment	173		149
Equity method income	17	$ 10
Alexander Forbes Group Holdings Limited
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value	$ 64		$ 57
Money market funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Share price (per share amount)	$ 1

Fair Value Measurements (Assets

Fair Value Measurements (Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Financial instruments owned:
Exchange traded equity securities	$ 82	$ 75
Fair Value, Measurements, Recurring
Financial instruments owned:
Total assets measured at fair value	340	691
Fiduciary Assets:
Fiduciary assets	235	582
Liabilities:
Total liabilities measured at fair value	358	352
Identical Assets (Level 1) | Fair Value, Measurements, Recurring
Financial instruments owned:
Total assets measured at fair value	330	678
Fiduciary Assets:
Fiduciary assets	235	582
Liabilities:
Total liabilities measured at fair value	0	0
Observable Inputs (Level 2) | Fair Value, Measurements, Recurring
Financial instruments owned:
Total assets measured at fair value	8	8
Fiduciary Assets:
Fiduciary assets	0	0
Liabilities:
Total liabilities measured at fair value	0	0
Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring
Financial instruments owned:
Total assets measured at fair value	2	5
Fiduciary Assets:
Fiduciary assets	0	0
Liabilities:
Total liabilities measured at fair value	358	352
U.S. treasury bills | Fair Value, Measurements, Recurring
Fiduciary Assets:
Fiduciary assets	30	55
U.S. treasury bills | Identical Assets (Level 1) | Fair Value, Measurements, Recurring
Fiduciary Assets:
Fiduciary assets	30	55
U.S. treasury bills | Observable Inputs (Level 2) | Fair Value, Measurements, Recurring
Fiduciary Assets:
Fiduciary assets	0	0
U.S. treasury bills | Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring
Fiduciary Assets:
Fiduciary assets	0	0
Money market funds | Fair Value, Measurements, Recurring
Fiduciary Assets:
Fiduciary assets	205	527
Money market funds | Identical Assets (Level 1) | Fair Value, Measurements, Recurring
Fiduciary Assets:
Fiduciary assets	205	527
Money market funds | Observable Inputs (Level 2) | Fair Value, Measurements, Recurring
Fiduciary Assets:
Fiduciary assets	0	0
Money market funds | Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring
Fiduciary Assets:
Fiduciary assets	0	0
Other Assets | Fair Value, Measurements, Recurring
Financial instruments owned:
Exchange traded equity securities	69	61
Mutual funds	179	192
Other equity investments	8	8
Other Assets | Identical Assets (Level 1) | Fair Value, Measurements, Recurring
Financial instruments owned:
Exchange traded equity securities	69	61
Mutual funds	179	192
Other equity investments	0	0
Other Assets | Observable Inputs (Level 2) | Fair Value, Measurements, Recurring
Financial instruments owned:
Exchange traded equity securities	0	0
Mutual funds	0	0
Other equity investments	8	8
Other Assets | Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring
Financial instruments owned:
Exchange traded equity securities	0	0
Mutual funds	0	0
Other equity investments	0	0
Cash and Cash Equivalents | Fair Value, Measurements, Recurring
Financial instruments owned:
Money market funds	82	425
Cash and Cash Equivalents | Identical Assets (Level 1) | Fair Value, Measurements, Recurring
Financial instruments owned:
Money market funds	82	425
Cash and Cash Equivalents | Observable Inputs (Level 2) | Fair Value, Measurements, Recurring
Financial instruments owned:
Money market funds	0	0
Cash and Cash Equivalents | Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring
Financial instruments owned:
Money market funds	0	0
Other Receivables | Fair Value, Measurements, Recurring
Financial instruments owned:
Contingent purchase consideration asset	2	5
Other Receivables | Identical Assets (Level 1) | Fair Value, Measurements, Recurring
Financial instruments owned:
Contingent purchase consideration asset	0	0
Other Receivables | Observable Inputs (Level 2) | Fair Value, Measurements, Recurring
Financial instruments owned:
Contingent purchase consideration asset	0	0
Other Receivables | Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring
Financial instruments owned:
Contingent purchase consideration asset	2	5
Accounts Payable and Accrued Liabilities and Other Liabilities | Fair Value, Measurements, Recurring
Liabilities:
Contingent purchase consideration liability	358	352
Accounts Payable and Accrued Liabilities and Other Liabilities | Identical Assets (Level 1) | Fair Value, Measurements, Recurring
Liabilities:
Contingent purchase consideration liability	0	0
Accounts Payable and Accrued Liabilities and Other Liabilities | Observable Inputs (Level 2) | Fair Value, Measurements, Recurring
Liabilities:
Contingent purchase consideration liability	0	0
Accounts Payable and Accrued Liabilities and Other Liabilities | Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring
Liabilities:
Contingent purchase consideration liability	$ 358	$ 352

