Moody's (MCO) 10-Q 29 Apr 21 2021 Q1 Quarterly report Financial data

Cover Page

Cover Page shares in Millions	3 Months Ended
	Mar. 31, 2021shares
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 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)	187.2
Entity Central Index Key	0001059556
Document Fiscal Period Focus	Q1
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
	Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Revenue	$ 1,600	$ 1,290
Expenses
Operating	393	340
Selling, general and administrative	293	301
Depreciation and amortization	59	49
Restructuring	2	(1)
Loss pursuant to the divestiture of MAKS	0	9
Total expenses	747	698
Operating income	853	592
Non-operating (expense) income, net
Interest expense, net	(7)	(40)
Other non-operating income, net	16	12
Total non-operating (expense) income, net	9	(28)
Income before provisions for income taxes	862	564
Provision for income taxes	126	77
Net income	736	487
Less: Net income (loss) attributable to noncontrolling interests	0	(1)
Net income attributable to Moody's	$ 736	$ 488
Earnings per share attributable to Moody's common shareholders
Basic (in usd per share)	$ 3.93	$ 2.60
Diluted (in usd per share)	$ 3.90	$ 2.57
Weighted average number of shares outstanding
Basic (in shares)	187.2	187.5
Diluted (in shares)	188.6	189.6

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement of Comprehensive Income [Abstract]
Net Income	$ 736	$ 487
Other Comprehensive Income (loss):
Foreign currency translation adjustment - Pre Tax	(147)	(175)
Foreign currency translation adjustments - Tax	6	5
Foreign currency translation adjustments - Net of Tax	(141)	(170)
Net gains (losses) on net investment hedges - Pre Tax	175	119
Net gains (losses) on net investment hedges, Tax	(42)	(30)
Net gains (losses) on net investment hedges, Net of Tax	133	89
Net investment hedges - reclassification of gains included in net income - Pre Tax	(1)	0
Net investment hedges - reclassification of gains included in net income - Tax	0	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	(48)
Net realized and unrealized (losses) gains on cash flow hedges - Tax	0	12
Net realized and unrealized (losses) gains on cash flow hedges - Net of Tax	0	(36)
Reclassification of losses (gains) included in net income - Pre Tax	1	1
Reclassification of losses (gains) included in net income - Tax	0	0
Reclassification of losses (gains) included in net income - Net of Tax	1	1
Pension and Other Retirement Benefits:
Amortization of actuarial losses and prior service costs included in net income - Pre Tax	3	2
Amortization of actuarial losses and prior service costs included in net income - Tax	(1)	(1)
Amortization of actuarial losses and prior service costs included in net income - Net of Tax	2	1
Net actuarial (losses) gains and prior service costs - Pre Tax	0	(1)
Net actuarial (losses) gains and prior service costs - Tax	0	0
Net actuarial (losses) gains and prior service costs - Net of Tax	0	(1)
Total other comprehensive income (loss) - Pre Tax	31	(102)
Total other comprehensive income (loss) - Tax	(37)	(14)
Total other comprehensive income (loss) - Net of Tax	(6)	(116)
Comprehensive income	730	371
Less: comprehensive income (loss) attributable to noncontrolling interests	2	(2)
Comprehensive Income Attributable to Moody's	$ 728	$ 373

CONSOLIDATED BALANCE SHEETS (UN

CONSOLIDATED BALANCE SHEETS (UNAUDITED) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 2,769	$ 2,597
Short-term investments	96	99
Accounts receivable, net of allowance for credit losses of $31 in 2021 and $34 in 2020	1,497	1,430
Other current assets	333	383
Total current assets	4,695	4,509
Property and equipment, net of accumulated depreciation of $946 in 2021 and $928 in 2020	269	278
Operating lease right-of-use assets	375	393
Goodwill	4,566	4,556
Intangible assets, net	1,810	1,824
Deferred tax assets, net	240	334
Other assets	545	515
Total assets	12,500	12,409
Current liabilities:
Accounts payable and accrued liabilities	828	1,039
Current portion of operating lease liabilities	94	94
Deferred revenue	1,232	1,089
Total current liabilities	2,154	2,222
Non-current portion of deferred revenue	96	98
Long-term debt	6,340	6,422
Deferred tax liabilities, net	404	404
Uncertain tax positions	402	483
Operating lease liabilities	406	427
Other liabilities	473	590
Total liabilities	10,275	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	739	735
Retained earnings	11,632	11,011
Treasury stock, at cost; 155,737,071 and 155,808,563 shares of common stock at March 31, 2021 and December 31, 2020	(9,904)	(9,748)
Accumulated other comprehensive loss	(440)	(432)
Total Moody's shareholders' equity	2,030	1,569
Noncontrolling interests	195	194
Total shareholders' equity	2,225	1,763
Total liabilities, noncontrolling interests and shareholders' equity	12,500	12,409
Series Common Stock
Shareholders' equity:
Common stock	$ 0	$ 0

CONSOLIDATED BALANCE SHEETS (_2

CONSOLIDATED BALANCE SHEETS (UNAUDITED) (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Accounts receivable, allowances	$ 31	$ 34
Accumulated depreciation, property and equipment	$ 946	$ 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)	155,737,071	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	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities
Net Income	$ 736	$ 487
Reconciliation of net income to net cash provided by operating activities:
Depreciation and amortization	59	49
Stock-based compensation	45	37
Deferred income taxes	44	57
Loss pursuant to the divestiture of MAKS	0	9
Changes in assets and liabilities:
Accounts receivable	(71)	(7)
Other current assets	67	(38)
Other assets	(30)	2
Accounts payable and accrued liabilities	(206)	(198)
Deferred revenue	146	64
Unrecognized tax benefits and other non-current tax liabilities	(78)	(18)
Other liabilities	(36)	(99)
Net cash provided by operating activities	676	345
Cash flows from investing activities
Capital additions	(14)	(21)
Purchases of investments	(65)	(78)
Sales and maturities of investments	45	23
Cash paid for acquisitions, net of cash acquired	(138)	(696)
Receipts from settlements of net investment hedges	1	0
Payments for settlements of net investment hedges	(23)	0
Net cash used in investing activities	(194)	(772)
Cash flows from financing activities
Issuance of notes	0	700
Issuance of commercial paper	0	789
Repayment of commercial paper	0	(305)
Proceeds from stock-based compensation plans	9	16
Repurchase of shares related to stock-based compensation	(51)	(71)
Treasury shares	(132)	(253)
Dividends	(116)	(105)
Debt issuance costs, extinguishment costs and related fees	0	(6)
Net cash (used in) provided by financing activities	(290)	765
Effect of exchange rate changes on cash and cash equivalents	(20)	(29)
Increase in cash and cash equivalents	172	309
Cash and cash equivalents, beginning of period	2,597	1,832
Cash and cash equivalents, end of period	$ 2,769	$ 2,141

CONSOLIDATED STATEMENT OF SHARE

CONSOLIDATED STATEMENT OF SHAREHOLDERS' EQUITY (UNAUDITED) - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Capital Surplus	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Loss	Total Moody's Shareholders' Equity	Non- Controlling Interests	Cumulative Effect, Period of Adoption, Adjustment	Cumulative Effect, Period of Adoption, AdjustmentRetained Earnings	Cumulative Effect, Period of Adoption, AdjustmentTotal Moody's Shareholders' Equity
Beginning Balance (in shares) at Dec. 31, 2019		342.9			155.2
Beginning Balance at Dec. 31, 2019	$ 831	$ 3	$ 642	$ 9,656	$ (9,250)	$ (439)	$ 612	$ 219	$ (2)	$ (2)	$ (2)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	487			488			488	(1)
Dividends	(101)			(101)			(101)	0
Stock-based compensation	37		37				37
Shares issued for stock-based compensation plans at average cost, net (in shares)					0.9
Shares issued for stock-based compensation plans at average cost, net	(84)		(63)		$ (21)		(84)
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)	(81)					(80)	(80)	(1)
Net actuarial gains and prior service cost	(1)					(1)	(1)
Amortization of prior service costs and actuarial losses	1					1	1
Net realized and unrealized gain (loss) on cash flow hedges (net of tax)	(35)					(35)	(35)
Ending Balance (in shares) at Mar. 31, 2020		342.9			155.4
Ending Balance at Mar. 31, 2020	799	$ 3	616	10,041	$ (9,524)	(554)	582	217
Beginning Balance (in shares) at Dec. 31, 2020		342.9			155.8
Beginning Balance at Dec. 31, 2020	1,763	$ 3	735	11,011	$ (9,748)	(432)	1,569	194
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	736			736			736	0
Dividends	(116)			(115)			(115)	(1)
Stock-based compensation	45		45				45
Shares issued for stock-based compensation plans at average cost, net (in shares)					0.6
Shares issued for stock-based compensation plans at average cost, net	(65)		(41)		$ (24)		(65)
Treasury shares repurchased (in shares)					(0.5)
Treasury shares repurchased	(132)				$ (132)		(132)
Currency translation adjustment, net of net investment hedge activity (net of tax)	(9)					(11)	(11)	2
Net actuarial gains and prior service cost	0
Amortization of prior service costs and actuarial losses	2					2	2
Net realized and unrealized gain (loss) on cash flow hedges (net of tax)	1					1	1
Ending Balance (in shares) at Mar. 31, 2021		342.9			155.7
Ending Balance at Mar. 31, 2021	$ 2,225	$ 3	$ 739	$ 11,632	$ (9,904)	$ (440)	$ 2,030	$ 195

CONSOLIDATED STATEMENT OF SHA_2

CONSOLIDATED STATEMENT OF SHAREHOLDERS' EQUITY (UNAUDITED) (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement of Stockholders' Equity [Abstract]
Dividends (in USD per share)	$ 0.62	$ 0.56
Currency translation adjustment, net of net investment hedge activity, tax expense (benefit)	$ 36	$ 25
Amortization of prior service costs and actuarial losses, tax expense (benefit)	$ 1	1
Net realized and unrealized gain on cash flow hedges, tax expense (benefit)		$ 12

DESCRIPTION OF BUSINESS AND BAS

DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION	3 Months Ended
	Mar. 31, 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. COVID-19

REVENUES

REVENUES	3 Months Ended
	Mar. 31, 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 2021 2020 MIS: Corporate finance (CFG) Investment-grade $ 134 $ 144 High-yield 141 75 Bank loans 180 89 Other accounts (1) 150 145 Total CFG 605 453 Financial institutions (FIG) Banking 109 86 Insurance 43 30 Managed investments 8 6 Other accounts 2 3 Total FIG 162 125 Public, project and infrastructure finance (PPIF) Public finance / sovereign 67 57 Project and infrastructure 76 52 Total PPIF 143 109 Structured finance (SFG) Asset-backed securities 26 22 RMBS 27 27 CMBS 24 17 Structured credit 38 29 Other accounts 1 1 Total SFG 116 96 Total ratings revenue 1,026 783 MIS Other 10 11 Total external revenue 1,036 794 Intersegment revenue 40 37 Total MIS 1,076 831 MA: Research, data and analytics (RD&A) 419 358 Enterprise risk solutions (ERS) 145 138 Total external revenue 564 496 Intersegment revenue 2 2 Total MA 566 498 Eliminations (42) (39) Total MCO $ 1,600 $ 1,290 (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 March 31, 2021 Three Months Ended March 31, 2020 U.S. Non-U.S Total U.S. Non-U.S Total MIS: Corporate finance (CFG) $ 414 $ 191 $ 605 $ 314 $ 139 $ 453 Financial institutions (FIG) 86 76 162 60 65 125 Public, project and infrastructure finance (PPIF) 78 65 143 68 41 109 Structured finance (SFG) 68 48 116 61 35 96 Total ratings revenue 646 380 1,026 503 280 783 MIS Other 1 9 10 — 11 11 Total MIS 647 389 1,036 503 291 794 MA: Research, data and analytics (RD&A) 183 236 419 158 200 358 Enterprise risk solutions (ERS) 55 90 145 53 85 138 Total MA 238 326 564 211 285 496 Total MCO $ 885 $ 715 $ 1,600 $ 714 $ 576 $ 1,290 The following table presents the Company’s reportable segment revenues disaggregated by segment and geographic region: Three Months Ended 2021 2020 MIS: U.S. $ 647 $ 503 Non-U.S.: EMEA 248 171 Asia-Pacific 97 81 Americas 44 39 Total Non-U.S. 389 291 Total MIS 1,036 794 MA: U.S. 238 211 Non-U.S.: EMEA 230 192 Asia-Pacific 59 55 Americas 37 38 Total Non-U.S. 326 285 Total MA 564 496 Total MCO $ 1,600 $ 1,290 The following tables summarize the split between transaction and relationship 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 relationship 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 relationship revenue represents subscription-based revenues. In the MA segment, relationship 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 March 31, 2021 2020 Transaction Relationship Total Transaction Relationship Total Corporate Finance $ 487 $ 118 $ 605 $ 338 $ 115 $ 453 80 % 20 % 100 % 75 % 25 % 100 % Financial Institutions $ 90 $ 72 $ 162 $ 60 $ 65 $ 125 56 % 44 % 100 % 48 % 52 % 100 % Public, Project and Infrastructure Finance $ 100 $ 43 $ 143 $ 69 $ 40 $ 109 70 % 30 % 100 % 63 % 37 % 100 % Structured Finance $ 66 $ 50 $ 116 $ 50 $ 46 $ 96 57 % 43 % 100 % 52 % 48 % 100 % MIS Other $ 2 $ 8 $ 10 $ 2 $ 9 $ 11 20 % 80 % 100 % 18 % 82 % 100 % Total MIS $ 745 $ 291 $ 1,036 $ 519 $ 275 $ 794 72 % 28 % 100 % 65 % 35 % 100 % Research, data and analytics $ 20 $ 399 $ 419 $ 18 $ 340 $ 358 5 % 95 % 100 % 5 % 95 % 100 % Enterprise risk solutions $ 23 $ 122 $ 145 $ 32 $ 106 $ 138 16 % 84 % 100 % 23 % 77 % 100 % Total MA $ 43 (1) $ 521 $ 564 $ 50 (1) $ 446 $ 496 8 % 92 % 100 % 10 % 90 % 100 % Total Moody's Corporation $ 788 $ 812 $ 1,600 $ 569 $ 721 $ 1,290 49 % 51 % 100 % 44 % 56 % 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 March 31, 2021 Three Months Ended March 31, 2020 MIS MA Total MIS MA Total Revenue recognized at a point in time $ 745 $ 29 $ 774 $ 519 $ 39 $ 558 Revenue recognized over time 291 535 826 275 457 732 Total $ 1,036 $ 564 $ 1,600 $ 794 $ 496 $ 1,290 Unbilled receivables, deferred revenue and remaining performance obligations Unbilled receivables At March 31, 2021 and December 31, 2020, accounts receivable, net included $452 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 March 31, 2021 and December 31, 2020, accounts receivable, net included $88 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 months ended March 31, 2021 and 2020 are as follows: Three Months Ended March 31, 2021 Three Months Ended March 31, 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 (96) (386) (482) (99) (336) (435) Increases due to amounts billable excluding amounts recognized as revenue during the period 174 452 626 161 343 504 Increases due to acquisitions during the period — 4 4 — 20 20 Effect of exchange rate changes (3) (4) (7) (5) (24) (29) Total changes in deferred revenue 75 66 141 57 3 60 Balance at March 31, $ 388 $ 940 $ 1,328 $ 379 $ 843 $ 1,222 Deferred revenue - current $ 295 $ 937 $ 1,232 $ 275 $ 838 1,113 Deferred revenue - noncurrent $ 93 $ 3 $ 96 $ 104 $ 5 109 The increase in deferred revenue during both the three months ended March 31, 2021 and 2020 is primarily due to the significant portion of contract renewals that occur during the first quarter within both segments. 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 March 31, 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 March 31, 2021 as well as amounts not yet invoiced to customers as of March 31, 2021, largely reflecting future revenue related to signed multi-year arrangements for hosted and installed subscription-based products. As of March 31, 2021, the aggregate amount of the transaction price allocated to remaining performance obligations was approximately $2.3 billion. The Company expects to recognize into revenue approximately 65% of this balance within one year, approximately 20% of this balance between one to two years and the remaining amount thereafter.

