Moody's (MCO) 10-K 22 Feb 21 2020 FY Annual report Financial data

Cover Page

Cover Page - USD ($) shares in Millions, $ in Billions	12 Months Ended
	Dec. 31, 2020	Jan. 31, 2021	Jun. 30, 2020
Entity Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Current Fiscal Year End Date	--12-31
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 Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
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
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 51
Entity Common Stock, Shares Outstanding (in shares)		187.1
Documents Incorporated by Reference	Portions of the Registrant’s definitive proxy statement for use in connection with its annual meeting of stockholders scheduled to be held on April 20, 2021, are incorporated by reference into Part III of this Form 10-K.
Entity Central Index Key	0001059556
Document Fiscal Period Focus	FY
Amendment Flag	false
Document Fiscal Year Focus	2020
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% 2015 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% 2019 Senior Note, 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 - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Revenue	$ 5,371	$ 4,829	$ 4,443
Expenses
Operating	1,475	1,387	1,246
Selling, general and administrative	1,229	1,167	1,080
Restructuring	50	60	49
Depreciation and amortization	220	200	192
Acquisition-Related Expenses	0	3	8
Loss pursuant to the divestiture of MAKS	9	14	0
Total expenses	2,983	2,831	2,575
Operating income	2,388	1,998	1,868
Non-operating (expense) income, net
Interest expense, net	(205)	(208)	(215)
Other non-operating income, net	46	20	19
Non-operating (expense) income, net	(159)	(188)	(196)
Income before provision for income taxes	2,229	1,810	1,672
Provision for income taxes	452	381	352
Net income	1,777	1,429	1,320
Less: Net (loss) income attributable to noncontrolling interests	(1)	7	10
Net income attributable to Moody’s	$ 1,778	$ 1,422	$ 1,310
Earnings per share
Basic (in USD per share)	$ 9.48	$ 7.51	$ 6.84
Diluted (in USD per share)	$ 9.39	$ 7.42	$ 6.74
Weighted average shares outstanding
Basic (in shares)	187.6	189.3	191.6
Diluted (in shares)	189.3	191.6	194.4

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 1,777	$ 1,429	$ 1,320
Foreign Currency Adjustments:
Foreign currency translation adjustment - Pre Tax	361	(22)	(315)
Foreign currency translation adjustment - Tax	(13)	(1)	0
Foreign currency translation adjustment - Net of Tax	348	(23)	(315)
Foreign currency translation adjustments - reclassification of losses included in net income - Pre Tax	0	32	0
Foreign currency translation adjustments - reclassification of losses included in net income - Tax	0	0	0
Foreign currency translation adjustments - reclassification of losses included in net income - Net of Tax	0	32	0
Net (losses) gains on net investment hedges - Pre Tax	(364)	35	41
Net (losses) gains on net investment hedges - Tax	91	(9)	(7)
Net (losses) gains on net investment hedges - Net of Tax	(273)	26	34
Net investment hedges - reclassification of gains included in net income - Pre Tax	(1)	(3)	0
Net investment hedges - reclassification of gains included in net income - Tax	0	1	0
Net investment hedges - reclassification of gains included in net income - Net of Tax	(1)	(2)	0
Cash Flow Hedges:
Net losses on cash flow hedges - Pre Tax	(68)	0	(1)
Net losses on cash flow hedges - Tax	17	0	0
Net losses on cash flow hedges - Net of Tax	(51)	0	(1)
Reclassification of (losses) gains included in net income - Pre Tax	3	0	0
Reclassification of (losses) gains included in net income - Tax	(1)	0	0
Reclassification of (losses) gains included in net income - Net of Tax	2	0	0
Pension and Other Retirement Benefits:
Amortization of actuarial losses and prior service costs and settlement charge included in net income, before tax	8	3	5
Amortization of actuarial losses and prior service costs and settlement charge included in net income - Tax	(2)	(1)	(1)
Amortization of actuarial losses and prior service costs and settlement charge included in net income - Net of Tax	6	2	4
Net actuarial (losses) gains and prior service costs - Pre Tax	(42)	(32)	6
Net actuarial losses and prior service costs, tax	(10)	(8)	2
Net actuarial (losses) gains and prior service costs - Net of Tax	(32)	(24)	4
Total other comprehensive (loss) income - Pre Tax	(103)	13	(264)
Total other comprehensive (loss)income - Tax	102	(2)	(10)
Total Other Comprehensive (Loss) Income	(1)	11	(274)
Comprehensive Income	1,776	1,440	1,046
Less: comprehensive (loss) income attributable to noncontrolling interests	(8)	11	(12)
Comprehensive Income Attributable to Moody’s	$ 1,784	$ 1,429	$ 1,058

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 2,597	$ 1,832
Short-term investments	99	98
Accounts receivable, net of allowances for credit losses of $34 in 2020 and $20 in 2019	1,430	1,419
Other current assets	383	330
Total current assets	4,509	3,679
Property and equipment, net	278	292
Operating lease right-of-use assets	393	456
Goodwill	4,556	3,722
Intangible assets, net	1,824	1,498
Deferred tax assets, net	334	229
Other assets	515	389
Total assets	12,409	10,265
Current liabilities:
Accounts payable and accrued liabilities	1,039	773
Current portion of operating lease liabilities	94	89
Deferred revenue	1,089	1,050
Total current liabilities	2,222	1,912
Non-current portion of deferred revenue	98	112
Long-term debt	6,422	5,581
Deferred tax liabilities, net	404	357
Uncertain tax positions	483	477
Operating lease liabilities	427	485
Other liabilities	590	504
Total liabilities	10,646	9,428
Contingencies
Redeemable noncontrolling interest	0	6
Shareholders’ equity:
Preferred stock, par value $.01 per share; 10,000,000 shares authorized; no shares issued and outstanding	0	0
Common stock	3	3
Capital surplus	735	642
Retained earnings	11,011	9,656
Treasury stock, at cost; 155,808,563 and 155,215,143 shares of common stock at December 31, 2020 and December 31, 2019, respectively	(9,748)	(9,250)
Accumulated other comprehensive loss	(432)	(439)
Total Moody’s shareholders’ equity	1,569	612
Noncontrolling interests	194	219
Total shareholders’ equity	1,763	831
Total liabilities, redeemable noncontrolling interest and shareholders’ equity	12,409	10,265
Series Common Stock
Shareholders’ equity:
Common stock	$ 0	$ 0

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Accounts receivable, allowances	$ 34	$ 20
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)	155,808,563	155,215,143
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 - USD ($) $ in Millions	12 Months Ended			24 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2020
Cash flows from operating activities
Net income	$ 1,777	$ 1,429	$ 1,320
Reconciliation of net income to net cash provided by operating activities:
Depreciation and amortization	220	200	192
Stock-based compensation	154	136	130
Deferred income taxes	(44)	(38)	(99)
Prepayment penalty relating to early redemption of debt	24	12	0
Settlement of treasury rate lock	(68)	0	0
ROU Asset impairment & other non-cash restructuring/impairment charges	36	38	0
Loss pursuant to the divestiture of MAKS	9	14	0
Changes in assets and liabilities:
Accounts receivable	31	(134)	(136)
Other current assets	(38)	(88)	(9)
Other assets	(49)	(69)	(17)
Lease obligations	(10)	(16)	0
Accounts payable and accrued liabilities	247	65	(99)
Deferred revenue	(29)	76	139
Unrecognized tax positions and other non-current tax liabilities	(12)	8	59
Other liabilities	(102)	42	(19)
Net cash provided by operating activities	2,146	1,675	1,461
Cash flows from investing activities
Capital additions	(103)	(69)	(91)
Purchases of investments	(181)	(138)	(193)
Sales and maturities of investments	104	174	161
Cash received upon disposal of a business, net of cash transferred to purchaser	0	226	6
Cash paid for acquisitions, net of cash acquired	(897)	(162)	(289)
Receipts from settlements of net investment hedges	2	12	0
Payments for settlements of net investment hedges	(2)	(7)	0
Net cash (used in) provided by investing activities	(1,077)	36	(406)
Cash flows from financing activities
Issuance of notes	1,491	824	1,090
Repayment of notes	(800)	(950)	(800)
Issuance of commercial paper	789	1,317	989
Repayment of commercial paper	(792)	(1,320)	(1,120)
Proceeds from stock-based compensation plans	51	45	47
Repurchase of shares related to stock-based compensation	(104)	(77)	(62)
Treasury shares	(503)	(991)	(203)
Dividends	(420)	(378)	(337)
Dividends to noncontrolling interests	(1)	(3)	(5)
Payment for noncontrolling interest	(23)	(12)	0
Debt issuance costs, extinguishment costs and related fees	(39)	(18)	(11)
Net cash used in financing activities	(351)	(1,563)	(412)
Effect of exchange rate changes on cash and cash equivalents	47	(1)	(30)
Increase in cash and cash equivalents	765	147	613
Cash and cash equivalents, beginning of period	1,832	1,685	1,072	$ 1,685
Cash and cash equivalents, end of period	$ 2,597	$ 1,832	$ 1,685	$ 2,597

CONSOLIDATED STATEMENT OF SHARE

CONSOLIDATED STATEMENT OF SHAREHOLDERS' EQUITY (DEFICIT) - USD ($) shares in Millions, $ in Millions	Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock	Capital Surplus	Retained Earnings	Retained EarningsCumulative Effect, Period of Adoption, Adjustment	Treasury Stock	Accumulated Other Comprehensive Loss	Accumulated Other Comprehensive LossCumulative Effect, Period of Adoption, Adjustment	Total Moody’s Shareholders’ Equity	Total Moody’s Shareholders’ EquityCumulative Effect, Period of Adoption, Adjustment	Non- Controlling Interests
Beginning Balance (in shares) at Dec. 31, 2017			342.9				151.9
Beginning Balance at Dec. 31, 2017	$ (115)		$ 3	$ 529	$ 7,465		$ (8,153)	$ (172)		$ (328)		$ 213
Beginning Balance (Accounting Standards Update 2014-09) at Dec. 31, 2017		$ 156				$ 156					$ 156
Beginning Balance (Accounting Standards Update 2016-01) at Dec. 31, 2017		0				2			$ (2)		0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,320				1,310					1,310		10
Dividends	(343)				(339)					(339)		(4)
Stock-based compensation	131			131						131
Shares issued for stock-based compensation plans at average cost, net (in shares)							1.5
Shares issued for stock-based compensation plans at average cost, net	(16)			(59)			$ 43			(16)
Treasury shares repurchased (in shares)							(1.2)
Treasury shares repurchased	(203)						$ (203)			(203)
Currency translation adjustment, net of net investment hedge activity	(281)							(259)		(259)		(22)
Net actuarial gains and prior service cost	4							4		4
Amortization of prior service costs and actuarial losses	4							4		4
Net realized and unrealized gain on cash flow hedges	(1)							(1)		(1)
Ending Balance (in shares) at Dec. 31, 2018			342.9				151.6
Ending Balance at Dec. 31, 2018	$ 656	$ 0	$ 3	601	8,594	20	$ (8,313)	(426)	$ (20)	459	0	197
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201802Member	us-gaap:AccountingStandardsUpdate201802Member
Net income	$ 1,429				1,422					1,422		7
Dividends	(383)				(380)					(380)		(3)
Stock-based compensation	136			136						136
Shares issued for stock-based compensation plans at average cost, net (in shares)							1.6
Shares issued for stock-based compensation plans at average cost, net	(32)			(70)			$ 38			(32)
Purchase of noncontrolling interest	(12)			(9)						(9)		(3)
Non-controlling interest resulting from majority acquisition of Vigeo Eiris	17									0		17
Treasury shares repurchased (in shares)							(5.2)
Treasury shares repurchased	(991)			(16)			$ (975)			(991)
Currency translation adjustment, net of net investment hedge activity	33							29		29		4
Net actuarial gains and prior service cost	(24)							(24)		(24)
Amortization of prior service costs and actuarial losses	2							2		2
Ending Balance (in shares) at Dec. 31, 2019			342.9				155.2
Ending Balance at Dec. 31, 2019	$ 831	$ (2)	$ 3	642	9,656	$ (2)	$ (9,250)	(439)		612	$ (2)	219
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201613Member
Net income	$ 1,777
Dividends	(424)				(421)					(421)		(3)
Stock-based compensation	154			154						154
Shares issued for stock-based compensation plans at average cost, net (in shares)							1.4
Shares issued for stock-based compensation plans at average cost, net	(53)			(58)			$ 5			(53)
Purchase of noncontrolling interest	(17)			(3)						(3)		(14)
Treasury shares repurchased (in shares)							(2)
Treasury shares repurchased	(503)			0			$ (503)			(503)
Currency translation adjustment, net of net investment hedge activity	74							82		82		(8)
Net actuarial gains and prior service cost	(32)							(32)		(32)
Amortization of prior service costs and actuarial losses	6							6		6
Net realized and unrealized gain on cash flow hedges	(49)							(49)		(49)
Ending Balance (in shares) at Dec. 31, 2020			342.9				155.8
Ending 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 (Loss), Including Portion Attributable to Nonredeemable Noncontrolling Interest	$ 1,778				$ 1,778					$ 1,778		$ 0

CONSOLIDATED STATEMENT OF SHA_2

CONSOLIDATED STATEMENT OF SHAREHOLDERS' EQUITY (DEFICIT) (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Stockholders' Equity [Abstract]
Dividends declared per share attributable to Moody's common shareholders (in USD per share)	$ 2.24	$ 2	$ 1.76
Currency translation adjustment, tax	$ (78)	$ 9	$ 7
Net actuarial losses and prior service costs, tax	(10)	(8)	2
Amortization of actuarial losses and prior service costs included in net income, tax	2	$ 1	1
Net unrealized and unrealized gain on cash flow hedges, tax	$ (16)		$ (1)