Fair Value Measurements (Change

Fair Value Measurements (Changes In Fair Value Of Level 3 Liabilities Representing Acquisition Related Contingent Consideration) (Details) - Contingent Consideration - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	$ 352	$ 243
Payments	(4)	(11)
Revaluation impact	10	1
Balance at March 31,	$ 358	$ 233

Derivatives (Narrative) (Detail

Derivatives (Narrative) (Details) - 3 months ended Mar. 31, 2022 $ in Millions	USD ($)	EUR (€)
Derivative [Line Items]
Net investment hedge, threshold percentage of the equity balance	80.00%
Decrease in net investment hedges | $	$ 29
Net Investment Hedging
Derivative [Line Items]
Derivative, notional amount | €		€ 1,100,000,000

Leases (Narrative) (Details)

Leases (Narrative) (Details) $ in Millions	Mar. 31, 2022USD ($)
Lessee, Lease, Description [Line Items]
Lessee, operating lease, lease not yet commenced, amount	$ 41
Minimum
Lessee, Lease, Description [Line Items]
Lessee, operating lease, term of contract (years)	10 years
Maximum
Lessee, Lease, Description [Line Items]
Lessee, operating lease, term of contract (years)	25 years

Leases (Lease Cost and Addition

Leases (Lease Cost and Additional Information) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Lessee, Lease, Description [Line Items]
Operating lease cost	$ 90	$ 94
Short-term lease cost	1	1
Variable lease cost	34	37
Sublease income	(5)	(8)
Net lease cost	120	124
Operating cash outflows from operating leases	99	99
Right of use assets obtained in exchange for new operating lease liabilities	$ 51	$ 22
Real Estate Lease
Lessee, Lease, Description [Line Items]
Weighted-average remaining lease term	8 years 8 months 12 days	8 years 3 months 18 days
Weighted-average discount rate, percent	2.75%	2.93%

Leases (Future Minimum Payments

Leases (Future Minimum Payments for Operating Leases) (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Leases [Abstract]
Remainder of 2022	$ 290
2023	356
2024	314
2025	282
2026	258
2027	223
Subsequent years	710
Total future lease payments	2,433
Less: Imputed interest	(271)
Total	2,162
Current lease liabilities	331	$ 332
Long-term lease liabilities	$ 1,831	$ 1,880

Retirement Benefits (Narrative)

Retirement Benefits (Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Contributions by employer		$ 68
Estimated future employer contributions in current fiscal year		110
United States
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, cost recognized		43	$ 39
United Kingdom
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, cost recognized		$ 44	$ 39
United Kingdom | Non-U.S. Plans | Geographic Concentration Risk
Defined Benefit Plan Disclosure [Line Items]
Concentration risk percentage	81.00%
Equity Funds | United States
Defined Benefit Plan Disclosure [Line Items]
Target asset allocation, percentage		60.00%
Actual asset allocation percentage of equity		62.00%
Equity Funds | United Kingdom
Defined Benefit Plan Disclosure [Line Items]
Target asset allocation, percentage		22.00%
Actual asset allocation percentage of equity		24.00%
Fixed Income Funds | United States
Defined Benefit Plan Disclosure [Line Items]
Target asset allocation, percentage		40.00%
Actual asset allocation percentage of equity		38.00%
Fixed Income Funds | United Kingdom
Defined Benefit Plan Disclosure [Line Items]
Target asset allocation, percentage		78.00%
Actual asset allocation percentage of equity		76.00%

Retirement Benefits (Schedule O

Retirement Benefits (Schedule Of Defined Benefit Plan Net Periodic Benefit Cost Combined U.S. and Significant Non-U.S. Plans) (Details) - Pension Benefits - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 8	$ 10
Interest cost	100	85
Expected return on plan assets	(202)	(208)
Recognized actuarial loss	39	52
Net periodic credit	(55)	(61)
United States
Defined Benefit Plan Disclosure [Line Items]
Interest cost	48	46
Expected return on plan assets	(84)	(82)
Recognized actuarial loss	19	23
Net periodic credit	(17)	(13)
Foreign Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	8	10
Interest cost	52	39
Expected return on plan assets	(118)	(126)
Recognized actuarial loss	20	29
Net periodic credit	$ (38)	$ (48)

