Moody's (MCO) 10-Q 29 Oct 21 2021 Q3 Quarterly report Financial data

Cover Page

Cover Page shares in Millions	9 Months Ended
	Sep. 30, 2021shares
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2021
Document Transition Report	false
Entity File Number	1-14037
Entity Registrant Name	Moody’s Corporation
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	13-3998945
Entity Address, Address Line One	7 World Trade Center at 250 Greenwich Street
Entity Address, City or Town	New York
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10007
City Area Code	(212)
Local Phone Number	553-0300
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 (in shares)	185.9
Entity Central Index Key	0001059556
Document Fiscal Period Focus	Q3
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Common Stock, par value $0.01 per share
Entity Information [Line Items]
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	MCO
Security Exchange Name	NYSE
1.75% Senior Notes Due 2027
Entity Information [Line Items]
Title of 12(b) Security	1.75% Senior Notes Due 2027
Trading Symbol	MCO 27
Security Exchange Name	NYSE
0.950% Senior Notes Due 2030
Entity Information [Line Items]
Title of 12(b) Security	0.950% Senior Notes Due 2030
Trading Symbol	MCO 30
Security Exchange Name	NYSE

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Revenue	$ 1,526	$ 1,356	$ 4,679	$ 4,081
Expenses
Operating	394	364	1,152	1,066
Selling, general and administrative	395	271	1,015	879
Depreciation and amortization	61	56	180	163
Restructuring	0	23	2	20
Loss pursuant to the divestiture of MAKS	0	0	0	9
Total expenses	850	714	2,349	2,137
Operating income	676	642	2,330	1,944
Non-operating (expense) income, net
Interest expense, net	(53)	(53)	(109)	(153)
Other non-operating (expense) income, net	(4)	10	18	38
Total non-operating (expense) income, net	(57)	(43)	(91)	(115)
Income before provision for income taxes	619	599	2,239	1,829
Provision for income taxes	145	132	452	366
Net income	474	467	1,787	1,463
Less: Net income (loss) attributable to noncontrolling interests	0	0	0	(1)
Net income attributable to Moody's	$ 474	$ 467	$ 1,787	$ 1,464
Earnings per share attributable to Moody's common shareholders
Basic (in usd per share)	$ 2.55	$ 2.49	$ 9.58	$ 7.80
Diluted (in usd per share)	$ 2.53	$ 2.47	$ 9.51	$ 7.73
Weighted average number of shares outstanding
Basic (in shares)	186	187.8	186.6	187.6
Diluted (in shares)	187.3	189.3	188	189.3

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Net Income	$ 474	$ 467	$ 1,787	$ 1,463
Other Comprehensive Income (Loss):
Foreign currency translation adjustment - Pre Tax	(124)	204	(234)	107
Foreign currency translation adjustments - Tax	5	(17)	9	(11)
Foreign currency translation adjustments - Net of Tax	(119)	187	(225)	96
Net gains (losses) on net investment hedges - Pre Tax	99	(191)	233	(169)
Net gains (losses) on net investment hedges, Tax	(26)	48	(56)	42
Net gains (losses) on net investment hedges - Net of Tax	73	(143)	177	(127)
Net investment hedges - reclassification of gains included in net income - Pre Tax			(2)	0
Net investment hedges - reclassification of gains included in net income - Tax			1	0
Net investment hedges - reclassification of gains included in net income - Net of Tax			(1)	0
Cash Flow Hedges:
Net realized and unrealized (losses) gains on cash flow hedges - Pre Tax			0	(68)
Net realized and unrealized (losses) gains on cash flow hedges - Tax			0	18
Net realized and unrealized (losses) gains on cash flow hedges - Net of Tax			0	(50)
Reclassification of losses (gains) included in net income - Pre Tax	1	0	2	1
Reclassification of losses (gains) included in net income - Tax	0	0	0	0
Reclassification of losses (gains) included in net income - Net of Tax	1	0	2	1
Pension and Other Retirement Benefits:
Amortization of actuarial losses and prior service costs included in net income - Pre Tax	3	2	16	5
Amortization of actuarial losses and prior service costs included in net income - Tax	(1)	0	(4)	(1)
Amortization of actuarial losses and prior service costs included in net income - Net of Tax	2	2	12	4
Net actuarial (losses) gains and prior service costs - Pre Tax	4	(9)	4	(1)
Net actuarial (losses) gains and prior service costs - Tax	(1)	2	(1)	0
Net actuarial (losses) gains and prior service costs - Net of Tax	3	(7)	3	(1)
Total other comprehensive income (loss) - Pre Tax	(17)	6	19	(125)
Total other comprehensive income (loss) - Tax	(23)	33	(51)	48
Total other comprehensive income (loss) - Net of Tax	(40)	39	(32)	(77)
Comprehensive income	434	506	1,755	1,386
Less: comprehensive income (loss) attributable to noncontrolling interests	(3)	1	(2)	(12)
Comprehensive Income Attributable to Moody's	$ 437	$ 505	$ 1,757	$ 1,398

CONSOLIDATED BALANCE SHEETS (UN

CONSOLIDATED BALANCE SHEETS (UNAUDITED) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 2,239	$ 2,597
Short-term investments	104	99
Accounts receivable, net of allowance for credit losses of $35 in 2021 and $34 in 2020	1,589	1,430
Other current assets	323	383
Total current assets	4,255	4,509
Property and equipment, net of accumulated depreciation of $988 in 2021 and $928 in 2020	301	278
Operating lease right-of-use assets	451	393
Goodwill	5,898	4,556
Intangible assets, net	2,510	1,824
Deferred tax assets, net	363	334
Other assets	636	515
Total assets	14,414	12,409
Current liabilities:
Accounts payable and accrued liabilities	1,084	1,039
Current portion of operating lease liabilities	103	94
Current portion of long-term debt	507	0
Deferred revenue	1,099	1,089
Total current liabilities	2,793	2,222
Non-current portion of deferred revenue	87	98
Long-term debt	6,969	6,422
Deferred tax liabilities, net	564	404
Uncertain tax positions	492	483
Operating lease liabilities	470	427
Other liabilities	420	590
Total liabilities	11,795	10,646
Contingencies
Shareholders' equity:
Preferred stock, par value $0.01 per share; 10,000,000 shares authorized; no shares issued and outstanding	0	0
Common stock	3	3
Capital surplus	832	735
Retained earnings	12,451	11,011
Treasury stock, at cost; 157,002,502 and 155,808,563 shares of common stock at September 30, 2021 and December 31, 2020	(10,394)	(9,748)
Accumulated other comprehensive loss	(462)	(432)
Total Moody's shareholders' equity	2,430	1,569
Noncontrolling interests	189	194
Total shareholders' equity	2,619	1,763
Total liabilities, noncontrolling interests and shareholders' equity	14,414	12,409
Series Common Stock
Shareholders' equity:
Common stock	$ 0	$ 0

CONSOLIDATED BALANCE SHEETS (_2

CONSOLIDATED BALANCE SHEETS (UNAUDITED) (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Accounts receivable, allowances	$ 35	$ 34
Accumulated depreciation, property and equipment	$ 988	$ 928
Preferred stock, par value (in usd per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in usd per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	1,000,000,000	1,000,000,000
Common stock, shares issued (in shares)	342,902,272	342,902,272
Treasury stock, shares (in shares)	157,002,502	155,808,563
Series Common Stock
Common stock, par value (in usd per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	10,000,000	10,000,000
Common stock, shares issued (in shares)	0	0
Common stock, shares outstanding (in shares)	0	0

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash flows from operating activities
Net Income	$ 1,787	$ 1,463
Reconciliation of net income to net cash provided by operating activities:
Depreciation and amortization	180	163
Stock-based compensation	127	110
Deferred income taxes	(79)	(1)
ROU Asset impairment & other non-cash restructuring/impairment charges	0	23
Loss pursuant to the divestiture of MAKS	0	9
Settlement of treasury rate lock	0	(68)
Prepayment penalty relating to early redemption of debt	0	24
Changes in assets and liabilities:
Accounts receivable	(137)	73
Other current assets	64	(8)
Other assets	(7)	(89)
Accounts payable and accrued liabilities	(20)	(28)
Deferred revenue	(75)	(171)
Unrecognized tax benefits and other non-current tax liabilities	(79)	(9)
Other liabilities	(55)	(3)
Net cash provided by operating activities	1,706	1,488
Cash flows from investing activities
Capital additions	(77)	(83)
Purchases of investments	(137)	(130)
Sales and maturities of investments	102	57
Cash paid for acquisitions, net of cash acquired	(2,026)	(699)
Receipts from settlements of net investment hedges	26	2
Payments for settlements of net investment hedges	(49)	0
Net cash used in investing activities	(2,161)	(853)
Cash flows from financing activities
Issuance of notes	1,178	1,491
Repayment of notes	0	(800)
Issuance of commercial paper	0	789
Repayment of commercial paper	0	(792)
Proceeds from stock-based compensation plans	30	41
Repurchase of shares related to stock-based compensation	(82)	(101)
Treasury shares	(628)	(253)
Dividends	(347)	(315)
Debt issuance costs, extinguishment costs and related fees	(13)	(39)
Dividends to noncontrolling interest	(3)	(1)
Payment to acquire noncontrolling interests	0	(17)
Net cash provided by financing activities	135	3
Effect of exchange rate changes on cash and cash equivalents	(38)	22
(Decrease) increase in cash and cash equivalents	(358)	660
Cash and cash equivalents, beginning of period	2,597	1,832
Cash and cash equivalents, end of period	$ 2,239	$ 2,492

CONSOLIDATED STATEMENT OF SHARE

CONSOLIDATED STATEMENT OF SHAREHOLDERS' EQUITY (UNAUDITED) - USD ($) shares in Millions, $ in Millions	Total	Total Moody's Shareholders' Equity	Common Stock	Capital Surplus	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Loss	Non- Controlling Interests	Cumulative Effect, Period of Adoption, Adjustment	Cumulative Effect, Period of Adoption, AdjustmentTotal Moody's Shareholders' Equity	Cumulative Effect, Period of Adoption, AdjustmentRetained Earnings
Beginning Balance (in shares) at Dec. 31, 2019			342.9			155.2
Beginning Balance at Dec. 31, 2019	$ 831	$ 612	$ 3	$ 642	$ 9,656	$ (9,250)	$ (439)	$ 219	$ (2)	$ (2)	$ (2)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,464	1,464			1,464
Net Income	1,463
Dividends	(315)	(314)			(314)			(1)
Stock-based compensation	110	110		110
Shares issued for stock-based compensation plans at average cost, net (in shares)						1.2
Shares issued for stock-based compensation plans at average cost, net	(53)	(53)		(51)		$ (2)
Purchase of noncontrolling interest	(17)	(2)		(2)				(15)
Treasury shares repurchased (in shares)						(1.1)
Treasury shares repurchased	(253)	(253)				$ (253)
Currency translation adjustment, net of net investment hedge activity (net of tax)	(31)	(19)					(19)	(12)
Net actuarial gains and prior service cost (net of tax)	(1)	(1)					(1)
Amortization of prior service costs/actuarial losses and settlement charge	4	4					4
Net realized and unrealized gain (loss) on cash flow hedges (net of tax)	(49)	(49)					(49)
Ending Balance (in shares) at Sep. 30, 2020			342.9			155.1
Ending Balance at Sep. 30, 2020	1,688	1,497	$ 3	699	10,804	$ (9,505)	(504)	191
Beginning Balance (in shares) at Jun. 30, 2020			342.9			155.2
Beginning Balance at Jun. 30, 2020	1,232	1,041	$ 3	651	10,442	$ (9,513)	(542)	191
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	467	467			467
Dividends	(106)	(105)			(105)			(1)
Stock-based compensation	38	38		38
Shares issued for stock-based compensation plans at average cost, net (in shares)						0.1
Shares issued for stock-based compensation plans at average cost, net	18	18		10		$ 8
Currency translation adjustment, net of net investment hedge activity (net of tax)	44	43					43	1
Net actuarial gains and prior service cost (net of tax)	(7)	(7)					(7)
Amortization of prior service costs/actuarial losses and settlement charge	2	2					2
Ending Balance (in shares) at Sep. 30, 2020			342.9			155.1
Ending Balance at Sep. 30, 2020	1,688	1,497	$ 3	699	10,804	$ (9,505)	(504)	191
Beginning Balance (in shares) at Dec. 31, 2020			342.9			155.8
Beginning Balance at Dec. 31, 2020	1,763	1,569	$ 3	735	11,011	$ (9,748)	(432)	194
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	1,787	1,787			1,787
Dividends	(350)	(347)			(347)			(3)
Stock-based compensation	127	127		127
Shares issued for stock-based compensation plans at average cost, net (in shares)						0.7
Shares issued for stock-based compensation plans at average cost, net	(48)	(48)		(30)		$ (18)
Treasury shares repurchased (in shares)						(1.9)
Treasury shares repurchased	(628)	(628)				$ (628)
Currency translation adjustment, net of net investment hedge activity (net of tax)	(49)	(47)					(47)	(2)
Net actuarial gains and prior service cost (net of tax)	3	3					3
Amortization of prior service costs/actuarial losses and settlement charge	12	12					12
Net realized and unrealized gain (loss) on cash flow hedges (net of tax)	2	2					2
Ending Balance (in shares) at Sep. 30, 2021			342.9			157
Ending Balance at Sep. 30, 2021	2,619	2,430	$ 3	832	12,451	$ (10,394)	(462)	189
Beginning Balance (in shares) at Jun. 30, 2021			342.9			156.7
Beginning Balance at Jun. 30, 2021	2,380	2,186	$ 3	784	12,094	$ (10,270)	(425)	194
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	474	474			474
Dividends	(119)	(117)			(117)			(2)
Stock-based compensation	41	41		41
Shares issued for stock-based compensation plans at average cost, net (in shares)						0
Shares issued for stock-based compensation plans at average cost, net	8	8		7		$ 1
Treasury shares repurchased (in shares)						(0.3)
Treasury shares repurchased	(125)	(125)				$ (125)
Currency translation adjustment, net of net investment hedge activity (net of tax)	(46)	(43)					(43)	(3)
Net actuarial gains and prior service cost (net of tax)	3	3					3
Amortization of prior service costs/actuarial losses and settlement charge	2	2					2
Net realized and unrealized gain (loss) on cash flow hedges (net of tax)	1	1					1
Ending Balance (in shares) at Sep. 30, 2021			342.9			157
Ending Balance at Sep. 30, 2021	$ 2,619	$ 2,430	$ 3	$ 832	$ 12,451	$ (10,394)	$ (462)	$ 189

CONSOLIDATED STATEMENT OF SHA_2

CONSOLIDATED STATEMENT OF SHAREHOLDERS' EQUITY (UNAUDITED) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Stockholders' Equity [Abstract]
Dividends (in USD per share)	$ 0.62	$ 0.56	$ 1.86	$ 1.68
Currency translation adjustment, net of net investment hedge activity, tax expense (benefit)	$ 21	$ (31)	$ 46	$ (31)
Net actuarial gains and prior service cost, tax expense (benefit)	1	(2)	1	0
Amortization of prior service costs and actuarial losses, tax expense (benefit)	$ 1	$ 0	$ 4	1
Net realized and unrealized gain on cash flow hedges, tax expense (benefit)				$ (18)

DESCRIPTION OF BUSINESS AND BAS

DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION	DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION Moody’s is a global integrated risk assessment firm that empowers organizations and investors to make better decisions. Moody’s reports in two reportable segments: MIS and MA. MIS publishes credit ratings and provides assessment services on a wide range of debt obligations and the entities that issue such obligations in markets worldwide. Revenue is primarily derived from the originators and issuers of such transactions who use MIS ratings in the distribution of their debt issues to investors. Additionally, MIS earns revenue from certain non-ratings-related operations which consist primarily of financial instrument pricing services in the Asia-Pacific region, revenue from providing ESG research, data and assessments and revenue from ICRA’s non-ratings operations. The revenue from these operations is included in the MIS Other LOB and is not material to the results of the MIS segment. MA is a global provider of data and analytic solutions which help companies make better and faster decisions. MA’s analytic models, industry insights, software tools and proprietary data assets allow companies to inform and perform many critical business activities with trust and confidence. MA’s approach to aggregating, broadening and deepening available data, research, analytic tools and software solutions fosters a more integrated and efficient delivery to MA's customers resulting in better decisions around risks and opportunities. These interim financial statements have been prepared in accordance with the instructions to Form 10-Q and should be read in conjunction with the Company’s consolidated financial statements and related notes in the Company’s 2020 annual report on Form 10-K filed with the SEC on February 22, 2021. The results of interim periods are not necessarily indicative of results for the full year or any subsequent period. In the opinion of management, all adjustments (including normal recurring accruals) considered necessary for a fair presentation of financial position, results of operations and cash flows at the dates and for the periods presented have been included. The year-end consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by accounting principles generally accepted in the United States of America. Certain reclassifications have been made to prior period amounts to conform to the current presentation. Adoption of New Accounting Standards On January 1, 2021, the Company adopted ASU No. 2019-04, “Codification Improvements to Topic 326, Financial Instruments—Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825 Financial Instruments.” This ASU clarifies and improves guidance related to the recently issued standards updates on credit losses, hedging, and recognition and measurement of financial instruments. The Company adopted this ASU prospectively and it did not have a material impact on the Company's current financial statements. On January 1, 2021, the Company adopted ASU No. 2019-12, "Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes." This ASU simplifies the accounting for income taxes by eliminating certain exceptions to the general principles in Topic 740, Income Taxes, and clarifies certain aspects of the existing guidance to promote consistency among reporting entities. Most amendments within this ASU are required to be applied on a prospective basis, while certain amendments must be applied on a retrospective or modified retrospective basis. The Company adopted this ASU prospectively and it did not have a material impact on the Company's current financial statements. Recently Issued Accounting Standards In January 2021, the FASB issued ASU 2021-01, “Reference Rate Reform - Scope,” which clarified the scope and application of the original guidance, ASU No. 2020-04, "Facilitation of the Effects of Reference Rate Reform on Financial Reporting" ("ASU No. 2020-04"), issued in March 2020. ASU No. 2020-04 provides temporary optional expedients and exceptions to the U.S. GAAP guidance on contract modifications and hedge accounting to ease the financial reporting burdens related to the expected market transition from the London Interbank Offered Rate (LIBOR) and other interbank offered rates to alternative reference rates. Both ASU's were effective upon issuance, and the Company may elect to apply the amendments prospectively through December 31, 2022 as the transition from LIBOR is completed. In October 2021, the FASB issued ASU 2021-08, "Business Combinations (Topic 805): Accounting for Contract Assets and Contract Liabilities from Contracts with Customers" ("ASU No. 2021-08"). ASU No. 2021-08 will require companies to apply the definition of a performance obligation under ASC Topic 606 to recognize and measure contract assets and contract liabilities (i.e., deferred revenue) relating to contracts with customers that are acquired in a business combination. Under current GAAP, an acquirer generally recognizes assets acquired and liabilities assumed in a business combination, including contract assets and contract liabilities arising from revenue contracts with customers, at fair value on the acquisition date. ASU No. 2021-08 will result in the acquirer recording acquired contract assets and liabilities on the same basis that would have been recorded by the acquiree before the acquisition under ASC Topic 606. ASU No. 2021-08 is effective for fiscal years beginning after December 15, 2022, with early adoption permitted. The Company is currently evaluating the impact of this ASU on its financial statements.

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Pursuant to a strategic reorganization in the MA operating segment which was completed in the second quarter of 2021, the Company realigned its MA reporting units used in assessing goodwill for impairment as of June 30, 2021. Accordingly, the Company revised its accounting policy for goodwill to reflect the change in MA's reporting units, which is discussed below. All other significant accounting policies described in the Form 10-K for the year ended December 31, 2020 remain unchanged. This reorganization did not result in a change to the Company's reportable segments. Goodwill Moody’s evaluates its goodwill for impairment at the reporting unit level, defined as an operating segment (i.e., MIS and MA), or one level below an operating segment (i.e., a component of an operating segment), annually as of July 31 or more frequently if impairment indicators arise in accordance with ASC Topic 350. The Company evaluates the recoverability of goodwill using a two-step impairment test approach at the reporting unit level. In the first step, the Company assesses various qualitative factors to determine whether the fair value of a reporting unit may be less than its carrying amount. If a determination is made based on the qualitative factors that an impairment does not exist, the Company is not required to perform further testing. If the aforementioned qualitative assessment results in the Company concluding that it is more likely than not that the fair value of a reporting unit may be less than its carrying amount, the fair value of the reporting unit will be quantitatively determined and compared to its carrying value including goodwill. If the fair value of the reporting unit exceeds the carrying value of the net assets assigned to that unit, goodwill is not impaired and the Company is not required to perform further testing. If the fair value of the reporting unit is less than the carrying value, the Company will record a goodwill impairment charge for the amount by which the carrying value exceeds the reporting unit’s fair value. The Company evaluates its reporting units on an annual basis, or more frequently if there are changes in the reporting structure of the Company due to acquisitions, reporting unit realignments or if there are indicators of potential impairment. For the reporting units where the Company is consistently able to conclude that no impairment exists using only a qualitative approach, the Company’s accounting policy is to perform the second step of the aforementioned goodwill impairment assessment at least once every three years. Goodwill is assigned to a reporting unit at the date when an acquisition is integrated into one of the established reporting units, and is based on which reporting unit is expected to benefit from the synergies of the acquisition. Prior to the second quarter of 2021, MA's reporting unit structure consisted of five reporting units (Content, ERS, MALS, Bureau van Dijk and Reis). Pursuant to a strategic reorganization in the MA segment which was completed in the second quarter of 2021, MA's reporting unit structure has been reorganized into two reporting units. MA’s two new reporting units generally consist of: i) businesses offering data and data-driven analytical solutions; and ii) risk-management software, workflow and CRE solutions. The Company performed qualitative assessments of the reporting units impacted by the reorganization immediately before and after the reorganization became effective. These qualitative assessments resulted in the Company determining that it was not more likely than not that the fair value of any reporting unit was less than its carrying amount.