STOCK-BASED COMPENSATION

STOCK-BASED COMPENSATION	3 Months Ended
	Mar. 31, 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 2021 2020 Stock-based compensation cost $ 45 $ 37 Tax benefit $ 11 $ 7 During the first three months of 2021, the Company granted 0.1 million employee stock options, which had a weighted average grant date fair value of $67.40 per share based on the Black-Scholes option-pricing model. The Company also granted 0.5 million shares of restricted stock in the first three months of 2021, which had a weighted average grant date fair value of $276.86 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 $268.82 per share. The following weighted average assumptions were used in determining the fair value for options granted in 2021: Expected dividend yield 0.90 % Expected stock volatility 28 % Risk-free interest rate 0.82 % Expected holding period 5.6 years Unrecognized stock-based compensation expense at March 31, 2021 was $12 million and $265 million for stock options and unvested restricted stock, respectively, which is expected to be recognized over a weighted average period of 2.6 years and 2.7 years, respectively. Additionally, there was $41 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 2.3 years. The following tables summarize information relating to stock option exercises and restricted stock vesting: Three Months Ended 2021 2020 Exercise of stock options: Proceeds from stock option exercises $ 6 $ 13 Aggregate intrinsic value $ 9 $ 46 Tax benefit realized upon exercise $ 2 $ 11 Number of shares exercised 0.1 0.2 Vesting of restricted stock: Fair value of shares vested $ 178 $ 191 Tax benefit realized upon vesting $ 41 $ 44 Number of shares vested 0.6 0.8 Vesting of performance-based restricted stock: Fair value of shares vested $ 29 $ 70 Tax benefit realized upon vesting $ 6 $ 17 Number of shares vested 0.1 0.3

INCOME TAXES

INCOME TAXES	3 Months Ended
	Mar. 31, 2021
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES Moody’s ETR was 14.6% and 13.7% for the three months ended March 31, 2021 and 2020, respectively. The increase in the ETR for the three months ended March 31, 2021 was primarily due to higher pretax income, which diluted the impact of the tax benefits discussed below that were recognized during the first quarter of 2021. 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 compensation of $19 million and net reductions in UTPs of $61 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 a decrease in its UTPs of $81 million ($71 million, net of federal tax) during the first quarter of 2021, which primarily related to the aforementioned resolution of uncertain tax positions. 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 return for 2019 remains open to examination and 2017 and 2018 are currently under examination. The Company’s New York City tax return for 2014 through 2017 are currently under examination. The Company’s U.K. tax return for 2012 is currently under examination and its returns for 2013 through 2019 remain open to 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: Three Months Ended March 31, 2021 2020 Income taxes paid $ 68 $ 29

WEIGHTED AVERAGE SHARES OUTSTAN

WEIGHTED AVERAGE SHARES OUTSTANDING	3 Months Ended
	Mar. 31, 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 March 31, 2021 2020 Basic 187.2 187.5 Dilutive effect of shares issuable under stock-based compensation plans 1.4 2.1 Diluted 188.6 189.6 Anti-dilutive options to purchase common shares and restricted stock as well as contingently issuable restricted stock which are excluded from the table above 0.3 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 March 31, 2021 and 2020.

CASH EQUIVALENTS AND INVESTMENT

CASH EQUIVALENTS AND INVESTMENTS	3 Months Ended
	Mar. 31, 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 March 31, 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) $ 1,639 $ — $ 1,639 $ 1,531 $ 96 $ 12 Mutual funds $ 49 $ 6 $ 55 $ — $ — $ 55 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 March 31, 2021 and December 31, 2020. The remaining contractual maturities for the certificates of deposits classified in other assets are 13 months to 23 months at both March 31, 2021 and 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 March 31, 2021 and December 31, 2020, the contract value of the COLI was $33 million and $17 million, respectively.

ACQUISITIONS

ACQUISITIONS	3 Months Ended
	Mar. 31, 2021
Business Combinations [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. 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 to be paid to sellers in 2021 (1) 1 Total consideration $ 139 (1) Represents additional consideration to be 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 95 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 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. At the date of the filing of this quarterly report on Form 10-Q, the Company has not completed the assignment of goodwill from this acquisition to its reporting units. 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. RDC is a component of the Bureau van Dijk reporting unit for purposes of the Company’s annual goodwill impairment assessment. Transaction costs Transaction costs directly related to the RDC acquisition were not material.

DERIVATIVE INSTRUMENTS AND HEDG

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES	3 Months Ended
	Mar. 31, 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 statement 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 March 31, As of December 31, 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 Total $ 1,380 $ 1,380 Refer to Note 15 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 statement 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 March 31, 2021 2020 Interest expense, net $ (7) $ (40) Descriptions Location on Consolidated Statements of Operations Net interest settlements and accruals on interest rate swaps Interest expense, net $ 5 $ 3 Fair value changes on interest rate swaps Interest expense, net $ (24) $ 58 Fair value changes on hedged debt Interest expense, net $ 24 $ (58) 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: March 31, 2021 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 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 March 31, 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, 2021 (After March 31,) € 265 2022 € 438 2023 € 442 2024 € 443 2026 € 450 Total € 2,038 Forward contracts designated as net investment hedges The Company also enters 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 March 31, 2021 December 31, 2020 Sell Buy Sell Buy Contract to sell EUR for USD € 560 $ 681 € 524 $ 627 Contract to sell GBP for EUR £ 134 € 155 £ 134 € 148 These forward contracts will expire in May 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 table 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 $ 16 $ — $ 1 $ — $ — $ — Cross currency swaps 72 66 — — 10 8 Long-term debt 45 23 — — — — Total net investment hedges $ 133 $ 89 $ 1 $ — $ 10 $ 8 Derivatives in Cash Flow Hedging Relationships Interest rate contracts — (36) (1) (1) — — Total $ 133 $ 53 $ — $ (1) $ 10 $ 8 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 March 31, 2021 December 31, 2020 Net investment hedges Cross currency swaps $ (52) $ (124) FX forwards 27 12 Long-term debt (63) (108) Total net investment hedges $ (88) $ (220) Cash flow hedges Interest rate contracts $ (50) $ (51) Cross currency swaps 2 2 Total cash flow hedges (48) (49) Total net loss in AOCL $ (136) $ (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 May 2021. The following table summarizes the notional amounts of the Company’s outstanding foreign exchange forwards: March 31, 2021 December 31, 2020 Notional amount of currency pair: Sell Buy Sell Buy Contracts to sell USD for GBP $ 402 £ 287 $ 295 £ 222 Contracts to sell USD for Japanese Yen $ 15 ¥ 1,600 $ 15 ¥ 1,600 Contracts to sell USD for Canadian dollars $ 100 C$ 126 $ 107 C$ 140 Contracts to sell USD for Singapore dollars $ 60 S$ 79 $ 59 S$ 79 Contracts to sell USD for Euros $ 493 € 405 $ 447 € 376 Contracts to sell Euros for GBP € 180 £ 157 € 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 Statement of Operations Three Months Ended 2021 2020 Foreign exchange forwards Other non-operating income, net $ (6) $ (40) 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 March 31, 2021 December 31, 2020 Assets: Derivatives designated as accounting hedges: Cross-currency swaps designated as net investment hedges Other assets $ 1 $ — Interest rate swaps designated as fair value hedges Other assets 38 57 FX forwards designated as net investment hedges Other current assets 23 — Total derivatives designated as accounting hedges 62 57 Derivatives not designated as accounting hedges: FX forwards on certain assets and liabilities Other current assets 8 31 Total assets $ 70 $ 88 Liabilities: Derivatives designated as accounting hedges: FX forwards designated as net investment hedges Accounts payable and accrued liabilities $ 2 $ 16 Cross-currency swaps designated as net investment hedges Accounts payable and accrued liabilities 11 23 Cross-currency swaps designated as net investment hedges Other liabilities 61 144 Interest rate swaps designated as fair value hedges Other liabilities 6 1 Total derivatives designated as accounting hedges 80 184 Non-derivatives designated as accounting hedges: Long-term debt designated as net investment hedge Long-term debt 1,469 1,530 Derivatives not designated as accounting hedges: FX forwards on certain assets and liabilities Accounts payable and accrued liabilities 28 2 Total liabilities $ 1,577 $ 1,716

GOODWILL AND OTHER ACQUIRED INT

GOODWILL AND OTHER ACQUIRED INTANGIBLE ASSETS	3 Months Ended
	Mar. 31, 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: Three Months Ended March 31, 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) — — — 95 — 95 95 — 95 Foreign currency translation adjustments 1 — 1 (86) — (86) (85) — (85) Ending balance $ 312 $ — $ 312 $ 4,266 $ (12) $ 4,254 $ 4,578 $ (12) $ 4,566 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 relate to the acquisition of Cortera. (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: March 31, December 31, Customer relationships $ 1,602 $ 1,623 Accumulated amortization (326) (313) Net customer relationships 1,276 1,310 Software/product technology 438 441 Accumulated amortization (183) (177) Net software/product technology 255 264 Database 180 144 Accumulated amortization (32) (29) Net database 148 115 Trade names 160 161 Accumulated amortization (40) (38) Net trade names 120 123 Other (1) 54 55 Accumulated amortization (43) (43) Net other 11 12 Total acquired intangible assets, net $ 1,810 $ 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 2021 2020 Amortization expense $ 35 $ 28 Estimated future amortization expense for acquired intangible assets subject to amortization is as follows: Year Ending December 31, 2021 (After March 31,) $ 99 2022 135 2023 130 2024 123 2025 121 Thereafter 1,202 Total estimated future amortization $ 1,810 Matters concerning the ICRA reporting unit On August 29, 2019, the board of directors of ICRA terminated the employment of ICRA's CEO and on September 28, 2019, the shareholders of ICRA voted to remove the former CEO from his position on ICRA's board of directors. ICRA appointed a new Managing Director & Group CEO effective August 10, 2020. ICRA has reported that the Securities and Exchange Board of India (SEBI) issued an adjudication order dated December 26, 2019 imposing a penalty of INR 25 lakh (approximately $35,000) on ICRA in connection with credit ratings assigned to one of ICRA’s customers and the customer’s subsidiaries. ICRA has further reported that: (i) it had appealed that order; and (ii) it has received a related "show cause" notice from SEBI asking ICRA to demonstrate why the penalty imposed should not be increased. In an order dated September 22, 2020, SEBI increased the penalty imposed on ICRA from INR 25 lakh to INR 1 crore (approximately $140,000) and ICRA has disclosed that it has appealed that order. In addition, ICRA has disclosed that it completed the internal examinations it conducted into anonymous allegations that were forwarded to ICRA by SEBI, certain additional allegations made during the course of that examination, and a separate anonymous complaint. ICRA reported that its Board of Directors have taken appropriate actions based on the findings of the completed examinations. As of the date of this quarter 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	3 Months Ended
	Mar. 31, 2021
Restructuring and Related Activities [Abstract]
RESTRUCTURING	RESTRUCTURING 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 $25 to $30 million per year. This program relates to a strategic reorganization in the MA reportable segment and is estimated to result in total pre-tax charges of approximately $20 to $30 million, consisting of severance and related costs primarily determined under the Company’s existing severance plans. The 2020 MA Strategic Reorganization Restructuring Program is expected to be substantially complete in the first half of 2021. Cash outlays associated with this program are expected to be $20 to $30 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 2021 2020 2020 MA Strategic Reorganization Restructuring Program $ 2 $ — Changes to the restructuring liability for the aforementioned restructuring program during the first three 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 (5) Balance as of March 31, 2021 $ 15 Cumulative expense incurred to date 2020 MA Strategic Reorganization Restructuring Program: $ 20 As of March 31, 2021, the remaining $15 million restructuring liability related to the 2020 MA Strategic Reorganization Restructuring Program is expected to be paid out through 2022.