Retirement Benefits (Schedule_2

Retirement Benefits (Schedule Of Defined Benefit Plan Net Periodic Benefit Cost Amounts Recorded in Consolidated Statement of Income) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Compensation and benefits expense (Operating income)	$ (1,445)	$ (1,358)
Other net benefit (credits) cost	(62)	(71)
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Compensation and benefits expense (Operating income)	8	10
Other net benefit (credits) cost	(63)	(71)
Total credit	$ (55)	$ (61)

Retirement Benefits (Schedule_3

Retirement Benefits (Schedule Of Defined Benefit Plan Weighted Average Assumption Used In Calculating Net Periodic Benefit Cost) (Details) - Pension Benefits	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Weighted average assumptions:
Expected return on plan assets	4.56%	4.72%
Discount rate	2.28%	1.92%
Rate of compensation increase	2.16%	1.85%

Debt (Schedule Of Outstanding D

Debt (Schedule Of Outstanding Debt) (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021	Apr. 09, 2021	Apr. 08, 2021
Debt Instrument [Line Items]
Current portion of long-term debt	$ 366	$ 17
Short-term debt	1,191	17
Long-term debt	10,918	10,950
Long-term debt, net	10,552	10,933
Commercial Paper
Debt Instrument [Line Items]
Short-term debt	825	0	$ 2,000	$ 1,500
3.30% Senior Debt Obligations Due 2023
Debt Instrument [Line Items]
Long-term debt	$ 350	349
Interest rate	3.30%
4.05% Senior Debt Obligations Due 2023
Debt Instrument [Line Items]
Long-term debt	$ 250	249
Interest rate	4.05%
3.50% Senior Debt Obligations Due 2024
Debt Instrument [Line Items]
Long-term debt	$ 599	599
Interest rate	3.50%
3.875% Senior Debt Obligations Due 2024
Debt Instrument [Line Items]
Long-term debt	$ 997	997
Interest rate	3.875%
3.50% Senior Debt Obligations Due 2025
Debt Instrument [Line Items]
Long-term debt	$ 498	498
Interest rate	3.50%
1.349% Senior Debt Obligations Due 2026
Debt Instrument [Line Items]
Long-term debt	$ 615	629
Interest rate	1.349%
3.75% Senior Debt Obligations Due 2026
Debt Instrument [Line Items]
Long-term debt	$ 598	598
Interest rate	3.75%
4.375% Senior Debt Obligations Due 2029
Debt Instrument [Line Items]
Long-term debt	$ 1,499	1,499
Interest rate	4.375%
1.979% Senior Debt Obligations Due 2030
Debt Instrument [Line Items]
Long-term debt	$ 600	614
Interest rate	1.979%
2.250% Senior Debt Obligations Due 2030
Debt Instrument [Line Items]
Long-term debt	$ 739	739
Interest rate	2.25%
2.375% Senior Debt Obligations Due 2031
Debt Instrument [Line Items]
Long-term debt	$ 396	$ 397
Interest rate	2.375%	2.375%
5.875% Senior Debt Obligations Due 2033
Debt Instrument [Line Items]
Long-term debt	$ 298	$ 298
Interest rate	5.875%
4.75% Senior Debt Obligations Due 2039
Debt Instrument [Line Items]
Long-term debt	$ 495	495
Interest rate	4.75%
4.35% Senior Debt Obligation Due 2047
Debt Instrument [Line Items]
Long-term debt	$ 493	493
Interest rate	4.35%
4.20% Senior Debt Obligations Due 2048
Debt Instrument [Line Items]
Long-term debt	$ 593	593
Interest rate	4.20%
4.90% Senior Debt Obligations Due 2049
Debt Instrument [Line Items]
Long-term debt	$ 1,238	1,238
Interest rate	4.90%
2.90% Senior Debt Obligations Due 2051
Debt Instrument [Line Items]
Long-term debt	$ 346	$ 346
Interest rate	2.90%	2.90%
5.70% Mortgage Due 2035
Debt Instrument [Line Items]
Long-term debt	$ 312	$ 316
Interest rate	5.70%
Other
Debt Instrument [Line Items]
Long-term debt	$ 2	$ 3

Debt (Narrative) (Details)