REVENUES

REVENUES	9 Months Ended
	Sep. 30, 2021
Revenue from Contract with Customer [Abstract]
REVENUES	REVENUES Revenue by Category The following table presents the Company’s revenues disaggregated by LOB: Three Months Ended Nine Months Ended 2021 2020 2021 2020 MIS: Corporate finance (CFG) Investment-grade $ 105 $ 141 $ 341 $ 576 High-yield 82 101 347 275 Bank loans 145 73 482 205 Other accounts (1) 156 146 473 430 Total CFG 488 461 1,643 1,486 Financial institutions (FIG) Banking 105 95 315 269 Insurance 38 31 114 105 Managed investments 8 6 29 20 Other accounts 2 2 7 7 Total FIG 153 134 465 401 Public, project and infrastructure finance (PPIF) Public finance / sovereign 61 71 191 192 Project and infrastructure 69 62 212 183 Total PPIF 130 133 403 375 Structured finance (SFG) Asset-backed securities 29 25 88 70 RMBS 31 24 89 74 CMBS 26 15 73 45 Structured credit 57 24 148 74 Other accounts — — 1 2 Total SFG 143 88 399 265 Total ratings revenue 914 816 2,910 2,527 MIS Other 11 9 31 30 Total external revenue 925 825 2,941 2,557 Intersegment revenue 42 38 124 110 Total MIS 967 863 3,065 2,667 MA: Research, data and analytics (RD&A) 445 386 1,299 1,110 Enterprise risk solutions (ERS) 156 145 439 414 Total external revenue 601 531 1,738 1,524 Intersegment revenue 2 1 6 5 Total MA 603 532 1,744 1,529 Eliminations (44) (39) (130) (115) Total MCO $ 1,526 $ 1,356 $ 4,679 $ 4,081 (1) Other includes: recurring monitoring fees of a rated debt obligation and/or entities that issue such obligations as well as fees from programs such as commercial paper, medium term notes, and ICRA corporate finance revenue. The following table presents the Company’s revenues disaggregated by LOB and geographic area: Three Months Ended September 30, 2021 Three Months Ended September 30, 2020 U.S. Non-U.S Total U.S. Non-U.S Total MIS: Corporate finance $ 334 $ 154 $ 488 $ 311 $ 150 $ 461 Financial institutions 71 82 153 59 75 134 Public, project and infrastructure finance 76 54 130 82 51 133 Structured finance 98 45 143 54 34 88 Total ratings revenue 579 335 914 506 310 816 MIS Other 1 10 11 — 9 9 Total MIS 580 345 925 506 319 825 MA: Research, data and analytics 203 242 445 167 219 386 Enterprise risk solutions 61 95 156 56 89 145 Total MA 264 337 601 223 308 531 Total MCO $ 844 $ 682 $ 1,526 $ 729 $ 627 $ 1,356 Nine Months Ended September 30, 2021 Nine Months Ended September 30, 2020 U.S. Non-U.S Total U.S. Non-U.S Total MIS: Corporate finance $ 1,093 $ 550 $ 1,643 $ 1,038 $ 448 $ 1,486 Financial institutions 226 239 465 189 212 401 Public, project and infrastructure finance 233 170 403 237 138 375 Structured finance 254 145 399 160 105 265 Total ratings revenue 1,806 1,104 2,910 1,624 903 2,527 MIS Other 3 28 31 1 29 30 Total MIS 1,809 1,132 2,941 1,625 932 2,557 MA: Research, data and analytics 576 723 1,299 492 618 1,110 Enterprise risk solutions 175 264 439 163 251 414 Total MA 751 987 1,738 655 869 1,524 Total MCO $ 2,560 $ 2,119 $ 4,679 $ 2,280 $ 1,801 $ 4,081 The following table presents the Company’s reportable segment revenues disaggregated by segment and geographic region: Three Months Ended Nine Months Ended 2021 2020 2021 2020 MIS: U.S. $ 580 $ 506 $ 1,809 $ 1,625 Non-U.S.: EMEA 211 188 707 542 Asia-Pacific 90 99 287 270 Americas 44 32 138 120 Total Non-U.S. 345 319 1,132 932 Total MIS 925 825 2,941 2,557 MA: U.S. 264 223 751 655 Non-U.S.: EMEA 228 213 691 595 Asia-Pacific 59 57 173 166 Americas 50 38 123 108 Total Non-U.S. 337 308 987 869 Total MA 601 531 1,738 1,524 Total MCO $ 1,526 $ 1,356 $ 4,679 $ 4,081 The following tables summarize the split between transaction and recurring revenue. In the MIS segment, excluding MIS Other, transaction revenue represents the initial rating of a new debt issuance as well as other one-time fees while recurring revenue represents the recurring monitoring fees of a rated debt obligation and/or entities that issue such obligations, as well as revenue from programs such as commercial paper, medium-term notes and shelf registrations. In MIS Other, transaction revenue represents revenue from professional services and recurring revenue represents subscription-based revenues. In the MA segment, recurring revenue represents subscription-based revenues and software maintenance revenue. Transaction revenue in MA represents perpetual software license fees and revenue from software implementation services, risk management advisory projects, and training and certification services. Three Months Ended September 30, 2021 2020 Transaction Recurring Total Transaction Recurring Total Corporate Finance $ 366 $ 122 $ 488 $ 347 $ 114 $ 461 75 % 25 % 100 % 75 % 25 % 100 % Financial Institutions $ 83 $ 70 $ 153 $ 67 $ 67 $ 134 54 % 46 % 100 % 50 % 50 % 100 % Public, Project and Infrastructure Finance $ 88 $ 42 $ 130 $ 92 $ 41 $ 133 68 % 32 % 100 % 69 % 31 % 100 % Structured Finance $ 93 $ 50 $ 143 $ 41 $ 47 $ 88 65 % 35 % 100 % 47 % 53 % 100 % MIS Other $ 1 $ 10 $ 11 $ 1 $ 8 $ 9 9 % 91 % 100 % 11 % 89 % 100 % Total MIS $ 631 $ 294 $ 925 $ 548 $ 277 $ 825 68 % 32 % 100 % 66 % 34 % 100 % Research, data and analytics $ 21 $ 424 $ 445 $ 19 $ 367 $ 386 5 % 95 % 100 % 5 % 95 % 100 % Enterprise risk solutions $ 15 $ 141 $ 156 $ 32 $ 113 $ 145 10 % 90 % 100 % 22 % 78 % 100 % Total MA $ 36 (1) $ 565 $ 601 $ 51 $ 480 $ 531 6 % 94 % 100 % 10 % 90 % 100 % Total Moody's Corporation $ 667 $ 859 $ 1,526 $ 599 $ 757 $ 1,356 44 % 56 % 100 % 44 % 56 % 100 % Nine Months Ended September 30, 2021 2020 Transaction Recurring Total Transaction Recurring Total Corporate Finance $ 1,280 $ 363 $ 1,643 $ 1,142 $ 344 $ 1,486 78 % 22 % 100 % 77 % 23 % 100 % Financial Institutions $ 252 $ 213 $ 465 $ 203 $ 198 $ 401 54 % 46 % 100 % 51 % 49 % 100 % Public, Project and Infrastructure Finance $ 276 $ 127 $ 403 $ 257 $ 118 $ 375 68 % 32 % 100 % 69 % 31 % 100 % Structured Finance $ 251 $ 148 $ 399 $ 126 $ 139 $ 265 63 % 37 % 100 % 48 % 52 % 100 % MIS Other $ 3 $ 28 $ 31 $ 3 $ 27 $ 30 10 % 90 % 100 % 10 % 90 % 100 % Total MIS $ 2,062 $ 879 $ 2,941 $ 1,731 $ 826 $ 2,557 70 % 30 % 100 % 68 % 32 % 100 % Research, data and analytics $ 63 $ 1,236 $ 1,299 $ 53 $ 1,057 $ 1,110 5 % 95 % 100 % 5 % 95 % 100 % Enterprise risk solutions $ 54 $ 385 $ 439 $ 90 $ 324 $ 414 12 % 88 % 100 % 22 % 78 % 100 % Total MA $ 117 (1) $ 1,621 $ 1,738 $ 143 $ 1,381 $ 1,524 7 % 93 % 100 % 9 % 91 % 100 % Total Moody's Corporation $ 2,179 $ 2,500 $ 4,679 $ 1,874 $ 2,207 $ 4,081 47 % 53 % 100 % 46 % 54 % 100 % (1) Revenue from software implementation services and risk management advisory projects, while classified by management as transactional revenue, is recognized over time under the Revenue Accounting Standard (please also refer to the following table). The following table presents the timing of revenue recognition: Three Months Ended September 30, 2021 Nine Months Ended September 30, 2021 MIS MA Total MIS MA Total Revenue recognized at a point in time $ 631 $ 29 $ 660 $ 2,062 $ 78 $ 2,140 Revenue recognized over time 294 572 866 879 1,660 2,539 Total $ 925 $ 601 $ 1,526 $ 2,941 $ 1,738 $ 4,679 Three Months Ended September 30, 2020 Nine Months Ended September 30, 2020 MIS MA Total MIS MA Total Revenue recognized at a point in time $ 548 $ 30 $ 578 $ 1,731 $ 89 $ 1,820 Revenue recognized over time 277 501 778 826 1,435 2,261 Total $ 825 $ 531 $ 1,356 $ 2,557 $ 1,524 $ 4,081 Unbilled receivables, deferred revenue and remaining performance obligations Unbilled receivables At September 30, 2021 and December 31, 2020, accounts receivable, net included $425 million and $361 million, respectively, of unbilled receivables, net related to the MIS segment. Certain MIS arrangements contain contractual terms whereby the customers are billed in arrears for annual monitoring services, requiring revenue to be accrued as an unbilled receivable as such services are provided. In addition, for certain MA arrangements, the timing of when the Company has the unconditional right to consideration and recognizes revenue occurs prior to invoicing the customer. Consequently, at September 30, 2021 and December 31, 2020, accounts receivable, net included $128 million and $98 million, respectively, of unbilled receivables, net related to the MA segment. Deferred revenue The Company recognizes deferred revenue when a contract requires a customer to pay consideration to the Company in advance of when revenue related to that contract is recognized. This deferred revenue is relieved when the Company satisfies the related performance obligation and revenue is recognized. Significant changes in the deferred revenue balances during the three and nine months ended September 30, 2021 and 2020 are as follows: Three Months Ended September 30, 2021 Three Months Ended September 30, 2020 MIS MA Total MIS MA Total Balance at June 30, $ 368 $ 867 $ 1,235 $ 365 $ 740 $ 1,105 Changes in deferred revenue Revenue recognized that was included in the deferred revenue balance at the beginning of the period (118) (484) (602) (118) (347) (465) Increases due to amounts billable excluding amounts recognized as revenue during the period 85 393 478 83 273 356 Increases due to acquisitions during the period — 89 89 — — — Effect of exchange rate changes (2) (12) (14) 5 19 24 Total changes in deferred revenue (35) (14) (49) (30) (55) (85) Balance at September 30, $ 333 $ 853 $ 1,186 $ 335 $ 685 $ 1,020 Nine Months Ended September 30, 2021 Nine Months Ended September 30, 2020 MIS MA Total MIS MA Total Balance at December 31, $ 313 $ 874 $ 1,187 $ 322 $ 840 $ 1,162 Changes in deferred revenue Revenue recognized that was included in the deferred revenue balance at the beginning of the period (200) (814) (1,014) (207) (781) (988) Increases due to amounts billable excluding amounts recognized as revenue during the period 224 713 937 219 607 826 Increases due to acquisitions during the period — 93 93 — 20 20 Effect of exchange rate changes (4) (13) (17) 1 (1) — Total changes in deferred revenue 20 (21) (1) 13 (155) (142) Balance at September 30, $ 333 $ 853 $ 1,186 $ 335 $ 685 $ 1,020 Deferred revenue - current $ 247 $ 852 $ 1,099 $ 237 $ 681 918 Deferred revenue - non-current $ 86 $ 1 $ 87 $ 98 $ 4 102 For the MIS segment, the changes in the deferred revenue balance during the three and nine months ended September 30, 2021 were primarily related to the significant portion of contract renewals that occur during the first quarter of each year and are generally recognized over a one-year period. For the MA segment, the decrease in deferred revenue for the three months ended September 30, 2021 was primarily due to the recognition of annual subscription and maintenance billings from December 2020 and January 2021. For the nine months ended September 30, 2021, the decrease in the deferred revenue balance is attributable to recognition of revenues related to the aforementioned December 2020 billings being partially offset by the impact of the high concentration of January 2021 billings. Remaining performance obligations Remaining performance obligations in the MIS segment largely reflect deferred revenue related to monitoring fees for certain structured finance products, primarily CMBS, where the issuers can elect to pay the monitoring fees for the life of the security in advance. As of September 30, 2021, the aggregate amount of the transaction price allocated to remaining performance obligations was approximately $120 million. The Company expects to recognize into revenue approximately 20% of this balance within one year, approximately 50% of this balance between one to five years and the remaining amount thereafter. With respect to the remaining performance obligations for the MIS segment, the Company has applied a practical expedient set forth in ASC Topic 606 permitting the omission from the amounts stated above relating to unsatisfied performance obligations for contracts with an original expected length of one year or less. Remaining performance obligations in the MA segment include both amounts recorded as deferred revenue on the balance sheet as of September 30, 2021 as well as amounts not yet invoiced to customers as of September 30, 2021, largely reflecting future revenue related to signed multi-year arrangements for hosted and installed subscription-based products. As of September 30, 2021, the aggregate amount of the transaction price allocated to remaining performance obligations was approximately $2.7 billion. The Company expects to recognize into revenue approximately 65% of this balance within one year, approximately 25% of this balance between one to two years and the remaining amount thereafter.

STOCK-BASED COMPENSATION

STOCK-BASED COMPENSATION	9 Months Ended
	Sep. 30, 2021
Share-based Payment Arrangement, Noncash Expense [Abstract]
STOCK-BASED COMPENSATION	STOCK-BASED COMPENSATION Presented below is a summary of the stock-based compensation cost and associated tax benefit included in the accompanying consolidated statements of operations: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Stock-based compensation cost $ 41 $ 38 $ 127 $ 110 Tax benefit $ 8 $ 8 $ 29 $ 22 On September 15, 2021, the Company acquired RMS, which is discussed in more detail in Note 8. As part of the acquisition, certain RMS employees' unvested equity awards (employee stock options and restricted stock) with an acquisition-date fair value of $32 million were converted into equity awards of the Company based on an exchange ratio as defined in the purchase agreement. The portion of the fair value of the replacement awards related to services provided prior to the acquisition was $5 million and was accounted for as consideration transferred (See Note 8). The remaining portion of the replacement awards of $27 million, which is associated with a future service requirement, will be recognized as compensation expense over the remaining vesting period. Moody's has reserved 1.2 million shares of the Company's common stock for issuance under the acquired RMS equity compensation plans. During the first nine months of 2021, the Company granted 0.2 million employee stock options (including RMS replacement option awards), which had a weighted average grant date fair value of $113.91 per share. The Company also granted 0.6 million shares of restricted stock in the first nine months of 2021 (including RMS replacement restricted stock awards), which had a weighted average grant date fair value of $286.08 per share. Both the employee stock options and restricted stock generally vest ratably over four years. Additionally, the Company granted 0.1 million shares of performance-based awards whereby the number of shares that ultimately vest are based on the achievement of certain non-market-based performance metrics of the Company over three years. The weighted average grant date fair value of these awards was $269.88 per share. The following weighted average assumptions were used in determining the fair value using the Black-Scholes option-pricing model for options granted in 2021 (excluding the aforementioned RMS replacement awards): Expected dividend yield 0.89 % Expected stock volatility 28 % Risk-free interest rate 0.81 % Expected holding period 5.6 years Due to the RMS replacement option awards being heavily in-the-money at the acquisition date, the Company utilized a binomial valuation approach to determine the fair value of the options, which approximated the intrinsic value of the replaced awards at the acquisition date. Unrecognized stock-based compensation expense at September 30, 2021 was $25 million and $211 million for stock options and unvested restricted stock, respectively, which is expected to be recognized over a weighted average period of 2.3 years and 2.5 years, respectively. Additionally, there was $35 million of unrecognized stock-based compensation expense relating to the aforementioned non-market-based performance-based awards, which is expected to be recognized over a weighted average period of 2.0 years. The following tables summarize information relating to stock option exercises and restricted stock vesting: Nine Months Ended 2021 2020 Exercise of stock options: Proceeds from stock option exercises $ 20 $ 32 Aggregate intrinsic value $ 44 $ 102 Tax benefit realized upon exercise $ 11 $ 24 Number of shares exercised 0.2 0.5 Vesting of restricted stock: Fair value of shares vested $ 193 $ 195 Tax benefit realized upon vesting $ 45 $ 45 Number of shares vested 0.7 0.8 Vesting of performance-based restricted stock: Fair value of shares vested $ 28 $ 70 Tax benefit realized upon vesting $ 7 $ 17 Number of shares vested 0.1 0.3

INCOME TAXES

INCOME TAXES	9 Months Ended
	Sep. 30, 2021
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES Moody’s effective tax rate was 23.4% and 22.0% for the three months ended September 30, 2021 and 2020, respectively and 20.2% and 20.0% for the nine months ended September 30, 2021 and 2020. The Company’s year-to-date tax expense differs from the tax computed by applying its estimated annual effective tax rate to the year-to-date pre-tax earnings primarily due to Excess Tax Benefits from stock-based compensation of $29 million and net reductions in UTPs of $66 million related to a settlement and a lapse of a statute of limitations. The Company classifies interest related to UTPs in interest expense, net in its consolidated statements of operations. Penalties, if incurred, would be recognized in other non-operating (expense) income, net. The Company had an increase in its UTPs of $85 million ($84 million net of federal tax) during the third quarter of 2021 and an increase in its UTPs of $9 million ($17 million, net of federal tax) during the first nine months of 2021. The increase in both periods included UTPs assumed in the acquisition of RMS. The increase in the year-to-date period was partially offset by a tax settlement and a statute of limitation lapse in the first quarter of 2021. The Company also reversed $40 million in accrued interest in connection with these matters in the first quarter of 2021. Moody’s Corporation and subsidiaries are subject to U.S. federal income tax as well as income tax in various state, local and foreign jurisdictions. The Company’s U.S. federal income tax returns for 2017 and 2018 are currently under examination and 2019 through 2020 remain open to examination. The Company’s New York State tax returns for 2017 through 2018 are currently under examination and New York City tax returns for 2014 through 2017 are currently under examination. For ongoing audits, it is possible the balance of UTPs could decrease in the next twelve months as a result of the settlement of these audits, which might involve the payment of additional taxes, the adjustment of certain deferred taxes and/or the recognition of tax benefits. It is also possible that new issues might be raised by tax authorities which could necessitate increases to the balance of UTPs. As the Company is unable to predict the timing or outcome of these audits, it is therefore unable to estimate the amount of changes to the balance of UTPs at this time. However, the Company believes that it has adequately provided for its financial exposure relating to all open tax years by tax jurisdiction in accordance with the applicable provisions of Topic 740 of the ASC regarding UTPs. The following table shows the amount the Company paid for income taxes: Nine Months Ended September 30, 2021 2020 Income taxes paid $ 501 $ 374

WEIGHTED AVERAGE SHARES OUTSTAN

WEIGHTED AVERAGE SHARES OUTSTANDING	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
WEIGHTED AVERAGE SHARES OUTSTANDING	WEIGHTED AVERAGE SHARES OUTSTANDING Below is a reconciliation of basic to diluted shares outstanding: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Basic 186.0 187.8 186.6 187.6 Dilutive effect of shares issuable under stock-based compensation plans 1.3 1.5 1.4 1.7 Diluted 187.3 189.3 188.0 189.3 Anti-dilutive options to purchase common shares and restricted stock as well as contingently issuable restricted stock which are excluded from the table above 0.1 0.3 0.2 0.3 The calculation of diluted EPS requires certain assumptions regarding the use of both cash proceeds and assumed proceeds that would be received upon the exercise of stock options and vesting of restricted stock outstanding as of September 30, 2021 and 2020.

CASH EQUIVALENTS AND INVESTMENT

CASH EQUIVALENTS AND INVESTMENTS	9 Months Ended
	Sep. 30, 2021
Cash and Cash Equivalents [Abstract]
CASH EQUIVALENTS AND INVESTMENTS	CASH EQUIVALENTS AND INVESTMENTS The table below provides additional information on the Company’s cash equivalents and investments: As of September 30, 2021 Balance sheet location Cost Gains/(Losses) Fair Value Cash and cash equivalents Short-term Other Certificates of deposit and money market deposit accounts (1) $ 1,004 $ — $ 1,004 $ 891 $ 104 $ 9 Mutual funds $ 50 $ 8 $ 58 $ — $ — $ 58 As of December 31, 2020 Balance sheet location Cost Gains/(Losses) Fair Value Cash and cash Short-term Other Certificates of deposit and money market deposit accounts (1) $ 1,430 $ — $ 1,430 $ 1,325 $ 99 $ 6 Mutual funds $ 54 $ 6 $ 60 $ — $ — $ 60 (1) Consists of time deposits and money market deposit accounts. The remaining contractual maturities for the certificates of deposits classified as short-term investments were one month to 12 months at both September 30, 2021 and December 31, 2020. The remaining contractual maturities for the certificates of deposits classified in other assets are 13 months to 24 months at September 30, 2021 and 13 months to 23 months at December 31, 2020. Time deposits with a maturity of less than 90 days at time of purchase are classified as cash and cash equivalents. In addition, the Company invested in Corporate-Owned Life Insurance (COLI) in the first quarter of 2020. As of September 30, 2021 and December 31, 2020, the contract value of the COLI was $35 million and $17 million, respectively.

ACQUISITIONS

ACQUISITIONS	9 Months Ended
	Sep. 30, 2021
Business Combination and Asset Acquisition [Abstract]
ACQUISITIONS	ACQUISITIONS The business combinations described below are accounted for using the acquisition method of accounting whereby assets acquired and liabilities assumed were recognized at fair value on the date of the transaction. Any excess of the purchase price over the fair value of the assets acquired and liabilities assumed was recorded to goodwill. Goodwill typically results through expected synergies from combining operations of an acquiree and an acquirer, anticipated new customer acquisition and products, as well as from intangible assets that do not qualify for separate recognition. RMS On September 15, 2021, the Company acquired 100% of RMS, a global provider of climate and natural disaster risk modeling and analytics. The cash payment was funded with new debt financing and a combination of U.S. and offshore cash on hand. The acquisition will expand Moody’s insurance data and analytics business and accelerate the development of the Company’s global integrated risk capabilities to address the next generation of risk assessment. The table below details the total consideration relating to the acquisition: Cash paid at closing $ 1,931 Replacement equity compensation awards 5 Total consideration $ 1,936 Shown below is the preliminary purchase price allocation, which summarizes the fair value of the assets and liabilities assumed, at the date of acquisition: Cash $ 60 Accounts receivable 38 Other current assets 11 Property and equipment, net 13 Operating lease right-of-use assets 64 Intangible assets: Customer relationships (23 year useful life) 523 Product technology (7 year useful life) 212 Trade name (9 year useful life) 49 Total intangible assets (18 year weighted average useful life) 784 Goodwill 1,389 Deferred tax assets, net 46 Other assets 92 Liabilities: Accounts payable and accrued liabilities (101) Deferred revenue (89) Operating lease liabilities (68) Deferred tax liabilities, net (213) Uncertain tax positions (90) Total liabilities (561) Net assets acquired $ 1,936 The Company has performed a preliminary valuation analysis of the fair market value of assets and liabilities of the RMS business. The final purchase price allocation will be determined when the Company has completed and fully reviewed all information necessary to finalize the fair value of the acquired assets and liabilities, including deferred revenue. The final allocation could differ materially from the preliminary allocation. The final allocation may include changes in allocations to acquired intangible assets (including estimated useful lives of these assets) as well as goodwill and other changes to assets and liabilities including reserves for UTPs and deferred tax liabilities. Goodwill The goodwill recognized as a result of this acquisition includes, among other things, the value of combining the complementary product portfolios of Moody's and RMS, which is expected to extend the Company's reach into new market segments. The goodwill also includes the combined company's ability to accelerate technology innovations into new product adjacencies (leveraging RMS's team of data scientists, modelers and software engineers) as well as combining RMS's products with Moody’s core data and analytics offerings to provide holistic integrated risk solutions. Goodwill, of which $1,299 million and $90 million has been assigned to the MA and MIS segments, respectively, is not deductible for tax purposes. The amount of goodwill allocated to the MIS segment relates to the integration of certain of RMS's models/processes into the Company's ESG solutions offerings. Other assets in the table above includes an indemnification asset of $88 million related to uncertain tax positions assumed in the transaction, for which the Company expects to be indemnified by the sellers in the event of an unfavorable outcome. Transaction costs Transaction costs directly related to the RMS acquisition were $22 million and were recorded in SG&A expenses in the statement of operations. Supplementary Unaudited Pro Forma Information Supplemental information on an unaudited pro forma basis is presented below for the nine months ended September 30, 2021 and 2020 as if the acquisition of RMS occurred on January 1, 2020. The pro forma financial information is presented for comparative purposes only, based on certain estimates and assumptions, which the Company believes to be reasonable but not necessarily indicative of future results of operations or the results that would have been reported if the acquisition had been completed at January 1, 2020. The unaudited pro forma information includes amortization of acquired intangible assets, based on the preliminary purchase price allocation and an estimate of useful lives reflected above, and incremental financing costs resulting from the acquisition, net of income tax, which was estimated using the weighted average statutory tax rates in effect in the jurisdiction for which the pro forma adjustment relates. Nine Months Ended 2021 2020 Pro forma Revenue $ 4,910 $ 4,300 Pro forma Net Income attributable to Moody's $ 1,807 $ 1,342 The unaudited pro forma results do not include any anticipated cost savings or other effects of the planned integration of RMS. Accordingly, the pro forma results above are not necessarily indicative of the results that would have been reported if the acquisition had occurred on the dates indicated, nor are the pro forma results indicative of results which may occur in the future. The RMS results included in the above have been converted to U.S. GAAP from IFRS as issued by the IASB and have been translated to USD at rates in effect for the periods presented. The RMS amounts in the pro forma results include an addition to revenue of approximately $3 million and a reduction to revenue of approximately $21 million relating to a fair value adjustment to deferred revenue required as part of acquisition accounting for the nine months ended September 30, 2021 and 2020, respectively. The following acquisitions occurred prior to the third quarter 2021 and the Company has not presented pro forma combined results for these acquisitions because the impact on previously reported statements of operations would not have been material. Additionally, the near term impact to the Company’s operations and cash flows is not material. Cortera On March 19, 2021, the Company acquired 100% of Cortera, a provider of North American credit data and workflow solutions. The table below details the total consideration relating to the acquisition: Cash paid at closing $ 138 Additional consideration paid to sellers in 2021 (1) 1 Total consideration $ 139 (1) Represents additional consideration paid to the sellers following finalization of customary post-closing completion adjustments. Shown below is the preliminary purchase price allocation, which summarizes the fair value of the assets and liabilities assumed, at the date of acquisition: Current assets $ 7 Intangible assets: Database (10 year useful life) $ 38 Customer relationships (18 year useful life) 9 Product technology (8 year useful life) 9 Trade name (5 year useful life) 1 Total intangible assets (11 year weighted average useful life) 57 Goodwill (1) 79 Deferred tax assets (1) 16 Other assets 2 Liabilities: Accounts payable and accrued liabilities $ (1) Deferred revenue (4) Deferred tax liabilities (15) Other liabilities (2) Total liabilities (22) Net assets acquired $ 139 (1) During the third quarter of 2021, the Company received further information, that existed as of the acquisition date, with respect to Cortera’s deferred taxes. Accordingly, the Company recorded a measurement period adjustment of $16 million to its preliminary estimate for deferred tax assets. The Company has performed a preliminary valuation analysis of the fair market value of assets and liabilities of the Cortera business. The final purchase price allocation will be determined when the Company has completed and fully reviewed the detailed valuations. The final allocation could differ materially from the preliminary allocation. The final allocation may include changes in allocations to acquired intangible assets as well as goodwill and other changes to assets and liabilities including reserves for UTPs and deferred tax liabilities. The estimated useful lives of acquired intangibles assets are also preliminary. Current assets in the table above include acquired cash of $4 million and accounts receivable of approximately $2 million. Goodwill The goodwill recognized as a result of this acquisition includes, among other things, the value of combining the complementary risk assessment products of the Company and Cortera, which is expected to extend the Company’s reach to new and evolving market segments as well as cost savings synergies, expected new customer acquisitions and products. Goodwill, which has been assigned to the MA segment, is not deductible for tax purposes. Transaction costs Transaction costs directly related to the Cortera acquisition were not material. RDC On February 13, 2020, the Company acquired 100% of RDC, a provider of anti-money laundering and know-your-customer data and due diligence services. The table below details the total consideration relating to the acquisition: Cash paid at closing $ 700 Additional consideration paid to sellers in 2020 (1) 2 Total consideration $ 702 (1) Represents additional consideration paid to the sellers following finalization of customary post-closing completion adjustments. Shown below is the purchase price allocation, which summarizes the fair value of the assets and liabilities assumed, at the date of acquisition: Current assets $ 24 Intangible assets: Customer relationships (25 year useful life) $ 174 Database (10 year useful life) 86 Product technology (4 year useful life) 17 Trade name (3 year useful life) 3 Total intangible assets (19 year weighted average life) 280 Goodwill 494 Other assets 2 Liabilities: Accounts payable and accrued liabilities $ (5) Deferred revenue (20) Deferred tax liabilities (71) Other liabilities (2) Total liabilities (98) Net assets acquired $ 702 Current assets in the table above include acquired cash of $6 million and accounts receivable of approximately $14 million. Goodwill The goodwill recognized as a result of this acquisition includes, among other things, the value of combining the complementary product portfolios of the Company and RDC, which is expected to extend the Company’s reach to new and evolving market segments as well as cost savings synergies, expected new customer acquisitions and products. Goodwill, which has been assigned to the MA segment, is not deductible for tax purposes. Transaction costs Transaction costs directly related to the RDC acquisition were not material.