FAIR VALUE

FAIR VALUE	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
FAIR VALUE	FAIR VALUE The table below presents information about items that are carried at fair value at March 31, 2021 and December 31, 2020: Fair value Measurement as of March 31, 2021 Description Balance Level 1 Level 2 Assets: Derivatives (1) $ 70 $ — $ 70 Mutual funds 55 55 — Total $ 125 $ 55 $ 70 Liabilities: Derivatives (1) $ 108 $ — $ 108 Total $ 108 $ — $ 108 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 8 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	3 Months Ended
	Mar. 31, 2021
Other Balance Sheet And Statement Of Operations Information [Abstract]
OTHER BALANCE SHEET AND STATEMENT OF OPERATIONS INFORMATION	OTHER BALANCE SHEET AND STATEMENT OF OPERATIONS INFORMATION The following tables contain additional detail related to certain balance sheet captions: March 31, 2021 December 31, 2020 Other current assets: Prepaid taxes $ 73 $ 94 Prepaid expenses 88 91 Capitalized costs to obtain and fulfill sales contracts 96 93 Foreign exchange forwards on certain assets and liabilities 8 31 Derivative instruments designated as accounting hedges 23 — Other 45 74 Total other current assets $ 333 $ 383 Other assets: Investments in non-consolidated affiliates $ 149 $ 135 Deposits for real-estate leases 19 19 Indemnification assets related to acquisitions 15 15 Mutual funds and fixed deposits 67 66 Company owned life insurance (at contract value) 33 17 Costs to obtain sales contracts 143 134 Derivative instruments designated as accounting hedges 39 57 Pension and other retirement employee benefits 22 21 Other 58 51 Total other assets $ 545 $ 515 Accounts payable and accrued liabilities: Salaries and benefits $ 203 $ 197 Incentive compensation 62 226 Customer credits, advanced payments and advanced billings 43 42 Dividends 6 11 Professional service fees 57 53 Interest accrued on debt 33 82 Accounts payable 21 39 Income taxes 156 128 Pension and other retirement employee benefits 46 45 Accrued royalties 27 19 Foreign exchange forwards on certain assets and liabilities 28 2 Restructuring liability 15 18 Derivative instruments designated as accounting hedges 13 39 Other 118 138 Total accounts payable and accrued liabilities $ 828 $ 1,039 March 31, 2021 December 31, 2020 Other liabilities: Pension and other retirement employee benefits $ 249 $ 244 Interest accrued on UTPs 70 113 MAKS indemnification provisions 33 33 Income tax liability - non-current portion 18 18 Derivative instruments designated as accounting hedges 67 145 Other 36 37 Total other liabilities $ 473 $ 590 Loss pursuant to the Divestiture of MAKS: The $9 million loss during the three months ended March 31, 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 March 31, 2021 2020 FX (loss) gain $ (2) $ 13 Net periodic pension costs - other components 4 3 Income/(loss) from investments in non-consolidated affiliates 8 (3) Other 6 (1) Total $ 16 $ 12

COMPREHENSIVE INCOME AND ACCUMU

COMPREHENSIVE INCOME AND ACCUMULATED OTHER COMPREHENSIVE LOSS	3 Months Ended
	Mar. 31, 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 March 31, Location in the consolidated statement of operations Losses on cash flow hedges 2021 2020 Interest rate contract $ (1) $ (1) Other non-operating income, net Income tax effect of items above — — Provision for income taxes Total net losses on cash flow hedges (1) (1) Gains on net investment hedges FX forwards 1 — Other non-operating income, net Income tax effect of item above — — 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 (3) (2) Other non-operating income, net Income tax effect of item above 1 1 Provision for income taxes Total pension and other retirement benefits (2) (1) Total net losses included in Net Income attributable to reclassifications out of AOCL $ (2) $ (2) The following tables show changes in AOCL by component (net of tax): Three Months Ended March 31, 2021 Gains/(Losses) Pension and Other Retirement Benefits Cash Flow Hedges Foreign Currency Translation Adjustments Net Investment Hedges Total Balance December 31, 2020 $ (118) $ (49) $ (45) $ (220) $ (432) Other comprehensive income/(loss) before reclassifications — — (143) 133 (10) Amounts reclassified from AOCL 2 1 — (1) 2 Other comprehensive income/(loss) 2 1 (143) 132 (8) Balance March 31, 2021 $ (116) $ (48) $ (188) $ (88) $ (440) Three Months Ended March 31, 2020 Gains/(Losses) Pension and Other Retirement Benefits Cash Flow Hedges Foreign Currency Translation Adjustments Net Investment Hedges Total Balance December 31, 2019 $ (92) $ — $ (401) $ 54 $ (439) Other comprehensive income/(loss) before reclassifications (1) (36) (169) 89 (117) Amounts reclassified from AOCL 1 1 — — 2 Other comprehensive income/(loss) — (35) (169) 89 (115) Balance March 31, 2020 $ (92) $ (35) $ (570) $ 143 $ (554)

PENSION AND OTHER RETIREMENT BE

PENSION AND OTHER RETIREMENT BENEFITS	3 Months Ended
	Mar. 31, 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 March 31, Pension Plans Other Retirement Plans 2021 2020 2021 2020 Components of net periodic expense Service cost $ 5 $ 5 $ 1 $ 1 Interest cost 4 4 — — Expected return on plan assets (7) (5) — — Amortization of net actuarial loss from earlier periods 2 2 — — Net periodic expense $ 4 $ 6 $ 1 $ 1 The Company made payments of $1 million related to its unfunded U.S. DBPPs during the three months ended March 31, 2021. Additionally, the Company anticipates making payments of $44 million and $1 million to its unfunded U.S. DBPPs and U.S. other retirement plans, respectively, during the remainder of 2021.

INDEBTEDNESS

INDEBTEDNESS	3 Months Ended
	Mar. 31, 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 the 2012 Senior Notes due 2022, the 2017 Senior Notes due 2023, the 2017 Senior Notes due 2028 and the 2020 Senior Notes due 2025, 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: March 31, 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 $ 12 $ (1) $ (1) $ 510 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 588 — — (2) 586 2.625% 2017 Senior Notes, due 2023 500 10 — (1) 509 3.25% 2017 Senior Notes, due 2028 500 16 (4) (3) 509 4.25% 2018 Senior Notes, due 2029 400 — (2) (3) 395 4.875% 2018 Senior Notes, due 2048 400 — (6) (4) 390 0.950% 2019 Senior Notes, due 2030 881 — (3) (6) 872 3.75% 2020 Senior Notes, due 2025 700 (6) (1) (4) 689 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 $ 6,369 $ 32 $ (23) $ (38) $ 6,340 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 At March 31, 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 March 31, 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 Total 2021 (After March 31,) $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — 2022 500 — — — — — — — — — — — 500 2023 — — — — 500 — — — — — — — 500 2024 — 500 — — — — — — — — — — 500 2025 — — — — — — — — — 700 — — 700 Thereafter — — 600 588 — 500 400 400 881 — 300 500 4,169 Total $ 500 $ 500 $ 600 $ 588 $ 500 $ 500 $ 400 $ 400 $ 881 $ 700 $ 300 $ 500 $ 6,369 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 2021 2020 Income $ 3 $ 4 Expense on borrowings (41) (31) Income (expense) on UTPs and other tax related liabilities (2) 35 (8) Net periodic pension costs - interest component (4) (5) Interest expense, net $ (7) $ (40) Interest paid (1) $ 73 $ 49 (1) Interest paid includes net settlements on interest rate swaps more fully discussed in Note 8. (2) Income(expense) on UTPs and other tax related liabilities in 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 March 31, 2021 and December 31, 2020 are as follows: March 31, 2021 December 31, 2020 Carrying Amount Estimated Fair Value Carrying Amount Estimated Fair Value 4.50% 2012 Senior Notes, due 2022 $ 510 $ 525 $ 512 $ 530 4.875% 2013 Senior Notes, due 2024 498 555 498 562 5.25% 2014 Senior Notes, due 2044 598 775 598 828 1.75% 2015 Senior Notes, due 2027 586 641 610 674 2.625% 2017 Senior Notes, due 2023 509 518 510 522 3.25% 2017 Senior Notes, due 2028 509 537 524 561 4.25% 2018 Senior Notes, due 2029 395 453 394 480 4.875% 2018 Senior Notes, due 2048 390 493 390 544 0.950% 2019 Senior Notes, due 2030 872 915 909 974 3.75% 2020 Senior Notes, due 2025 689 764 693 785 3.25% 2020 Senior Notes, due 2050 293 292 293 329 2.55% 2020 Senior Notes, due 2060 491 404 491 467 Total $ 6,340 $ 6,872 $ 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	3 Months Ended
	Mar. 31, 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 March 31, 2021 Three Months Ended March 31, 2020 Operating lease cost $ 24 $ 24 Sublease income (1) (1) Variable lease cost 5 5 Total lease cost $ 28 $ 28 The following tables present other information related to the Company’s operating leases: Three Months Ended March 31, 2021 Three Months Ended March 31, 2020 Cash paid for amounts included in the measurement of operating lease liabilities $ 28 $ 26 Right-of-use assets obtained in exchange for new operating lease liabilities $ 4 $ 9 March 31, 2021 March 31, 2020 Weighted-average remaining lease term 5.9 years 6.7 years Weighted-average discount rate applied to operating leases 3.6 % 3.6 % The following table presents a maturity analysis of the future minimum lease payments included within the Company’s operating lease liabilities at March 31, 2021: Year Ending December 31, Operating Leases 2021 (After March 31) $ 83 2022 99 2023 94 2024 85 2025 77 After 2025 116 Total lease payments (undiscounted) 554 Less: Interest 54 Present value of lease liabilities: $ 500 Lease liabilities - current $ 94 Lease liabilities - noncurrent $ 406

CONTINGENCIES

CONTINGENCIES	3 Months Ended
	Mar. 31, 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 4 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	3 Months Ended
	Mar. 31, 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 2 for further details on the components of the Company’s revenue. Three Months Ended March 31, 2021 2020 MIS MA Eliminations Consolidated MIS MA Eliminations Consolidated Revenue $ 1,076 $ 566 $ (42) $ 1,600 $ 831 $ 498 $ (39) $ 1,290 Total Expenses 366 423 (42) 747 343 394 (39) 698 Operating income 710 143 — 853 488 104 — 592 Add: Depreciation and 18 41 — 59 16 33 — 49 Restructuring — 2 — 2 (1) — — (1) Loss pursuant to the divestiture of MAKS — — — — — 9 — 9 Adjusted Operating Income $ 728 $ 186 $ — $ 914 $ 503 $ 146 $ — $ 649 Consolidated Revenue Information by Geographic Area Three Months Ended March 31, 2021 2020 United States $ 885 $ 714 Non-U.S.: EMEA 478 363 Asia-Pacific 156 136 Americas 81 77 Total Non-U.S. 715 576 Total $ 1,600 $ 1,290

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	3 Months Ended
	Mar. 31, 2021
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	SUBSEQUENT EVENTOn April 27, 2021, the Board approved the declaration of a quarterly dividend of $0.62 per share of Moody’s common stock, payable on June 10, 2021 to shareholders of record at the close of business on May 20, 2021.

REVENUES (Tables)

REVENUES (Tables)	3 Months Ended
	Mar. 31, 2021
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following table presents the Company’s revenues disaggregated by LOB: Three Months Ended 2021 2020 MIS: Corporate finance (CFG) Investment-grade $ 134 $ 144 High-yield 141 75 Bank loans 180 89 Other accounts (1) 150 145 Total CFG 605 453 Financial institutions (FIG) Banking 109 86 Insurance 43 30 Managed investments 8 6 Other accounts 2 3 Total FIG 162 125 Public, project and infrastructure finance (PPIF) Public finance / sovereign 67 57 Project and infrastructure 76 52 Total PPIF 143 109 Structured finance (SFG) Asset-backed securities 26 22 RMBS 27 27 CMBS 24 17 Structured credit 38 29 Other accounts 1 1 Total SFG 116 96 Total ratings revenue 1,026 783 MIS Other 10 11 Total external revenue 1,036 794 Intersegment revenue 40 37 Total MIS 1,076 831 MA: Research, data and analytics (RD&A) 419 358 Enterprise risk solutions (ERS) 145 138 Total external revenue 564 496 Intersegment revenue 2 2 Total MA 566 498 Eliminations (42) (39) Total MCO $ 1,600 $ 1,290 (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 March 31, 2021 Three Months Ended March 31, 2020 U.S. Non-U.S Total U.S. Non-U.S Total MIS: Corporate finance (CFG) $ 414 $ 191 $ 605 $ 314 $ 139 $ 453 Financial institutions (FIG) 86 76 162 60 65 125 Public, project and infrastructure finance (PPIF) 78 65 143 68 41 109 Structured finance (SFG) 68 48 116 61 35 96 Total ratings revenue 646 380 1,026 503 280 783 MIS Other 1 9 10 — 11 11 Total MIS 647 389 1,036 503 291 794 MA: Research, data and analytics (RD&A) 183 236 419 158 200 358 Enterprise risk solutions (ERS) 55 90 145 53 85 138 Total MA 238 326 564 211 285 496 Total MCO $ 885 $ 715 $ 1,600 $ 714 $ 576 $ 1,290 The following tables summarize the split between transaction and relationship 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 relationship 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 relationship revenue represents subscription-based revenues. In the MA segment, relationship 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 March 31, 2021 2020 Transaction Relationship Total Transaction Relationship Total Corporate Finance $ 487 $ 118 $ 605 $ 338 $ 115 $ 453 80 % 20 % 100 % 75 % 25 % 100 % Financial Institutions $ 90 $ 72 $ 162 $ 60 $ 65 $ 125 56 % 44 % 100 % 48 % 52 % 100 % Public, Project and Infrastructure Finance $ 100 $ 43 $ 143 $ 69 $ 40 $ 109 70 % 30 % 100 % 63 % 37 % 100 % Structured Finance $ 66 $ 50 $ 116 $ 50 $ 46 $ 96 57 % 43 % 100 % 52 % 48 % 100 % MIS Other $ 2 $ 8 $ 10 $ 2 $ 9 $ 11 20 % 80 % 100 % 18 % 82 % 100 % Total MIS $ 745 $ 291 $ 1,036 $ 519 $ 275 $ 794 72 % 28 % 100 % 65 % 35 % 100 % Research, data and analytics $ 20 $ 399 $ 419 $ 18 $ 340 $ 358 5 % 95 % 100 % 5 % 95 % 100 % Enterprise risk solutions $ 23 $ 122 $ 145 $ 32 $ 106 $ 138 16 % 84 % 100 % 23 % 77 % 100 % Total MA $ 43 (1) $ 521 $ 564 $ 50 (1) $ 446 $ 496 8 % 92 % 100 % 10 % 90 % 100 % Total Moody's Corporation $ 788 $ 812 $ 1,600 $ 569 $ 721 $ 1,290 49 % 51 % 100 % 44 % 56 % 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 March 31, 2021 Three Months Ended March 31, 2020 MIS MA Total MIS MA Total Revenue recognized at a point in time $ 745 $ 29 $ 774 $ 519 $ 39 $ 558 Revenue recognized over time 291 535 826 275 457 732 Total $ 1,036 $ 564 $ 1,600 $ 794 $ 496 $ 1,290
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 2021 2020 MIS: U.S. $ 647 $ 503 Non-U.S.: EMEA 248 171 Asia-Pacific 97 81 Americas 44 39 Total Non-U.S. 389 291 Total MIS 1,036 794 MA: U.S. 238 211 Non-U.S.: EMEA 230 192 Asia-Pacific 59 55 Americas 37 38 Total Non-U.S. 326 285 Total MA 564 496 Total MCO $ 1,600 $ 1,290
Schedule of Changes in the Deferred Revenue Balances	Significant changes in the deferred revenue balances during the three months ended March 31, 2021 and 2020 are as follows: Three Months Ended March 31, 2021 Three Months Ended March 31, 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 (96) (386) (482) (99) (336) (435) Increases due to amounts billable excluding amounts recognized as revenue during the period 174 452 626 161 343 504 Increases due to acquisitions during the period — 4 4 — 20 20 Effect of exchange rate changes (3) (4) (7) (5) (24) (29) Total changes in deferred revenue 75 66 141 57 3 60 Balance at March 31, $ 388 $ 940 $ 1,328 $ 379 $ 843 $ 1,222 Deferred revenue - current $ 295 $ 937 $ 1,232 $ 275 $ 838 1,113 Deferred revenue - noncurrent $ 93 $ 3 $ 96 $ 104 $ 5 109