DESCRIPTION OF BUSINESS AND BAS

DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION	12 Months Ended
	Dec. 31, 2020
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, programs and facilities, and the entities that issue such obligations in markets worldwide, including various corporate, financial institution and governmental obligations, and structured finance securities. Revenue is primarily derived from the originators and issuers of such transactions who use MIS ratings to support 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. Certain reclassifications have been made to prior period amounts to conform to the current presentation. Adoption of New Accounting Standards On January 1, 2019, the Company adopted ASU No. 2016-02, “Leases (Topic 842)” and elected to apply the provisions of the New Lease Accounting Standard on the date of adoption with adjustments to the assets and liabilities on its opening balance sheet, with no cumulative-effect adjustment to the opening balance of retained earnings required. Accordingly, the Company did not restate prior year comparative periods for the impact of the New Lease Accounting Standard. On January 1, 2020, the Company adopted ASU No. 2016-13, “Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.” The Company has implemented policies and procedures in compliance with the “expected credit loss” impairment model, which included: (1) refinement of the grouping of receivables with similar risk characteristics; and (2) processes to identify information that can be used to develop reasonable and supportable forecasts of factors that could affect the collectability of the reported amount of the receivable. As the Company's accounts receivable are short-term in nature, the adoption of this ASU did not have a material impact to the Company's allowance for bad debts or its policies and procedures for determining the allowance. Refer to Note 2 for further information on how the Company determines its reserves for expected credit losses. The Company recorded a $2 million cumulative-effect adjustment to retained earnings to increase its allowance for credit losses upon adoption. On January 1, 2020, the Company adopted ASU No. 2018-15, “Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement that is a Service Contract.” This ASU requires implementation costs incurred by customers in cloud computing arrangements (i.e., hosting arrangements) to be capitalized under the same provisions of authoritative guidance for internal-use software, and amortized over the non-cancellable term of the cloud computing arrangements plus any option renewal periods that are reasonably certain to be exercised by the customer or for which the exercise is controlled by the service provider. The Company is now required to present the amortization of capitalized implementation costs in the same line item in the statement of operations as the fees associated with the hosting service (i.e. operating and SG&A expense) and classify the related payments in the statement of cash flows in the same manner as payments made for fees associated with the hosting service (i.e. cash flows from operating activities). This ASU also requires capitalization of implementation costs in the balance sheet to be consistent with the location of prepayment of fees for the hosting element (i.e. within other current assets or other assets). The Company adopted this ASU prospectively to all implementation costs incurred after the date of adoption and it did not have a material impact on the Company's current financial statements. The future impact to the Company's financial statements will relate to the aforementioned classification of these capitalized costs and related amortization. In March 2020, FASB issued ASU No. 2020-04, "Facilitation of the Effects of Reference Rate Reform on Financial Reporting". The ASU 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. This guidance was effective beginning on March 12, 2020, and the Company may elect to apply the amendments prospectively through December 31, 2022 as the transition from LIBOR is completed. On December 31, 2020, the Company adopted ASU No. 2018-14, “Compensation—Retirement Benefits—Defined Benefit Plans—General (Subtopic 715-20): Disclosure Framework—Changes to the Disclosure Requirements for Defined Benefit Plans”. This ASU eliminates requirements for certain disclosures and requires additional disclosures under defined benefit pension plans and other postretirement plans. The Company is also now required to present a narrative description of significant gains or losses in the benefit obligation over the past year. The Company adopted this ASU retrospectively for all periods presented with the new required disclosures presented in Note 15. COVID-19 The Company experienced disruption in certain sectors of its business beginning late in the first quarter of 2020 resulting from market volatility associated with the COVID-19 crisis. However, at the date of the filing of this annual report on Form 10-K, the Company is unable to predict either the potential near-term or longer-term impact that the COVID-19 crisis may have on its financial position and operating results due to numerous uncertainties regarding the duration and severity of the crisis, including the length of time to distribute a vaccine. As a result, it is reasonably possible that the Company could experience material impacts including, but not limited to: reductions in revenue and cash flows; additional credit losses related to accounts receivables; asset impairment charges; and changes in the funded status of defined benefit pension plans. While it is reasonably possible that the COVID-19 crisis could impact the results of operations and cash flows of the Company in the near term, Moody's believes that it has adequate liquidity to maintain its operations with minimal disruption and to maintain compliance with its debt covenants. In order to maximize liquidity and to increase available cash on hand through this period of uncertainty, the Company increased its long-term borrowings by $700 million as more fully discussed in Note 18. In addition, the Company reduced discretionary spending, including temporarily suspending its share repurchase program beginning late in the first quarter of 2020 and spanning through the third quarter. The Company resumed its share repurchase program in the fourth quarter of 2020. The Coronavirus Aid, Relief, and Economic Security Act (“CARES Act”) was enacted on March 27, 2020 in the United States. The Company utilized certain provisions in the CARES Act and other IRS guidance which permit the deferral of certain income and payroll tax remittances.