DERIVATIVE INSTRUMENTS AND HEDG

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES	9 Months Ended
	Sep. 30, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES	DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES The Company is exposed to global market risks, including risks from changes in FX rates and changes in interest rates. Accordingly, the Company uses derivatives in certain instances to manage the aforementioned financial exposures that occur in the normal course of business. The Company does not hold or issue derivatives for speculative purposes. Derivatives and non-derivative instruments designated as accounting hedges: Fair Value Hedges Interest Rate Swaps The Company has entered into interest rate swaps to convert the fixed interest rate on certain of its long-term debt to a floating interest rate based on the 3-month LIBOR and 6-month LIBOR. The purpose of these hedges is to mitigate the risk associated with changes in the fair value of the long-term debt, thus the Company has designated these swaps as fair value hedges. The fair value of the swaps is adjusted quarterly with a corresponding adjustment to the carrying value of the debt. The changes in the fair value of the swaps and the underlying hedged item generally offset and the net cash settlements on the swaps are recorded each period within interest expense, net in the Company’s consolidated statements of operations. The following table summarizes the Company’s interest rate swaps designated as fair value hedges: Notional Amount Hedged Item Nature of Swap As of September 30, 2021 As of December 31, 2020 Floating Interest Rate 2012 Senior Notes due 2022 Pay Floating/Receive Fixed $ 330 $ 330 3-month USD LIBOR 2017 Senior Notes due 2023 Pay Floating/Receive Fixed $ 250 $ 250 3-month USD LIBOR 2017 Senior Notes due 2028 Pay Floating/Receive Fixed $ 500 $ 500 3-month USD LIBOR 2020 Senior Notes due 2025 Pay Floating/Receive Fixed $ 300 $ 300 6-month USD LIBOR 2014 Senior Notes due 2044 Pay Floating/Receive Fixed $ 300 $ — 3-month USD LIBOR 2018 Senior Notes due 2048 Pay Floating/Receive Fixed $ 300 $ — 3-month USD LIBOR Total $ 1,980 $ 1,380 Refer to Note 16 for information on the cumulative amount of fair value hedging adjustments included in the carrying amount of the above hedged items. The following table summarizes the impact to the statements of operations of the Company’s interest rate swaps designated as fair value hedges: Total amounts of financial statement line item presented in the statements of operations in which the effects of fair value hedges are recorded Amount of income/(loss) recognized in the consolidated statements of operations Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Interest expense, net $ (53) $ (53) $ (109) $ (153) Descriptions Location on Consolidated Statements of Operations Net interest settlements and accruals on interest rate swaps Interest expense, net $ 6 $ 6 $ 17 $ 14 Fair value changes on interest rate swaps Interest expense, net $ (16) $ (7) $ (40) $ 53 Fair value changes on hedged debt Interest expense, net $ 16 $ 7 $ 40 $ (53) Net investment hedges Debt designated as net investment hedges The Company has designated €500 million of the 2015 Senior Notes Due 2027 and €750 million of the 2019 Senior Notes due 2030 as net investment hedges to mitigate FX exposure related to a portion of the Company’s euro net investment in certain foreign subsidiaries against changes in euro/USD exchange rates. These hedges are designated as accounting hedges under the applicable sections of ASC Topic 815 and will end upon the repayment of the notes in 2027 and 2030, respectively, unless terminated early at the discretion of the Company. Cross currency swaps designated as net investment hedges The Company enters into cross-currency swaps to mitigate FX exposure related to a portion of the Company’s euro net investment in certain foreign subsidiaries against changes in euro/USD exchange rates. The following table provides information on the cross-currency swaps designated as net investment hedges under ASC Topic 815: September 30, 2021 Pay Receive Nature of Swap Notional Amount Weighted Average Interest Rate Notional Amount Weighted Average Interest Rate Pay Fixed/Receive Fixed € 1,060 2.15% $ 1,220 4.45% Pay Floating/Receive Floating 1,466 Based on 3-month EURIBOR 1,680 Based on 3-month USD LIBOR Total € 2,526 $ 2,900 December 31, 2020 Pay Receive Nature of Swap Notional Amount Weighted Average Interest Rate Notional Amount Weighted Average Interest Rate Pay Fixed/Receive Fixed € 1,079 1.43% $ 1,220 3.96% Pay Floating/Receive Floating 959 Based on 3-month EURIBOR 1,080 Based on 3-month USD LIBOR Total € 2,038 $ 2,300 As of September 30, 2021 these hedges will expire and the notional amounts will be settled as follows unless terminated early at the discretion of the Company: Years Ending December 31, 2022 € 438 2023 € 442 2024 € 443 2026 € 450 2027 € 246 2028 € 507 Total € 2,526 Forward contracts designated as net investment hedges The Company also entered into forward contracts to mitigate FX exposure related to a portion of the Company’s euro net investment in certain foreign subsidiaries against changes in euro/USD and GBP/euro exchange rates. The following table summarizes the notional amounts of the Company's outstanding forward contracts that were designated as net investment hedges: Notional amount of net investment hedges September 30, 2021 December 31, 2020 Sell Buy Sell Buy Contract to sell EUR for USD € — $ — € 524 $ 627 Contract to sell GBP for EUR £ — € — £ 134 € 148 These forward contracts expired in August 2021. Cash Flow Hedges Interest Rate Forward Contracts In January 2020, the Company entered into $300 million notional amount treasury rate locks with an average locked-in U.S. 30-year Treasury rate of 2.0103%, which were designated as cash flow hedges and used to manage the Company’s interest rate risk during the period prior to an anticipated issuance of 30-year debt. The treasury lock interest rate forward contracts matured on April 30, 2020, resulting in a cumulative loss of $68 million, which was recognized in AOCL. The loss on the Treasury rate lock will be reclassified from AOCL to earnings in the same period that the hedged transaction (i.e. interest payments on the 3.25% 2020 Senior Notes, due 2050) impacts earnings. The following tables provide information on the gains/(losses) on the Company’s net investment and cash flow hedges: Derivative and Non-Derivative Instruments in Net Investment Hedging Relationships Amount of Gain/(Loss) Recognized in AOCL on Derivative, net of Tax Amount of Gain/(Loss) Reclassified from AOCL into Income, net of Tax Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing) Three Months Ended Three Months Ended Three Months Ended 2021 2020 2021 2020 2021 2020 FX forward contracts $ 2 $ 1 $ — $ — $ — $ — Cross currency swaps 44 (98) — — 8 10 Long-term debt 26 (46) — — — — Total net investment hedges $ 72 $ (143) $ — $ — $ 8 $ 10 Derivatives in Cash Flow Hedging Relationships Interest rate contracts 1 (1) (1) (1) — — Total cash flow hedges 1 (1) (1) (1) — — Total $ 73 $ (144) $ (1) $ (1) $ 8 $ 10 Derivative and Non-Derivative Instruments in Net Investment Hedging Relationships Amount of Gain/(Loss) Recognized in AOCL on Derivative, net of Tax Amount of Gain/(Loss) Reclassified from AOCL into Income, net of Tax Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing) Nine Months Ended September 30, Nine Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 2021 2020 FX forward contracts $ 18 $ 1 $ 1 $ — $ — $ — Cross currency swaps 98 (81) — — 27 40 Long-term debt 61 (47) — — — — Total net investment hedges $ 177 $ (127) $ 1 $ — $ 27 $ 40 Derivatives in Cash Flow Hedging Relationships Interest rate contracts — (51) (2) (2) — — Total cash flow hedges — (51) (2) (2) — — Total $ 177 $ (178) $ (1) $ (2) $ 27 $ 40 The cumulative amount of net investment hedge and cash flow hedge gains (losses) remaining in AOCL is as follows: Cumulative Gains/(Losses), net of tax September 30, 2021 December 31, 2020 Net investment hedges Cross currency swaps $ (26) $ (124) FX forwards 29 12 Long-term debt (47) (108) Total net investment hedges $ (44) $ (220) Cash flow hedges Interest rate contracts $ (49) $ (51) Cross currency swaps 2 2 Total cash flow hedges (47) (49) Total net loss in AOCL $ (91) $ (269) Derivatives not designated as accounting hedges: Foreign exchange forwards The Company also enters into foreign exchange forward contracts to mitigate the change in fair value on certain assets and liabilities denominated in currencies other than a subsidiary’s functional currency. These forward contracts are not designated as accounting hedges under the applicable sections of Topic 815 of the ASC. Accordingly, changes in the fair value of these contracts are recognized immediately in other non-operating income, net in the Company’s consolidated statements of operations along with the FX gain or loss recognized on the assets and liabilities denominated in a currency other than the subsidiary’s functional currency. These contracts have expiration dates at various times through January 2022. The following table summarizes the notional amounts of the Company’s outstanding foreign exchange forwards: September 30, 2021 December 31, 2020 Notional amount of currency pair: Sell Buy Sell Buy Contracts to sell USD for GBP $ 190 £ 138 $ 295 £ 222 Contracts to sell USD for Japanese yen $ 18 ¥ 2,000 $ 15 ¥ 1,600 Contracts to sell USD for Canadian dollars $ 120 C$ 150 $ 107 C$ 140 Contracts to sell USD for Singapore dollars $ 66 S$ 90 $ 59 S$ 79 Contracts to sell USD for euros $ 282 € 240 $ 447 € 376 Contracts to sell Euros for GBP € — £ — € 135 £ 121 Contracts to sell USD for Russian ruble $ 13 ₽ 1,000 $ 13 ₽ 1,000 Contracts to sell USD for Indian rupee $ 18 ₹ 1,350 $ 18 ₹ 1,350 NOTE: € = euro, £ = British pound, $ = U.S. dollar, ¥ = Japanese yen, C$ = Canadian dollar, S$= Singapore dollars, ₽ = Russian ruble, ₹= Indian rupee The following table summarizes the impact to the consolidated statements of operations relating to the net losses on the Company’s derivatives which are not designated as hedging instruments: Derivatives not designated as accounting hedges Location on Consolidated Statements of Operations Three Months Ended Nine Months Ended 2021 2020 2021 2020 Foreign exchange forwards Other non-operating income, net $ (18) $ 36 $ (25) $ 1 Foreign exchange forwards relating to RMS acquisition (1) Other non-operating income, net $ (13) $ — $ (13) $ — (1) The Company entered into a forward contract to sell $1,675 million for €1,200 to hedge a portion of the GBP denominated RMS purchase price. The contract was terminated on September 14, 2021 and resulted in a $13 million loss. The table below shows the classification between assets and liabilities on the Company’s consolidated balance sheets for the fair value of the derivative instrument as well as the carrying value of its non-derivative debt instruments designated and qualifying as net investment hedges: Derivative and Non-Derivative Instruments Balance Sheet Location September 30, 2021 December 31, 2020 Assets: Derivatives designated as accounting hedges: Cross-currency swaps designated as net investment hedges Other current assets $ 2 $ — Cross-currency swaps designated as net investment hedges Other assets 26 — Interest rate swaps designated as fair value hedges Other current assets 8 — Interest rate swaps designated as fair value hedges Other assets 23 57 Total derivatives designated as accounting hedges 59 57 Derivatives not designated as accounting hedges: FX forwards on certain assets and liabilities Other current assets — 31 Total assets $ 59 $ 88 Liabilities: Derivatives designated as accounting hedges: FX forwards designated as net investment hedges Accounts payable and accrued liabilities $ — $ 16 Cross-currency swaps designated as net investment hedges Accounts payable and accrued liabilities 7 23 Cross-currency swaps designated as net investment hedges Other liabilities 32 144 Interest rate swaps designated as fair value hedges Other liabilities 14 1 Total derivatives designated as accounting hedges 53 184 Non-derivatives designated as accounting hedges: Long-term debt designated as net investment hedge Long-term debt 1,448 1,530 Derivatives not designated as accounting hedges: FX forwards on certain assets and liabilities Accounts payable and accrued liabilities 10 2 Total liabilities $ 1,511 $ 1,716

GOODWILL AND OTHER ACQUIRED INT

GOODWILL AND OTHER ACQUIRED INTANGIBLE ASSETS	9 Months Ended
	Sep. 30, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL AND OTHER ACQUIRED INTANGIBLE ASSETS	GOODWILL AND OTHER ACQUIRED INTANGIBLE ASSETS The following table summarizes the activity in goodwill for the periods indicated: Nine Months Ended September 30, 2021 MIS MA Consolidated Gross goodwill Accumulated impairment Net Gross goodwill Accumulated Net Gross goodwill Accumulated Net Balance at beginning $ 311 $ — $ 311 $ 4,257 $ (12) $ 4,245 $ 4,568 $ (12) $ 4,556 Additions/ adjustments (1) 90 — 90 1,388 — 1,388 1,478 — 1,478 Foreign currency translation adjustments (5) — (5) (131) — (131) (136) — (136) Ending balance $ 396 $ — $ 396 $ 5,514 $ (12) $ 5,502 $ 5,910 $ (12) $ 5,898 Year Ended December 31, 2020 MIS MA Consolidated Gross goodwill Accumulated impairment charge Net goodwill Gross goodwill Accumulated impairment charge Net goodwill Gross goodwill Accumulated impairment charge Net goodwill Balance at beginning $ 315 $ — $ 315 $ 3,419 $ (12) $ 3,407 $ 3,734 $ (12) $ 3,722 Additions/ adjustments (2) (2) — (2) 628 — 628 626 — 626 Foreign currency translation (2) — (2) 210 — 210 208 — 208 Ending balance $ 311 $ — $ 311 $ 4,257 $ (12) $ 4,245 $ 4,568 $ (12) $ 4,556 (1) The 2021 additions/adjustments for the MA segment in the table above primarily relate to the acquisition of Cortera and RMS. The 2021 additions/adjustments for the MIS segment relate to certain revenue synergies from the RMS acquisition that are expected to benefit the ESG solutions group within the MIS Other LOB. (2) The 2020 additions/adjustments for the MA segment in the table above relate to the acquisitions of RDC, AM, ZMFS, and Catylist. Acquired intangible assets and related amortization consisted of: September 30, December 31, Customer relationships $ 2,108 $ 1,623 Accumulated amortization (360) (313) Net customer relationships 1,748 1,310 Software/product technology 654 441 Accumulated amortization (203) (177) Net software/product technology 451 264 Database 180 144 Accumulated amortization (42) (29) Net database 138 115 Trade names 207 161 Accumulated amortization (44) (38) Net trade names 163 123 Other (1) 54 55 Accumulated amortization (44) (43) Net other 10 12 Total acquired intangible assets, net $ 2,510 $ 1,824 (1) Other intangible assets primarily consist of trade secrets, covenants not to compete, and acquired ratings methodologies and models. Amortization expense relating to acquired intangible assets is as follows: Three Months Ended Nine Months Ended 2021 2020 2021 2020 Amortization expense $ 37 $ 31 $ 108 $ 90 Estimated future amortization expense for acquired intangible assets subject to amortization is as follows: Year Ending December 31, 2021 (After September 30,) $ 49 2022 194 2023 191 2024 187 2025 182 Thereafter 1,707 Total estimated future amortization $ 2,510 Matters concerning the ICRA reporting unit ICRA has reported various matters relating to: (i) an adjudication order and fine imposed by the Securities and Exchange Board of India (SEBI) in connection with credit ratings assigned to one of ICRA’s customers and the customer’s subsidiaries, which are being appealed by ICRA; (ii) an increase in the original fine, which also is being appealed by ICRA; (iii) the completion of internal examinations regarding various anonymous complaints; and (iv) actions taken by ICRA’s board based on the examinations’ findings. As of the date of this quarterly report on Form 10-Q, the Company is unable to estimate the financial impact, if any, that may result from a potential unfavorable conclusion of these matters or any other ICRA inquiry. An unfavorable resolution of such matters may negatively impact ICRA’s future operating results, which could result in an impairment of goodwill and amortizable intangible assets in future quarters.

RESTRUCTURING

RESTRUCTURING	9 Months Ended
	Sep. 30, 2021
Restructuring and Related Activities [Abstract]
RESTRUCTURING	RESTRUCTURING On July 29, 2020, the chief executive officer of Moody’s approved a restructuring program (the “2020 Real Estate Rationalization Restructuring Program”) primarily in response to the COVID-19 pandemic which revolves around the rationalization and exit of certain real estate leases. The exit from certain leased office space began in the third quarter of 2020 and was substantially completed at December 31, 2020. The 2020 Restructuring Program primarily reflects non-cash charges related to the impairment of operating lease right-of-use assets and leasehold improvements. The 2020 Restructuring Program is expected to result in an estimated annualized savings of approximately $5 to $6 million a year. On December 22, 2020, the chief executive officer of Moody’s approved a restructuring program (the “2020 MA Strategic Reorganization Restructuring Program”) that the Company estimates will result in annualized savings of $20 million per year. This program relates to a strategic reorganization in the MA reportable segment consisting of severance and related costs primarily determined under the Company’s existing severance plans. The 2020 MA Strategic Reorganization Restructuring Program resulted in a total of $20 million in pre-tax charges and was substantially complete at June 30, 2021. Cash outlays associated with this program are expected to be $20 million, which will be paid through 2022. Total expense included in the accompanying consolidated statements of operations relating to the aforementioned restructuring program is below: Three Months Ended Nine Months Ended 2021 2020 2021 2020 2018 Restructuring Program $ — $ — $ — $ (3) 2020 Real Estate Rationalization Restructuring Program — 23 — 23 2020 MA Strategic Reorganization Restructuring Program — — 2 — Total Restructuring $ — $ 23 $ 2 $ 20 Changes to the restructuring liability for the aforementioned restructuring program during the first nine months of 2021 were as follows: Employee Termination Costs Balance as of December 31, 2020 $ 18 2020 MA Strategic Reorganization Restructuring Program: Cost incurred and adjustments 2 Cash payments and adjustments (12) Balance as of September 30, 2021 $ 8 Cumulative expense incurred to date 2020 Real Estate Rationalization Restructuring Program $ 36 2020 MA Strategic Reorganization Restructuring Program $ 20

FAIR VALUE

FAIR VALUE	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
FAIR VALUE	FAIR VALUE The table below presents information about items that are carried at fair value at September 30, 2021 and December 31, 2020: Fair value Measurement as of September 30, 2021 Description Balance Level 1 Level 2 Assets: Derivatives (1) $ 59 $ — $ 59 Mutual funds 58 58 — Total $ 117 $ 58 $ 59 Liabilities: Derivatives (1) $ 63 $ — $ 63 Total $ 63 $ — $ 63 Fair value Measurement as of December 31, 2020 Description Balance Level 1 Level 2 Assets: Derivatives (1) $ 88 $ — $ 88 Mutual funds 60 60 — Total $ 148 $ 60 $ 88 Liabilities: Derivatives (1) $ 186 $ — $ 186 Total $ 186 $ — $ 186 (1) Represents FX forward contracts, interest rate swaps and cross-currency swaps as more fully described in Note 9 to the condensed consolidated financial statements. The following are descriptions of the methodologies utilized by the Company to estimate the fair value of its derivative contracts, mutual funds and money market mutual funds: Derivatives: In determining the fair value of the derivative contracts in the table above, the Company utilizes industry standard valuation models. Where applicable, these models project future cash flows and discount the future amounts to a present value using spot rates, forward points, currency volatilities, interest rates as well as the risk of non-performance of the Company and the counterparties with whom it has derivative contracts. The Company established strict counterparty credit guidelines and only enters into transactions with financial institutions that adhere to these guidelines. Accordingly, the risk of counterparty default is deemed to be minimal. Mutual funds and money market mutual funds: The mutual funds in the table above are deemed to be equity securities with readily determinable fair values with changes in the fair value recognized through net income under ASC Topic 321. The fair value of these instruments is determined using Level 1 inputs as defined in the ASC Topic 820.

OTHER BALANCE SHEET AND STATEME

OTHER BALANCE SHEET AND STATEMENT OF OPERATIONS INFORMATION	9 Months Ended
	Sep. 30, 2021
Other Balance Sheet And Statement Of Operations Information [Abstract]
OTHER BALANCE SHEET AND STATEMENT OF OPERATIONS INFORMATION	OTHER BALANCE SHEET AND STATEMENTS OF OPERATIONS INFORMATION The following tables contain additional detail related to certain balance sheet captions: September 30, 2021 December 31, 2020 Other current assets: Prepaid taxes $ 81 $ 94 Prepaid expenses 98 91 Capitalized costs to obtain and fulfill sales contracts 89 93 Foreign exchange forwards on certain assets and liabilities — 31 Derivative instruments designated as accounting hedges 10 — Other 45 74 Total other current assets $ 323 $ 383 Other assets: Investments in non-consolidated affiliates $ 149 $ 135 Deposits for real-estate leases 15 19 Indemnification assets related to acquisitions 103 15 Mutual funds and fixed deposits 67 66 Company owned life insurance (at contract value) 35 17 Costs to obtain sales contracts 137 134 Derivative instruments designated as accounting hedges 49 57 Pension and other retirement employee benefits 19 21 Other 62 51 Total other assets $ 636 $ 515 Accounts payable and accrued liabilities: Salaries and benefits $ 196 $ 197 Incentive compensation 248 226 Customer credits, advanced payments and advanced billings 96 42 Dividends 5 11 Professional service fees 68 53 Interest accrued on debt 46 82 Accounts payable 30 39 Income taxes 201 128 Pension and other retirement employee benefits 46 45 Accrued royalties 19 19 Foreign exchange forwards on certain assets and liabilities 10 2 Restructuring liability 8 18 Derivative instruments designated as accounting hedges 7 39 Other 104 138 Total accounts payable and accrued liabilities $ 1,084 $ 1,039 September 30, 2021 December 31, 2020 Other liabilities: Pension and other retirement employee benefits $ 204 $ 244 Interest accrued on UTPs 82 113 MAKS indemnification provisions 33 33 Income tax liability - non-current portion 18 18 Derivative instruments designated as accounting hedges 46 145 Other 37 37 Total other liabilities $ 420 $ 590 Loss pursuant to the Divestiture of MAKS: The $9 million loss during the nine months ended September 30, 2020 relates to customary post-closing completion adjustments pursuant to the fourth quarter 2019 divestiture of MAKS. Other Non-Operating Income (Expense): The following table summarizes the components of other non-operating income (expense): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 FX gain (loss) $ (2) $ 2 $ (2) $ 7 Purchase price hedge loss (1) (13) — (13) — Net periodic pension costs - other components 4 3 5 10 Income from investments in non-consolidated affiliates 6 4 15 4 Other 1 1 13 17 Total $ (4) $ 10 $ 18 $ 38 (1) The amounts for the three and nine months ended September 30, 2021 represent a loss on a forward contract used to hedge a portion of the GBP denominated RMS purchase price.

COMPREHENSIVE INCOME AND ACCUMU

COMPREHENSIVE INCOME AND ACCUMULATED OTHER COMPREHENSIVE LOSS	9 Months Ended
	Sep. 30, 2021
Equity [Abstract]
COMPREHENSIVE INCOME AND ACCUMULATED OTHER COMPREHENSIVE LOSS	COMPREHENSIVE INCOME AND ACCUMULATED OTHER COMPREHENSIVE LOSS The following table provides details about the reclassifications out of AOCL: Three Months Ended September 30, Location in the consolidated statements of operations Losses on cash flow hedges 2021 2020 Interest rate contract $ (1) $ — Other non-operating income, net Income tax effect of item above — — Provision for income taxes Total net losses on cash flow hedges (1) — Pension and other retirement benefits Amortization of actuarial losses and prior service costs included in net income (2) (2) Other non-operating income, net Settlement charge (1) — Other non-operating income, net Total before income taxes (3) (2) Income tax effect of items above 1 — Provision for income taxes Total pension and other retirement benefits (2) (2) Total net losses included in Net Income attributable to reclassifications out of AOCL $ (3) $ (2) Nine Months Ended September 30, Location in the consolidated statements of operations Losses on cash flow hedges 2021 2020 Interest rate contract $ (2) $ (1) Other non-operating income, net Income tax effect of item above — — Provision for income taxes Total net losses on cash flow hedges (2) (1) Gains on net investment hedges FX forwards 2 — Other non-operating income, net Income tax effect of item above (1) — Provision for income taxes Total net gains on net investment hedges 1 — Pension and other retirement benefits Amortization of actuarial losses and prior service costs included in net income (8) (5) Other non-operating income, net Settlement charge (8) — Other non-operating income, net Total before income taxes (16) (5) Income tax effect of items above 4 1 Provision for income taxes Total pension and other retirement benefits (12) (4) Total net losses included in Net Income attributable to reclassifications out of AOCL $ (13) $ (5) The following tables show changes in AOCL by component (net of tax): Three Months Ended September 30, 2021 2020 Gains/(Losses) Pension and Other Retirement Benefits Cash Flow Hedges Foreign Currency Translation Adjustments Net Investment Hedges Total Pension and Other Retirement Benefits Cash Flow Hedges Foreign Currency Translation Adjustments Net Investment Hedges Total Balance June 30, $ (108) $ (48) $ (152) $ (117) $ (425) $ (84) $ (49) $ (479) $ 70 $ (542) Other comprehensive income/(loss) before reclassifications 3 — (116) 73 (40) (7) — 186 (143) 36 Amounts reclassified from AOCL 2 1 — — 3 2 — — — 2 Other comprehensive income/(loss) 5 1 (116) 73 (37) (5) — 186 (143) 38 Balance September 30, $ (103) $ (47) $ (268) $ (44) $ (462) $ (89) $ (49) $ (293) $ (73) $ (504) Nine Months Ended September 30, 2021 2020 Gains/(Losses) Pension and Other Retirement Benefits Cash Flow Hedges Foreign Currency Translation Adjustments Net Investment Hedges Total Pension and Other Retirement Benefits Cash Flow Hedges Foreign Currency Translation Adjustments Net Investment Hedges Total Balance December 31, $ (118) $ (49) $ (45) $ (220) $ (432) $ (92) $ — $ (401) $ 54 $ (439) Other comprehensive income/(loss) before reclassifications 3 — (223) 177 (43) (1) (50) 108 (127) (70) Amounts reclassified from AOCL 12 2 — (1) 13 4 1 — — 5 Other comprehensive income/(loss) 15 2 (223) 176 (30) 3 (49) 108 (127) (65) Balance September 30, $ (103) $ (47) $ (268) $ (44) $ (462) $ (89) $ (49) $ (293) $ (73) $ (504)

PENSION AND OTHER RETIREMENT BE

PENSION AND OTHER RETIREMENT BENEFITS	9 Months Ended
	Sep. 30, 2021
Retirement Benefits [Abstract]
PENSION AND OTHER RETIREMENT BENEFITS	PENSION AND OTHER RETIREMENT BENEFITS Moody’s maintains funded and unfunded noncontributory DBPPs. The DBPPs provide defined benefits using a cash balance formula based on years of service and career average salary for its employees or final average pay for selected executives. The Company also provides certain healthcare and life insurance benefits for retired U.S. employees. The retirement healthcare plans are contributory; the life insurance plans are noncontributory. Moody’s funded and unfunded U.S. pension plans, the U.S. retirement healthcare plans and the U.S. retirement life insurance plans are collectively referred to herein as the “Retirement Plans”. The U.S. retirement healthcare plans and the U.S. retirement life insurance plans are collectively referred to herein as the “Other Retirement Plans.” The non-U.S. defined benefit pension plans are immaterial. Through 2007, substantially all U.S. employees were eligible to participate in the Company’s DBPPs. Effective January 1, 2008, the Company no longer offers DBPPs to U.S. employees hired or rehired on or after January 1, 2008 and new hires in the U.S. instead will receive a retirement contribution in similar benefit value under the Company’s Profit Participation Plan. Current participants of the Company’s Retirement Plans and Other Retirement Plans continue to accrue benefits based on existing plan formulas. The components of net periodic benefit expense related to the Retirement Plans and Other Retirement Plans are as follows: Three Months Ended September 30, Pension Plans Other Retirement Plans 2021 2020 2021 2020 Components of net periodic expense Service cost $ 4 $ 5 $ 1 $ — Interest cost 4 4 — 1 Expected return on plan assets (7) (5) — — Amortization of net actuarial loss from earlier periods 3 2 — — Loss on settlement of pension obligation 1 — — — Net periodic expense $ 5 $ 6 $ 1 $ 1 Nine Months Ended September 30, Pension Plans Other Retirement Plans 2021 2020 2021 2020 Components of net periodic expense Service cost $ 14 $ 13 $ 3 $ 2 Interest cost 11 13 1 1 Expected return on plan assets (20) (15) — — Amortization of net actuarial loss from earlier periods 8 5 — — Loss on settlement of pension obligation 8 — — — Net periodic expense $ 21 $ 16 $ 4 $ 3 The Company made contributions of $46 million related to its unfunded U.S. DBPPs during the nine months ended September 30, 2021. Anticipated contributions for the remainder of 2021 are not expected to be material.

INDEBTEDNESS

INDEBTEDNESS	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
INDEBTEDNESS	INDEBTEDNESS The Company’s debt is recorded at its carrying amount, which represents the issuance amount plus or minus any issuance premium or discount, except for certain debt as depicted in the table below, which are recorded at the carrying amount adjusted for the fair value of an interest rate swap used to hedge the fair value of the note. The following table summarizes total indebtedness: September 30, 2021 Notes Payable: Principal Amount Fair Value of Interest Rate Swaps (1) Unamortized (Discount) Premium Unamortized Debt Issuance Costs Carrying Value 4.50% 2012 Senior Notes, due 2022 $ 500 $ 7 $ — $ — $ 507 4.875% 2013 Senior Notes, due 2024 500 (5) (1) (1) 493 5.25% 2014 Senior Notes, due 2044 600 (4) 3 (5) 594 1.75% 2015 Senior Notes, due 2027 579 — — (2) 577 2.625% 2017 Senior Notes, due 2023 500 8 — (1) 507 3.25% 2017 Senior Notes, due 2028 500 15 (3) (3) 509 4.25% 2018 Senior Notes, due 2029 400 — (2) (2) 396 4.875% 2018 Senior Notes, due 2048 400 — (6) (4) 390 0.950% 2019 Senior Notes, due 2030 869 — (2) (5) 862 3.75% 2020 Senior Notes, due 2025 700 (5) (1) (4) 690 3.25% 2020 Senior Notes, due 2050 300 — (4) (3) 293 2.55% 2020 Senior Notes, due 2060 500 — (4) (5) 491 2.00% 2021 Senior Note, due 2031 600 — (8) (5) 587 2.75% 2021 Senior Note, due 2041 600 — (14) (6) 580 Total debt $ 7,548 $ 16 $ (42) $ (46) $ 7,476 Current portion (507) Total long-term debt $ 6,969 December 31, 2020 Notes Payable: Principal Amount Fair Value of Interest Rate Swaps (1) Unamortized (Discount) Premium Unamortized Debt Issuance Costs Carrying Value 4.50% 2012 Senior Notes, due 2022 $ 500 $ 14 $ (1) $ (1) $ 512 4.875% 2013 Senior Notes, due 2024 500 — (1) (1) 498 5.25% 2014 Senior Notes, due 2044 600 — 3 (5) 598 1.75% 2015 Senior Notes, due 2027 612 — — (2) 610 2.625% 2017 Senior Notes, due 2023 500 12 — (2) 510 3.25% 2017 Senior Notes, due 2028 500 31 (4) (3) 524 4.25% 2018 Senior Notes, due 2029 400 — (3) (3) 394 4.875% 2018 Senior Notes, due 2048 400 — (6) (4) 390 0.950% 2019 Senior Notes, due 2030 918 — (3) (6) 909 3.75% 2020 Senior Notes, due 2025 700 (1) (1) (5) 693 3.25% 2020 Senior Notes, due 2050 300 — (4) (3) 293 2.55% 2020 Senior Notes, due 2060 500 — (4) (5) 491 Total long-term debt $ 6,430 $ 56 $ (24) $ (40) $ 6,422 (1) The fair value of interest rate swaps in the table above represents the cumulative amount of fair value hedging adjustments included in the carrying amount of the hedged debt. Notes Payable In the third quarter of 2021, the Company issued the 2021 Senior Notes, due 2031 and the 2021 Senior Notes due 2041. The key terms of these debt issuances are set forth in the table above. At September 30, 2021, the Company was in compliance with all covenants contained within all of the debt agreements. All the debt agreements contain cross default provisions which state that default under one of the aforementioned debt instruments could in turn permit lenders under other debt instruments to declare borrowings outstanding under those instruments to be immediately due and payable. As of September 30, 2021, there were no such cross defaults. The repayment schedule for the Company’s borrowings is as follows: Year Ending December 31, 2012 Senior Notes due 2022 2013 Senior Notes due 2024 2014 Senior Notes due 2044 2015 Senior Notes due 2027 2017 Senior Notes due 2023 2017 Senior Notes due 2028 2018 Senior Notes due 2029 2018 Senior Notes due 2048 2019 Senior Notes due 2030 2020 Senior Notes due 2025 2020 Senior Notes due 2050 2020 Senior Notes due 2060 2021 Senior Notes due 2031 2021 Senior Notes due 2041 Total 2021 (After September 30,) $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — 2022 500 — — — — — — — — — — — — — $ 500 2023 — — — — 500 — — — — — — — — — $ 500 2024 — 500 — — — — — — — — — — — — $ 500 2025 — — — — — — — — — 700 — — — — $ 700 Thereafter — — 600 579 — 500 400 400 869 — 300 500 600 600 $ 5,348 Total $ 500 $ 500 $ 600 $ 579 $ 500 $ 500 $ 400 $ 400 $ 869 $ 700 $ 300 $ 500 $ 600 $ 600 $ 7,548 Interest expense, net The following table summarizes the components of interest as presented in the consolidated statements of operations and the cash paid for interest: Three Months Ended Nine Months Ended 2021 2020 2021 2020 Income $ 3 $ 2 $ 7 $ 9 Expense on borrowings (47) (42) (129) (121) Income (expense) on UTPs and other tax related liabilities (2) (5) (9) 25 (27) Net periodic pension costs - interest component (4) (4) (12) (14) Interest expense, net $ (53) $ (53) $ (109) $ (153) Interest paid (1) $ 53 $ 47 $ 139 $ 119 (1) Interest paid includes net settlements on interest rate swaps more fully discussed in Note 9. (2) Income (expense) on UTPs and other tax related liabilities for the nine months ended September 30, 2021 includes a $40 million benefit relating to the reversal of tax-related interest accruals pursuant to the resolution of tax matters. The fair value and carrying value of the Company’s debt as of September 30, 2021 and December 31, 2020 are as follows: September 30, 2021 December 31, 2020 Carrying Amount Estimated Fair Value Carrying Amount Estimated Fair Value 4.50% 2012 Senior Notes, due 2022 $ 507 $ 515 $ 512 $ 530 4.875% 2013 Senior Notes, due 2024 493 545 498 562 5.25% 2014 Senior Notes, due 2044 594 808 598 828 1.75% 2015 Senior Notes, due 2027 577 629 610 674 2.625% 2017 Senior Notes, due 2023 507 514 510 522 3.25% 2017 Senior Notes, due 2028 509 544 524 561 4.25% 2018 Senior Notes, due 2029 396 460 394 480 4.875% 2018 Senior Notes, due 2048 390 526 390 544 0.950% 2019 Senior Notes, due 2030 862 898 909 974 3.75% 2020 Senior Notes, due 2025 690 761 693 785 3.25% 2020 Senior Notes, due 2050 293 309 293 329 2.55% 2020 Senior Notes, due 2060 491 437 491 467 2.00% 2021 Senior Note, due 2031 587 588 — — 2.75% 2021 Senior Note, due 2041 580 584 — — Total $ 7,476 $ 8,118 $ 6,422 $ 7,256 The fair value of the Company’s long-term debt is estimated based on quoted market prices for similar instruments. Accordingly, the inputs used to estimate the fair value of the Company’s long-term debt are classified as Level 2 inputs within the fair value hierarchy.