Debt (Narrative) (Details) - USD ($)	Apr. 15, 2021	Apr. 02, 2021	Apr. 01, 2021	Dec. 31, 2021	Mar. 31, 2022	Apr. 09, 2021	Apr. 08, 2021
Debt Instrument [Line Items]
Commercial paper outstanding					$ 825,000,000
Other Debt Facilities
Debt Instrument [Line Items]
Long-term line of credit				$ 0	0
Debt instrument, unused borrowing capacity				$ 508,000,000	$ 483,000,000
2.375% Senior Debt Obligations Due 2031
Debt Instrument [Line Items]
Interest rate				2.375%	2.375%
2.90% Senior Debt Obligations Due 2051
Debt Instrument [Line Items]
Interest rate				2.90%	2.90%
2.75% Senior Debt Obligations Due January 2022
Debt Instrument [Line Items]
Interest rate				2.75%
Repayments of debt				$ 500,000,000
Commercial Paper
Debt Instrument [Line Items]
Short-term debt				0	$ 825,000,000	$ 2,000,000,000	$ 1,500,000,000
Effective interest rate (percent)					0.91%
Revolving Credit Facility | New Facility
Debt Instrument [Line Items]
Debt facilities, maximum borrowing capacity		$ 2,800,000,000
Term of debt		5 years
Long-term line of credit					$ 0
Revolving Credit Facility | Old Facility
Debt Instrument [Line Items]
Debt facilities, maximum borrowing capacity			$ 1,800,000,000
Term of debt			5 years
Revolving Credit Facility | 364-day Facility
Debt Instrument [Line Items]
Debt facilities, maximum borrowing capacity			$ 1,000,000,000
Term of debt			364 days
Senior Notes
Debt Instrument [Line Items]
Repayments of debt	$ 500,000,000
Senior Notes | 2.375% Senior Debt Obligations Due 2031
Debt Instrument [Line Items]
Debt instrument face amount				400,000,000
Senior Notes | 2.90% Senior Debt Obligations Due 2051
Debt Instrument [Line Items]
Debt instrument face amount				$ 350,000,000

Debt (Estimated Fair Value of S

Debt (Estimated Fair Value of Significant Financial Instruments) (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term debt	$ 1,191	$ 17
Long-term debt	10,552	10,933
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term debt	1,195	17
Long-term debt	$ 11,004	$ 12,466

Restructuring Costs (Narrative)

Restructuring Costs (Narrative) (Details) - Jardine Lloyd Thompson Group plc - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Restructuring Cost and Reserve [Line Items]
Costs incurred	$ 30	$ 163
Acquisition related
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cost incurred to date	30
Acquisition related | Corporate
Restructuring Cost and Reserve [Line Items]
Costs incurred	8
Acquisition related | Risk and Insurance Services Segment
Restructuring Cost and Reserve [Line Items]
Costs incurred	16
Acquisition related | Consulting Segment
Restructuring Cost and Reserve [Line Items]
Costs incurred	$ 6

Restructuring Costs (Restructur

Restructuring Costs (Restructuring Activities) (Details) - Jardine Lloyd Thompson Group plc - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Restructuring Reserve [Roll Forward]
Liability at beginning of period	$ 69	$ 106
Restructuring charges	30	163
Cash payments	(39)	(178)
Non-cash charges	(6)	(22)
Liability at end of period	54	69
Severance
Restructuring Reserve [Roll Forward]
Liability at beginning of period	35	52
Restructuring charges	3	38
Cash payments	(16)	(55)
Non-cash charges	0	0
Liability at end of period	22	35
Real Estate Related Costs
Restructuring Reserve [Roll Forward]
Liability at beginning of period	34	51
Restructuring charges	6	31
Cash payments	(4)	(26)
Non-cash charges	(4)	(22)
Liability at end of period	32	34
Information Technology
Restructuring Reserve [Roll Forward]
Liability at beginning of period	0	2
Restructuring charges	5	23
Cash payments	(3)	(25)
Non-cash charges	(2)	0
Liability at end of period	0	0
Consulting and Other Outside Services
Restructuring Reserve [Roll Forward]
Liability at beginning of period	0	1
Restructuring charges	16	71
Cash payments	(16)	(72)
Non-cash charges	0	0
Liability at end of period	$ 0	$ 0

Common Stock (Details)

Common Stock (Details) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 23, 2022	Dec. 31, 2021
Equity, Class of Treasury Stock [Line Items]
Common stock repurchased (in shares)		1,000,000
Purchase of treasury shares	$ 500,000,000	$ 119,000,000
Payments for repurchase of common stock	$ 500,000,000	$ 112,000,000
Stock-based compensation, shares issued during period (in shares)	1,800,000	2,000,000
Common Stock
Equity, Class of Treasury Stock [Line Items]
Share repurchases program, authorized amount (up to)			$ 5,000,000,000
Stock repurchase program, remaining authorized repurchase amount	$ 5,800,000,000			$ 1,300,000,000
Common stock repurchased (in shares)	3,200,000