STOCK-BASED COMPENSATION (Table

STOCK-BASED COMPENSATION (Tables)	3 Months Ended
	Mar. 31, 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 2021 2020 Stock-based compensation cost $ 45 $ 37 Tax benefit $ 11 $ 7
Weighted Average Assumptions used in Determining Fair Value for Options Granted	The following weighted average assumptions were used in determining the fair value for options granted in 2021: Expected dividend yield 0.90 % Expected stock volatility 28 % Risk-free interest rate 0.82 % 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: Three Months Ended 2021 2020 Exercise of stock options: Proceeds from stock option exercises $ 6 $ 13 Aggregate intrinsic value $ 9 $ 46 Tax benefit realized upon exercise $ 2 $ 11 Number of shares exercised 0.1 0.2 Vesting of restricted stock: Fair value of shares vested $ 178 $ 191 Tax benefit realized upon vesting $ 41 $ 44 Number of shares vested 0.6 0.8 Vesting of performance-based restricted stock: Fair value of shares vested $ 29 $ 70 Tax benefit realized upon vesting $ 6 $ 17 Number of shares vested 0.1 0.3

INCOME TAXES (Tables)

INCOME TAXES (Tables)	3 Months Ended
	Mar. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes Paid	The following table shows the amount the Company paid for income taxes: Three Months Ended March 31, 2021 2020 Income taxes paid $ 68 $ 29

WEIGHTED AVERAGE SHARES OUTST_2

WEIGHTED AVERAGE SHARES OUTSTANDING (Tables)	3 Months Ended
	Mar. 31, 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 March 31, 2021 2020 Basic 187.2 187.5 Dilutive effect of shares issuable under stock-based compensation plans 1.4 2.1 Diluted 188.6 189.6 Anti-dilutive options to purchase common shares and restricted stock as well as contingently issuable restricted stock which are excluded from the table above 0.3 0.3

CASH EQUIVALENTS AND INVESTME_2

CASH EQUIVALENTS AND INVESTMENTS (Tables)	3 Months Ended
	Mar. 31, 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 March 31, 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) $ 1,639 $ — $ 1,639 $ 1,531 $ 96 $ 12 Mutual funds $ 49 $ 6 $ 55 $ — $ — $ 55 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 March 31, 2021 and December 31, 2020. The remaining contractual maturities for the certificates of deposits classified in other assets are 13 months to 23 months at both March 31, 2021 and 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)	3 Months Ended
	Mar. 31, 2021
Business Combinations [Abstract]
Schedule of Business Acquisitions, by Acquisition	The table below details the total consideration relating to the acquisition: Cash paid at closing $ 138 Additional consideration to be paid to sellers in 2021 (1) 1 Total consideration $ 139 (1) Represents additional consideration to be 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: 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 95 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 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

DERIVATIVE INSTRUMENTS AND HE_2

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES (Tables)	3 Months Ended
	Mar. 31, 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 March 31, As of December 31, 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 Total $ 1,380 $ 1,380 March 31, 2021 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 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 statement 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 March 31, 2021 2020 Interest expense, net $ (7) $ (40) Descriptions Location on Consolidated Statements of Operations Net interest settlements and accruals on interest rate swaps Interest expense, net $ 5 $ 3 Fair value changes on interest rate swaps Interest expense, net $ (24) $ 58 Fair value changes on hedged debt Interest expense, net $ 24 $ (58)
Schedule of Net Investment Hedges, Notional Amount That Will Be Settled At Expiry	As of March 31, 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, 2021 (After March 31,) € 265 2022 € 438 2023 € 442 2024 € 443 2026 € 450 Total € 2,038
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 March 31, 2021 December 31, 2020 Sell Buy Sell Buy Contract to sell EUR for USD € 560 $ 681 € 524 $ 627 Contract to sell GBP for EUR £ 134 € 155 £ 134 € 148 The following table summarizes the notional amounts of the Company’s outstanding foreign exchange forwards: March 31, 2021 December 31, 2020 Notional amount of currency pair: Sell Buy Sell Buy Contracts to sell USD for GBP $ 402 £ 287 $ 295 £ 222 Contracts to sell USD for Japanese Yen $ 15 ¥ 1,600 $ 15 ¥ 1,600 Contracts to sell USD for Canadian dollars $ 100 C$ 126 $ 107 C$ 140 Contracts to sell USD for Singapore dollars $ 60 S$ 79 $ 59 S$ 79 Contracts to sell USD for Euros $ 493 € 405 $ 447 € 376 Contracts to sell Euros for GBP € 180 £ 157 € 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 table 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 $ 16 $ — $ 1 $ — $ — $ — Cross currency swaps 72 66 — — 10 8 Long-term debt 45 23 — — — — Total net investment hedges $ 133 $ 89 $ 1 $ — $ 10 $ 8 Derivatives in Cash Flow Hedging Relationships Interest rate contracts — (36) (1) (1) — — Total $ 133 $ 53 $ — $ (1) $ 10 $ 8
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 March 31, 2021 December 31, 2020 Net investment hedges Cross currency swaps $ (52) $ (124) FX forwards 27 12 Long-term debt (63) (108) Total net investment hedges $ (88) $ (220) Cash flow hedges Interest rate contracts $ (50) $ (51) Cross currency swaps 2 2 Total cash flow hedges (48) (49) Total net loss in AOCL $ (136) $ (269) The following tables show changes in AOCL by component (net of tax): Three Months Ended March 31, 2021 Gains/(Losses) Pension and Other Retirement Benefits Cash Flow Hedges Foreign Currency Translation Adjustments Net Investment Hedges Total Balance December 31, 2020 $ (118) $ (49) $ (45) $ (220) $ (432) Other comprehensive income/(loss) before reclassifications — — (143) 133 (10) Amounts reclassified from AOCL 2 1 — (1) 2 Other comprehensive income/(loss) 2 1 (143) 132 (8) Balance March 31, 2021 $ (116) $ (48) $ (188) $ (88) $ (440) Three Months Ended March 31, 2020 Gains/(Losses) Pension and Other Retirement Benefits Cash Flow Hedges Foreign Currency Translation Adjustments Net Investment Hedges Total Balance December 31, 2019 $ (92) $ — $ (401) $ 54 $ (439) Other comprehensive income/(loss) before reclassifications (1) (36) (169) 89 (117) Amounts reclassified from AOCL 1 1 — — 2 Other comprehensive income/(loss) — (35) (169) 89 (115) Balance March 31, 2020 $ (92) $ (35) $ (570) $ 143 $ (554)
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 Statement of Operations Three Months Ended 2021 2020 Foreign exchange forwards Other non-operating income, net $ (6) $ (40)
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 March 31, 2021 December 31, 2020 Assets: Derivatives designated as accounting hedges: Cross-currency swaps designated as net investment hedges Other assets $ 1 $ — Interest rate swaps designated as fair value hedges Other assets 38 57 FX forwards designated as net investment hedges Other current assets 23 — Total derivatives designated as accounting hedges 62 57 Derivatives not designated as accounting hedges: FX forwards on certain assets and liabilities Other current assets 8 31 Total assets $ 70 $ 88 Liabilities: Derivatives designated as accounting hedges: FX forwards designated as net investment hedges Accounts payable and accrued liabilities $ 2 $ 16 Cross-currency swaps designated as net investment hedges Accounts payable and accrued liabilities 11 23 Cross-currency swaps designated as net investment hedges Other liabilities 61 144 Interest rate swaps designated as fair value hedges Other liabilities 6 1 Total derivatives designated as accounting hedges 80 184 Non-derivatives designated as accounting hedges: Long-term debt designated as net investment hedge Long-term debt 1,469 1,530 Derivatives not designated as accounting hedges: FX forwards on certain assets and liabilities Accounts payable and accrued liabilities 28 2 Total liabilities $ 1,577 $ 1,716

GOODWILL AND OTHER ACQUIRED I_2

GOODWILL AND OTHER ACQUIRED INTANGIBLE ASSETS (Tables)	3 Months Ended
	Mar. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Activity in Goodwill	The following table summarizes the activity in goodwill for the periods indicated: Three Months Ended March 31, 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) — — — 95 — 95 95 — 95 Foreign currency translation adjustments 1 — 1 (86) — (86) (85) — (85) Ending balance $ 312 $ — $ 312 $ 4,266 $ (12) $ 4,254 $ 4,578 $ (12) $ 4,566 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 relate to the acquisition of Cortera. (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: March 31, December 31, Customer relationships $ 1,602 $ 1,623 Accumulated amortization (326) (313) Net customer relationships 1,276 1,310 Software/product technology 438 441 Accumulated amortization (183) (177) Net software/product technology 255 264 Database 180 144 Accumulated amortization (32) (29) Net database 148 115 Trade names 160 161 Accumulated amortization (40) (38) Net trade names 120 123 Other (1) 54 55 Accumulated amortization (43) (43) Net other 11 12 Total acquired intangible assets, net $ 1,810 $ 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 2021 2020 Amortization expense $ 35 $ 28
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 March 31,) $ 99 2022 135 2023 130 2024 123 2025 121 Thereafter 1,202 Total estimated future amortization $ 1,810

RESTRUCTURING (Tables)

RESTRUCTURING (Tables)	3 Months Ended
	Mar. 31, 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 2021 2020 2020 MA Strategic Reorganization Restructuring Program $ 2 $ —
Changes to the Restructuring Liability	Changes to the restructuring liability for the aforementioned restructuring program during the first three 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 (5) Balance as of March 31, 2021 $ 15 Cumulative expense incurred to date 2020 MA Strategic Reorganization Restructuring Program: $ 20

FAIR VALUE (Tables)

FAIR VALUE (Tables)	3 Months Ended
	Mar. 31, 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 March 31, 2021 and December 31, 2020: Fair value Measurement as of March 31, 2021 Description Balance Level 1 Level 2 Assets: Derivatives (1) $ 70 $ — $ 70 Mutual funds 55 55 — Total $ 125 $ 55 $ 70 Liabilities: Derivatives (1) $ 108 $ — $ 108 Total $ 108 $ — $ 108 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 8 to the condensed consolidated financial statements.

OTHER BALANCE SHEET AND STATE_2

OTHER BALANCE SHEET AND STATEMENT OF OPERATIONS INFORMATION (Tables)	3 Months Ended
	Mar. 31, 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: March 31, 2021 December 31, 2020 Other current assets: Prepaid taxes $ 73 $ 94 Prepaid expenses 88 91 Capitalized costs to obtain and fulfill sales contracts 96 93 Foreign exchange forwards on certain assets and liabilities 8 31 Derivative instruments designated as accounting hedges 23 — Other 45 74 Total other current assets $ 333 $ 383 Other assets: Investments in non-consolidated affiliates $ 149 $ 135 Deposits for real-estate leases 19 19 Indemnification assets related to acquisitions 15 15 Mutual funds and fixed deposits 67 66 Company owned life insurance (at contract value) 33 17 Costs to obtain sales contracts 143 134 Derivative instruments designated as accounting hedges 39 57 Pension and other retirement employee benefits 22 21 Other 58 51 Total other assets $ 545 $ 515 Accounts payable and accrued liabilities: Salaries and benefits $ 203 $ 197 Incentive compensation 62 226 Customer credits, advanced payments and advanced billings 43 42 Dividends 6 11 Professional service fees 57 53 Interest accrued on debt 33 82 Accounts payable 21 39 Income taxes 156 128 Pension and other retirement employee benefits 46 45 Accrued royalties 27 19 Foreign exchange forwards on certain assets and liabilities 28 2 Restructuring liability 15 18 Derivative instruments designated as accounting hedges 13 39 Other 118 138 Total accounts payable and accrued liabilities $ 828 $ 1,039 March 31, 2021 December 31, 2020 Other liabilities: Pension and other retirement employee benefits $ 249 $ 244 Interest accrued on UTPs 70 113 MAKS indemnification provisions 33 33 Income tax liability - non-current portion 18 18 Derivative instruments designated as accounting hedges 67 145 Other 36 37 Total other liabilities $ 473 $ 590
Other Non-Operating	The following table summarizes the components of other non-operating income (expense): Three Months Ended March 31, 2021 2020 FX (loss) gain $ (2) $ 13 Net periodic pension costs - other components 4 3 Income/(loss) from investments in non-consolidated affiliates 8 (3) Other 6 (1) Total $ 16 $ 12

COMPREHENSIVE INCOME AND ACCU_2

COMPREHENSIVE INCOME AND ACCUMULATED OTHER COMPREHENSIVE LOSS (Tables)	3 Months Ended
	Mar. 31, 2021
Equity [Abstract]
Reclassifications out of AOCI	The following table provides details about the reclassifications out of AOCL: Three Months Ended March 31, Location in the consolidated statement of operations Losses on cash flow hedges 2021 2020 Interest rate contract $ (1) $ (1) Other non-operating income, net Income tax effect of items above — — Provision for income taxes Total net losses on cash flow hedges (1) (1) Gains on net investment hedges FX forwards 1 — Other non-operating income, net Income tax effect of item above — — 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 (3) (2) Other non-operating income, net Income tax effect of item above 1 1 Provision for income taxes Total pension and other retirement benefits (2) (1) Total net losses included in Net Income attributable to reclassifications out of AOCL $ (2) $ (2)
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 March 31, 2021 December 31, 2020 Net investment hedges Cross currency swaps $ (52) $ (124) FX forwards 27 12 Long-term debt (63) (108) Total net investment hedges $ (88) $ (220) Cash flow hedges Interest rate contracts $ (50) $ (51) Cross currency swaps 2 2 Total cash flow hedges (48) (49) Total net loss in AOCL $ (136) $ (269) The following tables show changes in AOCL by component (net of tax): Three Months Ended March 31, 2021 Gains/(Losses) Pension and Other Retirement Benefits Cash Flow Hedges Foreign Currency Translation Adjustments Net Investment Hedges Total Balance December 31, 2020 $ (118) $ (49) $ (45) $ (220) $ (432) Other comprehensive income/(loss) before reclassifications — — (143) 133 (10) Amounts reclassified from AOCL 2 1 — (1) 2 Other comprehensive income/(loss) 2 1 (143) 132 (8) Balance March 31, 2021 $ (116) $ (48) $ (188) $ (88) $ (440) Three Months Ended March 31, 2020 Gains/(Losses) Pension and Other Retirement Benefits Cash Flow Hedges Foreign Currency Translation Adjustments Net Investment Hedges Total Balance December 31, 2019 $ (92) $ — $ (401) $ 54 $ (439) Other comprehensive income/(loss) before reclassifications (1) (36) (169) 89 (117) Amounts reclassified from AOCL 1 1 — — 2 Other comprehensive income/(loss) — (35) (169) 89 (115) Balance March 31, 2020 $ (92) $ (35) $ (570) $ 143 $ (554)