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Basis of Consolidation The consolidated financial statements include those of Moody’s Corporation and its majority- and wholly-owned subsidiaries. The effects of all intercompany transactions have been eliminated. Investments in companies for which the Company has significant influence over operating and financial policies but not a controlling interest are accounted for on an equity basis whereby the Company records its proportional share of the investment’s net income or loss as part of other non-operating income (expense), net and any dividends received reduce the carrying amount of the investment. The Company applies the guidelines set forth in Topic 810 of the ASC in assessing its interests in variable interest entities to decide whether to consolidate an entity. The Company has reviewed the potential variable interest entities and determined that there are no consolidation requirements under Topic 810 of the ASC. The Company consolidates its ICRA subsidiaries on a three month lag. Cash and Cash Equivalents Cash equivalents principally consist of investments in money market mutual funds and money market deposit accounts as well as high-grade commercial paper and certificates of deposit with maturities of three months or less when purchased. Short-term Investments Short-term investments are securities with maturities greater than 90 days at the time of purchase that are available for operations in the next 12 months. The Company’s short-term investments primarily consist of certificates of deposit and their cost approximates fair value due to the short-term nature of the instruments. Interest and dividends on these investments are recorded into income when earned. Property and Equipment Property and equipment are stated at cost and are depreciated using the straight-line method over their estimated useful lives. Expenditures for maintenance and repairs that do not extend the economic useful life of the related assets are charged to expense as incurred. Computer Software Developed or Obtained for Internal Use The Company capitalizes costs related to software developed or obtained for internal use. These assets, included in property and equipment in the consolidated balance sheets, relate to the Company’s financial, website and other systems. Such costs generally consist of direct costs for third-party license fees, professional services provided by third parties and employee compensation, in each case incurred either during the application development stage or in connection with upgrades and enhancements that increase functionality. Such costs are depreciated over their estimated useful lives on a straight-line basis. Costs incurred during the preliminary project stage of development as well as maintenance costs are expensed as incurred. The Company also capitalizes implementation costs incurred in cloud computing arrangements (i.e., hosting arrangements) and depreciates the costs over the non-cancellable term of the cloud computing arrangements plus any option renewal periods that are reasonably certain to be exercised or for which the exercise is controlled by the service provider. The Company classifies the amortization of capitalized implementation costs in the same line item in the statement of operations as the fees associated with the hosting service (i.e., operating and SG&A expense) and classifies the related payments in the statement of cash flows in the same manner as payments made for fees associated with the hosting service (i.e. cash flows from operating activities). In addition, the capitalization of implementation costs is reflected in the balance sheet consistent with the location of prepayment of fees for the hosting element (i.e., within other current assets or other assets). Goodwill and Other Acquired Intangible Assets Moody’s evaluates its goodwill for impairment at the reporting unit level, defined as an operating segment (i.e., MIS and MA), or one level below an operating segment (i.e., a component of an operating segment), annually as of July 31 or more frequently if impairment indicators arise in accordance with ASC Topic 350. The Company evaluates the recoverability of goodwill using a two-step impairment test approach at the reporting unit level. In the first step, the Company assesses various qualitative factors to determine whether the fair value of a reporting unit may be less than its carrying amount. If a determination is made based on the qualitative factors that an impairment does not exist, the Company is not required to perform further testing. If the aforementioned qualitative assessment results in the Company concluding that it is more likely than not that the fair value of a reporting unit may be less than its carrying amount, the fair value of the reporting unit will be quantitatively determined and compared to its carrying value including goodwill. If the fair value of the reporting unit exceeds the carrying value of the net assets assigned to that unit, goodwill is not impaired and the Company is not required to perform further testing. If the fair value of the reporting unit is less than the carrying value, the Company will record a goodwill impairment charge for the amount by which the carrying value exceeds the reporting unit’s fair value. The Company evaluates its reporting units on an annual basis, or more frequently if there are changes in the reporting structure of the Company due to acquisitions, reporting unit realignments or if there are indicators of potential impairment. For the reporting units where the Company is consistently able to conclude that no impairment exists using only a qualitative approach, the Company’s accounting policy is to perform the second step of the aforementioned goodwill impairment assessment at least once every three years. Goodwill is assigned to a reporting unit at the date when an acquisition is integrated into one of the established reporting units, and is based on which reporting unit is expected to benefit from the synergies of the acquisition. For purposes of assessing the recoverability of goodwill, the Company has seven primary reporting units: two within the Company’s ratings business (one for the ICRA business and one that encompasses all of Moody’s other ratings operations) and five reporting units within MA: Content, ERS, MALS, Bureau van Dijk and Reis. Impairment of long-lived assets and definite-lived intangible assets Long-lived assets (including ROU Assets) and amortizable intangible assets are reviewed for recoverability whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. Under the first step of the recoverability assessment, the Company compares the estimated undiscounted future cash flows attributable to the asset or asset group to their carrying value. If the undiscounted future cash flows are greater than the carrying value, no further assessment is required. If the undiscounted future cash flows are less than the carrying