LEASES

LEASES	9 Months Ended
	Sep. 30, 2021
Leases [Abstract]
LEASES	LEASES The Company has operating leases, substantially all of which relate to the lease of office space. The Company’s leases which are classified as finance leases are not material to the consolidated financial statements. Certain of the Company’s leases include options to renew, with renewal terms that can extend the lease term from one year to 20 years at the Company’s discretion. The following table presents the components of the Company’s lease cost: Three Months Ended Nine Months Ended 2021 2020 2021 2020 Operating lease cost $ 24 $ 24 $ 71 $ 72 Sublease income (2) (1) (4) (3) Variable lease cost 5 4 15 14 Total lease cost $ 27 $ 27 $ 82 $ 83 The following tables present other information related to the Company’s operating leases: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Cash paid for amounts included in the measurement of operating lease liabilities $ 27 $ 27 $ 83 $ 80 Right-of-use assets obtained in exchange for new operating lease liabilities $ 117 $ 7 $ 123 $ 26 September 30, 2021 September 30, 2020 Weighted-average remaining lease term 5.9 years 6.3 years Weighted-average discount rate applied to operating leases 3.1 % 3.6 % The following table presents a maturity analysis of the future minimum lease payments included within the Company’s operating lease liabilities at September 30, 2021: Year Ending December 31, Operating Leases 2021 (After September 30) $ 30 2022 119 2023 115 2024 105 2025 90 After 2025 167 Total lease payments (undiscounted) 626 Less: Interest 53 Present value of lease liabilities: $ 573 Lease liabilities - current $ 103 Lease liabilities - noncurrent $ 470

CONTINGENCIES

CONTINGENCIES	9 Months Ended
	Sep. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
CONTINGENCIES	CONTINGENCIES Given the nature of the Company's activities, Moody’s and its subsidiaries are subject to legal and tax proceedings, governmental, regulatory and legislative investigations, subpoenas and other inquiries, and claims and litigation by governmental and private parties that are based on ratings assigned by MIS or that are otherwise incidental to the Company’s business. Moody’s and MIS also are subject to periodic reviews, inspections, examinations and investigations by regulators in the U.S. and other jurisdictions, any of which may result in claims, legal proceedings, assessments, fines, penalties or restrictions on business activities. Moody’s also is subject to ongoing tax audits as addressed in Note 5 to the consolidated financial statements. Management periodically assesses the Company’s liabilities and contingencies in connection with these matters based upon the latest information available. For claims, litigation and proceedings and governmental investigations and inquiries not related to income taxes, the Company records liabilities in the consolidated financial statements when it is both probable that a liability has been incurred and the amount of loss can be reasonably estimated and periodically adjusts these as appropriate. When the reasonable estimate of the loss is within a range of amounts, the minimum amount of the range is accrued unless some higher amount within the range is a better estimate than another amount within the range. In instances when a loss is reasonably possible but uncertainties exist related to the probable outcome and/or the amount or range of loss, management does not record a liability but discloses the contingency if material. As additional information becomes available, the Company adjusts its assessments and estimates of such matters accordingly. Moody’s also discloses material pending legal proceedings pursuant to SEC rules and other pending matters as it may determine to be appropriate. In view of the inherent difficulty of assessing the potential outcome of legal proceedings, governmental, regulatory and legislative investigations and inquiries, claims and litigation and similar matters and contingencies, particularly when the claimants seek large or indeterminate damages or assert novel legal theories or the matters involve a large number of parties, the Company often cannot predict what the eventual outcome of the pending matters will be or the timing of any resolution of such matters. The Company also may be unable to predict the impact (if any) that any such matters may have on how its business is conducted, on its competitive position or on its financial position, results of operations or cash flows. As the process to resolve any pending matters progresses, management will continue to review the latest information available and assess its ability to predict the outcome of such matters and the effects, if any, on its operations and financial condition and to accrue for and disclose such matters as and when required. However, because such matters are inherently unpredictable and unfavorable developments or resolutions can occur, the ultimate outcome of such matters, including the amount of any loss, may differ from those estimates.

SEGMENT INFORMATION

SEGMENT INFORMATION	9 Months Ended
	Sep. 30, 2021
Segment Reporting [Abstract]
SEGMENT INFORMATION	SEGMENT INFORMATION The Company is organized into two operating segments: MIS and MA and accordingly, the Company reports in two reportable segments: MIS and MA. The MIS segment consists of five LOBs. The CFG, FIG, PPIF and SFG LOBs generate revenue principally from fees for the assignment and ongoing monitoring of credit ratings on debt obligations and the entities that issue such obligations in markets worldwide. The MIS Other LOB primarily consists of financial instruments pricing services in the Asia-Pacific region, ICRA non-ratings revenue and revenue from providing ESG research, data and assessments. The MA segment develops a wide range of products and services that support the risk management activities of institutional participants in global financial markets. The MA segment consists of two LOBs - RD&A and ERS. Revenue for MIS and expenses for MA include intersegment fees charged to MA for the rights to use and distribute content, data and products developed by MIS. Additionally, revenue for MA and expenses for MIS include an intersegment fee charged to MIS from MA for certain MA products and services utilized in MIS’s ratings process. These intersegment fees are generally based on the market value of the products and services being transferred between the segments. Overhead expenses include costs such as rent and occupancy, information technology and support staff such as finance, human resources and legal. Such costs and corporate expenses that exclusively benefit one segment are fully charged to that segment. For overhead costs and corporate expenses that benefit both segments, costs are allocated to each segment based on the segment’s share of full-year 2019 actual revenue which comprises a “Baseline Pool” that will remain fixed over time. In subsequent periods, incremental overhead costs (or reductions thereof) will be allocated to each segment based on the prevailing shares of total revenue represented by each segment. “Eliminations” in the following table represent intersegment revenue/expense. Moody’s does not report the Company’s assets by reportable segment, as this metric is not used by the chief operating decision maker to allocate resources to the segments. Consequently, it is not practical to show assets by reportable segment. Financial Information by Segment The table below shows revenue, operating income and Adjusted Operating Income by reportable segment. Adjusted Operating Income is a financial metric utilized by the Company’s chief operating decision maker to assess the profitability of each reportable segment. Refer to Note 3 for further details on the components of the Company’s revenue. Three Months Ended September 30, 2021 2020 MIS MA Eliminations Consolidated MIS MA Eliminations Consolidated Revenue $ 967 $ 603 $ (44) $ 1,526 $ 863 $ 532 $ (39) $ 1,356 Total Expenses 404 490 (44) 850 339 414 (39) 714 Operating income 563 113 — 676 524 118 — 642 Add: Depreciation and 17 44 — 61 17 39 — 56 Restructuring — — — — 13 10 — 23 Adjusted Operating Income $ 580 $ 157 $ — $ 737 $ 554 $ 167 $ — $ 721 Nine Months Ended September 30, 2021 2020 MIS MA Eliminations Consolidated MIS MA Eliminations Consolidated Revenue $ 3,065 $ 1,744 $ (130) $ 4,679 $ 2,667 $ 1,529 $ (115) $ 4,081 Total Expenses 1,132 1,347 (130) 2,349 1,051 1,201 (115) 2,137 Operating income 1,933 397 — 2,330 1,616 328 — 1,944 Add: Depreciation and 53 127 — 180 52 111 — 163 Restructuring — 2 — 2 12 8 — 20 Loss pursuant to the divestiture of MAKS — — — — — 9 — 9 Adjusted Operating Income $ 1,986 $ 526 $ — $ 2,512 $ 1,680 $ 456 $ — $ 2,136 Consolidated Revenue Information by Geographic Area Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 United States $ 844 $ 729 $ 2,560 $ 2,280 Non-U.S.: EMEA 439 401 1,398 1,137 Asia-Pacific 149 156 460 436 Americas 94 70 261 228 Total Non-U.S. 682 627 2,119 1,801 Total $ 1,526 $ 1,356 $ 4,679 $ 4,081

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	9 Months Ended
	Sep. 30, 2021
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	SUBSEQUENT EVENTS On October 26, 2021, the Board approved the declaration of a quarterly dividend of $0.62 per share of Moody’s common stock, payable on December 14, 2021 to shareholders of record at the close of business on November 23, 2021. On October 13, 2021, Moody's completed a minority investment in BitSight, a cybersecurity ratings company. The consideration transferred by Moody's for this investment comprised $250 million in cash and the contribution of Moody's minority interest in VisibleRisk, a cybersecurity risk ratings joint venture. Moody's expects to recognize an approximate $30 to $40 million non-cash gain in the fourth quarter of 2021 relating to the exchange of its minority investment in VisibleRisk for shares of BitSight.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Goodwill	Goodwill Moody’s evaluates its goodwill for impairment at the reporting unit level, defined as an operating segment (i.e., MIS and MA), or one level below an operating segment (i.e., a component of an operating segment), annually as of July 31 or more frequently if impairment indicators arise in accordance with ASC Topic 350. The Company evaluates the recoverability of goodwill using a two-step impairment test approach at the reporting unit level. In the first step, the Company assesses various qualitative factors to determine whether the fair value of a reporting unit may be less than its carrying amount. If a determination is made based on the qualitative factors that an impairment does not exist, the Company is not required to perform further testing. If the aforementioned qualitative assessment results in the Company concluding that it is more likely than not that the fair value of a reporting unit may be less than its carrying amount, the fair value of the reporting unit will be quantitatively determined and compared to its carrying value including goodwill. If the fair value of the reporting unit exceeds the carrying value of the net assets assigned to that unit, goodwill is not impaired and the Company is not required to perform further testing. If the fair value of the reporting unit is less than the carrying value, the Company will record a goodwill impairment charge for the amount by which the carrying value exceeds the reporting unit’s fair value. The Company evaluates its reporting units on an annual basis, or more frequently if there are changes in the reporting structure of the Company due to acquisitions, reporting unit realignments or if there are indicators of potential impairment. For the reporting units where the Company is consistently able to conclude that no impairment exists using only a qualitative approach, the Company’s accounting policy is to perform the second step of the aforementioned goodwill impairment assessment at least once every three years. Goodwill is assigned to a reporting unit at the date when an acquisition is integrated into one of the established reporting units, and is based on which reporting unit is expected to benefit from the synergies of the acquisition. Prior to the second quarter of 2021, MA's reporting unit structure consisted of five reporting units (Content, ERS, MALS, Bureau van Dijk and Reis). Pursuant to a strategic reorganization in the MA segment which was completed in the second quarter of 2021, MA's reporting unit structure has been reorganized into two reporting units. MA’s two new reporting units generally consist of: i) businesses offering data and data-driven analytical solutions; and ii) risk-management software, workflow and CRE solutions. The Company performed qualitative assessments of the reporting units impacted by the reorganization immediately before and after the reorganization became effective. These qualitative assessments resulted in the Company determining that it was not more likely than not that the fair value of any reporting unit was less than its carrying amount.

REVENUES (Tables)

REVENUES (Tables)	9 Months Ended
	Sep. 30, 2021
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following table presents the Company’s revenues disaggregated by LOB: Three Months Ended Nine Months Ended 2021 2020 2021 2020 MIS: Corporate finance (CFG) Investment-grade $ 105 $ 141 $ 341 $ 576 High-yield 82 101 347 275 Bank loans 145 73 482 205 Other accounts (1) 156 146 473 430 Total CFG 488 461 1,643 1,486 Financial institutions (FIG) Banking 105 95 315 269 Insurance 38 31 114 105 Managed investments 8 6 29 20 Other accounts 2 2 7 7 Total FIG 153 134 465 401 Public, project and infrastructure finance (PPIF) Public finance / sovereign 61 71 191 192 Project and infrastructure 69 62 212 183 Total PPIF 130 133 403 375 Structured finance (SFG) Asset-backed securities 29 25 88 70 RMBS 31 24 89 74 CMBS 26 15 73 45 Structured credit 57 24 148 74 Other accounts — — 1 2 Total SFG 143 88 399 265 Total ratings revenue 914 816 2,910 2,527 MIS Other 11 9 31 30 Total external revenue 925 825 2,941 2,557 Intersegment revenue 42 38 124 110 Total MIS 967 863 3,065 2,667 MA: Research, data and analytics (RD&A) 445 386 1,299 1,110 Enterprise risk solutions (ERS) 156 145 439 414 Total external revenue 601 531 1,738 1,524 Intersegment revenue 2 1 6 5 Total MA 603 532 1,744 1,529 Eliminations (44) (39) (130) (115) Total MCO $ 1,526 $ 1,356 $ 4,679 $ 4,081 (1) Other includes: recurring monitoring fees of a rated debt obligation and/or entities that issue such obligations as well as fees from programs such as commercial paper, medium term notes, and ICRA corporate finance revenue. The following table presents the Company’s revenues disaggregated by LOB and geographic area: Three Months Ended September 30, 2021 Three Months Ended September 30, 2020 U.S. Non-U.S Total U.S. Non-U.S Total MIS: Corporate finance $ 334 $ 154 $ 488 $ 311 $ 150 $ 461 Financial institutions 71 82 153 59 75 134 Public, project and infrastructure finance 76 54 130 82 51 133 Structured finance 98 45 143 54 34 88 Total ratings revenue 579 335 914 506 310 816 MIS Other 1 10 11 — 9 9 Total MIS 580 345 925 506 319 825 MA: Research, data and analytics 203 242 445 167 219 386 Enterprise risk solutions 61 95 156 56 89 145 Total MA 264 337 601 223 308 531 Total MCO $ 844 $ 682 $ 1,526 $ 729 $ 627 $ 1,356 Nine Months Ended September 30, 2021 Nine Months Ended September 30, 2020 U.S. Non-U.S Total U.S. Non-U.S Total MIS: Corporate finance $ 1,093 $ 550 $ 1,643 $ 1,038 $ 448 $ 1,486 Financial institutions 226 239 465 189 212 401 Public, project and infrastructure finance 233 170 403 237 138 375 Structured finance 254 145 399 160 105 265 Total ratings revenue 1,806 1,104 2,910 1,624 903 2,527 MIS Other 3 28 31 1 29 30 Total MIS 1,809 1,132 2,941 1,625 932 2,557 MA: Research, data and analytics 576 723 1,299 492 618 1,110 Enterprise risk solutions 175 264 439 163 251 414 Total MA 751 987 1,738 655 869 1,524 Total MCO $ 2,560 $ 2,119 $ 4,679 $ 2,280 $ 1,801 $ 4,081 The following tables summarize the split between transaction and recurring revenue. In the MIS segment, excluding MIS Other, transaction revenue represents the initial rating of a new debt issuance as well as other one-time fees while recurring revenue represents the recurring monitoring fees of a rated debt obligation and/or entities that issue such obligations, as well as revenue from programs such as commercial paper, medium-term notes and shelf registrations. In MIS Other, transaction revenue represents revenue from professional services and recurring revenue represents subscription-based revenues. In the MA segment, recurring revenue represents subscription-based revenues and software maintenance revenue. Transaction revenue in MA represents perpetual software license fees and revenue from software implementation services, risk management advisory projects, and training and certification services. Three Months Ended September 30, 2021 2020 Transaction Recurring Total Transaction Recurring Total Corporate Finance $ 366 $ 122 $ 488 $ 347 $ 114 $ 461 75 % 25 % 100 % 75 % 25 % 100 % Financial Institutions $ 83 $ 70 $ 153 $ 67 $ 67 $ 134 54 % 46 % 100 % 50 % 50 % 100 % Public, Project and Infrastructure Finance $ 88 $ 42 $ 130 $ 92 $ 41 $ 133 68 % 32 % 100 % 69 % 31 % 100 % Structured Finance $ 93 $ 50 $ 143 $ 41 $ 47 $ 88 65 % 35 % 100 % 47 % 53 % 100 % MIS Other $ 1 $ 10 $ 11 $ 1 $ 8 $ 9 9 % 91 % 100 % 11 % 89 % 100 % Total MIS $ 631 $ 294 $ 925 $ 548 $ 277 $ 825 68 % 32 % 100 % 66 % 34 % 100 % Research, data and analytics $ 21 $ 424 $ 445 $ 19 $ 367 $ 386 5 % 95 % 100 % 5 % 95 % 100 % Enterprise risk solutions $ 15 $ 141 $ 156 $ 32 $ 113 $ 145 10 % 90 % 100 % 22 % 78 % 100 % Total MA $ 36 (1) $ 565 $ 601 $ 51 $ 480 $ 531 6 % 94 % 100 % 10 % 90 % 100 % Total Moody's Corporation $ 667 $ 859 $ 1,526 $ 599 $ 757 $ 1,356 44 % 56 % 100 % 44 % 56 % 100 % Nine Months Ended September 30, 2021 2020 Transaction Recurring Total Transaction Recurring Total Corporate Finance $ 1,280 $ 363 $ 1,643 $ 1,142 $ 344 $ 1,486 78 % 22 % 100 % 77 % 23 % 100 % Financial Institutions $ 252 $ 213 $ 465 $ 203 $ 198 $ 401 54 % 46 % 100 % 51 % 49 % 100 % Public, Project and Infrastructure Finance $ 276 $ 127 $ 403 $ 257 $ 118 $ 375 68 % 32 % 100 % 69 % 31 % 100 % Structured Finance $ 251 $ 148 $ 399 $ 126 $ 139 $ 265 63 % 37 % 100 % 48 % 52 % 100 % MIS Other $ 3 $ 28 $ 31 $ 3 $ 27 $ 30 10 % 90 % 100 % 10 % 90 % 100 % Total MIS $ 2,062 $ 879 $ 2,941 $ 1,731 $ 826 $ 2,557 70 % 30 % 100 % 68 % 32 % 100 % Research, data and analytics $ 63 $ 1,236 $ 1,299 $ 53 $ 1,057 $ 1,110 5 % 95 % 100 % 5 % 95 % 100 % Enterprise risk solutions $ 54 $ 385 $ 439 $ 90 $ 324 $ 414 12 % 88 % 100 % 22 % 78 % 100 % Total MA $ 117 (1) $ 1,621 $ 1,738 $ 143 $ 1,381 $ 1,524 7 % 93 % 100 % 9 % 91 % 100 % Total Moody's Corporation $ 2,179 $ 2,500 $ 4,679 $ 1,874 $ 2,207 $ 4,081 47 % 53 % 100 % 46 % 54 % 100 % (1) Revenue from software implementation services and risk management advisory projects, while classified by management as transactional revenue, is recognized over time under the Revenue Accounting Standard (please also refer to the following table). The following table presents the timing of revenue recognition: Three Months Ended September 30, 2021 Nine Months Ended September 30, 2021 MIS MA Total MIS MA Total Revenue recognized at a point in time $ 631 $ 29 $ 660 $ 2,062 $ 78 $ 2,140 Revenue recognized over time 294 572 866 879 1,660 2,539 Total $ 925 $ 601 $ 1,526 $ 2,941 $ 1,738 $ 4,679 Three Months Ended September 30, 2020 Nine Months Ended September 30, 2020 MIS MA Total MIS MA Total Revenue recognized at a point in time $ 548 $ 30 $ 578 $ 1,731 $ 89 $ 1,820 Revenue recognized over time 277 501 778 826 1,435 2,261 Total $ 825 $ 531 $ 1,356 $ 2,557 $ 1,524 $ 4,081
Company's Reportable Segment Revenues Disaggregated by Segment and Geographic Region	The following table presents the Company’s reportable segment revenues disaggregated by segment and geographic region: Three Months Ended Nine Months Ended 2021 2020 2021 2020 MIS: U.S. $ 580 $ 506 $ 1,809 $ 1,625 Non-U.S.: EMEA 211 188 707 542 Asia-Pacific 90 99 287 270 Americas 44 32 138 120 Total Non-U.S. 345 319 1,132 932 Total MIS 925 825 2,941 2,557 MA: U.S. 264 223 751 655 Non-U.S.: EMEA 228 213 691 595 Asia-Pacific 59 57 173 166 Americas 50 38 123 108 Total Non-U.S. 337 308 987 869 Total MA 601 531 1,738 1,524 Total MCO $ 1,526 $ 1,356 $ 4,679 $ 4,081
Schedule of Changes in the Deferred Revenue Balances	Significant changes in the deferred revenue balances during the three and nine months ended September 30, 2021 and 2020 are as follows: Three Months Ended September 30, 2021 Three Months Ended September 30, 2020 MIS MA Total MIS MA Total Balance at June 30, $ 368 $ 867 $ 1,235 $ 365 $ 740 $ 1,105 Changes in deferred revenue Revenue recognized that was included in the deferred revenue balance at the beginning of the period (118) (484) (602) (118) (347) (465) Increases due to amounts billable excluding amounts recognized as revenue during the period 85 393 478 83 273 356 Increases due to acquisitions during the period — 89 89 — — — Effect of exchange rate changes (2) (12) (14) 5 19 24 Total changes in deferred revenue (35) (14) (49) (30) (55) (85) Balance at September 30, $ 333 $ 853 $ 1,186 $ 335 $ 685 $ 1,020 Nine Months Ended September 30, 2021 Nine Months Ended September 30, 2020 MIS MA Total MIS MA Total Balance at December 31, $ 313 $ 874 $ 1,187 $ 322 $ 840 $ 1,162 Changes in deferred revenue Revenue recognized that was included in the deferred revenue balance at the beginning of the period (200) (814) (1,014) (207) (781) (988) Increases due to amounts billable excluding amounts recognized as revenue during the period 224 713 937 219 607 826 Increases due to acquisitions during the period — 93 93 — 20 20 Effect of exchange rate changes (4) (13) (17) 1 (1) — Total changes in deferred revenue 20 (21) (1) 13 (155) (142) Balance at September 30, $ 333 $ 853 $ 1,186 $ 335 $ 685 $ 1,020 Deferred revenue - current $ 247 $ 852 $ 1,099 $ 237 $ 681 918 Deferred revenue - non-current $ 86 $ 1 $ 87 $ 98 $ 4 102

STOCK-BASED COMPENSATION (Table

STOCK-BASED COMPENSATION (Tables)	9 Months Ended
	Sep. 30, 2021
Share-based Payment Arrangement, Noncash Expense [Abstract]
Stock-Based Compensation Cost and Associated Tax Benefit	Presented below is a summary of the stock-based compensation cost and associated tax benefit included in the accompanying consolidated statements of operations: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Stock-based compensation cost $ 41 $ 38 $ 127 $ 110 Tax benefit $ 8 $ 8 $ 29 $ 22
Weighted Average Assumptions used in Determining Fair Value for Options Granted	The following weighted average assumptions were used in determining the fair value using the Black-Scholes option-pricing model for options granted in 2021 (excluding the aforementioned RMS replacement awards): Expected dividend yield 0.89 % Expected stock volatility 28 % Risk-free interest rate 0.81 % Expected holding period 5.6 years
Stock Option Exercises and Restricted Stock Vesting	The following tables summarize information relating to stock option exercises and restricted stock vesting: Nine Months Ended 2021 2020 Exercise of stock options: Proceeds from stock option exercises $ 20 $ 32 Aggregate intrinsic value $ 44 $ 102 Tax benefit realized upon exercise $ 11 $ 24 Number of shares exercised 0.2 0.5 Vesting of restricted stock: Fair value of shares vested $ 193 $ 195 Tax benefit realized upon vesting $ 45 $ 45 Number of shares vested 0.7 0.8 Vesting of performance-based restricted stock: Fair value of shares vested $ 28 $ 70 Tax benefit realized upon vesting $ 7 $ 17 Number of shares vested 0.1 0.3

INCOME TAXES (Tables)

INCOME TAXES (Tables)	9 Months Ended
	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Income Taxes Paid	The following table shows the amount the Company paid for income taxes: Nine Months Ended September 30, 2021 2020 Income taxes paid $ 501 $ 374

WEIGHTED AVERAGE SHARES OUTST_2

WEIGHTED AVERAGE SHARES OUTSTANDING (Tables)	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Reconciliation of Basic to Diluted Shares Outstanding	Below is a reconciliation of basic to diluted shares outstanding: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Basic 186.0 187.8 186.6 187.6 Dilutive effect of shares issuable under stock-based compensation plans 1.3 1.5 1.4 1.7 Diluted 187.3 189.3 188.0 189.3 Anti-dilutive options to purchase common shares and restricted stock as well as contingently issuable restricted stock which are excluded from the table above 0.1 0.3 0.2 0.3

CASH EQUIVALENTS AND INVESTME_2

CASH EQUIVALENTS AND INVESTMENTS (Tables)	9 Months Ended
	Sep. 30, 2021
Cash and Cash Equivalents [Abstract]
Schedule of Cash and Cash Equivalents and Investments	The table below provides additional information on the Company’s cash equivalents and investments: As of September 30, 2021 Balance sheet location Cost Gains/(Losses) Fair Value Cash and cash equivalents Short-term Other Certificates of deposit and money market deposit accounts (1) $ 1,004 $ — $ 1,004 $ 891 $ 104 $ 9 Mutual funds $ 50 $ 8 $ 58 $ — $ — $ 58 As of December 31, 2020 Balance sheet location Cost Gains/(Losses) Fair Value Cash and cash Short-term Other Certificates of deposit and money market deposit accounts (1) $ 1,430 $ — $ 1,430 $ 1,325 $ 99 $ 6 Mutual funds $ 54 $ 6 $ 60 $ — $ — $ 60 (1) Consists of time deposits and money market deposit accounts. The remaining contractual maturities for the certificates of deposits classified as short-term investments were one month to 12 months at both September 30, 2021 and December 31, 2020. The remaining contractual maturities for the certificates of deposits classified in other assets are 13 months to 24 months at September 30, 2021 and 13 months to 23 months at December 31, 2020. Time deposits with a maturity of less than 90 days at time of purchase are classified as cash and cash equivalents.