PENSION AND OTHER RETIREMENT _2

PENSION AND OTHER RETIREMENT BENEFITS (Tables)	3 Months Ended
	Mar. 31, 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 March 31, Pension Plans Other Retirement Plans 2021 2020 2021 2020 Components of net periodic expense Service cost $ 5 $ 5 $ 1 $ 1 Interest cost 4 4 — — Expected return on plan assets (7) (5) — — Amortization of net actuarial loss from earlier periods 2 2 — — Net periodic expense $ 4 $ 6 $ 1 $ 1

INDEBTEDNESS (Tables)

INDEBTEDNESS (Tables)	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
Summary of Total Indebtedness	The following table summarizes total indebtedness: March 31, 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 $ 12 $ (1) $ (1) $ 510 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 588 — — (2) 586 2.625% 2017 Senior Notes, due 2023 500 10 — (1) 509 3.25% 2017 Senior Notes, due 2028 500 16 (4) (3) 509 4.25% 2018 Senior Notes, due 2029 400 — (2) (3) 395 4.875% 2018 Senior Notes, due 2048 400 — (6) (4) 390 0.950% 2019 Senior Notes, due 2030 881 — (3) (6) 872 3.75% 2020 Senior Notes, due 2025 700 (6) (1) (4) 689 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 $ 6,369 $ 32 $ (23) $ (38) $ 6,340 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 Total 2021 (After March 31,) $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — 2022 500 — — — — — — — — — — — 500 2023 — — — — 500 — — — — — — — 500 2024 — 500 — — — — — — — — — — 500 2025 — — — — — — — — — 700 — — 700 Thereafter — — 600 588 — 500 400 400 881 — 300 500 4,169 Total $ 500 $ 500 $ 600 $ 588 $ 500 $ 500 $ 400 $ 400 $ 881 $ 700 $ 300 $ 500 $ 6,369
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 2021 2020 Income $ 3 $ 4 Expense on borrowings (41) (31) Income (expense) on UTPs and other tax related liabilities (2) 35 (8) Net periodic pension costs - interest component (4) (5) Interest expense, net $ (7) $ (40) Interest paid (1) $ 73 $ 49 (1) Interest paid includes net settlements on interest rate swaps more fully discussed in Note 8. (2) Income(expense) on UTPs and other tax related liabilities in 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 March 31, 2021 and December 31, 2020 are as follows: March 31, 2021 December 31, 2020 Carrying Amount Estimated Fair Value Carrying Amount Estimated Fair Value 4.50% 2012 Senior Notes, due 2022 $ 510 $ 525 $ 512 $ 530 4.875% 2013 Senior Notes, due 2024 498 555 498 562 5.25% 2014 Senior Notes, due 2044 598 775 598 828 1.75% 2015 Senior Notes, due 2027 586 641 610 674 2.625% 2017 Senior Notes, due 2023 509 518 510 522 3.25% 2017 Senior Notes, due 2028 509 537 524 561 4.25% 2018 Senior Notes, due 2029 395 453 394 480 4.875% 2018 Senior Notes, due 2048 390 493 390 544 0.950% 2019 Senior Notes, due 2030 872 915 909 974 3.75% 2020 Senior Notes, due 2025 689 764 693 785 3.25% 2020 Senior Notes, due 2050 293 292 293 329 2.55% 2020 Senior Notes, due 2060 491 404 491 467 Total $ 6,340 $ 6,872 $ 6,422 $ 7,256

LEASES (Tables)

LEASES (Tables)	3 Months Ended
	Mar. 31, 2021
Leases [Abstract]
Components of Lease Cost	The following table presents the components of the Company’s lease cost: Three Months Ended March 31, 2021 Three Months Ended March 31, 2020 Operating lease cost $ 24 $ 24 Sublease income (1) (1) Variable lease cost 5 5 Total lease cost $ 28 $ 28
Schedule of Operating Leases Information	The following tables present other information related to the Company’s operating leases: Three Months Ended March 31, 2021 Three Months Ended March 31, 2020 Cash paid for amounts included in the measurement of operating lease liabilities $ 28 $ 26 Right-of-use assets obtained in exchange for new operating lease liabilities $ 4 $ 9 March 31, 2021 March 31, 2020 Weighted-average remaining lease term 5.9 years 6.7 years Weighted-average discount rate applied to operating leases 3.6 % 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 March 31, 2021: Year Ending December 31, Operating Leases 2021 (After March 31) $ 83 2022 99 2023 94 2024 85 2025 77 After 2025 116 Total lease payments (undiscounted) 554 Less: Interest 54 Present value of lease liabilities: $ 500 Lease liabilities - current $ 94 Lease liabilities - noncurrent $ 406

SEGMENT INFORMATION (Tables)

SEGMENT INFORMATION (Tables)	3 Months Ended
	Mar. 31, 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 2 for further details on the components of the Company’s revenue. Three Months Ended March 31, 2021 2020 MIS MA Eliminations Consolidated MIS MA Eliminations Consolidated Revenue $ 1,076 $ 566 $ (42) $ 1,600 $ 831 $ 498 $ (39) $ 1,290 Total Expenses 366 423 (42) 747 343 394 (39) 698 Operating income 710 143 — 853 488 104 — 592 Add: Depreciation and 18 41 — 59 16 33 — 49 Restructuring — 2 — 2 (1) — — (1) Loss pursuant to the divestiture of MAKS — — — — — 9 — 9 Adjusted Operating Income $ 728 $ 186 $ — $ 914 $ 503 $ 146 $ — $ 649
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 2021 2020 MIS: U.S. $ 647 $ 503 Non-U.S.: EMEA 248 171 Asia-Pacific 97 81 Americas 44 39 Total Non-U.S. 389 291 Total MIS 1,036 794 MA: U.S. 238 211 Non-U.S.: EMEA 230 192 Asia-Pacific 59 55 Americas 37 38 Total Non-U.S. 326 285 Total MA 564 496 Total MCO $ 1,600 $ 1,290
Operating Segments
Segment Reporting Information [Line Items]
Company's Reportable Segment Revenues Disaggregated by Segment and Geographic Region	Three Months Ended March 31, 2021 2020 United States $ 885 $ 714 Non-U.S.: EMEA 478 363 Asia-Pacific 156 136 Americas 81 77 Total Non-U.S. 715 576 Total $ 1,600 $ 1,290

Description of Business and B_2

Description of Business and Basis of Presentation - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2021segment
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of reportable segments	2

Revenues - Revenue by Category

Revenues - Revenue by Category (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Disaggregation of Revenue [Line Items]
Revenue	$ 1,600	$ 1,290
Eliminations
Disaggregation of Revenue [Line Items]
Revenue	(42)	(39)
MIS
Disaggregation of Revenue [Line Items]
Revenue	1,036	794
MIS | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	1,076	831
MIS | Eliminations
Disaggregation of Revenue [Line Items]
Revenue	40	37
MIS | Corporate Finance (CFG)
Disaggregation of Revenue [Line Items]
Revenue	605	453
MIS | Corporate Finance (CFG) | Investment-grade
Disaggregation of Revenue [Line Items]
Revenue	134	144
MIS | Corporate Finance (CFG) | High-yield
Disaggregation of Revenue [Line Items]
Revenue	141	75
MIS | Corporate Finance (CFG) | Bank loans
Disaggregation of Revenue [Line Items]
Revenue	180	89
MIS | Corporate Finance (CFG) | Other accounts
Disaggregation of Revenue [Line Items]
Revenue	150	145
MIS | Financial Institutions (FIG)
Disaggregation of Revenue [Line Items]
Revenue	162	125
MIS | Financial Institutions (FIG) | Other accounts
Disaggregation of Revenue [Line Items]
Revenue	2	3
MIS | Financial Institutions (FIG) | Banking
Disaggregation of Revenue [Line Items]
Revenue	109	86
MIS | Financial Institutions (FIG) | Insurance
Disaggregation of Revenue [Line Items]
Revenue	43	30
MIS | Financial Institutions (FIG) | Managed investments
Disaggregation of Revenue [Line Items]
Revenue	8	6
MIS | Public, Project And Infrastructure Finance (PPIF)
Disaggregation of Revenue [Line Items]
Revenue	143	109
MIS | Public, Project And Infrastructure Finance (PPIF) | Public finance / sovereign
Disaggregation of Revenue [Line Items]
Revenue	67	57
MIS | Public, Project And Infrastructure Finance (PPIF) | Project and infrastructure
Disaggregation of Revenue [Line Items]
Revenue	76	52
MIS | Structured Finance (SFG)
Disaggregation of Revenue [Line Items]
Revenue	116	96
MIS | Structured Finance (SFG) | Other accounts
Disaggregation of Revenue [Line Items]
Revenue	1	1
MIS | Structured Finance (SFG) | Asset-backed securities
Disaggregation of Revenue [Line Items]
Revenue	26	22
MIS | Structured Finance (SFG) | RMBS
Disaggregation of Revenue [Line Items]
Revenue	27	27
MIS | Structured Finance (SFG) | CMBS
Disaggregation of Revenue [Line Items]
Revenue	24	17
MIS | Structured Finance (SFG) | Structured credit
Disaggregation of Revenue [Line Items]
Revenue	38	29
MIS | Rating Revenue
Disaggregation of Revenue [Line Items]
Revenue	1,026	783
MIS | MIS Other
Disaggregation of Revenue [Line Items]
Revenue	10	11
MA
Disaggregation of Revenue [Line Items]
Revenue	564	496
MA | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	566	498
MA | Eliminations
Disaggregation of Revenue [Line Items]
Revenue	2	2
MA | Research, Data And Analytics (RD&A)
Disaggregation of Revenue [Line Items]
Revenue	419	358
MA | Enterprise Risk Solutions (ERS)
Disaggregation of Revenue [Line Items]
Revenue	$ 145	$ 138

Revenues - Revenues Disaggregat

Revenues - Revenues Disaggregated by Line of Business and Geographical Area (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Disaggregation of Revenue [Line Items]
Revenue	$ 1,600	$ 1,290
United States
Disaggregation of Revenue [Line Items]
Revenue	885	714
Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	715	576
MIS
Disaggregation of Revenue [Line Items]
Revenue	1,036	794
MIS | United States
Disaggregation of Revenue [Line Items]
Revenue	647	503
MIS | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	389	291
MIS | Corporate Finance (CFG)
Disaggregation of Revenue [Line Items]
Revenue	605	453
MIS | Corporate Finance (CFG) | United States
Disaggregation of Revenue [Line Items]
Revenue	414	314
MIS | Corporate Finance (CFG) | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	191	139
MIS | Financial Institutions (FIG)
Disaggregation of Revenue [Line Items]
Revenue	162	125
MIS | Financial Institutions (FIG) | United States
Disaggregation of Revenue [Line Items]
Revenue	86	60
MIS | Financial Institutions (FIG) | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	76	65
MIS | Public, Project And Infrastructure Finance (PPIF)
Disaggregation of Revenue [Line Items]
Revenue	143	109
MIS | Public, Project And Infrastructure Finance (PPIF) | United States
Disaggregation of Revenue [Line Items]
Revenue	78	68
MIS | Public, Project And Infrastructure Finance (PPIF) | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	65	41
MIS | Structured Finance (SFG)
Disaggregation of Revenue [Line Items]
Revenue	116	96
MIS | Structured Finance (SFG) | United States
Disaggregation of Revenue [Line Items]
Revenue	68	61
MIS | Structured Finance (SFG) | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	48	35
MIS | Rating Revenue
Disaggregation of Revenue [Line Items]
Revenue	1,026	783
MIS | Rating Revenue | United States
Disaggregation of Revenue [Line Items]
Revenue	646	503
MIS | Rating Revenue | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	380	280
MIS | MIS Other
Disaggregation of Revenue [Line Items]
Revenue	10	11
MIS | MIS Other | United States
Disaggregation of Revenue [Line Items]
Revenue	1	0
MIS | MIS Other | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	9	11
MA
Disaggregation of Revenue [Line Items]
Revenue	564	496
MA | United States
Disaggregation of Revenue [Line Items]
Revenue	238	211
MA | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	326	285
MA | Research, Data And Analytics (RD&A)
Disaggregation of Revenue [Line Items]
Revenue	419	358
MA | Research, Data And Analytics (RD&A) | United States
Disaggregation of Revenue [Line Items]
Revenue	183	158
MA | Research, Data And Analytics (RD&A) | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	236	200
MA | Enterprise Risk Solutions (ERS)
Disaggregation of Revenue [Line Items]
Revenue	145	138
MA | Enterprise Risk Solutions (ERS) | United States
Disaggregation of Revenue [Line Items]
Revenue	55	53
MA | Enterprise Risk Solutions (ERS) | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	$ 90	$ 85

Revenues - Consolidated Revenue

Revenues - Consolidated Revenue Information by Geographic Area (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Segment Reporting Information [Line Items]
Revenue	$ 1,600	$ 1,290
MIS
Segment Reporting Information [Line Items]
Revenue	1,036	794
MA
Segment Reporting Information [Line Items]
Revenue	564	496
United States
Segment Reporting Information [Line Items]
Revenue	885	714
United States | MIS
Segment Reporting Information [Line Items]
Revenue	647	503
United States | MA
Segment Reporting Information [Line Items]
Revenue	238	211
EMEA
Segment Reporting Information [Line Items]
Revenue	478	363
EMEA | MIS
Segment Reporting Information [Line Items]
Revenue	248	171
EMEA | MA
Segment Reporting Information [Line Items]
Revenue	230	192
Asia-Pacific
Segment Reporting Information [Line Items]
Revenue	156	136
Asia-Pacific | MIS
Segment Reporting Information [Line Items]
Revenue	97	81
Asia-Pacific | MA
Segment Reporting Information [Line Items]
Revenue	59	55
Americas
Segment Reporting Information [Line Items]
Revenue	81	77
Americas | MIS
Segment Reporting Information [Line Items]
Revenue	44	39
Americas | MA
Segment Reporting Information [Line Items]
Revenue	37	38
Non-U.S.
Segment Reporting Information [Line Items]
Revenue	715	576
Non-U.S. | MIS
Segment Reporting Information [Line Items]
Revenue	389	291
Non-U.S. | MA
Segment Reporting Information [Line Items]
Revenue	$ 326	$ 285