value, Moody's proceeds with step two of the assessment. Under step two of this assessment, Moody's is required to determine the fair value of the asset or asset group (reduced by the estimated cost to sell the asset for assets or disposal groups classified as held-for-sale) and recognize an impairment loss if the carrying amount exceeds its fair value. Stock-Based Compensation The Company records compensation expense for all share-based payment award transactions granted to employees based on the fair value of the equity instrument at the time of grant. This includes shares issued under stock option and restricted stock plans. Derivative Instruments and Hedging Activities Based on the Company’s risk management policy, from time to time the Company may use derivative financial instruments to reduce exposure to changes in foreign exchange rates and interest rates. The Company does not enter into derivative financial instruments for speculative purposes. All derivative financial instruments are recorded on the balance sheet at their respective fair values on a gross basis. The changes in the value of derivatives that qualify as fair value hedges are recorded in the same income statement line item in earnings in which the corresponding adjustment to the carrying value of the hedged item is presented. The entire change in the fair value of derivatives that qualify as cash flow hedges is recorded to OCI and such amounts are reclassified from AOCI to the same income statement line in earnings in the same period or periods during which the hedged transaction affects income. Effective with the Company’s early adoption of ASC 2017-12, the Company changed the method by which it assesses effectiveness for net investment hedges from the forward-method to the spot-method. The Company considers the spot-method an improved method of assessing hedge effectiveness, as spot rate changes relating to the hedging instrument’s notional amount perfectly offset the currency translation adjustment on the hedged net investment in the Company’s foreign subsidiaries. The entire change in the fair value of derivatives that qualify as net investment hedges is initially recorded to OCI. Those changes in fair value attributable to components included in the assessment of hedge effectiveness in a net investment hedge are recorded in the currency translation adjustment component of OCI and remain in AOCI until the period in which the hedged item affects earnings. Those changes in fair value attributable to components excluded from the assessment of hedge effectiveness in a net investment hedge are recorded to OCI and amortized to earnings using a systematic and rational method over the duration of the hedge. Any changes in the fair value of derivatives that the Company does not designate as hedging instruments under Topic 815 of the ASC are recorded in the consolidated statements of operations in the period in which they occur. Revenue Recognition and Costs to Obtain or Fulfill a Contract with a Customer Revenue recognition: Revenue is recognized when control of promised goods or services is transferred to the customer, in an amount that reflects the consideration the Company expects to be entitled to in exchange for those goods or services. When contracts with customers contain multiple performance obligations, the Company accounts for individual performance obligations separately if they are distinct. The transaction price is allocated to each distinct performance obligation on a relative SSP basis. The Company determines the SSP by using the price charged for a deliverable when sold separately or uses management’s best estimate of SSP for goods or services not sold separately using estimation techniques that maximize observable data points, including: internal factors relevant to its pricing practices such as costs and margin objectives; standalone sales prices of similar products; pricing policies; percentage of the fee charged for a primary product or service relative to a related product or service; and customer segment and geography. Additional consideration is also given to market conditions such as competitor pricing strategies and market trends. Sales, usage-based, value added and other taxes are excluded from revenues. MIS Revenue In the MIS segment, revenue arrangements with multiple elements are generally comprised of two distinct performance obligations, a rating and the related monitoring service. Revenue attributed to ratings of issued securities is generally recognized when the rating is delivered to the issuer. Revenue attributed to monitoring of issuers or issued securities is recognized ratably over the period in which the monitoring is performed, generally one year. In the case of certain structured finance products, primarily CMBS, issuers can elect to pay all of the annual monitoring fees upfront. These fees are deferred and recognized over the future monitoring periods based on the expected lives of the rated securities. MIS arrangements generally have standard contractual terms for which the stated payments are due at conclusion of the ratings process for ratings and either upfront or in arrears for monitoring services; and are signed by customers either on a per issue basis or at the beginning of the relationship with the customer. In situations when customer fees for an arrangement may be variable, the Company estimates the variable consideration at inception using the expected value method based on analysis of similar contracts in the same line of business, which is constrained based on the Company’s assessment of the realization of the adjustment amount. The Company allocates the transaction price within arrangements that include multiple performance obligations based upon the relative SSP of each service. The SSP for both rating and monitoring services is generally based upon observable selling prices where the rating or monitoring service is sold separately to similar customers. MA Revenue In the MA segment, products and services offered by the Company include hosted research and data subscriptions, installed software subscriptions, perpetual installed software licenses and related maintenance, or PCS, and professional services. Subscription and PCS contracts are generally invoiced in advance of the contractual coverage period, which is principally one year, but can range from 3-5 years; while perpetual software licenses are generally invoiced upon delivery and professional services are invoiced as those services are provided. Payment terms and conditions vary by contract type, but primarily include a requirement of payment within 30 to 60 days. Revenue from research, data and other hosted subscriptions is recognized ratably over the related subscription period as MA's performance obligation to provide access to these products is progressively fulfilled over the stated term of the contract. A large portion of these services are invoiced in the months of November, December and January. Revenue