ACQUISITIONS (Tables)

ACQUISITIONS (Tables)	9 Months Ended
	Sep. 30, 2021
Business Combination and Asset Acquisition [Abstract]
Schedule of Business Acquisitions, by Acquisition	The table below details the total consideration relating to the acquisition: Cash paid at closing $ 1,931 Replacement equity compensation awards 5 Total consideration $ 1,936 The table below details the total consideration relating to the acquisition: Cash paid at closing $ 138 Additional consideration paid to sellers in 2021 (1) 1 Total consideration $ 139 (1) Represents additional consideration paid to the sellers following finalization of customary post-closing completion adjustments. The table below details the total consideration relating to the acquisition: Cash paid at closing $ 700 Additional consideration paid to sellers in 2020 (1) 2 Total consideration $ 702 (1) Represents additional consideration paid to the sellers following finalization of customary post-closing completion adjustments.
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	Shown below is the preliminary purchase price allocation, which summarizes the fair value of the assets and liabilities assumed, at the date of acquisition: Cash $ 60 Accounts receivable 38 Other current assets 11 Property and equipment, net 13 Operating lease right-of-use assets 64 Intangible assets: Customer relationships (23 year useful life) 523 Product technology (7 year useful life) 212 Trade name (9 year useful life) 49 Total intangible assets (18 year weighted average useful life) 784 Goodwill 1,389 Deferred tax assets, net 46 Other assets 92 Liabilities: Accounts payable and accrued liabilities (101) Deferred revenue (89) Operating lease liabilities (68) Deferred tax liabilities, net (213) Uncertain tax positions (90) Total liabilities (561) Net assets acquired $ 1,936 Shown below is the preliminary purchase price allocation, which summarizes the fair value of the assets and liabilities assumed, at the date of acquisition: Current assets $ 7 Intangible assets: Database (10 year useful life) $ 38 Customer relationships (18 year useful life) 9 Product technology (8 year useful life) 9 Trade name (5 year useful life) 1 Total intangible assets (11 year weighted average useful life) 57 Goodwill (1) 79 Deferred tax assets (1) 16 Other assets 2 Liabilities: Accounts payable and accrued liabilities $ (1) Deferred revenue (4) Deferred tax liabilities (15) Other liabilities (2) Total liabilities (22) Net assets acquired $ 139 (1) During the third quarter of 2021, the Company received further information, that existed as of the acquisition date, with respect to Cortera’s deferred taxes. Accordingly, the Company recorded a measurement period adjustment of $16 million to its preliminary estimate for deferred tax assets. Shown below is the purchase price allocation, which summarizes the fair value of the assets and liabilities assumed, at the date of acquisition: Current assets $ 24 Intangible assets: Customer relationships (25 year useful life) $ 174 Database (10 year useful life) 86 Product technology (4 year useful life) 17 Trade name (3 year useful life) 3 Total intangible assets (19 year weighted average life) 280 Goodwill 494 Other assets 2 Liabilities: Accounts payable and accrued liabilities $ (5) Deferred revenue (20) Deferred tax liabilities (71) Other liabilities (2) Total liabilities (98) Net assets acquired $ 702
Business Acquisition, Pro Forma Information	Supplemental information on an unaudited pro forma basis is presented below for the nine months ended September 30, 2021 and 2020 as if the acquisition of RMS occurred on January 1, 2020. The pro forma financial information is presented for comparative purposes only, based on certain estimates and assumptions, which the Company believes to be reasonable but not necessarily indicative of future results of operations or the results that would have been reported if the acquisition had been completed at January 1, 2020. The unaudited pro forma information includes amortization of acquired intangible assets, based on the preliminary purchase price allocation and an estimate of useful lives reflected above, and incremental financing costs resulting from the acquisition, net of income tax, which was estimated using the weighted average statutory tax rates in effect in the jurisdiction for which the pro forma adjustment relates. Nine Months Ended 2021 2020 Pro forma Revenue $ 4,910 $ 4,300 Pro forma Net Income attributable to Moody's $ 1,807 $ 1,342

DERIVATIVE INSTRUMENTS AND HE_2

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES (Tables)	9 Months Ended
	Sep. 30, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments	The following table summarizes the Company’s interest rate swaps designated as fair value hedges: Notional Amount Hedged Item Nature of Swap As of September 30, 2021 As of December 31, 2020 Floating Interest Rate 2012 Senior Notes due 2022 Pay Floating/Receive Fixed $ 330 $ 330 3-month USD LIBOR 2017 Senior Notes due 2023 Pay Floating/Receive Fixed $ 250 $ 250 3-month USD LIBOR 2017 Senior Notes due 2028 Pay Floating/Receive Fixed $ 500 $ 500 3-month USD LIBOR 2020 Senior Notes due 2025 Pay Floating/Receive Fixed $ 300 $ 300 6-month USD LIBOR 2014 Senior Notes due 2044 Pay Floating/Receive Fixed $ 300 $ — 3-month USD LIBOR 2018 Senior Notes due 2048 Pay Floating/Receive Fixed $ 300 $ — 3-month USD LIBOR Total $ 1,980 $ 1,380 September 30, 2021 Pay Receive Nature of Swap Notional Amount Weighted Average Interest Rate Notional Amount Weighted Average Interest Rate Pay Fixed/Receive Fixed € 1,060 2.15% $ 1,220 4.45% Pay Floating/Receive Floating 1,466 Based on 3-month EURIBOR 1,680 Based on 3-month USD LIBOR Total € 2,526 $ 2,900 December 31, 2020 Pay Receive Nature of Swap Notional Amount Weighted Average Interest Rate Notional Amount Weighted Average Interest Rate Pay Fixed/Receive Fixed € 1,079 1.43% $ 1,220 3.96% Pay Floating/Receive Floating 959 Based on 3-month EURIBOR 1,080 Based on 3-month USD LIBOR Total € 2,038 $ 2,300
Gains and Losses on Derivatives Designated as Hedging Instruments	The following table summarizes the impact to the statements of operations of the Company’s interest rate swaps designated as fair value hedges: Total amounts of financial statement line item presented in the statements of operations in which the effects of fair value hedges are recorded Amount of income/(loss) recognized in the consolidated statements of operations Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Interest expense, net $ (53) $ (53) $ (109) $ (153) Descriptions Location on Consolidated Statements of Operations Net interest settlements and accruals on interest rate swaps Interest expense, net $ 6 $ 6 $ 17 $ 14 Fair value changes on interest rate swaps Interest expense, net $ (16) $ (7) $ (40) $ 53 Fair value changes on hedged debt Interest expense, net $ 16 $ 7 $ 40 $ (53)
Schedule of Net Investment Hedges, Notional Amount That Will Be Settled At Expiry	As of September 30, 2021 these hedges will expire and the notional amounts will be settled as follows unless terminated early at the discretion of the Company: Years Ending December 31, 2022 € 438 2023 € 442 2024 € 443 2026 € 450 2027 € 246 2028 € 507 Total € 2,526
Summary of Notional Amounts of Outstanding Foreign Exchange Forwards	The following table summarizes the notional amounts of the Company's outstanding forward contracts that were designated as net investment hedges: Notional amount of net investment hedges September 30, 2021 December 31, 2020 Sell Buy Sell Buy Contract to sell EUR for USD € — $ — € 524 $ 627 Contract to sell GBP for EUR £ — € — £ 134 € 148 The following table summarizes the notional amounts of the Company’s outstanding foreign exchange forwards: September 30, 2021 December 31, 2020 Notional amount of currency pair: Sell Buy Sell Buy Contracts to sell USD for GBP $ 190 £ 138 $ 295 £ 222 Contracts to sell USD for Japanese yen $ 18 ¥ 2,000 $ 15 ¥ 1,600 Contracts to sell USD for Canadian dollars $ 120 C$ 150 $ 107 C$ 140 Contracts to sell USD for Singapore dollars $ 66 S$ 90 $ 59 S$ 79 Contracts to sell USD for euros $ 282 € 240 $ 447 € 376 Contracts to sell Euros for GBP € — £ — € 135 £ 121 Contracts to sell USD for Russian ruble $ 13 ₽ 1,000 $ 13 ₽ 1,000 Contracts to sell USD for Indian rupee $ 18 ₹ 1,350 $ 18 ₹ 1,350 NOTE: € = euro, £ = British pound, $ = U.S. dollar, ¥ = Japanese yen, C$ = Canadian dollar, S$= Singapore dollars, ₽ = Russian ruble, ₹= Indian rupee
Amount of Gain/(Loss) Recognized in AOCI on Derivative Net Investment Hedging Relationships (Effectiveness Portion)	The following tables provide information on the gains/(losses) on the Company’s net investment and cash flow hedges: Derivative and Non-Derivative Instruments in Net Investment Hedging Relationships Amount of Gain/(Loss) Recognized in AOCL on Derivative, net of Tax Amount of Gain/(Loss) Reclassified from AOCL into Income, net of Tax Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing) Three Months Ended Three Months Ended Three Months Ended 2021 2020 2021 2020 2021 2020 FX forward contracts $ 2 $ 1 $ — $ — $ — $ — Cross currency swaps 44 (98) — — 8 10 Long-term debt 26 (46) — — — — Total net investment hedges $ 72 $ (143) $ — $ — $ 8 $ 10 Derivatives in Cash Flow Hedging Relationships Interest rate contracts 1 (1) (1) (1) — — Total cash flow hedges 1 (1) (1) (1) — — Total $ 73 $ (144) $ (1) $ (1) $ 8 $ 10 Derivative and Non-Derivative Instruments in Net Investment Hedging Relationships Amount of Gain/(Loss) Recognized in AOCL on Derivative, net of Tax Amount of Gain/(Loss) Reclassified from AOCL into Income, net of Tax Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing) Nine Months Ended September 30, Nine Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 2021 2020 FX forward contracts $ 18 $ 1 $ 1 $ — $ — $ — Cross currency swaps 98 (81) — — 27 40 Long-term debt 61 (47) — — — — Total net investment hedges $ 177 $ (127) $ 1 $ — $ 27 $ 40 Derivatives in Cash Flow Hedging Relationships Interest rate contracts — (51) (2) (2) — — Total cash flow hedges — (51) (2) (2) — — Total $ 177 $ (178) $ (1) $ (2) $ 27 $ 40
Components of Accumulated Other Comprehensive Income	The cumulative amount of net investment hedge and cash flow hedge gains (losses) remaining in AOCL is as follows: Cumulative Gains/(Losses), net of tax September 30, 2021 December 31, 2020 Net investment hedges Cross currency swaps $ (26) $ (124) FX forwards 29 12 Long-term debt (47) (108) Total net investment hedges $ (44) $ (220) Cash flow hedges Interest rate contracts $ (49) $ (51) Cross currency swaps 2 2 Total cash flow hedges (47) (49) Total net loss in AOCL $ (91) $ (269) The following tables show changes in AOCL by component (net of tax): Three Months Ended September 30, 2021 2020 Gains/(Losses) Pension and Other Retirement Benefits Cash Flow Hedges Foreign Currency Translation Adjustments Net Investment Hedges Total Pension and Other Retirement Benefits Cash Flow Hedges Foreign Currency Translation Adjustments Net Investment Hedges Total Balance June 30, $ (108) $ (48) $ (152) $ (117) $ (425) $ (84) $ (49) $ (479) $ 70 $ (542) Other comprehensive income/(loss) before reclassifications 3 — (116) 73 (40) (7) — 186 (143) 36 Amounts reclassified from AOCL 2 1 — — 3 2 — — — 2 Other comprehensive income/(loss) 5 1 (116) 73 (37) (5) — 186 (143) 38 Balance September 30, $ (103) $ (47) $ (268) $ (44) $ (462) $ (89) $ (49) $ (293) $ (73) $ (504) Nine Months Ended September 30, 2021 2020 Gains/(Losses) Pension and Other Retirement Benefits Cash Flow Hedges Foreign Currency Translation Adjustments Net Investment Hedges Total Pension and Other Retirement Benefits Cash Flow Hedges Foreign Currency Translation Adjustments Net Investment Hedges Total Balance December 31, $ (118) $ (49) $ (45) $ (220) $ (432) $ (92) $ — $ (401) $ 54 $ (439) Other comprehensive income/(loss) before reclassifications 3 — (223) 177 (43) (1) (50) 108 (127) (70) Amounts reclassified from AOCL 12 2 — (1) 13 4 1 — — 5 Other comprehensive income/(loss) 15 2 (223) 176 (30) 3 (49) 108 (127) (65) Balance September 30, $ (103) $ (47) $ (268) $ (44) $ (462) $ (89) $ (49) $ (293) $ (73) $ (504)
Gains and Losses Recognized in Consolidated Statement of Operations on Derivatives Not Designated as Hedging instruments	The following table summarizes the impact to the consolidated statements of operations relating to the net losses on the Company’s derivatives which are not designated as hedging instruments: Derivatives not designated as accounting hedges Location on Consolidated Statements of Operations Three Months Ended Nine Months Ended 2021 2020 2021 2020 Foreign exchange forwards Other non-operating income, net $ (18) $ 36 $ (25) $ 1 Foreign exchange forwards relating to RMS acquisition (1) Other non-operating income, net $ (13) $ — $ (13) $ — (1) The Company entered into a forward contract to sell $1,675 million for €1,200 to hedge a portion of the GBP denominated RMS purchase price. The contract was terminated on September 14, 2021 and resulted in a $13 million loss.
Fair Value of Derivative Instruments	The table below shows the classification between assets and liabilities on the Company’s consolidated balance sheets for the fair value of the derivative instrument as well as the carrying value of its non-derivative debt instruments designated and qualifying as net investment hedges: Derivative and Non-Derivative Instruments Balance Sheet Location September 30, 2021 December 31, 2020 Assets: Derivatives designated as accounting hedges: Cross-currency swaps designated as net investment hedges Other current assets $ 2 $ — Cross-currency swaps designated as net investment hedges Other assets 26 — Interest rate swaps designated as fair value hedges Other current assets 8 — Interest rate swaps designated as fair value hedges Other assets 23 57 Total derivatives designated as accounting hedges 59 57 Derivatives not designated as accounting hedges: FX forwards on certain assets and liabilities Other current assets — 31 Total assets $ 59 $ 88 Liabilities: Derivatives designated as accounting hedges: FX forwards designated as net investment hedges Accounts payable and accrued liabilities $ — $ 16 Cross-currency swaps designated as net investment hedges Accounts payable and accrued liabilities 7 23 Cross-currency swaps designated as net investment hedges Other liabilities 32 144 Interest rate swaps designated as fair value hedges Other liabilities 14 1 Total derivatives designated as accounting hedges 53 184 Non-derivatives designated as accounting hedges: Long-term debt designated as net investment hedge Long-term debt 1,448 1,530 Derivatives not designated as accounting hedges: FX forwards on certain assets and liabilities Accounts payable and accrued liabilities 10 2 Total liabilities $ 1,511 $ 1,716

GOODWILL AND OTHER ACQUIRED I_2

GOODWILL AND OTHER ACQUIRED INTANGIBLE ASSETS (Tables)	9 Months Ended
	Sep. 30, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Activity in Goodwill	The following table summarizes the activity in goodwill for the periods indicated: Nine Months Ended September 30, 2021 MIS MA Consolidated Gross goodwill Accumulated impairment Net Gross goodwill Accumulated Net Gross goodwill Accumulated Net Balance at beginning $ 311 $ — $ 311 $ 4,257 $ (12) $ 4,245 $ 4,568 $ (12) $ 4,556 Additions/ adjustments (1) 90 — 90 1,388 — 1,388 1,478 — 1,478 Foreign currency translation adjustments (5) — (5) (131) — (131) (136) — (136) Ending balance $ 396 $ — $ 396 $ 5,514 $ (12) $ 5,502 $ 5,910 $ (12) $ 5,898 Year Ended December 31, 2020 MIS MA Consolidated Gross goodwill Accumulated impairment charge Net goodwill Gross goodwill Accumulated impairment charge Net goodwill Gross goodwill Accumulated impairment charge Net goodwill Balance at beginning $ 315 $ — $ 315 $ 3,419 $ (12) $ 3,407 $ 3,734 $ (12) $ 3,722 Additions/ adjustments (2) (2) — (2) 628 — 628 626 — 626 Foreign currency translation (2) — (2) 210 — 210 208 — 208 Ending balance $ 311 $ — $ 311 $ 4,257 $ (12) $ 4,245 $ 4,568 $ (12) $ 4,556 (1) The 2021 additions/adjustments for the MA segment in the table above primarily relate to the acquisition of Cortera and RMS. The 2021 additions/adjustments for the MIS segment relate to certain revenue synergies from the RMS acquisition that are expected to benefit the ESG solutions group within the MIS Other LOB. (2) The 2020 additions/adjustments for the MA segment in the table above relate to the acquisitions of RDC, AM, ZMFS, and Catylist.
Acquired Intangible Assets and Related Amortization	Acquired intangible assets and related amortization consisted of: September 30, December 31, Customer relationships $ 2,108 $ 1,623 Accumulated amortization (360) (313) Net customer relationships 1,748 1,310 Software/product technology 654 441 Accumulated amortization (203) (177) Net software/product technology 451 264 Database 180 144 Accumulated amortization (42) (29) Net database 138 115 Trade names 207 161 Accumulated amortization (44) (38) Net trade names 163 123 Other (1) 54 55 Accumulated amortization (44) (43) Net other 10 12 Total acquired intangible assets, net $ 2,510 $ 1,824 (1) Other intangible assets primarily consist of trade secrets, covenants not to compete, and acquired ratings methodologies and models.
Amortization Expense Relating to Acquired Intangible Assets	Amortization expense relating to acquired intangible assets is as follows: Three Months Ended Nine Months Ended 2021 2020 2021 2020 Amortization expense $ 37 $ 31 $ 108 $ 90
Estimated Future Amortization Expense for Acquired Intangible Assets Subject to Amortization	Estimated future amortization expense for acquired intangible assets subject to amortization is as follows: Year Ending December 31, 2021 (After September 30,) $ 49 2022 194 2023 191 2024 187 2025 182 Thereafter 1,707 Total estimated future amortization $ 2,510

RESTRUCTURING (Tables)

RESTRUCTURING (Tables)	9 Months Ended
	Sep. 30, 2021
Restructuring and Related Activities [Abstract]
Restructuring Expenses Included in Consolidated Statements of Operations	Total expense included in the accompanying consolidated statements of operations relating to the aforementioned restructuring program is below: Three Months Ended Nine Months Ended 2021 2020 2021 2020 2018 Restructuring Program $ — $ — $ — $ (3) 2020 Real Estate Rationalization Restructuring Program — 23 — 23 2020 MA Strategic Reorganization Restructuring Program — — 2 — Total Restructuring $ — $ 23 $ 2 $ 20
Changes to the Restructuring Liability	Changes to the restructuring liability for the aforementioned restructuring program during the first nine months of 2021 were as follows: Employee Termination Costs Balance as of December 31, 2020 $ 18 2020 MA Strategic Reorganization Restructuring Program: Cost incurred and adjustments 2 Cash payments and adjustments (12) Balance as of September 30, 2021 $ 8 Cumulative expense incurred to date 2020 Real Estate Rationalization Restructuring Program $ 36 2020 MA Strategic Reorganization Restructuring Program $ 20

FAIR VALUE (Tables)

FAIR VALUE (Tables)	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Financial Instruments Carried at Fair Value on Recurring Basis	The table below presents information about items that are carried at fair value at September 30, 2021 and December 31, 2020: Fair value Measurement as of September 30, 2021 Description Balance Level 1 Level 2 Assets: Derivatives (1) $ 59 $ — $ 59 Mutual funds 58 58 — Total $ 117 $ 58 $ 59 Liabilities: Derivatives (1) $ 63 $ — $ 63 Total $ 63 $ — $ 63 Fair value Measurement as of December 31, 2020 Description Balance Level 1 Level 2 Assets: Derivatives (1) $ 88 $ — $ 88 Mutual funds 60 60 — Total $ 148 $ 60 $ 88 Liabilities: Derivatives (1) $ 186 $ — $ 186 Total $ 186 $ — $ 186 (1) Represents FX forward contracts, interest rate swaps and cross-currency swaps as more fully described in Note 9 to the condensed consolidated financial statements.

OTHER BALANCE SHEET AND STATE_2

OTHER BALANCE SHEET AND STATEMENT OF OPERATIONS INFORMATION (Tables)	9 Months Ended
	Sep. 30, 2021
Other Balance Sheet And Statement Of Operations Information [Abstract]
Additional Details Related to Certain Balance Sheet Captions	The following tables contain additional detail related to certain balance sheet captions: September 30, 2021 December 31, 2020 Other current assets: Prepaid taxes $ 81 $ 94 Prepaid expenses 98 91 Capitalized costs to obtain and fulfill sales contracts 89 93 Foreign exchange forwards on certain assets and liabilities — 31 Derivative instruments designated as accounting hedges 10 — Other 45 74 Total other current assets $ 323 $ 383 Other assets: Investments in non-consolidated affiliates $ 149 $ 135 Deposits for real-estate leases 15 19 Indemnification assets related to acquisitions 103 15 Mutual funds and fixed deposits 67 66 Company owned life insurance (at contract value) 35 17 Costs to obtain sales contracts 137 134 Derivative instruments designated as accounting hedges 49 57 Pension and other retirement employee benefits 19 21 Other 62 51 Total other assets $ 636 $ 515 Accounts payable and accrued liabilities: Salaries and benefits $ 196 $ 197 Incentive compensation 248 226 Customer credits, advanced payments and advanced billings 96 42 Dividends 5 11 Professional service fees 68 53 Interest accrued on debt 46 82 Accounts payable 30 39 Income taxes 201 128 Pension and other retirement employee benefits 46 45 Accrued royalties 19 19 Foreign exchange forwards on certain assets and liabilities 10 2 Restructuring liability 8 18 Derivative instruments designated as accounting hedges 7 39 Other 104 138 Total accounts payable and accrued liabilities $ 1,084 $ 1,039 September 30, 2021 December 31, 2020 Other liabilities: Pension and other retirement employee benefits $ 204 $ 244 Interest accrued on UTPs 82 113 MAKS indemnification provisions 33 33 Income tax liability - non-current portion 18 18 Derivative instruments designated as accounting hedges 46 145 Other 37 37 Total other liabilities $ 420 $ 590
Other Non-Operating	The following table summarizes the components of other non-operating income (expense): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 FX gain (loss) $ (2) $ 2 $ (2) $ 7 Purchase price hedge loss (1) (13) — (13) — Net periodic pension costs - other components 4 3 5 10 Income from investments in non-consolidated affiliates 6 4 15 4 Other 1 1 13 17 Total $ (4) $ 10 $ 18 $ 38 (1) The amounts for the three and nine months ended September 30, 2021 represent a loss on a forward contract used to hedge a portion of the GBP denominated RMS purchase price.

COMPREHENSIVE INCOME AND ACCU_2

COMPREHENSIVE INCOME AND ACCUMULATED OTHER COMPREHENSIVE LOSS (Tables)	9 Months Ended
	Sep. 30, 2021
Equity [Abstract]
Reclassifications out of AOCI	The following table provides details about the reclassifications out of AOCL: Three Months Ended September 30, Location in the consolidated statements of operations Losses on cash flow hedges 2021 2020 Interest rate contract $ (1) $ — Other non-operating income, net Income tax effect of item above — — Provision for income taxes Total net losses on cash flow hedges (1) — Pension and other retirement benefits Amortization of actuarial losses and prior service costs included in net income (2) (2) Other non-operating income, net Settlement charge (1) — Other non-operating income, net Total before income taxes (3) (2) Income tax effect of items above 1 — Provision for income taxes Total pension and other retirement benefits (2) (2) Total net losses included in Net Income attributable to reclassifications out of AOCL $ (3) $ (2) Nine Months Ended September 30, Location in the consolidated statements of operations Losses on cash flow hedges 2021 2020 Interest rate contract $ (2) $ (1) Other non-operating income, net Income tax effect of item above — — Provision for income taxes Total net losses on cash flow hedges (2) (1) Gains on net investment hedges FX forwards 2 — Other non-operating income, net Income tax effect of item above (1) — Provision for income taxes Total net gains on net investment hedges 1 — Pension and other retirement benefits Amortization of actuarial losses and prior service costs included in net income (8) (5) Other non-operating income, net Settlement charge (8) — Other non-operating income, net Total before income taxes (16) (5) Income tax effect of items above 4 1 Provision for income taxes Total pension and other retirement benefits (12) (4) Total net losses included in Net Income attributable to reclassifications out of AOCL $ (13) $ (5)
Components of Accumulated Other Comprehensive Income	The cumulative amount of net investment hedge and cash flow hedge gains (losses) remaining in AOCL is as follows: Cumulative Gains/(Losses), net of tax September 30, 2021 December 31, 2020 Net investment hedges Cross currency swaps $ (26) $ (124) FX forwards 29 12 Long-term debt (47) (108) Total net investment hedges $ (44) $ (220) Cash flow hedges Interest rate contracts $ (49) $ (51) Cross currency swaps 2 2 Total cash flow hedges (47) (49) Total net loss in AOCL $ (91) $ (269) The following tables show changes in AOCL by component (net of tax): Three Months Ended September 30, 2021 2020 Gains/(Losses) Pension and Other Retirement Benefits Cash Flow Hedges Foreign Currency Translation Adjustments Net Investment Hedges Total Pension and Other Retirement Benefits Cash Flow Hedges Foreign Currency Translation Adjustments Net Investment Hedges Total Balance June 30, $ (108) $ (48) $ (152) $ (117) $ (425) $ (84) $ (49) $ (479) $ 70 $ (542) Other comprehensive income/(loss) before reclassifications 3 — (116) 73 (40) (7) — 186 (143) 36 Amounts reclassified from AOCL 2 1 — — 3 2 — — — 2 Other comprehensive income/(loss) 5 1 (116) 73 (37) (5) — 186 (143) 38 Balance September 30, $ (103) $ (47) $ (268) $ (44) $ (462) $ (89) $ (49) $ (293) $ (73) $ (504) Nine Months Ended September 30, 2021 2020 Gains/(Losses) Pension and Other Retirement Benefits Cash Flow Hedges Foreign Currency Translation Adjustments Net Investment Hedges Total Pension and Other Retirement Benefits Cash Flow Hedges Foreign Currency Translation Adjustments Net Investment Hedges Total Balance December 31, $ (118) $ (49) $ (45) $ (220) $ (432) $ (92) $ — $ (401) $ 54 $ (439) Other comprehensive income/(loss) before reclassifications 3 — (223) 177 (43) (1) (50) 108 (127) (70) Amounts reclassified from AOCL 12 2 — (1) 13 4 1 — — 5 Other comprehensive income/(loss) 15 2 (223) 176 (30) 3 (49) 108 (127) (65) Balance September 30, $ (103) $ (47) $ (268) $ (44) $ (462) $ (89) $ (49) $ (293) $ (73) $ (504)

PENSION AND OTHER RETIREMENT _2

PENSION AND OTHER RETIREMENT BENEFITS (Tables)	9 Months Ended
	Sep. 30, 2021
Retirement Benefits [Abstract]
Components of Net Periodic Benefit Expense Related to Post-Retirement Plans	The components of net periodic benefit expense related to the Retirement Plans and Other Retirement Plans are as follows: Three Months Ended September 30, Pension Plans Other Retirement Plans 2021 2020 2021 2020 Components of net periodic expense Service cost $ 4 $ 5 $ 1 $ — Interest cost 4 4 — 1 Expected return on plan assets (7) (5) — — Amortization of net actuarial loss from earlier periods 3 2 — — Loss on settlement of pension obligation 1 — — — Net periodic expense $ 5 $ 6 $ 1 $ 1 Nine Months Ended September 30, Pension Plans Other Retirement Plans 2021 2020 2021 2020 Components of net periodic expense Service cost $ 14 $ 13 $ 3 $ 2 Interest cost 11 13 1 1 Expected return on plan assets (20) (15) — — Amortization of net actuarial loss from earlier periods 8 5 — — Loss on settlement of pension obligation 8 — — — Net periodic expense $ 21 $ 16 $ 4 $ 3

INDEBTEDNESS (Tables)