Revenues - Transaction and Rela

Revenues - Transaction and Relationship Revenue (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Disaggregation of Revenue [Line Items]
Revenue	$ 1,600	$ 1,290
Percentage of Revenues	100.00%	100.00%
MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 1,036	$ 794
Percentage of Revenues	100.00%	100.00%
MA
Disaggregation of Revenue [Line Items]
Revenue	$ 564	$ 496
Percentage of Revenues	100.00%	100.00%
Corporate Finance (CFG) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 605	$ 453
Percentage of Revenues	100.00%	100.00%
Financial Institutions (FIG) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 162	$ 125
Percentage of Revenues	100.00%	100.00%
Public, Project And Infrastructure Finance (PPIF) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 143	$ 109
Percentage of Revenues	100.00%	100.00%
Structured Finance (SFG) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 116	$ 96
Percentage of Revenues	100.00%	100.00%
MIS Other | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 10	$ 11
Percentage of Revenues	100.00%	100.00%
Research, Data And Analytics (RD&A) | MA
Disaggregation of Revenue [Line Items]
Revenue	$ 419	$ 358
Percentage of Revenues	100.00%	100.00%
Enterprise Risk Solutions (ERS) | MA
Disaggregation of Revenue [Line Items]
Revenue	$ 145	$ 138
Percentage of Revenues	100.00%	100.00%
Transaction Revenue
Disaggregation of Revenue [Line Items]
Revenue	$ 788	$ 569
Percentage of Revenues	49.00%	44.00%
Transaction Revenue | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 745	$ 519
Percentage of Revenues	72.00%	65.00%
Transaction Revenue | MA
Disaggregation of Revenue [Line Items]
Revenue	$ 43	$ 50
Percentage of Revenues	8.00%	10.00%
Transaction Revenue | Corporate Finance (CFG) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 487	$ 338
Percentage of Revenues	80.00%	75.00%
Transaction Revenue | Financial Institutions (FIG) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 90	$ 60
Percentage of Revenues	56.00%	48.00%
Transaction Revenue | Public, Project And Infrastructure Finance (PPIF) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 100	$ 69
Percentage of Revenues	70.00%	63.00%
Transaction Revenue | Structured Finance (SFG) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 66	$ 50
Percentage of Revenues	57.00%	52.00%
Transaction Revenue | MIS Other | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 2	$ 2
Percentage of Revenues	20.00%	18.00%
Transaction Revenue | Research, Data And Analytics (RD&A) | MA
Disaggregation of Revenue [Line Items]
Revenue	$ 20	$ 18
Percentage of Revenues	5.00%	5.00%
Transaction Revenue | Enterprise Risk Solutions (ERS) | MA
Disaggregation of Revenue [Line Items]
Revenue	$ 23	$ 32
Percentage of Revenues	16.00%	23.00%
Relationship Revenue
Disaggregation of Revenue [Line Items]
Revenue	$ 812	$ 721
Percentage of Revenues	51.00%	56.00%
Relationship Revenue | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 291	$ 275
Percentage of Revenues	28.00%	35.00%
Relationship Revenue | MA
Disaggregation of Revenue [Line Items]
Revenue	$ 521	$ 446
Percentage of Revenues	92.00%	90.00%
Relationship Revenue | Corporate Finance (CFG) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 118	$ 115
Percentage of Revenues	20.00%	25.00%
Relationship Revenue | Financial Institutions (FIG) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 72	$ 65
Percentage of Revenues	44.00%	52.00%
Relationship Revenue | Public, Project And Infrastructure Finance (PPIF) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 43	$ 40
Percentage of Revenues	30.00%	37.00%
Relationship Revenue | Structured Finance (SFG) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 50	$ 46
Percentage of Revenues	43.00%	48.00%
Relationship Revenue | MIS Other | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 8	$ 9
Percentage of Revenues	80.00%	82.00%
Relationship Revenue | Research, Data And Analytics (RD&A) | MA
Disaggregation of Revenue [Line Items]
Revenue	$ 399	$ 340
Percentage of Revenues	95.00%	95.00%
Relationship Revenue | Enterprise Risk Solutions (ERS) | MA
Disaggregation of Revenue [Line Items]
Revenue	$ 122	$ 106
Percentage of Revenues	84.00%	77.00%

Revenues - Revenue Recognition

Revenues - Revenue Recognition Timing (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Disaggregation of Revenue [Line Items]
Revenue recognized	$ 1,600	$ 1,290
At Point in Time
Disaggregation of Revenue [Line Items]
Revenue recognized	774	558
Over Time
Disaggregation of Revenue [Line Items]
Revenue recognized	826	732
MIS
Disaggregation of Revenue [Line Items]
Revenue recognized	1,036	794
MIS | At Point in Time
Disaggregation of Revenue [Line Items]
Revenue recognized	745	519
MIS | Over Time
Disaggregation of Revenue [Line Items]
Revenue recognized	291	275
MA
Disaggregation of Revenue [Line Items]
Revenue recognized	564	496
MA | At Point in Time
Disaggregation of Revenue [Line Items]
Revenue recognized	29	39
MA | Over Time
Disaggregation of Revenue [Line Items]
Revenue recognized	$ 535	$ 457

Revenues - Additional Informati

Revenues - Additional Information (Detail) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
MIS
Disaggregation of Revenue [Line Items]
Unbilled Receivables	$ 452	$ 361
MA
Disaggregation of Revenue [Line Items]
Unbilled Receivables	$ 88	$ 98

Revenues - Schedule of Changes

Revenues - Schedule of Changes in the Deferred Revenue Balances (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Change in Contract with Customer, Liability [Abstract]
Beginning Balance	$ 1,187	$ 1,162
Revenue recognized that was included in the deferred revenue balance at the beginning of the period	(482)	(435)
Increases due to amounts billable excluding amounts recognized as revenue during the period	626	504
Increases due to acquisitions during the period	4	20
Effect of exchange rate changes	(7)	(29)
Total changes in deferred revenue	141	60
Ending Balance	1,328	1,222
Deferred revenue - current	1,232	1,113	$ 1,089
Deferred revenue - noncurrent	96	109	$ 98
MIS
Change in Contract with Customer, Liability [Abstract]
Beginning Balance	313	322
Revenue recognized that was included in the deferred revenue balance at the beginning of the period	(96)	(99)
Increases due to amounts billable excluding amounts recognized as revenue during the period	174	161
Increases due to acquisitions during the period	0	0
Effect of exchange rate changes	(3)	(5)
Total changes in deferred revenue	75	57
Ending Balance	388	379
Deferred revenue - current	295	275
Deferred revenue - noncurrent	93	104
MA
Change in Contract with Customer, Liability [Abstract]
Beginning Balance	874	840
Revenue recognized that was included in the deferred revenue balance at the beginning of the period	(386)	(336)
Increases due to amounts billable excluding amounts recognized as revenue during the period	452	343
Increases due to acquisitions during the period	4	20
Effect of exchange rate changes	(4)	(24)
Total changes in deferred revenue	66	3
Ending Balance	940	843
Deferred revenue - current	937	838
Deferred revenue - noncurrent	$ 3	$ 5

Revenues - Expected Recognition

Revenues - Expected Recognition Period for Remaining Performance Obligations (Detail) $ in Millions	Mar. 31, 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]: 2021-04-01
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]: 2022-04-01
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	$ 2,300
MA | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-04-01
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]: 2022-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, percentage	20.00%
Revenue, remaining performance obligation, period	1 year

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock-Based Compensation Cost and Associated Tax Benefit (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Share-based Payment Arrangement, Noncash Expense [Abstract]
Stock-based compensation cost	$ 45	$ 37
Tax benefit	$ 11	$ 7

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2021USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee stock options, granted (in shares) | shares	0.1
Employee stock options, weighted average grant date fair value (in usd per share) | $ / shares	$ 67.40
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Other than options, shares granted (in shares) | shares	0.5
Other than options, weighted average grant date fair value (in usd per share) | $ / shares	$ 276.86
Award vesting period (in years)	4 years
Unrecognized compensation expense | $	$ 265
Weighted average period to recognize expense	2 years 8 months 12 days
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)	4 years
Unrecognized compensation expense | $	$ 12
Weighted average period to recognize expense	2 years 7 months 6 days
Performance Based Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Other than options, shares granted (in shares) | shares	0.1
Other than options, weighted average grant date fair value (in usd per share) | $ / shares	$ 268.82
Award vesting period (in years)	3 years
Unrecognized compensation expense | $	$ 41
Weighted average period to recognize expense	2 years 3 months 18 days

Stock-Based Compensation - Weig

Stock-Based Compensation - Weighted Average Assumptions used in Determining Fair Value for Options Granted (Detail)	3 Months Ended
	Mar. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected dividend yield	0.90%
Expected stock volatility	28.00%
Risk-free interest rate	0.82%
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	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Proceeds from stock option exercises	$ 6	$ 13
Aggregate intrinsic value	9	46
Tax benefit realized upon exercise	$ 2	$ 11
Number of shares exercised (shares)	0.1	0.2
Restricted Stock
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Fair value of shares vested	$ 178	$ 191
Tax benefit realized upon vesting	$ 41	$ 44
Number of shares vested (shares)	0.6	0.8
Performance Based Restricted Stock
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Fair value of shares vested	$ 29	$ 70
Tax benefit realized upon vesting	$ 6	$ 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
	Mar. 31, 2021	Mar. 31, 2020
Income Tax Contingency [Line Items]
Effective tax rate (percent)	14.60%	13.70%
Excess tax benefits from stock compensation	$ 19
Overall increase (decrease) in unrecognized tax benefits (UTPs)	81
Reduction resulting from lapse of applicable statute of limitations and settlement	61
Interest accrued on UTPs	40
Net of Federal Tax
Income Tax Contingency [Line Items]
Overall increase (decrease) in unrecognized tax benefits (UTPs)	$ 71

Income Taxes - Income Taxes Pai

Income Taxes - Income Taxes Paid (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Tax Disclosure [Abstract]
Income taxes paid	$ 68	$ 29

Weighted Average Shares Outst_3

Weighted Average Shares Outstanding - Reconciliation of Basic to Diluted Shares Outstanding (Detail) - shares shares in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Earnings Per Share [Abstract]
Basic (in shares)	187.2	187.5
Dilutive effect of shares issuable under stock-based compensation plans (in shares)	1.4	2.1
Diluted (in shares)	188.6	189.6
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)	0.3	0.3

Cash Equivalents and Investme_3

Cash Equivalents and Investments (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Cash and Cash Equivalents [Line Items]
Fair Value	$ 55	$ 60
Cash and cash equivalents	2,769	2,597
Short-term investments	96	99
Certificates of deposit and money market deposit accounts
Cash and Cash Equivalents [Line Items]
Cost	1,639	1,430
Gains/(Losses)	0	0
Fair Value	1,639	1,430
Cash and cash equivalents	1,531	1,325
Short-term investments	96	99
Other assets	12	6
Mutual funds
Cash and Cash Equivalents [Line Items]
Cost	49	54
Gains/(Losses)	6	6
Fair Value	55	60
Cash and cash equivalents	0	0
Short-term investments	0	0
Other assets	$ 55	$ 60

Cash Equivalents and Investme_4

Cash Equivalents and Investments (Footnote) (Detail) - Certificates of deposit and money market deposit accounts	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Short-term Investments | Minimum
Cash and Cash Equivalents [Line Items]
Securities maturity period	1 month	1 month
Short-term Investments | Maximum
Cash and Cash Equivalents [Line Items]
Securities maturity period	12 months	12 months
Other assets | Minimum
Cash and Cash Equivalents [Line Items]
Securities maturity period	13 months
Other assets | Maximum
Cash and Cash Equivalents [Line Items]
Securities maturity period	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	Mar. 31, 2021	Dec. 31, 2020
Cash and Cash Equivalents [Abstract]
Company owned life insurance (at contract value)	$ 33	$ 17

Acquisitions - Narrative (Detai

Acquisitions - Narrative (Details) - USD ($) $ in Millions	Mar. 19, 2021	Feb. 13, 2020
Cortera
Business Acquisition [Line Items]
Business acquisition interests acquired	100.00%
Acquired cash included in current assets	$ 4
Accounts receivable gross included in current assets	$ 2
Regulatory Data Corporation
Business Acquisition [Line Items]
Business acquisition interests acquired		100.00%
Acquired cash included in current assets		$ 6
Accounts receivable gross included in current assets		$ 14

Acquisitions - Total Considerat

Acquisitions - Total Consideration Relating to Acquisition (Details) - USD ($) $ in Millions	Mar. 19, 2021	Feb. 13, 2020
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	Mar. 19, 2021	Feb. 13, 2020	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Business Acquisition [Line Items]
Goodwill			$ 4,566	$ 4,556	$ 3,722
Cortera
Business Acquisition [Line Items]
Current assets	$ 7
Total intangible assets	57
Goodwill	95
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
Acquired finite-lived intangible asset, useful life	11 years
Cortera | Database
Business Acquisition [Line Items]
Total intangible assets	$ 38
Liabilities:
Finite-lived intangible asset, useful life	10 years
Cortera | Customer relationships
Business Acquisition [Line Items]
Total intangible assets	$ 9
Liabilities:
Finite-lived intangible asset, useful life	18 years
Cortera | Product technology
Business Acquisition [Line Items]
Total intangible assets	$ 9
Liabilities:
Finite-lived intangible asset, useful life	8 years
Cortera | Trade names
Business Acquisition [Line Items]
Total intangible assets	$ 1
Liabilities:
Finite-lived intangible asset, useful life	5 years
Regulatory Data Corporation
Business Acquisition [Line Items]
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 | 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

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	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Derivative [Line Items]
Notional Amount	$ 1,380	$ 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

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
	Mar. 31, 2021	Mar. 31, 2020
Derivative Instruments, Gain (Loss) [Line Items]
Interest expense, net	$ (7)	$ (40)
Designated as Hedging Instrument | Interest Rate Swap | Interest Expense
Derivative Instruments, Gain (Loss) [Line Items]
Fair value changes on interest rate swaps	(24)	58
Fair value changes on hedged debt	24	(58)
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	$ 5	$ 3