from the sale of a software license, when considered distinct from the related software implementation services, is generally recognized at the time the product master or first copy is delivered or transferred to the customer. PCS is generally recognized ratably over the contractual period commencing when the software license is fully delivered. Revenue from installed software subscriptions, which includes PCS, is bifurcated into a software license performance obligation and a PCS performance obligation, which follow the patterns of recognition described above. However, in instances where the software license (perpetual or subscription) and related implementation services are considered to be one combined performance obligation, revenue is recognized over time using cost based input methods. Due to the strategic shift in the MA business towards SaaS solutions, revenue generated from these types of arrangements were not material in the years ended December 31, 2020, 2019 and 2018. For implementation services and other service projects within the ERS and ESA businesses for which fees are fixed, the Company determined progress towards completion is most accurately measured on a percentage-of-completion basis (input method) as this approach utilizes the most directly observable data points and is therefore used to recognize the related revenue. For implementation services where price varies based on time expended, a time-based measure of progress towards completion of the performance obligation is utilized. Revenue from professional services rendered is generally recognized as the services are performed over time. Products and services offered within the MA segment are sold either stand-alone or together in various combinations. In instances where an arrangement contains multiple performance obligations, the Company accounts for the individual performance obligations separately if they are considered distinct. Revenue is generally allocated to all performance obligations based upon the relative SSP at contract inception. For certain performance obligations, judgment is required to determine the SSP. Revenue is recognized for each performance obligation based upon the conditions for revenue recognition noted above. In the MA segment, customers usually pay a fixed fee for the products and services based on signed contracts. However, accounting for variable consideration is applied mainly for: i) estimates for cancellation rights and price concessions and ii) T&M based services. The Company estimates the variable consideration associated with cancellation rights and price concessions based on the expected amount to be provided to customers and reduces the amount of revenue to be recognized. T&M based contracts represent about half of MA’s service projects within the ERS and ESA businesses. The Company provides agreed upon services at a contracted daily or hourly rate. The commitment represents a series of goods and services that are substantially the same and have the same pattern of transfer to the customer. As such, if T&M services are sold with other MA products, the Company allocates the variable consideration entirely to the T&M performance obligation if the services are sold at standard pricing or at a similar discount level compared to other performance obligations in the same revenue contract. If these criteria are not met, the Company estimates variable consideration for each performance obligation upfront. Each form of variable consideration is included in the transaction price only to the extent that it is probable that a significant reversal of any incremental revenue will not occur. Costs to Obtain or Fulfill a Contract with a Customer: Costs to obtain a contract with a customer Costs incurred to obtain customer contracts, such as sales commissions, are deferred and recorded within other current assets and other assets when such costs are determined to be incremental to obtaining a contract, would not have been incurred otherwise and the Company expects to recover those costs. These costs are amortized to expense on a systematic basis consistent with the transfer of the products or services to the customer. Depending on the line of business to which the contract relates, this may be based upon the average economic life of the products sold or average period for which services are provided, inclusive of anticipated contract renewals. Determining the estimated economic life of the products sold requires judgment with respect to anticipated future technological changes. The Company had a balance of $180 million and $159 million in such deferred costs as of December 31, 2020 and December 31, 2019, respectively, and recognized $59 million, $53 million and $38 million of related amortization during the years ended December 31, 2020, December 31, 2019 and December 31, 2018, respectively, which is included within SG&A expenses in the consolidated statement of operations. Costs incurred to obtain customer contracts are only in the MA segment. Cost to fulfill a contract with a customer Costs incurred to fulfill customer contracts, are deferred and recorded within other current assets and other assets when such costs relate directly to a contract, generate or enhance resources of the Company that will be used in satisfying performance obligations in the future and the Company expects to recover those costs. The Company capitalizes work-in-process costs for in-progress MIS ratings, which is recognized consistent with the rendering of the related services to the customers, as ratings are issued. The Company had a balance of $12 million and $11 million in such deferred costs as of December 31, 2020 and December 31, 2019, respectively, and recognized $47 million, $42 million and $40 million of amortization of the costs during the years ended December 31, 2020, December 31, 2019 and December 31, 2018, respectively, which is included within operating expenses in the consolidated statement of operations. In addition, within the MA segment, the Company capitalizes royalty costs related to third-party information data providers associated with hosted company information and business intelligence products. These costs are amortized to expense consistent with the recognition pattern of the related revenue over time. The Company had a balance of $35 million and $40 million in such deferred costs as of December 31, 2020 and December 31, 2019, respectively, and recognized $66 million, $56 million and $54 million of related amortization during the years ended December 31, 2020, December 31, 2019 and December 31, 2018, respectively, which is included within operating expenses in the consolidated statement of operations. Accounts Receivable Allowances In order to determine an estimate of expected credit losses, receivables are segmented based on similar risk characteristics including historical credit loss patterns and industry or class of customers to calculate reserve rates. The Company uses an aging