Claims, Lawsuits And Other Co_2

Claims, Lawsuits And Other Contingencies (Details) - Jardine Lloyd Thompson Group plc case in Thousands, £ in Millions, $ in Millions	1 Months Ended	48 Months Ended
	Dec. 31, 2021USD ($)	Dec. 31, 2018case	Mar. 31, 2022USD ($)	Mar. 31, 2022GBP (£)	Dec. 31, 2020USD ($)	Dec. 31, 2020GBP (£)	Feb. 28, 2019USD ($)	Feb. 28, 2019GBP (£)
Loss Contingencies [Line Items]
Individual cases analyzed | case		14
Loss contingency accrual			$ 13	£ 10	$ 210	£ 155	$ 77	£ 59
United States
Loss Contingencies [Line Items]
Loss contingency, damages sought, value	$ 29
Columbia
Loss Contingencies [Line Items]
Loss contingency, damages sought, value	$ 2

Segment Information (Selected I

Segment Information (Selected Information And Details For MMC's Operating Segments) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Segment Reporting Information [Line Items]
Revenue	$ 5,549	$ 5,083
Operating Income (Loss)	1,445	1,358
Loss on deconsolidation of Russian businesses	(39)	0
Risk and Insurance Services Segment
Segment Reporting Information [Line Items]
Revenue	3,549	3,225
Interest on fiduciary funds	4	5
Consulting Segment
Segment Reporting Information [Line Items]
Revenue	2,010	1,873
Operating Segments
Segment Reporting Information [Line Items]
Revenue	5,559	5,098
Operating Income (Loss)	1,513	1,421
Operating Segments | Risk and Insurance Services Segment
Segment Reporting Information [Line Items]
Revenue	3,549	3,225
Operating Income (Loss)	1,121	1,060
Interest on fiduciary funds	4	5
Loss on deconsolidation of Russian businesses	(27)
Operating Segments | Consulting Segment
Segment Reporting Information [Line Items]
Revenue	2,010	1,873
Operating Income (Loss)	392	361
Corporate/Eliminations
Segment Reporting Information [Line Items]
Revenue	(10)	(15)
Operating Income (Loss)	(68)	(63)
Intersegment Eliminations | Consulting Segment
Segment Reporting Information [Line Items]
Revenue	10	$ 15
Loss on deconsolidation of Russian businesses	$ (12)

Segment Information (Details of

Segment Information (Details of Operating Segment Revenue) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Segment Reporting Information [Line Items]
Revenue	$ 5,549	$ 5,083
Risk and Insurance Services Segment
Segment Reporting Information [Line Items]
Revenue	3,549	3,225
Risk and Insurance Services Segment | Marsh Insurance Group
Segment Reporting Information [Line Items]
Revenue	2,546	2,325
Risk and Insurance Services Segment | Guy Carpenter Reinsurance Group
Segment Reporting Information [Line Items]
Revenue	999	895
Consulting Segment
Segment Reporting Information [Line Items]
Revenue	2,010	1,873
Consulting Segment | Mercer Consulting Group
Segment Reporting Information [Line Items]
Revenue	1,343	1,288
Consulting Segment | Oliver Wyman Group Consulting Group
Segment Reporting Information [Line Items]
Revenue	667	585
Operating Segments
Segment Reporting Information [Line Items]
Revenue	5,559	5,098
Operating Segments | Risk and Insurance Services Segment
Segment Reporting Information [Line Items]
Revenue	3,549	3,225
Operating Segments | Risk and Insurance Services Segment | Marsh Insurance Group
Segment Reporting Information [Line Items]
Revenue	2,549	2,329
Operating Segments | Risk and Insurance Services Segment | Guy Carpenter Reinsurance Group
Segment Reporting Information [Line Items]
Revenue	1,000	896
Operating Segments | Consulting Segment
Segment Reporting Information [Line Items]
Revenue	2,010	1,873
Operating Segments | Consulting Segment | Mercer Consulting Group
Segment Reporting Information [Line Items]
Revenue	1,343	1,288
Operating Segments | Consulting Segment | Oliver Wyman Group Consulting Group
Segment Reporting Information [Line Items]
Revenue	667	585
Corporate/Eliminations
Segment Reporting Information [Line Items]
Revenue	$ (10)	$ (15)