Derivative Instruments And He_5

Derivative Instruments And Hedging Activities - Additional Information (Detail)	1 Months Ended
	Jan. 31, 2020USD ($)	Mar. 31, 2021USD ($)	Mar. 31, 2021EUR (€)	Dec. 31, 2020USD ($)	Apr. 30, 2020USD ($)
Derivative [Line Items]
Cumulative loss		$ 440,000,000		$ 432,000,000
Designated as Hedging Instrument
Derivative [Line Items]
Cumulative loss		136,000,000		269,000,000
Net Investment Hedging
Derivative [Line Items]
Cumulative loss		88,000,000		220,000,000
Net Investment Hedging | Currency Swap
Derivative [Line Items]
Cumulative loss		52,000,000		124,000,000
Net Investment Hedging | Designated as Hedging Instrument | Currency Swap
Derivative [Line Items]
Notional Amount | €			€ 2,038,000,000
Cash Flow Hedging
Derivative [Line Items]
Cumulative loss		48,000,000		49,000,000
Cash Flow Hedging | Currency Swap
Derivative [Line Items]
Cumulative loss		(2,000,000)		(2,000,000)
Cash Flow Hedging | Forward Contracts
Derivative [Line Items]
Cumulative loss					$ 68,000,000
Cash Flow Hedging | Interest rate contract
Derivative [Line Items]
Cumulative loss		$ 50,000,000		$ 51,000,000
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 | Currency Swap
Derivative [Line Items]
Notional Amount | €			€ 500,000,000
2019 Senior Notes Due 2030 | Net Investment Hedging | Designated as Hedging Instrument | 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) - Currency Swap - Net Investment Hedging € in Millions, $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2021USD ($)	Dec. 31, 2020USD ($)	Mar. 31, 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 | €			€ 2,038	€ 2,038
Currency Paid | 1.43%
Derivative [Line Items]
Notional Amount | €			€ 1,079	€ 1,079
Weighted Average Fixed Interest Rate	1.43%	1.43%	1.43%	1.43%
Currency Paid | 3-month EURIBOR
Derivative [Line Items]
Notional Amount | €			€ 959	€ 959
Weighted Average Floating Interest Rate	Based on 3-month EURIBOR	Based on 3-month EURIBOR
Currency Received
Derivative [Line Items]
Notional Amount | $	$ 2,300	$ 2,300
Currency Received | 3.96%
Derivative [Line Items]
Notional Amount | $	$ 1,220	$ 1,220
Weighted Average Fixed Interest Rate	3.96%	3.96%	3.96%	3.96%
Currency Received | 3-month U.S. LIBOR
Derivative [Line Items]
Notional Amount | $	$ 1,080	$ 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 - Currency Swap € in Millions	Mar. 31, 2021EUR (€)
Net Investment Hedging
Derivative [Line Items]
Notional Amount	€ 2,038
2021
Derivative [Line Items]
Notional Amount	265
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

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	Mar. 31, 2021USD ($)	Mar. 31, 2021EUR (€)	Mar. 31, 2021GBP (£)	Dec. 31, 2020USD ($)	Dec. 31, 2020EUR (€)	Dec. 31, 2020GBP (£)
Contract to sell EUR for USD
Derivative [Line Items]
Notional Amount	$ 681	€ 560		$ 627	€ 524
Contract to sell GBP for EUR
Derivative [Line Items]
Notional Amount		€ 155	£ 134		€ 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
	Mar. 31, 2021	Mar. 31, 2020
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Hedging Relationships, Amount of Gain/(Loss) Recognized in AOCI on Derivative, net of Tax	$ 0	$ (36)
Total, Amount of Gain/(Loss) Recognized in AOCI on Derivative, net of Tax	133	53
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)	(1)
Total, Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax	0	(1)
Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	10	8
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	133	89
Net investment hedges - reclassification of gains included in net income - Net of Tax	1	0
Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	10	8
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	16	0
Net investment hedges - reclassification of gains included in net income - Net of Tax	1	0
Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	0	0
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	72	66
Net investment hedges - reclassification of gains included in net income - Net of Tax	0	0
Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	10	8
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	45	23
Net investment hedges - reclassification of gains included in net income - Net of Tax	0	0
Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	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	0	(36)
Cash Flow Hedging Relationships, Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax	(1)	(1)
Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	$ 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	Mar. 31, 2021	Dec. 31, 2020
Derivative [Line Items]
Cumulative Gains/(Losses), net of tax	$ (440)	$ (432)
Designated as Hedging Instrument
Derivative [Line Items]
Cumulative Gains/(Losses), net of tax	(136)	(269)
Net Investment Hedging
Derivative [Line Items]
Cumulative Gains/(Losses), net of tax	(88)	(220)
Net Investment Hedging | Cross currency swaps
Derivative [Line Items]
Cumulative Gains/(Losses), net of tax	(52)	(124)
Net Investment Hedging | FX forwards
Derivative [Line Items]
Cumulative Gains/(Losses), net of tax	27	12
Net Investment Hedging | Long-term debt
Derivative [Line Items]
Cumulative Gains/(Losses), net of tax	(63)	(108)
Cash Flow Hedging
Derivative [Line Items]
Cumulative Gains/(Losses), net of tax	(48)	(49)
Cash Flow Hedging | Cross currency swaps
Derivative [Line Items]
Cumulative Gains/(Losses), net of tax	2	2
Cash Flow Hedging | Interest rate contract
Derivative [Line Items]
Cumulative Gains/(Losses), net of tax	$ (50)	$ (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

Mar. 31, 2021USD ($)

Mar. 31, 2021EUR (€)

Mar. 31, 2021GBP (£)

Mar. 31, 2021JPY (¥)

Mar. 31, 2021CAD ($)

Mar. 31, 2021SGD ($)

Mar. 31, 2021RUB (₽)

Mar. 31, 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

$ 402

£ 287

$ 295

£ 222

Contracts to sell USD for Japanese Yen

Derivative [Line Items]

Notional Amount

15

¥ 1,600

15

¥ 1,600

Contracts to sell USD for Canadian dollars

Derivative [Line Items]

Notional Amount

100

$ 126

107

$ 140

Contracts to sell USD for Singapore dollars

Derivative [Line Items]

Notional Amount

60

$ 79

59

$ 79

Contracts to sell USD for Euros

Derivative [Line Items]

Notional Amount

493

€ 405

447

€ 376

Contracts to sell Euros for GBP

Derivative [Line Items]

Notional Amount

€ 180

£ 157

€ 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) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Other non-operating income, net
Derivative Instruments, Gain (Loss) [Line Items]
Foreign exchange forwards amount of gain (loss) recognized in income	$ (6)	$ (40)

Derivative Instruments And H_13

Derivative Instruments And Hedging Activities - Fair Value of Derivative Instruments (Detail) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Derivatives, Fair Value [Line Items]
Assets	$ 70	$ 88
Liabilities	1,577	1,716
Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Assets	62	57
Liabilities	80	184
Designated as Hedging Instrument | Long-term debt | Net Investment Hedging
Derivatives, Fair Value [Line Items]
Liabilities	1,469	1,530
Designated as Hedging Instrument | Currency Swap | Other assets | Net Investment Hedging
Derivatives, Fair Value [Line Items]
Assets	1	0
Designated as Hedging Instrument | Currency Swap | Accounts payable and accrued liabilities | Net Investment Hedging
Derivatives, Fair Value [Line Items]
Liabilities	11	23
Designated as Hedging Instrument | Currency Swap | Other liabilities | Net Investment Hedging
Derivatives, Fair Value [Line Items]
Liabilities	61	144
Designated as Hedging Instrument | Interest Rate Swap | Other assets | Fair Value Hedging
Derivatives, Fair Value [Line Items]
Assets	38	57
Designated as Hedging Instrument | Interest Rate Swap | Other liabilities | Fair Value Hedging
Derivatives, Fair Value [Line Items]
Liabilities	6	1
Designated as Hedging Instrument | FX forwards | Other current assets | Net Investment Hedging
Derivatives, Fair Value [Line Items]
Assets	23	0
Designated as Hedging Instrument | FX forwards | Accounts payable and accrued liabilities | Net Investment Hedging
Derivatives, Fair Value [Line Items]
Liabilities	2	16
Not Designated as Accounting Hedges | FX forwards | Other current assets
Derivatives, Fair Value [Line Items]
Assets	8	31
Not Designated as Accounting Hedges | FX forwards | Accounts payable and accrued liabilities
Derivatives, Fair Value [Line Items]
Liabilities	$ 28	$ 2

Goodwill And Other Acquired I_3

Goodwill And Other Acquired Intangible Assets - Activity in Goodwill (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 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	95	626
Foreign currency translation adjustments	(85)	208
Ending balance, goodwill gross	4,578	4,568
Ending balance, Accumulated impairment charge	(12)	(12)
Ending balance, goodwill net	4,566	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	0	(2)
Foreign currency translation adjustments	1	(2)
Ending balance, goodwill gross	312	311
Ending balance, Accumulated impairment charge	0	0
Ending balance, goodwill net	312	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	95	628
Foreign currency translation adjustments	(86)	210
Ending balance, goodwill gross	4,266	4,257
Ending balance, Accumulated impairment charge	(12)	(12)
Ending balance, goodwill net	$ 4,254	$ 4,245

Goodwill And Other Acquired I_4

Goodwill And Other Acquired Intangible Assets - Acquired Intangible Assets and Related Amortization (Detail) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, net	$ 1,810	$ 1,824
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, gross	1,602	1,623
Accumulated amortization	(326)	(313)
Acquired intangible assets, net	1,276	1,310
Software/product technology
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, gross	438	441
Accumulated amortization	(183)	(177)
Acquired intangible assets, net	255	264
Database
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, gross	180	144
Accumulated amortization	(32)	(29)
Acquired intangible assets, net	148	115
Trade names
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, gross	160	161
Accumulated amortization	(40)	(38)
Acquired intangible assets, net	120	123
Other
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, gross	54	55
Accumulated amortization	(43)	(43)
Acquired intangible assets, net	$ 11	$ 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
	Mar. 31, 2021	Mar. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense	$ 35	$ 28

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	Mar. 31, 2021USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2021 (After March 31,)	$ 99
2022	135
2023	130
2024	123
2025	121
Thereafter	1,202
Total estimated future amortization	$ 1,810

Goodwill And Other Acquired I_7

Goodwill And Other Acquired Intangible Assets - Additional Information (Details) $ in Thousands, ₨ in Millions	Sep. 22, 2020INR (₨)	Sep. 22, 2020USD ($)	Dec. 26, 2019INR (₨)	Dec. 26, 2019USD ($)
Indian Credit Ratings Agency
Loss Contingencies [Line Items]
Penalty in period	₨ 10	$ 140	₨ 2.5	$ 35

Restructuring - Additional Info

Restructuring - Additional Information (Detail) - USD ($) $ in Millions	Dec. 22, 2020	Mar. 31, 2021	Dec. 31, 2022	Dec. 31, 2020
2020 MA Strategic Reorganization Restructuring Program
Restructuring Cost and Reserve [Line Items]
Remaining restructuring liability		$ 15
2020 MA Strategic Reorganization Restructuring Program | Minimum | Forecast
Restructuring Cost and Reserve [Line Items]
Payments for restructuring			$ 20
2020 MA Strategic Reorganization Restructuring Program | Minimum | Estimated Annual Savings
Restructuring Cost and Reserve [Line Items]
Effect on future earnings, amount	$ 25
2020 MA Strategic Reorganization Restructuring Program | Maximum | Forecast
Restructuring Cost and Reserve [Line Items]
Payments for restructuring			$ 30
2020 MA Strategic Reorganization Restructuring Program | Maximum | Estimated Annual Savings
Restructuring Cost and Reserve [Line Items]
Effect on future earnings, amount	30
Employee Termination Costs
Restructuring Cost and Reserve [Line Items]
Remaining restructuring liability		15		$ 18
Employee Termination Costs | 2020 MA Strategic Reorganization Restructuring Program
Restructuring Cost and Reserve [Line Items]
Payments for restructuring		$ 5
Employee Termination Costs | 2020 MA Strategic Reorganization Restructuring Program | Minimum
Restructuring Cost and Reserve [Line Items]
Restructuring expected cost	20
Employee Termination Costs | 2020 MA Strategic Reorganization Restructuring Program | Maximum
Restructuring Cost and Reserve [Line Items]
Restructuring expected cost	$ 30

Restructuring - Restructuring E

Restructuring - Restructuring Expenses Included in Consolidated Statements of Operations (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Restructuring Cost and Reserve [Line Items]
Restructuring	$ 2	$ (1)
2020 MA Strategic Reorganization Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring	$ 2	$ 0

Restructuring - Changes in Rest

Restructuring - Changes in Restructuring Liability (Details) $ in Millions	3 Months Ended
	Mar. 31, 2021USD ($)
Employee Termination Costs
Restructuring Reserve [Roll Forward]
Restructuring liability, Beginning Balance	$ 18
Restructuring liability, Ending Balance	15
2020 MA Strategic Reorganization Restructuring Program
Restructuring Reserve [Roll Forward]
Restructuring liability, Ending Balance	15
2020 MA Strategic Reorganization Restructuring Program | Employee Termination Costs
Restructuring Reserve [Roll Forward]
Cost incurred and adjustments	2
Cash payments and adjustments	(5)
Cumulative expense incurred to date	$ 20

Fair Value - Financial Instrume

Fair Value - Financial Instruments Carried at Fair Value on Recurring Basis (Detail) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Assets:
Derivatives	$ 70	$ 88
Mutual funds	55	60
Total	125	148
Liabilities:
Derivatives	108	186
Total	108	186
Level 1
Assets:
Derivatives	0	0
Mutual funds	55	60
Total	55	60
Liabilities:
Derivatives	0	0
Total	0	0
Level 2
Assets:
Derivatives	70	88
Mutual funds	0	0
Total	70	88
Liabilities:
Derivatives	108	186
Total	$ 108	$ 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	Mar. 31, 2021	Dec. 31, 2020
Other current assets:
Prepaid taxes	$ 73	$ 94
Prepaid expenses	88	91
Capitalized costs to obtain and fulfill sales contracts	96	93
Foreign exchange forwards on certain assets and liabilities	8	31
Derivative instruments designated as accounting hedges	23	0
Other	45	74
Total other current assets	333	383
Other assets:
Investments in non-consolidated affiliates	149	135
Deposits for real-estate leases	19	19
Indemnification assets related to acquisitions	15	15
Mutual funds and fixed deposits	67	66
Company owned life insurance (at contract value)	33	17
Costs to obtain sales contracts	143	134
Cross currency and interest rate swaps	39	57
Pension and other retirement employee benefits	22	21
Other	58	51
Total other assets	545	515
Accounts payable and accrued liabilities:
Salaries and benefits	203	197
Incentive compensation	62	226
Customer credits, advanced payments and advanced billings	43	42
Dividends	6	11
Professional service fees	57	53
Interest accrued on debt	33	82
Accounts payable	21	39
Income taxes	156	128
Pension and other retirement employee benefits	46	45
Accrued royalties	27	19
Foreign exchange forwards on certain assets and liabilities	28	2
Restructuring liability	15	18
Derivative instruments designated as accounting hedges	13	39
Other	118	138
Total accounts payable and accrued liabilities	828	1,039
Other liabilities:
Pension and other retirement employee benefits	249	244
Interest accrued on UTPs	70	113
MAKS indemnification provisions	33	33
Income tax liability - non-current portion	18	18
Derivative instruments designated as accounting hedges	67	145
Other	36	37
Total other liabilities	$ 473	$ 590