method for developing its allowance for credit losses by which receivable balances are stratified based on aging category. A reserve rate is calculated for each aging category which is generally based on historical information, and is adjusted, when necessary, for current conditions (e.g., macroeconomic or industry related) and reasonable and supportable forecasts about the future. The Company also considers customer specific information (e.g., bankruptcy or financial difficulty) when estimating its expected credit losses, as well as the economic environment of the customers, both from an industry and geographic perspective, in evaluating the need for allowances. Expected credit losses are reflected as additions to the accounts receivable allowance. Actual uncollectible account write-offs are recorded against the allowance. During the year ended December 31, 2020, the Company recorded a net provision for expected credit losses of $26 million. The increase in the provision for expected credit losses for the current period was primarily attributable to the aforementioned estimated effects of COVID-19. Leases The Company has operating leases, of which substantially all 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. The Company determines if an arrangement meets the definition of a lease at contract inception. The Company recognizes in its consolidated balance sheet a lease liability and an ROU Asset for all leases with a lease term greater than 12 months. In determining the length of the lease term, the Company utilizes judgment in assessing the likelihood of whether it is reasonably certain that it will exercise an option to extend or early-terminate a lease, if such options are provided in the lease agreement. ROU Assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. ROU Assets and lease liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. As substantially all of the Company’s leases do not provide an implicit interest rate, the Company uses its estimated secured incremental borrowing rates at the lease commencement date in determining the present value of lease payments. These secured incremental borrowing rates are attributable to the currency in which the lease is denominated. At commencement, the Company’s initial measurement of the ROU Asset is calculated as the present value of the remaining lease payments (i.e., lease liability), with additive adjustments reflecting: initial direct costs (e.g., broker commissions) and prepaid lease payments (if any); and reduced by any lease incentives provided by the lessor if: (i) received before lease commencement or (ii) receipt of the lease incentive is contingent upon future events for which the occurrence is both probable and within the Company’s control. Lease expense for minimum operating lease payments is recognized on a straight-line basis over the lease term. This straight-line lease expense represents a single lease cost which is comprised of both an interest accretion component relating to the lease liability and amortization of the ROU Assets. The Company records this single lease cost in operating and SG&A expenses. However, in situations where an operating lease ROU Asset has been impaired, the subsequent amortization of the ROU Asset is then recorded on a straight-line basis over the remaining lease term and is combined with accretion expense on the lease liability to result in single operating lease cost (which subsequent to impairment will no longer follow a straight-line recognition pattern). The Company has lease agreements which include lease and non-lease components. For the Company’s office space leases, the lease components (e.g., fixed rent payments) and non-lease components (e.g., fixed common-area maintenance costs) are combined and accounted for as a single lease component. Variable lease payments (e.g. variable common-area-maintenance costs) are only included in the initial measurement of the lease liability to the extent those payments depend on an index or a rate. Variable lease payments not included in the lease liability are recognized in net income in the period in which the obligation for those payments is incurred. Contingencies Moody’s is involved in legal and tax proceedings, governmental, regulatory and legislative investigations and inquiries, claims and litigation that are incidental to the Company’s business, including claims based on ratings assigned by MIS. Moody’s is also subject to ongoing tax audits in the normal course of business. Management periodically assesses the Company’s liabilities and contingencies in connection with these matters based upon the latest information available. Moody’s discloses material pending legal proceedings pursuant to SEC rules and other pending matters as it may determine to be appropriate. 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. Operating Expenses Operating expenses include costs associated with the development and production of the Company’s products and services and their delivery to customers. These expenses principally include employee compensation and benefits and travel costs that are incurred in connection with these activities. Operating expenses are charged to income as incurred. Selling, General and Administrative Expenses SG&A expenses include such items as compensation and benefits for corporate officers and staff and compensation and other expenses related to sales. They also include items such as office rent, business insurance, professional fees and gains and losses from sales and disposals of assets. SG&A expenses are charged to income as incurred. Foreign Currency Translation For all operations outside the U.S. where the Company has designated the local currency as the functional currency, assets and liabilities are translated into U.S. dollars using end of year exchange rates, and revenue and expenses are translated using average exchange rates for the year. For these foreign operations, currency translation adjustments are recorded to other comprehensive income. Comprehensive Income Comprehensive income represents the change in net assets of a business enterprise during a period due to transactions and other events and circumstances from non-owner sources including foreign currency translation impacts, net actuarial gains and losses and net prior service costs related to pension and other retirement plans and gains and losses on derivative instruments designated as net investment hedges or cash flow hedges. Comprehensive income items, including cumulative translation adjustments of entities that are less-than-wholly-owned subsidiaries, will be reclassified to noncontrolling interests and thereby, adjusting accumulated other comprehensive income proportionately in accordance with the percentage of ownership interest of the NCI shareholder. Income Taxes The Company accounts for income taxes under the asset and liability method in accordance with ASC Topic 740. Therefore, income tax expense is based on reported income before