INDEBTEDNESS (Tables)	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Summary of Total Indebtedness	The following table summarizes total indebtedness: September 30, 2021 Notes Payable: Principal Amount Fair Value of Interest Rate Swaps (1) Unamortized (Discount) Premium Unamortized Debt Issuance Costs Carrying Value 4.50% 2012 Senior Notes, due 2022 $ 500 $ 7 $ — $ — $ 507 4.875% 2013 Senior Notes, due 2024 500 (5) (1) (1) 493 5.25% 2014 Senior Notes, due 2044 600 (4) 3 (5) 594 1.75% 2015 Senior Notes, due 2027 579 — — (2) 577 2.625% 2017 Senior Notes, due 2023 500 8 — (1) 507 3.25% 2017 Senior Notes, due 2028 500 15 (3) (3) 509 4.25% 2018 Senior Notes, due 2029 400 — (2) (2) 396 4.875% 2018 Senior Notes, due 2048 400 — (6) (4) 390 0.950% 2019 Senior Notes, due 2030 869 — (2) (5) 862 3.75% 2020 Senior Notes, due 2025 700 (5) (1) (4) 690 3.25% 2020 Senior Notes, due 2050 300 — (4) (3) 293 2.55% 2020 Senior Notes, due 2060 500 — (4) (5) 491 2.00% 2021 Senior Note, due 2031 600 — (8) (5) 587 2.75% 2021 Senior Note, due 2041 600 — (14) (6) 580 Total debt $ 7,548 $ 16 $ (42) $ (46) $ 7,476 Current portion (507) Total long-term debt $ 6,969 December 31, 2020 Notes Payable: Principal Amount Fair Value of Interest Rate Swaps (1) Unamortized (Discount) Premium Unamortized Debt Issuance Costs Carrying Value 4.50% 2012 Senior Notes, due 2022 $ 500 $ 14 $ (1) $ (1) $ 512 4.875% 2013 Senior Notes, due 2024 500 — (1) (1) 498 5.25% 2014 Senior Notes, due 2044 600 — 3 (5) 598 1.75% 2015 Senior Notes, due 2027 612 — — (2) 610 2.625% 2017 Senior Notes, due 2023 500 12 — (2) 510 3.25% 2017 Senior Notes, due 2028 500 31 (4) (3) 524 4.25% 2018 Senior Notes, due 2029 400 — (3) (3) 394 4.875% 2018 Senior Notes, due 2048 400 — (6) (4) 390 0.950% 2019 Senior Notes, due 2030 918 — (3) (6) 909 3.75% 2020 Senior Notes, due 2025 700 (1) (1) (5) 693 3.25% 2020 Senior Notes, due 2050 300 — (4) (3) 293 2.55% 2020 Senior Notes, due 2060 500 — (4) (5) 491 Total long-term debt $ 6,430 $ 56 $ (24) $ (40) $ 6,422 (1) The fair value of interest rate swaps in the table above represents the cumulative amount of fair value hedging adjustments included in the carrying amount of the hedged debt.
Principal Payments Due on Long-Term Borrowings	The repayment schedule for the Company’s borrowings is as follows: Year Ending December 31, 2012 Senior Notes due 2022 2013 Senior Notes due 2024 2014 Senior Notes due 2044 2015 Senior Notes due 2027 2017 Senior Notes due 2023 2017 Senior Notes due 2028 2018 Senior Notes due 2029 2018 Senior Notes due 2048 2019 Senior Notes due 2030 2020 Senior Notes due 2025 2020 Senior Notes due 2050 2020 Senior Notes due 2060 2021 Senior Notes due 2031 2021 Senior Notes due 2041 Total 2021 (After September 30,) $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — 2022 500 — — — — — — — — — — — — — $ 500 2023 — — — — 500 — — — — — — — — — $ 500 2024 — 500 — — — — — — — — — — — — $ 500 2025 — — — — — — — — — 700 — — — — $ 700 Thereafter — — 600 579 — 500 400 400 869 — 300 500 600 600 $ 5,348 Total $ 500 $ 500 $ 600 $ 579 $ 500 $ 500 $ 400 $ 400 $ 869 $ 700 $ 300 $ 500 $ 600 $ 600 $ 7,548
Summary of Components of Interest as Presented in Consolidated Statements of Operations	The following table summarizes the components of interest as presented in the consolidated statements of operations and the cash paid for interest: Three Months Ended Nine Months Ended 2021 2020 2021 2020 Income $ 3 $ 2 $ 7 $ 9 Expense on borrowings (47) (42) (129) (121) Income (expense) on UTPs and other tax related liabilities (2) (5) (9) 25 (27) Net periodic pension costs - interest component (4) (4) (12) (14) Interest expense, net $ (53) $ (53) $ (109) $ (153) Interest paid (1) $ 53 $ 47 $ 139 $ 119 (1) Interest paid includes net settlements on interest rate swaps more fully discussed in Note 9. (2) Income (expense) on UTPs and other tax related liabilities for the nine months ended September 30, 2021 includes a $40 million benefit relating to the reversal of tax-related interest accruals pursuant to the resolution of tax matters.
Fair Value and Carrying Value of Long-Term Debt	The fair value and carrying value of the Company’s debt as of September 30, 2021 and December 31, 2020 are as follows: September 30, 2021 December 31, 2020 Carrying Amount Estimated Fair Value Carrying Amount Estimated Fair Value 4.50% 2012 Senior Notes, due 2022 $ 507 $ 515 $ 512 $ 530 4.875% 2013 Senior Notes, due 2024 493 545 498 562 5.25% 2014 Senior Notes, due 2044 594 808 598 828 1.75% 2015 Senior Notes, due 2027 577 629 610 674 2.625% 2017 Senior Notes, due 2023 507 514 510 522 3.25% 2017 Senior Notes, due 2028 509 544 524 561 4.25% 2018 Senior Notes, due 2029 396 460 394 480 4.875% 2018 Senior Notes, due 2048 390 526 390 544 0.950% 2019 Senior Notes, due 2030 862 898 909 974 3.75% 2020 Senior Notes, due 2025 690 761 693 785 3.25% 2020 Senior Notes, due 2050 293 309 293 329 2.55% 2020 Senior Notes, due 2060 491 437 491 467 2.00% 2021 Senior Note, due 2031 587 588 — — 2.75% 2021 Senior Note, due 2041 580 584 — — Total $ 7,476 $ 8,118 $ 6,422 $ 7,256

LEASES (Tables)

LEASES (Tables)	9 Months Ended
	Sep. 30, 2021
Leases [Abstract]
Components of Lease Cost	The following table presents the components of the Company’s lease cost: Three Months Ended Nine Months Ended 2021 2020 2021 2020 Operating lease cost $ 24 $ 24 $ 71 $ 72 Sublease income (2) (1) (4) (3) Variable lease cost 5 4 15 14 Total lease cost $ 27 $ 27 $ 82 $ 83
Schedule of Operating Leases Information	The following tables present other information related to the Company’s operating leases: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Cash paid for amounts included in the measurement of operating lease liabilities $ 27 $ 27 $ 83 $ 80 Right-of-use assets obtained in exchange for new operating lease liabilities $ 117 $ 7 $ 123 $ 26 September 30, 2021 September 30, 2020 Weighted-average remaining lease term 5.9 years 6.3 years Weighted-average discount rate applied to operating leases 3.1 % 3.6 %
Lessee, Operating Lease, Liability, Maturity	The following table presents a maturity analysis of the future minimum lease payments included within the Company’s operating lease liabilities at September 30, 2021: Year Ending December 31, Operating Leases 2021 (After September 30) $ 30 2022 119 2023 115 2024 105 2025 90 After 2025 167 Total lease payments (undiscounted) 626 Less: Interest 53 Present value of lease liabilities: $ 573 Lease liabilities - current $ 103 Lease liabilities - noncurrent $ 470

SEGMENT INFORMATION (Tables)

SEGMENT INFORMATION (Tables)	9 Months Ended
	Sep. 30, 2021
Segment Reporting Information [Line Items]
Financial Information by Segment	The table below shows revenue, operating income and Adjusted Operating Income by reportable segment. Adjusted Operating Income is a financial metric utilized by the Company’s chief operating decision maker to assess the profitability of each reportable segment. Refer to Note 3 for further details on the components of the Company’s revenue. Three Months Ended September 30, 2021 2020 MIS MA Eliminations Consolidated MIS MA Eliminations Consolidated Revenue $ 967 $ 603 $ (44) $ 1,526 $ 863 $ 532 $ (39) $ 1,356 Total Expenses 404 490 (44) 850 339 414 (39) 714 Operating income 563 113 — 676 524 118 — 642 Add: Depreciation and 17 44 — 61 17 39 — 56 Restructuring — — — — 13 10 — 23 Adjusted Operating Income $ 580 $ 157 $ — $ 737 $ 554 $ 167 $ — $ 721 Nine Months Ended September 30, 2021 2020 MIS MA Eliminations Consolidated MIS MA Eliminations Consolidated Revenue $ 3,065 $ 1,744 $ (130) $ 4,679 $ 2,667 $ 1,529 $ (115) $ 4,081 Total Expenses 1,132 1,347 (130) 2,349 1,051 1,201 (115) 2,137 Operating income 1,933 397 — 2,330 1,616 328 — 1,944 Add: Depreciation and 53 127 — 180 52 111 — 163 Restructuring — 2 — 2 12 8 — 20 Loss pursuant to the divestiture of MAKS — — — — — 9 — 9 Adjusted Operating Income $ 1,986 $ 526 $ — $ 2,512 $ 1,680 $ 456 $ — $ 2,136
Company's Reportable Segment Revenues Disaggregated by Segment and Geographic Region	The following table presents the Company’s reportable segment revenues disaggregated by segment and geographic region: Three Months Ended Nine Months Ended 2021 2020 2021 2020 MIS: U.S. $ 580 $ 506 $ 1,809 $ 1,625 Non-U.S.: EMEA 211 188 707 542 Asia-Pacific 90 99 287 270 Americas 44 32 138 120 Total Non-U.S. 345 319 1,132 932 Total MIS 925 825 2,941 2,557 MA: U.S. 264 223 751 655 Non-U.S.: EMEA 228 213 691 595 Asia-Pacific 59 57 173 166 Americas 50 38 123 108 Total Non-U.S. 337 308 987 869 Total MA 601 531 1,738 1,524 Total MCO $ 1,526 $ 1,356 $ 4,679 $ 4,081
Operating Segments
Segment Reporting Information [Line Items]
Company's Reportable Segment Revenues Disaggregated by Segment and Geographic Region	Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 United States $ 844 $ 729 $ 2,560 $ 2,280 Non-U.S.: EMEA 439 401 1,398 1,137 Asia-Pacific 149 156 460 436 Americas 94 70 261 228 Total Non-U.S. 682 627 2,119 1,801 Total $ 1,526 $ 1,356 $ 4,679 $ 4,081

Description of Business and B_2

Description of Business and Basis of Presentation - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2021segment
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of reportable segments	2

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Details) - reporting_unit	3 Months Ended	6 Months Ended
	Mar. 31, 2021	Sep. 30, 2021
MA
Segment Reporting Information [Line Items]
Number of reporting units	5	2

Revenues - Revenue by Category

Revenues - Revenue by Category (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation of Revenue [Line Items]
Revenue	$ 1,526	$ 1,356	$ 4,679	$ 4,081
Eliminations
Disaggregation of Revenue [Line Items]
Revenue	(44)	(39)	(130)	(115)
MIS
Disaggregation of Revenue [Line Items]
Revenue	925	825	2,941	2,557
MIS | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	967	863	3,065	2,667
MIS | Eliminations
Disaggregation of Revenue [Line Items]
Revenue	42	38	124	110
MIS | Corporate Finance (CFG)
Disaggregation of Revenue [Line Items]
Revenue	488	461	1,643	1,486
MIS | Corporate Finance (CFG) | Investment-grade
Disaggregation of Revenue [Line Items]
Revenue	105	141	341	576
MIS | Corporate Finance (CFG) | High-yield
Disaggregation of Revenue [Line Items]
Revenue	82	101	347	275
MIS | Corporate Finance (CFG) | Bank loans
Disaggregation of Revenue [Line Items]
Revenue	145	73	482	205
MIS | Corporate Finance (CFG) | Other accounts
Disaggregation of Revenue [Line Items]
Revenue	156	146	473	430
MIS | Financial Institutions (FIG)
Disaggregation of Revenue [Line Items]
Revenue	153	134	465	401
MIS | Financial Institutions (FIG) | Other accounts
Disaggregation of Revenue [Line Items]
Revenue	2	2	7	7
MIS | Financial Institutions (FIG) | Banking
Disaggregation of Revenue [Line Items]
Revenue	105	95	315	269
MIS | Financial Institutions (FIG) | Insurance
Disaggregation of Revenue [Line Items]
Revenue	38	31	114	105
MIS | Financial Institutions (FIG) | Managed investments
Disaggregation of Revenue [Line Items]
Revenue	8	6	29	20
MIS | Public, Project And Infrastructure Finance (PPIF)
Disaggregation of Revenue [Line Items]
Revenue	130	133	403	375
MIS | Public, Project And Infrastructure Finance (PPIF) | Public finance / sovereign
Disaggregation of Revenue [Line Items]
Revenue	61	71	191	192
MIS | Public, Project And Infrastructure Finance (PPIF) | Project and infrastructure
Disaggregation of Revenue [Line Items]
Revenue	69	62	212	183
MIS | Structured Finance (SFG)
Disaggregation of Revenue [Line Items]
Revenue	143	88	399	265
MIS | Structured Finance (SFG) | Other accounts
Disaggregation of Revenue [Line Items]
Revenue	0	0	1	2
MIS | Structured Finance (SFG) | Asset-backed securities
Disaggregation of Revenue [Line Items]
Revenue	29	25	88	70
MIS | Structured Finance (SFG) | RMBS
Disaggregation of Revenue [Line Items]
Revenue	31	24	89	74
MIS | Structured Finance (SFG) | CMBS
Disaggregation of Revenue [Line Items]
Revenue	26	15	73	45
MIS | Structured Finance (SFG) | Structured credit
Disaggregation of Revenue [Line Items]
Revenue	57	24	148	74
MIS | Rating Revenue
Disaggregation of Revenue [Line Items]
Revenue	914	816	2,910	2,527
MIS | MIS Other
Disaggregation of Revenue [Line Items]
Revenue	11	9	31	30
MA
Disaggregation of Revenue [Line Items]
Revenue	601	531	1,738	1,524
MA | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	603	532	1,744	1,529
MA | Eliminations
Disaggregation of Revenue [Line Items]
Revenue	2	1	6	5
MA | Research, Data And Analytics (RD&A)
Disaggregation of Revenue [Line Items]
Revenue	445	386	1,299	1,110
MA | Enterprise Risk Solutions (ERS)
Disaggregation of Revenue [Line Items]
Revenue	$ 156	$ 145	$ 439	$ 414

Revenues - Revenues Disaggregat

Revenues - Revenues Disaggregated by Line of Business and Geographical Area (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation of Revenue [Line Items]
Revenue	$ 1,526	$ 1,356	$ 4,679	$ 4,081
United States
Disaggregation of Revenue [Line Items]
Revenue	844	729	2,560	2,280
Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	682	627	2,119	1,801
MIS
Disaggregation of Revenue [Line Items]
Revenue	925	825	2,941	2,557
MIS | United States
Disaggregation of Revenue [Line Items]
Revenue	580	506	1,809	1,625
MIS | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	345	319	1,132	932
MIS | Corporate Finance (CFG)
Disaggregation of Revenue [Line Items]
Revenue	488	461	1,643	1,486
MIS | Corporate Finance (CFG) | United States
Disaggregation of Revenue [Line Items]
Revenue	334	311	1,093	1,038
MIS | Corporate Finance (CFG) | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	154	150	550	448
MIS | Financial Institutions (FIG)
Disaggregation of Revenue [Line Items]
Revenue	153	134	465	401
MIS | Financial Institutions (FIG) | United States
Disaggregation of Revenue [Line Items]
Revenue	71	59	226	189
MIS | Financial Institutions (FIG) | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	82	75	239	212
MIS | Public, Project And Infrastructure Finance (PPIF)
Disaggregation of Revenue [Line Items]
Revenue	130	133	403	375
MIS | Public, Project And Infrastructure Finance (PPIF) | United States
Disaggregation of Revenue [Line Items]
Revenue	76	82	233	237
MIS | Public, Project And Infrastructure Finance (PPIF) | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	54	51	170	138
MIS | Structured Finance (SFG)
Disaggregation of Revenue [Line Items]
Revenue	143	88	399	265
MIS | Structured Finance (SFG) | United States
Disaggregation of Revenue [Line Items]
Revenue	98	54	254	160
MIS | Structured Finance (SFG) | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	45	34	145	105
MIS | Rating Revenue
Disaggregation of Revenue [Line Items]
Revenue	914	816	2,910	2,527
MIS | Rating Revenue | United States
Disaggregation of Revenue [Line Items]
Revenue	579	506	1,806	1,624
MIS | Rating Revenue | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	335	310	1,104	903
MIS | MIS Other
Disaggregation of Revenue [Line Items]
Revenue	11	9	31	30
MIS | MIS Other | United States
Disaggregation of Revenue [Line Items]
Revenue	1	0	3	1
MIS | MIS Other | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	10	9	28	29
MA
Disaggregation of Revenue [Line Items]
Revenue	601	531	1,738	1,524
MA | United States
Disaggregation of Revenue [Line Items]
Revenue	264	223	751	655
MA | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	337	308	987	869
MA | Research, Data And Analytics (RD&A)
Disaggregation of Revenue [Line Items]
Revenue	445	386	1,299	1,110
MA | Research, Data And Analytics (RD&A) | United States
Disaggregation of Revenue [Line Items]
Revenue	203	167	576	492
MA | Research, Data And Analytics (RD&A) | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	242	219	723	618
MA | Enterprise Risk Solutions (ERS)
Disaggregation of Revenue [Line Items]
Revenue	156	145	439	414
MA | Enterprise Risk Solutions (ERS) | United States
Disaggregation of Revenue [Line Items]
Revenue	61	56	175	163
MA | Enterprise Risk Solutions (ERS) | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	$ 95	$ 89	$ 264	$ 251

Revenues - Consolidated Revenue

Revenues - Consolidated Revenue Information by Geographic Area (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting Information [Line Items]
Revenue	$ 1,526	$ 1,356	$ 4,679	$ 4,081
MIS
Segment Reporting Information [Line Items]
Revenue	925	825	2,941	2,557
MA
Segment Reporting Information [Line Items]
Revenue	601	531	1,738	1,524
United States
Segment Reporting Information [Line Items]
Revenue	844	729	2,560	2,280
United States | MIS
Segment Reporting Information [Line Items]
Revenue	580	506	1,809	1,625
United States | MA
Segment Reporting Information [Line Items]
Revenue	264	223	751	655
Non-U.S.
Segment Reporting Information [Line Items]
Revenue	682	627	2,119	1,801
Non-U.S. | MIS
Segment Reporting Information [Line Items]
Revenue	345	319	1,132	932
Non-U.S. | MA
Segment Reporting Information [Line Items]
Revenue	337	308	987	869
EMEA
Segment Reporting Information [Line Items]
Revenue	439	401	1,398	1,137
EMEA | MIS
Segment Reporting Information [Line Items]
Revenue	211	188	707	542
EMEA | MA
Segment Reporting Information [Line Items]
Revenue	228	213	691	595
Asia-Pacific
Segment Reporting Information [Line Items]
Revenue	149	156	460	436
Asia-Pacific | MIS
Segment Reporting Information [Line Items]
Revenue	90	99	287	270
Asia-Pacific | MA
Segment Reporting Information [Line Items]
Revenue	59	57	173	166
Americas
Segment Reporting Information [Line Items]
Revenue	94	70	261	228
Americas | MIS
Segment Reporting Information [Line Items]
Revenue	44	32	138	120
Americas | MA
Segment Reporting Information [Line Items]
Revenue	$ 50	$ 38	$ 123	$ 108

Revenues - Transaction and Rela

Revenues - Transaction and Relationship Revenue (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation of Revenue [Line Items]
Revenue	$ 1,526	$ 1,356	$ 4,679	$ 4,081
Percentage of Revenues	100.00%	100.00%	100.00%	100.00%
MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 925	$ 825	$ 2,941	$ 2,557
Percentage of Revenues	100.00%	100.00%	100.00%	100.00%
MA
Disaggregation of Revenue [Line Items]
Revenue	$ 601	$ 531	$ 1,738	$ 1,524
Percentage of Revenues	100.00%	100.00%	100.00%	100.00%
Corporate Finance (CFG) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 488	$ 461	$ 1,643	$ 1,486
Percentage of Revenues	100.00%	100.00%	100.00%	100.00%
Financial Institutions (FIG) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 153	$ 134	$ 465	$ 401
Percentage of Revenues	100.00%	100.00%	100.00%	100.00%
Public, Project And Infrastructure Finance (PPIF) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 130	$ 133	$ 403	$ 375
Percentage of Revenues	100.00%	100.00%	100.00%	100.00%
Structured Finance (SFG) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 143	$ 88	$ 399	$ 265
Percentage of Revenues	100.00%	100.00%	100.00%	100.00%
MIS Other | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 11	$ 9	$ 31	$ 30
Percentage of Revenues	100.00%	100.00%	100.00%	100.00%
Research, Data And Analytics (RD&A) | MA
Disaggregation of Revenue [Line Items]
Revenue	$ 445	$ 386	$ 1,299	$ 1,110
Percentage of Revenues	100.00%	100.00%	100.00%	100.00%
Enterprise Risk Solutions (ERS) | MA
Disaggregation of Revenue [Line Items]
Revenue	$ 156	$ 145	$ 439	$ 414
Percentage of Revenues	100.00%	100.00%	100.00%	100.00%
Transaction Revenue
Disaggregation of Revenue [Line Items]
Revenue	$ 667	$ 599	$ 2,179	$ 1,874
Percentage of Revenues	44.00%	44.00%	47.00%	46.00%
Transaction Revenue | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 631	$ 548	$ 2,062	$ 1,731
Percentage of Revenues	68.00%	66.00%	70.00%	68.00%
Transaction Revenue | MA
Disaggregation of Revenue [Line Items]
Revenue	$ 36	$ 51	$ 117	$ 143
Percentage of Revenues	6.00%	10.00%	7.00%	9.00%
Transaction Revenue | Corporate Finance (CFG) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 366	$ 347	$ 1,280	$ 1,142
Percentage of Revenues	75.00%	75.00%	78.00%	77.00%
Transaction Revenue | Financial Institutions (FIG) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 83	$ 67	$ 252	$ 203
Percentage of Revenues	54.00%	50.00%	54.00%	51.00%
Transaction Revenue | Public, Project And Infrastructure Finance (PPIF) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 88	$ 92	$ 276	$ 257
Percentage of Revenues	68.00%	69.00%	68.00%	69.00%
Transaction Revenue | Structured Finance (SFG) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 93	$ 41	$ 251	$ 126
Percentage of Revenues	65.00%	47.00%	63.00%	48.00%
Transaction Revenue | MIS Other | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 1	$ 1	$ 3	$ 3
Percentage of Revenues	9.00%	11.00%	10.00%	10.00%
Transaction Revenue | Research, Data And Analytics (RD&A) | MA
Disaggregation of Revenue [Line Items]
Revenue	$ 21	$ 19	$ 63	$ 53
Percentage of Revenues	5.00%	5.00%	5.00%	5.00%
Transaction Revenue | Enterprise Risk Solutions (ERS) | MA
Disaggregation of Revenue [Line Items]
Revenue	$ 15	$ 32	$ 54	$ 90
Percentage of Revenues	10.00%	22.00%	12.00%	22.00%
Recurring Revenue
Disaggregation of Revenue [Line Items]
Revenue	$ 859	$ 757	$ 2,500	$ 2,207
Percentage of Revenues	56.00%	56.00%	53.00%	54.00%
Recurring Revenue | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 294	$ 277	$ 879	$ 826
Percentage of Revenues	32.00%	34.00%	30.00%	32.00%
Recurring Revenue | MA
Disaggregation of Revenue [Line Items]
Revenue	$ 565	$ 480	$ 1,621	$ 1,381
Percentage of Revenues	94.00%	90.00%	93.00%	91.00%
Recurring Revenue | Corporate Finance (CFG) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 122	$ 114	$ 363	$ 344
Percentage of Revenues	25.00%	25.00%	22.00%	23.00%
Recurring Revenue | Financial Institutions (FIG) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 70	$ 67	$ 213	$ 198
Percentage of Revenues	46.00%	50.00%	46.00%	49.00%
Recurring Revenue | Public, Project And Infrastructure Finance (PPIF) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 42	$ 41	$ 127	$ 118
Percentage of Revenues	32.00%	31.00%	32.00%	31.00%
Recurring Revenue | Structured Finance (SFG) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 50	$ 47	$ 148	$ 139
Percentage of Revenues	35.00%	53.00%	37.00%	52.00%
Recurring Revenue | MIS Other | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 10	$ 8	$ 28	$ 27
Percentage of Revenues	91.00%	89.00%	90.00%	90.00%
Recurring Revenue | Research, Data And Analytics (RD&A) | MA
Disaggregation of Revenue [Line Items]
Revenue	$ 424	$ 367	$ 1,236	$ 1,057
Percentage of Revenues	95.00%	95.00%	95.00%	95.00%
Recurring Revenue | Enterprise Risk Solutions (ERS) | MA
Disaggregation of Revenue [Line Items]
Revenue	$ 141	$ 113	$ 385	$ 324
Percentage of Revenues	90.00%	78.00%	88.00%	78.00%

Revenues - Revenue Recognition

Revenues - Revenue Recognition Timing (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation of Revenue [Line Items]
Revenue recognized	$ 1,526	$ 1,356	$ 4,679	$ 4,081
At Point in Time
Disaggregation of Revenue [Line Items]
Revenue recognized	660	578	2,140	1,820
Over Time
Disaggregation of Revenue [Line Items]
Revenue recognized	866	778	2,539	2,261
MIS
Disaggregation of Revenue [Line Items]
Revenue recognized	925	825	2,941	2,557
MIS | At Point in Time
Disaggregation of Revenue [Line Items]
Revenue recognized	631	548	2,062	1,731
MIS | Over Time
Disaggregation of Revenue [Line Items]
Revenue recognized	294	277	879	826
MA
Disaggregation of Revenue [Line Items]
Revenue recognized	601	531	1,738	1,524
MA | At Point in Time
Disaggregation of Revenue [Line Items]
Revenue recognized	29	30	78	89
MA | Over Time
Disaggregation of Revenue [Line Items]
Revenue recognized	$ 572	$ 501	$ 1,660	$ 1,435

Revenues - Additional Informati

Revenues - Additional Information (Detail) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
MIS
Disaggregation of Revenue [Line Items]
Unbilled Receivables	$ 425	$ 361
MA
Disaggregation of Revenue [Line Items]
Unbilled Receivables	$ 128	$ 98

Revenues - Schedule of Changes

Revenues - Schedule of Changes in the Deferred Revenue Balances (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Change in Contract with Customer, Liability [Abstract]
Beginning Balance	$ 1,235	$ 1,105	$ 1,187	$ 1,162
Revenue recognized that was included in the deferred revenue balance at the beginning of the period	(602)	(465)	(1,014)	(988)
Increases due to amounts billable excluding amounts recognized as revenue during the period	478	356	937	826
Increases due to acquisitions during the period	89	0	93	20
Effect of exchange rate changes	(14)	24	(17)	0
Total changes in deferred revenue	(49)	(85)	(1)	(142)
Ending Balance	1,186	1,020	1,186	1,020
Deferred revenue - current	1,099	918	1,099	918	$ 1,089
Deferred revenue - non-current	87	102	87	102	$ 98
MIS
Change in Contract with Customer, Liability [Abstract]
Beginning Balance	368	365	313	322
Revenue recognized that was included in the deferred revenue balance at the beginning of the period	(118)	(118)	(200)	(207)
Increases due to amounts billable excluding amounts recognized as revenue during the period	85	83	224	219
Increases due to acquisitions during the period	0	0	0	0
Effect of exchange rate changes	(2)	5	(4)	1
Total changes in deferred revenue	(35)	(30)	20	13
Ending Balance	333	335	333	335
Deferred revenue - current	247	237	247	237
Deferred revenue - non-current	86	98	86	98
MA
Change in Contract with Customer, Liability [Abstract]
Beginning Balance	867	740	874	840
Revenue recognized that was included in the deferred revenue balance at the beginning of the period	(484)	(347)	(814)	(781)
Increases due to amounts billable excluding amounts recognized as revenue during the period	393	273	713	607
Increases due to acquisitions during the period	89	0	93	20
Effect of exchange rate changes	(12)	19	(13)	(1)
Total changes in deferred revenue	(14)	(55)	(21)	(155)
Ending Balance	853	685	853	685
Deferred revenue - current	852	681	852	681
Deferred revenue - non-current	$ 1	$ 4	$ 1	$ 4

Revenues - Expected Recognition

Revenues - Expected Recognition Period for Remaining Performance Obligations (Detail) $ in Millions	Sep. 30, 2021USD ($)
MIS
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 120
MIS | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, percentage	20.00%
Revenue, remaining performance obligation, period	1 year
MIS | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, percentage	50.00%
Revenue, remaining performance obligation, period	4 years
MA
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 2,700
MA | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, percentage	65.00%
Revenue, remaining performance obligation, period	1 year
MA | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, percentage	25.00%
Revenue, remaining performance obligation, period	1 year

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock-Based Compensation Cost and Associated Tax Benefit (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-based Payment Arrangement, Noncash Expense [Abstract]
Stock-based compensation cost	$ 41	$ 38	$ 127	$ 110
Tax benefit	$ 8	$ 8	$ 29	$ 22

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	Sep. 15, 2021	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation cost		$ 41	$ 38	$ 127	$ 110
Employee stock options, granted (in shares)				0.2
Employee stock options, weighted average grant date fair value (in usd per share)				$ 113.91
RMS
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted, value, share-based payment arrangement, before forfeiture	$ 32
Unvested equity awards	5
Stock-based compensation cost	$ 27
RMS | 2015 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (shares)	1.2
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Other than options, shares granted (in shares)				0.6
Other than options, weighted average grant date fair value (in usd per share)				$ 286.08
Award vesting period (in years)				4 years
Unrecognized compensation expense		211		$ 211
Weighted average period to recognize expense				2 years 6 months
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)				4 years
Unrecognized compensation expense		25		$ 25
Weighted average period to recognize expense				2 years 3 months 18 days
Performance Based Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Other than options, shares granted (in shares)				0.1
Other than options, weighted average grant date fair value (in usd per share)				$ 269.88
Award vesting period (in years)				3 years
Unrecognized compensation expense		$ 35		$ 35
Weighted average period to recognize expense				2 years