Other Balance Sheet and State_4

Other Balance Sheet and Statement of Operations Information - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Other Balance Sheet And Statement Of Operations Information [Abstract]
Loss pursuant to the divestiture of MAKS	$ 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
	Mar. 31, 2021	Mar. 31, 2020
Other Balance Sheet And Statement Of Operations Information [Abstract]
FX (loss) gain	$ (2)	$ 13
Net periodic pension costs - other components	4	3
Income/(loss) from investments in non-consolidated affiliates	8	(3)
Other	6	(1)
Total	$ 16	$ 12

Comprehensive Income And Accu_3

Comprehensive Income And Accumulated Other Comprehensive Loss - Reclassification out of AOCI (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Derivative Instruments, Gain (Loss) [Line Items]
Other non-operating income, net	$ 16	$ 12
Provision for income taxes	(126)	(77)
Net income attributable to Moody's	736	488
Reclassification out of Accumulated Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Net income attributable to Moody's	(2)	(2)
Losses on cash flow hedges | Reclassification out of Accumulated Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Provision for income taxes	0	0
Net income attributable to Moody's	(1)	(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 income, net	(1)	(1)
Net Investment Hedges | Reclassification out of Accumulated Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Provision for income taxes	0	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 income, net	1	0
Total pension and other retirement benefits | Reclassification out of Accumulated Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Provision for income taxes	1	1
Net income attributable to Moody's	(2)	(1)
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 income, net	$ (3)	$ (2)

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
	Mar. 31, 2021	Mar. 31, 2020
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 1,569
Ending balance	2,030
Total
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(432)	$ (439)
Other comprehensive income/(loss) before reclassifications	(10)	(117)
Amounts reclassified from AOCL	2	2
Other comprehensive income/(loss)	(8)	(115)
Ending balance	(440)	(554)
Pension and Other Retirement Benefits
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(118)	(92)
Other comprehensive income/(loss) before reclassifications	0	(1)
Amounts reclassified from AOCL	2	1
Other comprehensive income/(loss)	2	0
Ending balance	(116)	(92)
Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(49)	0
Other comprehensive income/(loss) before reclassifications	0	(36)
Amounts reclassified from AOCL	1	1
Other comprehensive income/(loss)	1	(35)
Ending balance	(48)	(35)
Foreign Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(45)	(401)
Other comprehensive income/(loss) before reclassifications	(143)	(169)
Amounts reclassified from AOCL	0	0
Other comprehensive income/(loss)	(143)	(169)
Ending balance	(188)	(570)
Net Investment Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(220)	54
Other comprehensive income/(loss) before reclassifications	133	89
Amounts reclassified from AOCL	(1)	0
Other comprehensive income/(loss)	132	89
Ending balance	$ (88)	$ 143

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
	Mar. 31, 2021	Mar. 31, 2020
Components of net periodic expense
Interest cost	$ 4	$ 5
Pension Plans
Components of net periodic expense
Service cost	5	5
Interest cost	4	4
Expected return on plan assets	(7)	(5)
Amortization of net actuarial loss from earlier periods	2	2
Net periodic expense	4	6
Other Retirement Plans
Components of net periodic expense
Service cost	1	1
Interest cost	0	0
Expected return on plan assets	0	0
Amortization of net actuarial loss from earlier periods	0	0
Net periodic expense	$ 1	$ 1

Pension and Other Retirement _4

Pension and Other Retirement Benefits - Additional Information (Detail) - Unfunded Plan - United States $ in Millions	3 Months Ended
	Mar. 31, 2021USD ($)
Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Employer contributions	$ 1
Estimated additional payments, remainder of fiscal year	44
Other Retirement Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Estimated additional payments, remainder of fiscal year	$ 1

Indebtedness - Summary of Total

Indebtedness - Summary of Total Indebtedness (Detail) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Principal Amount	$ 6,369	$ 6,430
Fair Value of Interest Rate Swap	32	56
Unamortized (Discount) Premium	(23)	(24)
Unamortized Debt Issuance Costs	(38)	(40)
Long term debt	$ 6,340	$ 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	12	14
Unamortized (Discount) Premium	(1)	(1)
Unamortized Debt Issuance Costs	(1)	(1)
Long term debt	$ 510	$ 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	0	0
Unamortized (Discount) Premium	(1)	(1)
Unamortized Debt Issuance Costs	(1)	(1)
Long term debt	$ 498	$ 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	0	0
Unamortized (Discount) Premium	3	3
Unamortized Debt Issuance Costs	(5)	(5)
Long term debt	$ 598	$ 598
1.75% 2015 Senior Notes, due 2027
Debt Instrument [Line Items]
Notes payable, interest rate	1.75%	1.75%
Principal Amount	$ 588	$ 612
Fair Value of Interest Rate Swap	0	0
Unamortized (Discount) Premium	0	0
Unamortized Debt Issuance Costs	(2)	(2)
Long term debt	$ 586	$ 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	10	12
Unamortized (Discount) Premium	0	0
Unamortized Debt Issuance Costs	(1)	(2)
Long term debt	$ 509	$ 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	16	31
Unamortized (Discount) Premium	(4)	(4)
Unamortized Debt Issuance Costs	(3)	(3)
Long term debt	$ 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	(3)	(3)
Long term debt	$ 395	$ 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)
Long term debt	$ 390	$ 390
0.950% Senior Notes Due 2030
Debt Instrument [Line Items]
Notes payable, interest rate	0.95%	0.95%
Principal Amount	$ 881	$ 918
Fair Value of Interest Rate Swap	0	0
Unamortized (Discount) Premium	(3)	(3)
Unamortized Debt Issuance Costs	(6)	(6)
Long term debt	$ 872	$ 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	(6)	(1)
Unamortized (Discount) Premium	(1)	(1)
Unamortized Debt Issuance Costs	(4)	(5)
Long term debt	$ 689	$ 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)
Long term debt	$ 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)
Long term debt	$ 491	$ 491

Indebtedness - Principal Paymen

Indebtedness - Principal Payments Due on Long-Term Borrowings (Detail) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
2021 (After March 31,)	$ 0
2022	500
2023	500
2024	500
2025	700
Thereafter	4,169
Total principal payment	6,369	$ 6,430
4.50% 2012 Senior Notes, due 2022
Debt Instrument [Line Items]
2022	500
Total principal payment	500	500
4.875% 2013 Senior Notes, due 2024
Debt Instrument [Line Items]
2024	500
Total principal payment	500	500
5.25% 2014 Senior Notes, due 2044
Debt Instrument [Line Items]
Thereafter	600
Total principal payment	600	600
1.75% 2015 Senior Notes, due 2027
Debt Instrument [Line Items]
Thereafter	588
Total principal payment	588	612
2.625% 2017 Senior Notes, due 2023
Debt Instrument [Line Items]
2023	500
Total principal payment	500	500
3.25% 2017 Senior Notes, due 2028
Debt Instrument [Line Items]
Thereafter	500
Total principal payment	500	500
4.25% 2018 Senior Notes, due 2029
Debt Instrument [Line Items]
Thereafter	400
Total principal payment	400	400
4.875% 2018 Senior Notes, due 2048
Debt Instrument [Line Items]
Thereafter	400
Total principal payment	400	400
0.950% Senior Notes Due 2030
Debt Instrument [Line Items]
Thereafter	881
Total principal payment	881	918
3.75% 2020 Senior Notes, due 2025
Debt Instrument [Line Items]
2025	700
Total principal payment	700	700
3.25% 2020 Senior Notes, due 2050
Debt Instrument [Line Items]
Thereafter	300
Total principal payment	300	300
2.55% 2020 Senior Notes, due 2060
Debt Instrument [Line Items]
Thereafter	500
Total principal payment	$ 500	$ 500

Indebtedness - Summary of Compo

Indebtedness - Summary of Components of Interest as Presented in Consolidated Statements of Operations (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Debt Disclosure [Abstract]
Income	$ 3	$ 4
Expense on borrowings	(41)	(31)
Income (expense) on UTPs and other tax related liabilities	35	(8)
Net periodic pension costs - interest component	(4)	(5)
Interest expense, net	(7)	(40)
Interest paid	73	$ 49
Interest accrued on UTPs	$ 40

Indebtedness - Fair Value and C

Indebtedness - Fair Value and Carrying Value of Long-Term Debt (Detail) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Carrying Amount	$ 6,340	$ 6,422
Estimated Fair Value	6,872	7,256
4.50% 2012 Senior Notes, due 2022
Debt Instrument [Line Items]
Carrying Amount	510	512
Estimated Fair Value	$ 525	$ 530
Notes payable, interest rate	4.50%	4.50%
4.875% 2013 Senior Notes, due 2024
Debt Instrument [Line Items]
Carrying Amount	$ 498	$ 498
Estimated Fair Value	$ 555	$ 562
Notes payable, interest rate	4.875%	4.875%
5.25% 2014 Senior Notes, due 2044
Debt Instrument [Line Items]
Carrying Amount	$ 598	$ 598
Estimated Fair Value	$ 775	$ 828
Notes payable, interest rate	5.25%	5.25%
1.75% 2015 Senior Notes, due 2027
Debt Instrument [Line Items]
Carrying Amount	$ 586	$ 610
Estimated Fair Value	$ 641	$ 674
Notes payable, interest rate	1.75%	1.75%
2.625% 2017 Senior Notes, due 2023
Debt Instrument [Line Items]
Carrying Amount	$ 509	$ 510
Estimated Fair Value	$ 518	$ 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	$ 537	$ 561
Notes payable, interest rate	3.25%	3.25%
4.25% 2018 Senior Notes, due 2029
Debt Instrument [Line Items]
Carrying Amount	$ 395	$ 394
Estimated Fair Value	$ 453	$ 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	$ 493	$ 544
Notes payable, interest rate	4.875%	4.875%
0.950% Senior Notes Due 2030
Debt Instrument [Line Items]
Carrying Amount	$ 872	$ 909
Estimated Fair Value	$ 915	$ 974
Notes payable, interest rate	0.95%	0.95%
3.75% 2020 Senior Notes, due 2025
Debt Instrument [Line Items]
Carrying Amount	$ 689	$ 693
Estimated Fair Value	$ 764	$ 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	$ 292	$ 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	$ 404	$ 467
Notes payable, interest rate	2.55%	2.55%

Leases - Additional Information

Leases - Additional Information (Detail)	Mar. 31, 2021
Minimum
Operating Leased Assets [Line Items]
Lessee, operating lease, renewal term (years)	1 year
Maximum
Operating Leased Assets [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
	Mar. 31, 2021	Mar. 31, 2020
Lease, Cost [Abstract]
Operating lease cost	$ 24	$ 24
Sublease income	(1)	(1)
Variable lease cost	5	5
Total lease cost	$ 28	$ 28

Leases - Operating Leases Infor

Leases - Operating Leases Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Leases [Abstract]
Cash paid for amounts included in the measurement of operating lease liabilities	$ 28	$ 26
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 4	$ 9
Weighted-average remaining lease term (years)	5 years 10 months 24 days	6 years 8 months 12 days
Weighted-average discount rate applied to operating leases (percent)	3.60%	3.60%

Leases - Operating Leases, Futu

Leases - Operating Leases, Future Minimum Payment (Detail) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Leases [Abstract]
2021 (After March 31)	$ 83
2022	99
2023	94
2024	85
2025	77
After 2025	116
Total lease payments (undiscounted)	554
Less: Interest	54
Present value of lease liabilities:	500
Lease liabilities - current	94	$ 94
Lease liabilities - noncurrent	$ 406	$ 427

Segment Information - Additiona

Segment Information - Additional Information (Detail)	3 Months Ended
	Mar. 31, 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
	Mar. 31, 2021	Mar. 31, 2020
Segment Reporting Information, Operating Income (Loss) [Abstract]
Revenue	$ 1,600	$ 1,290
Total Expenses	747	698
Operating income	853	592
Depreciation and amortization	59	49
Restructuring	2	(1)
Loss pursuant to the divestiture of MAKS	0	9
Adjusted Operating Income	914	649
Eliminations
Segment Reporting Information, Operating Income (Loss) [Abstract]
Revenue	(42)	(39)
Total Expenses	(42)	(39)
Operating income	0	0
Depreciation and amortization	0	0
Restructuring	0	0
Loss pursuant to the divestiture of MAKS	0	0
Adjusted Operating Income	0	0
MIS
Segment Reporting Information, Operating Income (Loss) [Abstract]
Revenue	1,036	794
MIS | Operating Segments
Segment Reporting Information, Operating Income (Loss) [Abstract]
Revenue	1,076	831
Total Expenses	366	343
Operating income	710	488
Depreciation and amortization	18	16
Restructuring	0	(1)
Loss pursuant to the divestiture of MAKS	0	0
Adjusted Operating Income	728	503
MA
Segment Reporting Information, Operating Income (Loss) [Abstract]
Revenue	564	496
MA | Operating Segments
Segment Reporting Information, Operating Income (Loss) [Abstract]
Revenue	566	498
Total Expenses	423	394
Operating income	143	104
Depreciation and amortization	41	33
Restructuring	2	0
Loss pursuant to the divestiture of MAKS	0	9
Adjusted Operating Income	$ 186	$ 146

Segment Information - Consolida

Segment Information - Consolidated Revenue Information by Geographic Area (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Segment Reporting Information [Line Items]
Revenue	$ 1,600	$ 1,290
United States
Segment Reporting Information [Line Items]
Revenue	885	714
Non-U.S.
Segment Reporting Information [Line Items]
Revenue	715	576
EMEA
Segment Reporting Information [Line Items]
Revenue	478	363
Asia-Pacific
Segment Reporting Information [Line Items]
Revenue	156	136
Americas
Segment Reporting Information [Line Items]
Revenue	$ 81	$ 77

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - Subsequent Event	Apr. 27, 2021$ / shares
Subsequent Event [Line Items]
Dividend declared, declaration date	Apr. 27, 2021
Dividend declared, per share (in USD per share)	$ 0.62
Dividend declared, payable date	Jun. 10, 2021
Dividend declared, record date	May 20, 2021

Uncategorized Items - mco-20210

Label	Element	Value
Accounting Standards Update [Extensible List]	us-gaap_AccountingStandardsUpdateExtensibleList	us-gaap:AccountingStandardsUpdate201613Member