Stock-Based Compensation - Weig

Stock-Based Compensation - Weighted Average Assumptions used in Determining Fair Value for Options Granted (Detail)	9 Months Ended
	Sep. 30, 2021
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected dividend yield	0.89%
Expected stock volatility	28.00%
Risk-free interest rate	0.81%
Expected holding period	5 years 7 months 6 days

Stock-Based Compensation - St_2

Stock-Based Compensation - Stock Option Exercises and Restricted Stock Vesting (Detail) - USD ($) shares in Millions, $ in Millions	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Proceeds from stock option exercises	$ 20	$ 32
Aggregate intrinsic value	44	102
Tax benefit realized upon exercise	$ 11	$ 24
Number of shares exercised (shares)	0.2	0.5
Restricted Stock
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Fair value of shares vested	$ 193	$ 195
Tax benefit realized upon vesting	$ 45	$ 45
Number of shares vested (shares)	0.7	0.8
Performance Based Restricted Stock
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Fair value of shares vested	$ 28	$ 70
Tax benefit realized upon vesting	$ 7	$ 17
Number of shares vested (shares)	0.1	0.3

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Effective tax rate (percent)	23.40%		22.00%	20.20%	20.00%
Excess tax benefits from stock compensation				$ 29
Reduction resulting from lapse of applicable statute of limitations and settlement				66
Overall increase (decrease) in unrecognized tax benefits (UTPs)	$ 85			9
Overall increase (decrease) in unrecognized tax benefits (UTPs), net of federal tax	$ 84			17
Interest accrued on UTPs		$ 40		$ 40

Income Taxes - Income Taxes Pai

Income Taxes - Income Taxes Paid (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Income taxes paid	$ 501	$ 374

Weighted Average Shares Outst_3

Weighted Average Shares Outstanding - Reconciliation of Basic to Diluted Shares Outstanding (Detail) - shares shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Earnings Per Share [Abstract]
Basic (in shares)	186	187.8	186.6	187.6
Dilutive effect of shares issuable under stock-based compensation plans (in shares)	1.3	1.5	1.4	1.7
Diluted (in shares)	187.3	189.3	188	189.3
Anti-dilutive options to purchase common shares and restricted stock as well as contingently issuable restricted stock which are excluded from the table above (in shares)	0.1	0.3	0.2	0.3

Cash Equivalents and Investme_3

Cash Equivalents and Investments (Detail) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Cash and Cash Equivalents [Line Items]
Fair Value	$ 58	$ 60
Cash and cash equivalents	2,239	2,597
Short-term investments	104	99
Other assets	636	515
Certificates of deposit and money market deposit accounts
Cash and Cash Equivalents [Line Items]
Cost	1,004	1,430
Gains/(Losses)	0	0
Fair Value	1,004	1,430
Cash and cash equivalents	891	1,325
Short-term investments	104	99
Other assets	9	6
Mutual funds
Cash and Cash Equivalents [Line Items]
Cost	50	54
Gains/(Losses)	8	6
Fair Value	58	60
Cash and cash equivalents	0	0
Short-term investments	0	0
Other assets	$ 58	$ 60

Cash Equivalents and Investme_4

Cash Equivalents and Investments (Footnote) (Detail) - Certificates of deposit and money market deposit accounts	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Short-term Investments | Minimum
Cash and Cash Equivalents [Line Items]
Securities maturity period	1 month
Short-term Investments | Maximum
Cash and Cash Equivalents [Line Items]
Securities maturity period		12 months
Other assets | Minimum
Cash and Cash Equivalents [Line Items]
Securities maturity period	13 months	13 months
Other assets | Maximum
Cash and Cash Equivalents [Line Items]
Securities maturity period	24 months	23 months
Cash and Cash Equivalents | Maximum
Cash and Cash Equivalents [Line Items]
Securities maturity period	90 days

Cash Equivalents and Investme_5

Cash Equivalents and Investments (Narrative) (Detail) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Cash and Cash Equivalents [Abstract]
Company owned life insurance (at contract value)	$ 35	$ 17

Acquisitions - Narrative (Detai

Acquisitions - Narrative (Details) - USD ($) $ in Millions	Sep. 15, 2021	Mar. 19, 2021	Feb. 13, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Business Acquisition [Line Items]
Goodwill				$ 5,898		$ 4,556	$ 3,722
MA
Business Acquisition [Line Items]
Goodwill				5,502		4,245	3,407
MIS
Business Acquisition [Line Items]
Goodwill				396		$ 311	$ 315
RMS
Business Acquisition [Line Items]
Business acquisition interests acquired	100.00%
Total consideration	$ 1,936
Goodwill	1,389
Indemnification asset, amount	88
Transaction costs	22
RMS | Fair Value Adjustment to Deferred Revenue
Business Acquisition [Line Items]
Revenues				$ 3	$ (21)
RMS | MA
Business Acquisition [Line Items]
Goodwill	1,299
RMS | MIS
Business Acquisition [Line Items]
Goodwill	$ 90
Cortera
Business Acquisition [Line Items]
Business acquisition interests acquired		100.00%
Total consideration		$ 139
Goodwill		$ 79
Regulatory Data Corporation
Business Acquisition [Line Items]
Business acquisition interests acquired			100.00%
Total consideration			$ 702
Goodwill			$ 494

Acquisitions - Total Considerat

Acquisitions - Total Consideration Relating to Acquisition (Details) - USD ($) $ in Millions	Sep. 15, 2021	Mar. 19, 2021	Feb. 13, 2020
RMS
Business Acquisition [Line Items]
Cash paid at closing	$ 1,931
Replacement equity compensation awards	5
Total consideration	$ 1,936
Cortera
Business Acquisition [Line Items]
Cash paid at closing		$ 138
Additional consideration to be paid to sellers		1
Total consideration		$ 139
Regulatory Data Corporation
Business Acquisition [Line Items]
Cash paid at closing			$ 700
Additional consideration to be paid to sellers			2
Total consideration			$ 702

Acquisitions - Purchase Price A

Acquisitions - Purchase Price Allocation (Details) - USD ($) $ in Millions	Sep. 15, 2021	Mar. 19, 2021	Feb. 13, 2020	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Business Acquisition [Line Items]
Goodwill				$ 5,898	$ 4,556	$ 3,722
RMS
Business Acquisition [Line Items]
Cash	$ 60
Accounts receivable	38
Other current assets	11
Property and equipment, net	13
Operating lease right-of-use assets	64
Total intangible assets	784
Goodwill	1,389
Deferred tax assets, net	46
Other assets	92
Liabilities:
Accounts payable and accrued liabilities	(101)
Deferred revenue	(89)
Operating lease liabilities	(68)
Deferred tax liabilities	(213)
Uncertain tax positions	(90)
Total liabilities	(561)
Net assets acquired	$ 1,936
Acquired finite-lived intangible asset, useful life	18 years	11 years
RMS | Database
Liabilities:
Finite-lived intangible asset, useful life		10 years
RMS | Customer relationships
Business Acquisition [Line Items]
Total intangible assets	$ 523
Liabilities:
Finite-lived intangible asset, useful life	23 years	18 years
RMS | Product technology
Business Acquisition [Line Items]
Total intangible assets	$ 212
Liabilities:
Finite-lived intangible asset, useful life	7 years
RMS | Software/product technology
Liabilities:
Finite-lived intangible asset, useful life		8 years
RMS | Trade names
Business Acquisition [Line Items]
Total intangible assets	$ 49
Liabilities:
Finite-lived intangible asset, useful life	9 years	5 years
Cortera
Business Acquisition [Line Items]
Cash		$ 4
Accounts receivable		2
Current assets		7
Total intangible assets		57
Goodwill		79
Deferred tax assets, net		16
Other assets		2
Liabilities:
Accounts payable and accrued liabilities		(1)
Deferred revenue		(4)
Deferred tax liabilities		(15)
Other liabilities		(2)
Total liabilities		(22)
Net assets acquired		139
Cortera | Database
Business Acquisition [Line Items]
Total intangible assets		38
Cortera | Customer relationships
Business Acquisition [Line Items]
Total intangible assets		9
Cortera | Software/product technology
Business Acquisition [Line Items]
Total intangible assets		9
Cortera | Trade names
Business Acquisition [Line Items]
Total intangible assets		$ 1
Regulatory Data Corporation
Business Acquisition [Line Items]
Cash			$ 6
Accounts receivable			14
Current assets			24
Total intangible assets			280
Goodwill			494
Other assets			2
Liabilities:
Accounts payable and accrued liabilities			(5)
Deferred revenue			(20)
Deferred tax liabilities			(71)
Other liabilities			(2)
Total liabilities			(98)
Net assets acquired			$ 702
Acquired finite-lived intangible asset, useful life			19 years
Regulatory Data Corporation | Database
Business Acquisition [Line Items]
Total intangible assets			$ 86
Liabilities:
Finite-lived intangible asset, useful life			10 years
Regulatory Data Corporation | Customer relationships
Business Acquisition [Line Items]
Total intangible assets			$ 174
Liabilities:
Finite-lived intangible asset, useful life			25 years
Regulatory Data Corporation | Software/product technology
Business Acquisition [Line Items]
Total intangible assets			$ 17
Liabilities:
Finite-lived intangible asset, useful life			4 years
Regulatory Data Corporation | Trade names
Business Acquisition [Line Items]
Total intangible assets			$ 3
Liabilities:
Finite-lived intangible asset, useful life			3 years

Acquisitions - Pro Forma Inform

Acquisitions - Pro Forma Information (Details) - RMS - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Pro forma Revenue	$ 4,910	$ 4,300
Pro forma Net Income attributable to Moody's	$ 1,807	$ 1,342

Derivative Instruments And He_3

Derivative Instruments And Hedging Activities - Schedule of Interest Rate Swap (Details) - Fair Value Hedging - Interest Rate Swap - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Derivative [Line Items]
Notional Amount	$ 1,980	$ 1,380
2012 Senior Notes due 2022
Derivative [Line Items]
Nature of Swap	Pay Floating/Receive Fixed
Notional Amount	$ 330	330
Floating Interest Rate	3-month USD LIBOR
2017 Senior Notes due 2023
Derivative [Line Items]
Nature of Swap	Pay Floating/Receive Fixed
Notional Amount	$ 250	250
Floating Interest Rate	3-month USD LIBOR
2017 Senior Notes due 2028
Derivative [Line Items]
Nature of Swap	Pay Floating/Receive Fixed
Notional Amount	$ 500	500
Floating Interest Rate	3-month USD LIBOR
2020 Senior Notes due 2025
Derivative [Line Items]
Nature of Swap	Pay Floating/Receive Fixed
Notional Amount	$ 300	300
Floating Interest Rate	6-month USD LIBOR
2014 Senior Notes due 2044
Derivative [Line Items]
Nature of Swap	Pay Floating/Receive Fixed
Notional Amount	$ 300	0
Floating Interest Rate	3-month USD LIBOR
2018 Senior Notes due 2048
Derivative [Line Items]
Nature of Swap	Pay Floating/Receive Fixed
Notional Amount	$ 300	$ 0
Floating Interest Rate	3-month USD LIBOR

Derivative Instruments And He_4

Derivative Instruments And Hedging Activities - Summary of Net Gain (Loss) on Interest Rate Swaps Designated in Fair Value Hedge (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Derivative Instruments, Gain (Loss) [Line Items]
Interest expense, net	$ (53)	$ (53)	$ (109)	$ (153)
Designated as Hedging Instrument | Interest Rate Swap | Interest Expense
Derivative Instruments, Gain (Loss) [Line Items]
Fair value changes on interest rate swaps	(16)	(7)	(40)	53
Fair value changes on hedged debt	16	7	40	(53)
Designated as Hedging Instrument | Interest Rate Swap | Interest Expense | Fair Value hedge Net Interest Settlements and Accruals
Derivative Instruments, Gain (Loss) [Line Items]
Net interest settlements and accruals on interest rate swaps	$ 6	$ 6	$ 17	$ 14

Derivative Instruments And He_5

Derivative Instruments And Hedging Activities - Additional Information (Detail)	1 Months Ended
	Jan. 31, 2020USD ($)	Sep. 30, 2021USD ($)	Sep. 30, 2021EUR (€)	Dec. 31, 2020USD ($)	Apr. 30, 2020USD ($)
Derivative [Line Items]
Cumulative loss		$ 462,000,000		$ 432,000,000
Designated as Hedging Instrument
Derivative [Line Items]
Cumulative loss		91,000,000		269,000,000
Net Investment Hedging | Designated as Hedging Instrument
Derivative [Line Items]
Cumulative loss		44,000,000		220,000,000
Net Investment Hedging | Designated as Hedging Instrument | Cross-currency swap
Derivative [Line Items]
Notional Amount | €			€ 2,526,000,000
Cumulative loss		26,000,000		124,000,000
Cash Flow Hedging | Forward Contracts
Derivative [Line Items]
Cumulative loss					$ 68,000,000
Cash Flow Hedging | Designated as Hedging Instrument
Derivative [Line Items]
Cumulative loss		47,000,000		49,000,000
Cash Flow Hedging | Designated as Hedging Instrument | Cross-currency swap
Derivative [Line Items]
Cumulative loss		$ (2,000,000)		$ (2,000,000)
Cash Flow Hedging | Designated as Hedging Instrument | Forward Contracts
Derivative [Line Items]
Notional Amount	$ 300,000,000
Forward interest rate	2.0103%
Debt instrument, term	30 years
1.75% 2015 Senior Notes, due 2027
Derivative [Line Items]
Notes payable, interest rate		1.75%	1.75%	1.75%
1.75% 2015 Senior Notes, due 2027 | Net Investment Hedging | Designated as Hedging Instrument | Cross-currency swap
Derivative [Line Items]
Notional Amount | €			€ 500,000,000
2019 Senior Notes Due 2030 | Net Investment Hedging | Designated as Hedging Instrument | Cross-currency swap
Derivative [Line Items]
Notional Amount | €			€ 750,000,000
3.25% 2020 Senior Notes, due 2050
Derivative [Line Items]
Notes payable, interest rate		3.25%	3.25%	3.25%

Derivative Instruments And He_6

Derivative Instruments And Hedging Activities - Summary of Notional Amounts of Outstanding Cross Currency Swap (Detail) - Cross-currency swap - Net Investment Hedging € in Millions, $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2021USD ($)	Dec. 31, 2020USD ($)	Sep. 30, 2021EUR (€)	Dec. 31, 2020EUR (€)
3.96%
Derivative [Line Items]
Nature of Swap	Pay Fixed/Receive Fixed	Pay Fixed/Receive Fixed
3-month U.S. LIBOR
Derivative [Line Items]
Nature of Swap	Pay Floating/Receive Floating	Pay Floating/Receive Floating
Currency Paid
Derivative [Line Items]
Notional Amount | €			€ 2,526	€ 2,038
Currency Paid | 1.43%
Derivative [Line Items]
Notional Amount | €			€ 1,060	€ 1,079
Weighted Average Fixed Interest Rate	2.15%	1.43%	2.15%	1.43%
Currency Paid | 3-month EURIBOR
Derivative [Line Items]
Notional Amount | €			€ 1,466	€ 959
Weighted Average Floating Interest Rate	Based on 3-month EURIBOR	Based on 3-month EURIBOR
Currency Received
Derivative [Line Items]
Notional Amount | $	$ 2,900	$ 2,300
Currency Received | 3.96%
Derivative [Line Items]
Notional Amount | $	$ 1,220	$ 1,220
Weighted Average Fixed Interest Rate	4.45%	3.96%	4.45%	3.96%
Currency Received | 3-month U.S. LIBOR
Derivative [Line Items]
Notional Amount | $	$ 1,680	$ 1,080
Weighted Average Floating Interest Rate	Based on 3-month USD LIBOR	Based on 3-month USD LIBOR

Derivative Instruments And He_7

Derivative Instruments And Hedging Activities - Schedule of Notional Amount of Net Investment Hedges (Detail) - Designated as Hedging Instrument - Cross-currency swap € in Millions	Sep. 30, 2021EUR (€)
Net Investment Hedging
Derivative [Line Items]
Notional Amount	€ 2,526
2022
Derivative [Line Items]
Notional Amount	438
2023
Derivative [Line Items]
Notional Amount	442
2024
Derivative [Line Items]
Notional Amount	443
2026
Derivative [Line Items]
Notional Amount	450
2027
Derivative [Line Items]
Notional Amount	246
2028
Derivative [Line Items]
Notional Amount	€ 507

Derivative Instruments And He_8

Derivative Instruments And Hedging Activities - Summary of Notional Amounts of Outstanding Forward Contracts Designated as a Net Investment Hedge (Detail) - Net Investment Hedging - Designated as Hedging Instrument € in Millions, £ in Millions, $ in Millions	Sep. 30, 2021USD ($)	Sep. 30, 2021EUR (€)	Sep. 30, 2021GBP (£)	Dec. 31, 2020USD ($)	Dec. 31, 2020EUR (€)	Dec. 31, 2020GBP (£)
Contract to sell EUR for USD
Derivative [Line Items]
Notional Amount	$ 0	€ 0		$ 627	€ 524
Contract to sell GBP for EUR
Derivative [Line Items]
Notional Amount		€ 0	£ 0		€ 148	£ 134

Derivative Instruments And He_9

Derivative Instruments And Hedging Activities - Gains (Losses) Recognized in AOCI and Reclassified from AOCI on Derivatives (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Hedging Relationships, Amount of Gain/(Loss) Recognized in AOCI on Derivative, net of Tax			$ 0	$ (50)
Total, Amount of Gain/(Loss) Recognized in AOCI on Derivative, net of Tax	$ 73	$ (144)	177	(178)
Net investment hedges - reclassification of gains included in net income - Net of Tax			1	0
Cash Flow Hedging Relationships, Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax	(1)	0	(2)	(1)
Total, Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax	(1)	(1)	(1)	(2)
Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	8	10	27	40
Net Investment Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Net Investment Hedging Relationships, Amount of Gain/(Loss) Recognized in AOCI on Derivative, net of Tax	72	(143)	177	(127)
Net investment hedges - reclassification of gains included in net income - Net of Tax	0	0	1	0
Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	8	10	27	40
Cash Flow Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Hedging Relationships, Amount of Gain/(Loss) Recognized in AOCI on Derivative, net of Tax	1	(1)	0	(51)
Cash Flow Hedging Relationships, Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax	(1)	(1)	(2)	(2)
Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	0	0	0	0
FX forwards | Net Investment Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Net Investment Hedging Relationships, Amount of Gain/(Loss) Recognized in AOCI on Derivative, net of Tax	2	1	18	1
Net investment hedges - reclassification of gains included in net income - Net of Tax	0	0	1	0
Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	0	0	0	0
Cross-currency swap | Net Investment Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Net Investment Hedging Relationships, Amount of Gain/(Loss) Recognized in AOCI on Derivative, net of Tax	44	(98)	98	(81)
Net investment hedges - reclassification of gains included in net income - Net of Tax	0	0	0	0
Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	8	10	27	40
Long-term debt | Net Investment Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Net Investment Hedging Relationships, Amount of Gain/(Loss) Recognized in AOCI on Derivative, net of Tax	26	(46)	61	(47)
Net investment hedges - reclassification of gains included in net income - Net of Tax	0	0	0	0
Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	0	0	0	0
Interest rate contract | Cash Flow Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Hedging Relationships, Amount of Gain/(Loss) Recognized in AOCI on Derivative, net of Tax	1	(1)	0	(51)
Cash Flow Hedging Relationships, Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax	(1)	(1)	(2)	(2)
Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	$ 0	$ 0	$ 0	$ 0

Derivative Instruments And H_10

Derivative Instruments And Hedging Activities - Cumulative Amount of Unrecognized Hedge Losses Recorded in AOCI (Detail) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Derivative [Line Items]
Cumulative Gains/(Losses), net of tax	$ (462)	$ (432)
Designated as Hedging Instrument
Derivative [Line Items]
Cumulative Gains/(Losses), net of tax	(91)	(269)
Net Investment Hedging | Designated as Hedging Instrument
Derivative [Line Items]
Cumulative Gains/(Losses), net of tax	(44)	(220)
Net Investment Hedging | Cross currency swaps | Designated as Hedging Instrument
Derivative [Line Items]
Cumulative Gains/(Losses), net of tax	(26)	(124)
Net Investment Hedging | FX forwards | Designated as Hedging Instrument
Derivative [Line Items]
Cumulative Gains/(Losses), net of tax	29	12
Net Investment Hedging | Long-term debt | Designated as Hedging Instrument
Derivative [Line Items]
Cumulative Gains/(Losses), net of tax	(47)	(108)
Cash Flow Hedging | Designated as Hedging Instrument
Derivative [Line Items]
Cumulative Gains/(Losses), net of tax	(47)	(49)
Cash Flow Hedging | Cross currency swaps | Designated as Hedging Instrument
Derivative [Line Items]
Cumulative Gains/(Losses), net of tax	2	2
Cash Flow Hedging | Interest rate contract | Designated as Hedging Instrument
Derivative [Line Items]
Cumulative Gains/(Losses), net of tax	$ (49)	$ (51)

Derivative Instruments And H_11

Derivative Instruments And Hedging Activities - Summary of Notional Amounts of Outstanding Foreign Exchange Forwards (Detail) - Not Designated as Accounting Hedges ₽ in Millions, € in Millions, ₨ in Millions, ¥ in Millions, £ in Millions, $ in Millions, $ in Millions, $ in Millions

Sep. 30, 2021USD ($)

Sep. 30, 2021EUR (€)

Sep. 30, 2021GBP (£)

Sep. 30, 2021JPY (¥)

Sep. 30, 2021CAD ($)

Sep. 30, 2021SGD ($)

Sep. 30, 2021RUB (₽)

Sep. 30, 2021INR (₨)

Dec. 31, 2020USD ($)

Dec. 31, 2020EUR (€)

Dec. 31, 2020GBP (£)

Dec. 31, 2020JPY (¥)

Dec. 31, 2020CAD ($)

Dec. 31, 2020SGD ($)

Dec. 31, 2020RUB (₽)

Dec. 31, 2020INR (₨)

Contracts to sell USD for GBP

Derivative [Line Items]

Notional Amount

$ 190

£ 138

$ 295

£ 222

Contracts to sell USD for Japanese yen

Derivative [Line Items]

Notional Amount

18

¥ 2,000

15

¥ 1,600

Contracts to sell USD for Canadian dollars

Derivative [Line Items]

Notional Amount

120

$ 150

107

$ 140

Contracts to sell USD for Singapore dollars

Derivative [Line Items]

Notional Amount

66

$ 90

59

$ 79

Contracts to sell USD for euros

Derivative [Line Items]

Notional Amount

282

€ 240

447

€ 376

Contracts to sell Euros for GBP

Derivative [Line Items]

Notional Amount

€ 0

£ 0

€ 135

£ 121

Contracts to sell USD for Russian ruble

Derivative [Line Items]

Notional Amount

13

₽ 1,000

13

₽ 1,000

Contracts to sell USD for Indian rupee

Derivative [Line Items]

Notional Amount

$ 18

₨ 1,350

$ 18

₨ 1,350

Derivative Instruments And H_12

Derivative Instruments And Hedging Activities - Summary of Net Gain (Loss) on Foreign Exchange Forwards Not Designated as Hedging Instruments (Detail) £ in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2021USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2021GBP (£)
Derivative Instruments, Gain (Loss) [Line Items]
Foreign exchange forwards amount of gain (loss) recognized in income	$ (13)	$ 0	$ (13)	$ 0
Not Designated as Accounting Hedges | Forward Contracts
Derivative Instruments, Gain (Loss) [Line Items]
Foreign exchange forwards amount of gain (loss) recognized in income	(13)		(13)
Other non-operating income, net | Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Foreign exchange forwards amount of gain (loss) recognized in income	(18)	36	(25)	1
Other non-operating income, net | Designated as Hedging Instrument | RMS
Derivative Instruments, Gain (Loss) [Line Items]
Foreign exchange forwards amount of gain (loss) recognized in income	(13)	$ 0	(13)	$ 0
Other non-operating income, net | Not Designated as Accounting Hedges | RMS
Derivative Instruments, Gain (Loss) [Line Items]
Notional Amount	$ 1,675		$ 1,675		£ 1,200

Derivative Instruments And H_13

Derivative Instruments And Hedging Activities - Fair Value of Derivative Instruments (Detail) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Derivatives, Fair Value [Line Items]
Assets	$ 59	$ 88
Liabilities	1,511	1,716
Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Assets	59	57
Liabilities	53	184
Designated as Hedging Instrument | Long-term debt | Net Investment Hedging
Derivatives, Fair Value [Line Items]
Liabilities	1,448	1,530
Designated as Hedging Instrument | FX forwards | Accounts payable and accrued liabilities | Net Investment Hedging
Derivatives, Fair Value [Line Items]
Liabilities	0	16
Designated as Hedging Instrument | Cross-currency swap | Other current assets | Net Investment Hedging
Derivatives, Fair Value [Line Items]
Assets	2	0
Designated as Hedging Instrument | Cross-currency swap | Other assets | Net Investment Hedging
Derivatives, Fair Value [Line Items]
Assets	26	0
Designated as Hedging Instrument | Cross-currency swap | Accounts payable and accrued liabilities | Net Investment Hedging
Derivatives, Fair Value [Line Items]
Liabilities	7	23
Designated as Hedging Instrument | Cross-currency swap | Other liabilities | Net Investment Hedging
Derivatives, Fair Value [Line Items]
Liabilities	32	144
Designated as Hedging Instrument | Interest Rate Swap | Other current assets | Fair Value Hedging
Derivatives, Fair Value [Line Items]
Assets	8	0
Designated as Hedging Instrument | Interest Rate Swap | Other assets | Fair Value Hedging
Derivatives, Fair Value [Line Items]
Assets	23	57
Designated as Hedging Instrument | Interest Rate Swap | Other liabilities | Fair Value Hedging
Derivatives, Fair Value [Line Items]
Liabilities	14	1
Not Designated as Accounting Hedges | FX forwards | Other current assets
Derivatives, Fair Value [Line Items]
Assets	0	31
Not Designated as Accounting Hedges | FX forwards | Accounts payable and accrued liabilities
Derivatives, Fair Value [Line Items]
Liabilities	$ 10	$ 2

Goodwill And Other Acquired I_3

Goodwill And Other Acquired Intangible Assets - Activity in Goodwill (Detail) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Goodwill [Roll Forward]
Beginning balance, goodwill gross	$ 4,568	$ 3,734
Beginning balance, Accumulated impairment charge	(12)	(12)
Beginning balance, goodwill net	4,556	3,722
Additions/ adjustments	1,478	626
Foreign currency translation adjustments	(136)	208
Ending balance, goodwill gross	5,910	4,568
Ending balance, Accumulated impairment charge	(12)	(12)
Ending balance, goodwill net	5,898	4,556
MIS
Goodwill [Roll Forward]
Beginning balance, goodwill gross	311	315
Beginning balance, Accumulated impairment charge	0	0
Beginning balance, goodwill net	311	315
Additions/ adjustments	90	(2)
Foreign currency translation adjustments	(5)	(2)
Ending balance, goodwill gross	396	311
Ending balance, Accumulated impairment charge	0	0
Ending balance, goodwill net	396	311
MA
Goodwill [Roll Forward]
Beginning balance, goodwill gross	4,257	3,419
Beginning balance, Accumulated impairment charge	(12)	(12)
Beginning balance, goodwill net	4,245	3,407
Additions/ adjustments	1,388	628
Foreign currency translation adjustments	(131)	210
Ending balance, goodwill gross	5,514	4,257
Ending balance, Accumulated impairment charge	(12)	(12)
Ending balance, goodwill net	$ 5,502	$ 4,245

Goodwill And Other Acquired I_4

Goodwill And Other Acquired Intangible Assets - Acquired Intangible Assets and Related Amortization (Detail) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, net	$ 2,510	$ 1,824
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, gross	2,108	1,623
Accumulated amortization	(360)	(313)
Acquired intangible assets, net	1,748	1,310
Software/product technology
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, gross	654	441
Accumulated amortization	(203)	(177)
Acquired intangible assets, net	451	264
Database
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, gross	180	144
Accumulated amortization	(42)	(29)
Acquired intangible assets, net	138	115
Trade names
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, gross	207	161
Accumulated amortization	(44)	(38)
Acquired intangible assets, net	163	123
Other
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, gross	54	55
Accumulated amortization	(44)	(43)
Acquired intangible assets, net	$ 10	$ 12

Goodwill And Other Acquired I_5

Goodwill And Other Acquired Intangible Assets - Amortization Expense Relating to Acquired Intangible Assets (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense	$ 37	$ 31	$ 108	$ 90

Goodwill And Other Acquired I_6

Goodwill And Other Acquired Intangible Assets - Estimated Future Amortization Expense for Acquired Intangible Assets Subject to Amortization (Detail) $ in Millions	Sep. 30, 2021USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2021 (After September 30,)	$ 49
2022	194
2023	191
2024	187
2025	182
Thereafter	1,707
Total estimated future amortization	$ 2,510

Restructuring - Additional Info

Restructuring - Additional Information (Detail) - USD ($) $ in Millions	Dec. 22, 2020	Jul. 29, 2020	Sep. 30, 2021	Dec. 31, 2022	Dec. 31, 2020
2020 Real Estate Rationalization Restructuring Program | Estimated Annual Savings | Minimum
Restructuring Cost and Reserve [Line Items]
Effect on future earnings, amount		$ 5
2020 Real Estate Rationalization Restructuring Program | Estimated Annual Savings | Maximum
Restructuring Cost and Reserve [Line Items]
Effect on future earnings, amount		$ 6
2020 MA Strategic Reorganization Restructuring Program | Estimated Annual Savings
Restructuring Cost and Reserve [Line Items]
Effect on future earnings, amount	$ 20
2020 MA Strategic Reorganization Restructuring Program | Forecast
Restructuring Cost and Reserve [Line Items]
Payments for restructuring				$ 20
Employee Severance
Restructuring Cost and Reserve [Line Items]
Remaining restructuring liability			$ 8		$ 18
Employee Severance | 2020 Real Estate Rationalization Restructuring Program
Restructuring Cost and Reserve [Line Items]
Cost incurred to date			36
Employee Severance | 2020 MA Strategic Reorganization Restructuring Program
Restructuring Cost and Reserve [Line Items]
Cost incurred to date			20
Payments for restructuring			$ 12

Restructuring - Restructuring E

Restructuring - Restructuring Expenses Included in Consolidated Statements of Operations (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Restructuring Cost and Reserve [Line Items]
Restructuring	$ 0	$ 23	$ 2	$ 20
2018 Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring	0	0	0	(3)
2020 Real Estate Rationalization Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring	0	23	0	23
2020 MA Strategic Reorganization Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring	$ 0	$ 0	$ 2	$ 0

Restructuring - Changes in Rest

Restructuring - Changes in Restructuring Liability (Details) - Employee Severance $ in Millions	9 Months Ended
	Sep. 30, 2021USD ($)
Restructuring Reserve [Roll Forward]
Restructuring liability, Beginning Balance	$ 18
Restructuring liability, Ending Balance	8
2020 MA Strategic Reorganization Restructuring Program
Restructuring Reserve [Roll Forward]
Cost incurred and adjustments	2
Cash payments and adjustments	(12)
Cost incurred to date	20
2020 Real Estate Rationalization Restructuring Program
Restructuring Reserve [Roll Forward]
Cost incurred to date	$ 36

Fair Value - Financial Instrume

Fair Value - Financial Instruments Carried at Fair Value on Recurring Basis (Detail) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Assets:
Derivatives	$ 59	$ 88
Mutual funds	58	60
Total	117	148
Liabilities:
Derivatives	63	186
Total	63	186
Level 1
Assets:
Derivatives	0	0
Mutual funds	58	60
Total	58	60
Liabilities:
Derivatives	0	0
Total	0	0
Level 2
Assets:
Derivatives	59	88
Mutual funds	0	0
Total	59	88
Liabilities:
Derivatives	63	186
Total	$ 63	$ 186

Other Balance Sheet and State_3

Other Balance Sheet and Statement of Operations Information - Additional Details Related to Certain Balance Sheet Captions (Detail) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Other current assets:
Prepaid taxes	$ 81	$ 94
Prepaid expenses	98	91
Capitalized costs to obtain and fulfill sales contracts	89	93
Foreign exchange forwards on certain assets and liabilities	0	31
Derivative instruments designated as accounting hedges	10	0
Other	45	74
Total other current assets	323	383
Other assets:
Investments in non-consolidated affiliates	149	135
Deposits for real-estate leases	15	19
Indemnification assets related to acquisitions	103	15
Mutual funds and fixed deposits	67	66
Company owned life insurance (at contract value)	35	17
Costs to obtain sales contracts	137	134
Derivative instruments designated as accounting hedges	49	57
Pension and other retirement employee benefits	19	21
Other	62	51
Total other assets	636	515
Accounts payable and accrued liabilities:
Salaries and benefits	196	197
Incentive compensation	248	226
Customer credits, advanced payments and advanced billings	96	42
Dividends	5	11
Professional service fees	68	53
Interest accrued on debt	46	82
Accounts payable	30	39
Income taxes	201	128
Pension and other retirement employee benefits	46	45
Accrued royalties	19	19
Foreign exchange forwards on certain assets and liabilities	10	2
Restructuring liability	8	18
Derivative instruments designated as accounting hedges	7	39
Other	104	138
Total accounts payable and accrued liabilities	1,084	1,039
Other liabilities:
Pension and other retirement employee benefits	204	244
Interest accrued on UTPs	82	113
MAKS indemnification provisions	33	33
Income tax liability - non-current portion	18	18
Derivative instruments designated as accounting hedges	46	145
Other	37	37
Total other liabilities	$ 420	$ 590

Other Balance Sheet and State_4

Other Balance Sheet and Statement of Operations Information - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Other Balance Sheet And Statement Of Operations Information [Abstract]
Loss pursuant to the divestiture of MAKS	$ 0	$ 0	$ 0	$ 9

Other Balance Sheet and State_5

Other Balance Sheet and Statement of Operations Information - Other Non-Operating Interest (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Other Balance Sheet And Statement Of Operations Information [Abstract]
FX gain (loss)	$ (2)	$ 2	$ (2)	$ 7
Purchase price hedge loss	(13)	0	(13)	0
Net periodic pension costs - other components	4	3	5	10
Income from investments in non-consolidated affiliates	6	4	15	4
Other	1	1	13	17
Total	$ (4)	$ 10	$ 18	$ 38

Comprehensive Income And Accu_3

Comprehensive Income And Accumulated Other Comprehensive Loss - Reclassification out of AOCI (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Derivative Instruments, Gain (Loss) [Line Items]
Other non-operating (expense) income, net	$ (4)	$ 10	$ 18	$ 38
Total before income taxes	619	599	2,239	1,829
Provision for income taxes	(145)	(132)	(452)	(366)
Net income attributable to Moody's	474	467	1,787	1,464
Reclassification out of Accumulated Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Net income attributable to Moody's	(3)	(2)	(13)	(5)
Losses on cash flow hedges | Reclassification out of Accumulated Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Provision for income taxes	0	0	0	0
Net income attributable to Moody's	(1)	0	(2)	(1)
Losses on cash flow hedges | Reclassification out of Accumulated Other Comprehensive Income | Interest rate contract
Derivative Instruments, Gain (Loss) [Line Items]
Other non-operating (expense) income, net	(1)	0	(2)	(1)
Net Investment Hedges | Reclassification out of Accumulated Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Provision for income taxes			(1)	0
Net income attributable to Moody's			1	0
Net Investment Hedges | Reclassification out of Accumulated Other Comprehensive Income | FX forwards
Derivative Instruments, Gain (Loss) [Line Items]
Other non-operating (expense) income, net			2	0
Total pension and other retirement benefits | Reclassification out of Accumulated Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Total before income taxes	(3)	(2)	(16)	(5)
Provision for income taxes	1	0	4	1
Net income attributable to Moody's	(2)	(2)	(12)	(4)
Amortization of actuarial losses and prior service costs included in net income | Reclassification out of Accumulated Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Other non-operating (expense) income, net	(2)	(2)	(8)	(5)
Settlement charge | Reclassification out of Accumulated Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Other non-operating (expense) income, net	$ (1)	$ 0	$ (8)	$ 0

Comprehensive Income And Accu_4

Comprehensive Income And Accumulated Other Comprehensive Loss - Changes in Components of Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance			$ 1,569
Ending balance	$ 2,430		2,430
Total
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(425)	$ (542)	(432)	$ (439)
Other comprehensive income/(loss) before reclassifications	(40)	36	(43)	(70)
Amounts reclassified from AOCL	3	2	13	5
Other comprehensive income/(loss)	(37)	38	(30)	(65)
Ending balance	(462)	(504)	(462)	(504)
Pension and Other Retirement Benefits
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(108)	(84)	(118)	(92)
Other comprehensive income/(loss) before reclassifications	3	(7)	3	(1)
Amounts reclassified from AOCL	2	2	12	4
Other comprehensive income/(loss)	5	(5)	15	3
Ending balance	(103)	(89)	(103)	(89)
Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(48)	(49)	(49)	0
Other comprehensive income/(loss) before reclassifications	0	0	0	(50)
Amounts reclassified from AOCL	1	0	2	1
Other comprehensive income/(loss)	1	0	2	(49)
Ending balance	(47)	(49)	(47)	(49)
Foreign Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(152)	(479)	(45)	(401)
Other comprehensive income/(loss) before reclassifications	(116)	186	(223)	108
Amounts reclassified from AOCL	0	0	0	0
Other comprehensive income/(loss)	(116)	186	(223)	108
Ending balance	(268)	(293)	(268)	(293)
Net Investment Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(117)	70	(220)	54
Other comprehensive income/(loss) before reclassifications	73	(143)	177	(127)
Amounts reclassified from AOCL	0	0	(1)	0
Other comprehensive income/(loss)	73	(143)	176	(127)
Ending balance	$ (44)	$ (73)	$ (44)	$ (73)

Pension and Other Retirement _3

Pension and Other Retirement Benefits - Components of Net Periodic Benefit Expense Related to Post-Retirement Plans (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Components of net periodic expense
Interest cost	$ 4	$ 4	$ 12	$ 14
Pension Plans
Components of net periodic expense
Service cost	4	5	14	13
Interest cost	4	4	11	13
Expected return on plan assets	(7)	(5)	(20)	(15)
Amortization of net actuarial loss from earlier periods	3	2	8	5
Loss on settlement of pension obligation	1	0	8	0
Net periodic expense	5	6	21	16
Other Retirement Plans
Components of net periodic expense
Service cost	1	0	3	2
Interest cost	0	1	1	1
Expected return on plan assets	0	0	0	0
Amortization of net actuarial loss from earlier periods	0	0	0	0
Loss on settlement of pension obligation	0	0	0	0
Net periodic expense	$ 1	$ 1	$ 4	$ 3

Pension and Other Retirement _4

Pension and Other Retirement Benefits - Additional Information (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2021USD ($)
Unfunded Plan | Pension Plans | United States
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Employer contributions	$ 46

Indebtedness - Summary of Total

Indebtedness - Summary of Total Indebtedness (Detail) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Principal Amount	$ 7,548	$ 6,430
Fair Value of Interest Rate Swap	16	56
Unamortized (Discount) Premium	(42)	(24)
Unamortized Debt Issuance Costs	(46)	(40)
Carrying Amount	7,476	6,422
Current portion	(507)	0
Long term debt	$ 6,969	$ 6,422
4.50% 2012 Senior Notes, due 2022
Debt Instrument [Line Items]
Notes payable, interest rate	4.50%	4.50%
Principal Amount	$ 500	$ 500
Fair Value of Interest Rate Swap	7	14
Unamortized (Discount) Premium	0	(1)
Unamortized Debt Issuance Costs	0	(1)
Carrying Amount	$ 507	$ 512
4.875% 2013 Senior Notes, due 2024
Debt Instrument [Line Items]
Notes payable, interest rate	4.875%	4.875%
Principal Amount	$ 500	$ 500
Fair Value of Interest Rate Swap	(5)	0
Unamortized (Discount) Premium	(1)	(1)
Unamortized Debt Issuance Costs	(1)	(1)
Carrying Amount	$ 493	$ 498
5.25% 2014 Senior Notes, due 2044
Debt Instrument [Line Items]
Notes payable, interest rate	5.25%	5.25%
Principal Amount	$ 600	$ 600
Fair Value of Interest Rate Swap	(4)	0
Unamortized (Discount) Premium	3	3
Unamortized Debt Issuance Costs	(5)	(5)
Carrying Amount	$ 594	$ 598
1.75% 2015 Senior Notes, due 2027
Debt Instrument [Line Items]
Notes payable, interest rate	1.75%	1.75%
Principal Amount	$ 579	$ 612
Fair Value of Interest Rate Swap	0	0
Unamortized (Discount) Premium	0	0
Unamortized Debt Issuance Costs	(2)	(2)
Carrying Amount	$ 577	$ 610
2.625% 2017 Senior Notes, due 2023
Debt Instrument [Line Items]
Notes payable, interest rate	2.625%	2.625%
Principal Amount	$ 500	$ 500
Fair Value of Interest Rate Swap	8	12
Unamortized (Discount) Premium	0	0
Unamortized Debt Issuance Costs	(1)	(2)
Carrying Amount	$ 507	$ 510
3.25% 2017 Senior Notes, due 2028
Debt Instrument [Line Items]
Notes payable, interest rate	3.25%	3.25%
Principal Amount	$ 500	$ 500
Fair Value of Interest Rate Swap	15	31
Unamortized (Discount) Premium	(3)	(4)
Unamortized Debt Issuance Costs	(3)	(3)
Carrying Amount	$ 509	$ 524
4.25% 2018 Senior Notes, due 2029
Debt Instrument [Line Items]
Notes payable, interest rate	4.25%	4.25%
Principal Amount	$ 400	$ 400
Fair Value of Interest Rate Swap	0	0
Unamortized (Discount) Premium	(2)	(3)
Unamortized Debt Issuance Costs	(2)	(3)
Carrying Amount	$ 396	$ 394
4.875% 2018 Senior Notes, due 2048
Debt Instrument [Line Items]
Notes payable, interest rate	4.875%	4.875%
Principal Amount	$ 400	$ 400
Fair Value of Interest Rate Swap	0	0
Unamortized (Discount) Premium	(6)	(6)
Unamortized Debt Issuance Costs	(4)	(4)
Carrying Amount	$ 390	$ 390
0.950% Senior Notes Due 2030
Debt Instrument [Line Items]
Notes payable, interest rate	0.95%	0.95%
Principal Amount	$ 869	$ 918
Fair Value of Interest Rate Swap	0	0
Unamortized (Discount) Premium	(2)	(3)
Unamortized Debt Issuance Costs	(5)	(6)
Carrying Amount	$ 862	$ 909
3.75% 2020 Senior Notes, due 2025
Debt Instrument [Line Items]
Notes payable, interest rate	3.75%	3.75%
Principal Amount	$ 700	$ 700
Fair Value of Interest Rate Swap	(5)	(1)
Unamortized (Discount) Premium	(1)	(1)
Unamortized Debt Issuance Costs	(4)	(5)
Carrying Amount	$ 690	$ 693
3.25% 2020 Senior Notes, due 2050
Debt Instrument [Line Items]
Notes payable, interest rate	3.25%	3.25%
Principal Amount	$ 300	$ 300
Fair Value of Interest Rate Swap	0	0
Unamortized (Discount) Premium	(4)	(4)
Unamortized Debt Issuance Costs	(3)	(3)
Carrying Amount	$ 293	$ 293
2.55% 2020 Senior Notes, due 2060
Debt Instrument [Line Items]
Notes payable, interest rate	2.55%	2.55%
Principal Amount	$ 500	$ 500
Fair Value of Interest Rate Swap	0	0
Unamortized (Discount) Premium	(4)	(4)
Unamortized Debt Issuance Costs	(5)	(5)
Carrying Amount	$ 491	$ 491
2.00% 2021 Senior Note, due 2031
Debt Instrument [Line Items]
Notes payable, interest rate	2.00%
Principal Amount	$ 600
Fair Value of Interest Rate Swap	0
Unamortized (Discount) Premium	(8)
Unamortized Debt Issuance Costs	(5)
Carrying Amount	$ 587
2.75% 2021 Senior Note, due 2041
Debt Instrument [Line Items]
Notes payable, interest rate	2.75%
Principal Amount	$ 600
Fair Value of Interest Rate Swap	0
Unamortized (Discount) Premium	(14)
Unamortized Debt Issuance Costs	(6)
Carrying Amount	$ 580

Indebtedness - Principal Paymen

Indebtedness - Principal Payments Due on Long-Term Borrowings (Detail) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
2021 (After September 30,)	$ 0
2022	500
2023	500
2024	500
2025	700
Thereafter	5,348
Total principal payment	7,548	$ 6,430
4.50% 2012 Senior Notes, due 2022
Debt Instrument [Line Items]
2022	500
Total principal payment	$ 500	$ 500
Debt Instrument, Interest Rate, Stated Percentage	4.50%	4.50%
4.875% 2013 Senior Notes, due 2024
Debt Instrument [Line Items]
2024	$ 500
Total principal payment	$ 500	$ 500
Debt Instrument, Interest Rate, Stated Percentage	4.875%	4.875%
5.25% 2014 Senior Notes, due 2044
Debt Instrument [Line Items]
Thereafter	$ 600
Total principal payment	$ 600	$ 600
Debt Instrument, Interest Rate, Stated Percentage	5.25%	5.25%
1.75% 2015 Senior Notes, due 2027
Debt Instrument [Line Items]
Thereafter	$ 579
Total principal payment	$ 579	$ 612
Debt Instrument, Interest Rate, Stated Percentage	1.75%	1.75%
2.625% 2017 Senior Notes, due 2023
Debt Instrument [Line Items]
2023	$ 500
Total principal payment	$ 500	$ 500
Debt Instrument, Interest Rate, Stated Percentage	2.625%	2.625%
3.25% 2017 Senior Notes, due 2028
Debt Instrument [Line Items]
Thereafter	$ 500
Total principal payment	$ 500	$ 500
Debt Instrument, Interest Rate, Stated Percentage	3.25%	3.25%
4.25% 2018 Senior Notes, due 2029
Debt Instrument [Line Items]
Thereafter	$ 400
Total principal payment	$ 400	$ 400
Debt Instrument, Interest Rate, Stated Percentage	4.25%	4.25%
4.875% 2018 Senior Notes, due 2048
Debt Instrument [Line Items]
Thereafter	$ 400
Total principal payment	$ 400	$ 400
Debt Instrument, Interest Rate, Stated Percentage	4.875%	4.875%
0.950% Senior Notes Due 2030
Debt Instrument [Line Items]
Thereafter	$ 869
Total principal payment	$ 869	$ 918
Debt Instrument, Interest Rate, Stated Percentage	0.95%	0.95%
3.75% 2020 Senior Notes, due 2025
Debt Instrument [Line Items]
2025	$ 700
Total principal payment	$ 700	$ 700
Debt Instrument, Interest Rate, Stated Percentage	3.75%	3.75%
3.25% 2020 Senior Notes, due 2050
Debt Instrument [Line Items]
Thereafter	$ 300
Total principal payment	$ 300	$ 300
Debt Instrument, Interest Rate, Stated Percentage	3.25%	3.25%
2.55% 2020 Senior Notes, due 2060
Debt Instrument [Line Items]
Thereafter	$ 500
Total principal payment	$ 500	$ 500
Debt Instrument, Interest Rate, Stated Percentage	2.55%	2.55%
2.00% 2021 Senior Note, due 2031
Debt Instrument [Line Items]
Thereafter	$ 600
Total principal payment	$ 600
Debt Instrument, Interest Rate, Stated Percentage	2.00%
2.75% 2021 Senior Note, due 2041
Debt Instrument [Line Items]
Thereafter	$ 600
Total principal payment	$ 600
Debt Instrument, Interest Rate, Stated Percentage	2.75%

Indebtedness - Summary of Compo

Indebtedness - Summary of Components of Interest as Presented in Consolidated Statements of Operations (Detail) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Debt Disclosure [Abstract]
Income	$ 3		$ 2	$ 7	$ 9
Expense on borrowings	(47)		(42)	(129)	(121)
Income (expense) on UTPs and other tax related liabilities	(5)		(9)	25	(27)
Net periodic pension costs - interest component	(4)		(4)	(12)	(14)
Interest expense, net	(53)		(53)	(109)	(153)
Interest paid	$ 53		$ 47	139	$ 119
Interest accrued on UTPs		$ 40		$ 40

Indebtedness - Fair Value and C

Indebtedness - Fair Value and Carrying Value of Long-Term Debt (Detail) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Carrying Amount	$ 7,476	$ 6,422
Estimated Fair Value	8,118	7,256
4.50% 2012 Senior Notes, due 2022
Debt Instrument [Line Items]
Carrying Amount	507	512
Estimated Fair Value	$ 515	$ 530
Notes payable, interest rate	4.50%	4.50%
4.875% 2013 Senior Notes, due 2024
Debt Instrument [Line Items]
Carrying Amount	$ 493	$ 498
Estimated Fair Value	$ 545	$ 562
Notes payable, interest rate	4.875%	4.875%
5.25% 2014 Senior Notes, due 2044
Debt Instrument [Line Items]
Carrying Amount	$ 594	$ 598
Estimated Fair Value	$ 808	$ 828
Notes payable, interest rate	5.25%	5.25%
1.75% 2015 Senior Notes, due 2027
Debt Instrument [Line Items]
Carrying Amount	$ 577	$ 610
Estimated Fair Value	$ 629	$ 674
Notes payable, interest rate	1.75%	1.75%
2.625% 2017 Senior Notes, due 2023
Debt Instrument [Line Items]
Carrying Amount	$ 507	$ 510
Estimated Fair Value	$ 514	$ 522
Notes payable, interest rate	2.625%	2.625%
3.25% 2017 Senior Notes, due 2028
Debt Instrument [Line Items]
Carrying Amount	$ 509	$ 524
Estimated Fair Value	$ 544	$ 561
Notes payable, interest rate	3.25%	3.25%
4.25% 2018 Senior Notes, due 2029
Debt Instrument [Line Items]
Carrying Amount	$ 396	$ 394
Estimated Fair Value	$ 460	$ 480
Notes payable, interest rate	4.25%	4.25%
4.875% 2018 Senior Notes, due 2048
Debt Instrument [Line Items]
Carrying Amount	$ 390	$ 390
Estimated Fair Value	$ 526	$ 544
Notes payable, interest rate	4.875%	4.875%
0.950% Senior Notes Due 2030
Debt Instrument [Line Items]
Carrying Amount	$ 862	$ 909
Estimated Fair Value	$ 898	$ 974
Notes payable, interest rate	0.95%	0.95%
3.75% 2020 Senior Notes, due 2025
Debt Instrument [Line Items]
Carrying Amount	$ 690	$ 693
Estimated Fair Value	$ 761	$ 785
Notes payable, interest rate	3.75%	3.75%
3.25% 2020 Senior Notes, due 2050
Debt Instrument [Line Items]
Carrying Amount	$ 293	$ 293
Estimated Fair Value	$ 309	$ 329
Notes payable, interest rate	3.25%	3.25%
2.55% 2020 Senior Notes, due 2060
Debt Instrument [Line Items]
Carrying Amount	$ 491	$ 491
Estimated Fair Value	$ 437	$ 467
Notes payable, interest rate	2.55%	2.55%
2.00% 2021 Senior Note, due 2031
Debt Instrument [Line Items]
Carrying Amount	$ 587
Estimated Fair Value	$ 588
Notes payable, interest rate	2.00%
2.75% 2021 Senior Note, due 2041
Debt Instrument [Line Items]
Carrying Amount	$ 580
Estimated Fair Value	$ 584
Notes payable, interest rate	2.75%

Leases - Additional Information

Leases - Additional Information (Detail)	Sep. 30, 2021
Minimum
Lessee, Lease, Description [Line Items]
Lessee, operating lease, renewal term (years)	1 year
Maximum
Lessee, Lease, Description [Line Items]
Lessee, operating lease, renewal term (years)	20 years

Leases - Components of Lease Co

Leases - Components of Lease Cost (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Lease, Cost [Abstract]
Operating lease cost	$ 24	$ 24	$ 71	$ 72
Sublease income	(2)	(1)	(4)	(3)
Variable lease cost	5	4	15	14
Total lease cost	$ 27	$ 27	$ 82	$ 83

Leases - Operating Leases Infor

Leases - Operating Leases Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Leases [Abstract]
Cash paid for amounts included in the measurement of operating lease liabilities	$ 27	$ 27	$ 83	$ 80
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 117	$ 7	$ 123	$ 26
Weighted-average remaining lease term (years)	5 years 10 months 24 days	6 years 3 months 18 days	5 years 10 months 24 days	6 years 3 months 18 days
Weighted-average discount rate applied to operating leases (percent)	3.10%	3.60%	3.10%	3.60%

Leases - Operating Leases, Futu

Leases - Operating Leases, Future Minimum Payment (Detail) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Leases [Abstract]
2021 (After September 30)	$ 30
2022	119
2023	115
2024	105
2025	90
After 2025	167
Total lease payments (undiscounted)	626
Less: Interest	53
Present value of lease liabilities:	573
Lease liabilities - current	103	$ 94
Lease liabilities - noncurrent	$ 470	$ 427

Segment Information - Additiona

Segment Information - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2021lineOfBusinesssegment
Segment Reporting Information [Line Items]
Number of operating segments (segment) | segment	2
Number of reportable segments | segment	2
MIS
Segment Reporting Information [Line Items]
Number of lines of businesses | lineOfBusiness	5
MA
Segment Reporting Information [Line Items]
Number of lines of businesses | lineOfBusiness	2

Segment Information - Financial

Segment Information - Financial Information by Segment (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting Information, Operating Income (Loss) [Abstract]
Revenue	$ 1,526	$ 1,356	$ 4,679	$ 4,081
Total Expenses	850	714	2,349	2,137
Operating income	676	642	2,330	1,944
Depreciation and amortization	61	56	180	163
Restructuring	0	23	2	20
Loss pursuant to the divestiture of MAKS	0	0	0	9
Adjusted Operating Income	737	721	2,512	2,136
Eliminations
Segment Reporting Information, Operating Income (Loss) [Abstract]
Revenue	(44)	(39)	(130)	(115)
Total Expenses	(44)	(39)	(130)	(115)
Operating income	0	0	0	0
Depreciation and amortization	0	0	0	0
Restructuring	0	0	0	0
Loss pursuant to the divestiture of MAKS			0	0
Adjusted Operating Income	0	0	0	0
MIS
Segment Reporting Information, Operating Income (Loss) [Abstract]
Revenue	925	825	2,941	2,557
MIS | Operating Segments
Segment Reporting Information, Operating Income (Loss) [Abstract]
Revenue	967	863	3,065	2,667
Total Expenses	404	339	1,132	1,051
Operating income	563	524	1,933	1,616
Depreciation and amortization	17	17	53	52
Restructuring	0	13	0	12
Loss pursuant to the divestiture of MAKS			0	0
Adjusted Operating Income	580	554	1,986	1,680
MA
Segment Reporting Information, Operating Income (Loss) [Abstract]
Revenue	601	531	1,738	1,524
MA | Operating Segments
Segment Reporting Information, Operating Income (Loss) [Abstract]
Revenue	603	532	1,744	1,529
Total Expenses	490	414	1,347	1,201
Operating income	113	118	397	328
Depreciation and amortization	44	39	127	111
Restructuring	0	10	2	8
Loss pursuant to the divestiture of MAKS			0	9
Adjusted Operating Income	$ 157	$ 167	$ 526	$ 456

Segment Information - Consolida

Segment Information - Consolidated Revenue Information by Geographic Area (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting Information [Line Items]
Revenue	$ 1,526	$ 1,356	$ 4,679	$ 4,081
United States
Segment Reporting Information [Line Items]
Revenue	844	729	2,560	2,280
Non-U.S.
Segment Reporting Information [Line Items]
Revenue	682	627	2,119	1,801
EMEA
Segment Reporting Information [Line Items]
Revenue	439	401	1,398	1,137
Asia-Pacific
Segment Reporting Information [Line Items]
Revenue	149	156	460	436
Americas
Segment Reporting Information [Line Items]
Revenue	$ 94	$ 70	$ 261	$ 228

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - Subsequent Event - USD ($) $ / shares in Units, $ in Millions	Oct. 26, 2021	Oct. 13, 2021
Subsequent Event [Line Items]
Dividend declared, declaration date	Oct. 26, 2021
Dividend declared, per share (in USD per share)	$ 0.62
Dividend declared, payable date	Dec. 14, 2021
Dividend declared, record date	Nov. 23, 2021
Bitsight
Subsequent Event [Line Items]
Payments to acquire interest in subsidiaries and affiliates		$ 250
VisibleRisk | Minimum
Subsequent Event [Line Items]
Equity method investment, realized gain on disposal		30
VisibleRisk | Maximum
Subsequent Event [Line Items]
Equity method investment, realized gain on disposal		$ 40

Uncategorized Items - mco-20210

Label	Element	Value
Accounting Standards Update [Extensible Enumeration]	us-gaap_AccountingStandardsUpdateExtensibleList	Accounting Standards Update 2016-13 [Member]