income taxes and deferred income taxes reflect the effect of temporary differences between the amounts of assets and liabilities that are recognized for financial reporting purposes and the amounts that are recognized for income tax purposes. The Company classifies interest related to unrecognized tax benefits as a component of interest expense in its consolidated statements of operations. Penalties are recognized in other non-operating expenses. For UTPs, the Company first determines whether it is more-likely-than-not (defined as a likelihood of more than fifty percent) that a tax position will be sustained based on its technical merits as of the reporting date, assuming that taxing authorities will examine the position and have full knowledge of all relevant information. A tax position that meets this more-likely-than-not threshold is then measured and recognized at the largest amount of benefit that is greater than fifty percent likely to be realized upon effective settlement with a taxing authority. On December 22, 2017, the Tax Act was signed into law, resulting in all previously undistributed foreign earnings being subject to U.S. tax. The Company has provided deferred taxes for those entities whose earnings are not considered indefinitely reinvested. Fair Value of Financial Instruments The Company’s financial instruments include cash, cash equivalents, trade receivables and payables, and certain short-term investments consisting primarily of certificates of deposit and money market deposits, all of which are short-term in nature and, accordingly, approximate fair value. The Company also invests in mutual funds, which are accounted for as equity securities with readily determinable fair values under ASC Topic 321. The Company measures these investments at fair value with both realized gains and losses and unrealized holding gains and losses for these investments included in net income. Also, the Company uses derivative instruments to manage certain financial exposures that occur in the normal course of business. These derivative instruments are

REVENUES

REVENUES	12 Months Ended
	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
REVENUES	REVENUES Revenue by Category The following table presents the Company’s revenues disaggregated by LOB: Year Ended December 31, 2020 2019 2018 MIS: Corporate finance (CFG) Investment-grade $ 636 $ 379 $ 271 High-yield 352 258 175 Bank loans 287 313 379 Other accounts (CFG) (1) 582 547 554 Total CFG 1,857 1,497 1,379 Structured finance (SFG) Asset-backed securities 98 99 107 RMBS 96 95 98 CMBS 61 81 78 Structured credit 105 148 196 Other accounts (SFG) 2 4 2 Total SFG 362 427 481 Financial institutions (FIG) Banking 355 320 290 Insurance 137 119 114 Managed investments 28 25 25 Other accounts (FIG) 10 12 13 Total FIG 530 476 442 Public, project and infrastructure finance (PPIF) Public finance / sovereign 250 222 185 Project and infrastructure 246 224 206 Total PPIF 496 446 391 Total ratings revenue 3,245 2,846 2,693 MIS Other 47 29 19 Total external revenue 3,292 2,875 2,712 Intersegment royalty 148 134 124 Total MIS 3,440 3,009 2,836 MA: Research, data and analytics (RD&A) 1,514 1,273 1,121 Enterprise risk solutions (ERS) 565 522 451 Professional services (PS) (2) — 159 159 Total external revenue 2,079 1,954 1,731 Intersegment revenue 7 9 12 Total MA 2,086 1,963 1,743 Eliminations (155) (143) (136) Total MCO $ 5,371 $ 4,829 $ 4,443 (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. (2) Subsequent to the divestiture of MAKS in 2019, revenue from the MALS reporting unit, which previous to 2020 was reported in the PS LOB, is now reported as part of the RD&A LOB. Prior periods have not been reclassified as the amounts were not material. The following table presents the Company’s revenues disaggregated by LOB and geographic area: Year Ended December 31, 2020 Year Ended December 31, 2019 Year Ended December 31, 2018 U.S. Non-U.S. Total U.S. Non-U.S. Total U.S. Non-U.S. Total MIS: Corporate finance $ 1,291 $ 566 $ 1,857 $ 968 $ 529 $ 1,497 $ 894 $ 485 $ 1,379 Structured finance 214 148 362 270 157 427 301 180 481 Financial institutions 250 280 530 200 276 476 194 248 442 Public, project and infrastructure finance 311 185 496 282 164 446 229 162 391 Total ratings revenue 2,066 1,179 3,245 1,720 1,126 2,846 1,618 1,075 2,693 MIS Other 2 45 47 1 28 29 1 18 19 Total MIS 2,068 1,224 3,292 1,721 1,154 2,875 1,619 1,093 2,712 MA: Research, data and analytics 668 846 1,514 558 715 1,273 481 640 1,121 Enterprise risk solutions 219 346 565 201 321 522 170 281 451 Professional services (PS) (1) — — — 64 95 159 60 99 159 Total MA 887 1,192 2,079 823 1,131 1,954 711 1,020 1,731 Total MCO $ 2,955 $ 2,416 $ 5,371 $ 2,544 $ 2,285 $ 4,829 $ 2,330 $ 2,113 $ 4,443 (1) Subsequent to the divestiture of MAKS in 2019, revenue from the MALS reporting unit, which previous to 2020 was reported in the PS LOB, is now reported as part of the RD&A LOB. Prior periods have not been reclassified as the amounts were not material. The following table presents the Company's reportable segment revenues disaggregated by segment and geographic region: Year Ended December 31, 2020 2019 2018 MIS: U.S. $ 2,068 $ 1,721 $ 1,619 Non-U.S.: EMEA 727 686 669 Asia-Pacific 345 320 300 Americas 152 148 124 Total Non-U.S. 1,224 1,154 1,093 Total MIS 3,292 2,875 2,712 MA: U.S. 887 823 711 Non-U.S.: EMEA 818 760 708 Asia-Pacific 226 231 193 Americas 148 140 119 Total Non-U.S. 1,192 1,131 1,020 Total MA 2,079 1,954 1,731 Total MCO $ 5,371 $ 4,829 $ 4,443 The tables below 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 outsourcing engagements 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. Year Ended December 31, 2020 2019 2018 Transaction Relationship Total Transaction Relationship Total Transaction Relationship Total Corporate Finance $ 1,401 $ 456 $ 1,857 $ 1,057 $ 440 $ 1,497 $ 949 $ 430 $ 1,379 75 % 25 % 100 % 71 % 29 % 100 % 69 % 31 % 100 % Structured Finance $ 175 $ 187 $ 362 $ 246 $ 181 $ 427 $ 310 $ 171 $ 481 48 % 52 % 100 % 58 % 42 % 100 % 64 % 36 % 100 % Financial Institutions $ 265 $ 265 $ 530 $ 212 $ 264 $ 476 $ 187 $ 255 $ 442 50 % 50 % 100 % 45 % 55 % 100 % 42 % 58 % 100 % Public, Project and Infrastructure Finance $ 337 $ 159 $ 496 $ 292 $ 154 $ 446 $ 238 $ 153 $ 391 68 % 32 % 100 % 65 % 35 % 100 % 61 % 39 % 100 % MIS Other $ 4 $ 43 $ 47 $ 2 $ 27 $ 29 $ 2 $ 17 $ 19 9 % 91 % 100 % 7 % 93 % 100 % 11 % 89 % 100 % Total MIS $ 2,182 $ 1,110 $ 3,292 $ 1,809 $ 1,066 $ 2,875 $ 1,686 $ 1,026 $ 2,712 66 % 34 % 100 % 63 % 37 % 100 % 62 % 38 % 100 % Research, data and analytics $ 74 $ 1,440 $ 1,514 $ 16 $ 1,257 $ 1,273 $ 18 $ 1,103 $ 1,121 5 % 95 % 100 % 1 % 99 % 100 % 2 % 98 % 100 % Enterprise risk solutions $ 118 $ 447 $ 565 $ 118 $ 404 $ 522 $ 99 $ 352 $ 451 21 % 79 % 100 % 23 % 77 % 100 % 22 % 78 % 100 % Professional services (1) $ — $ — $ — $ 159 $ — $ 159 $ 159 $ — $ 159 — % — % — % 100 % — % 100 % 100 % — % 100 % Total MA $ 192 $ 1,887 $ 2,079 $ 293 $ 1,661 $ 1,954 $ 276 $ 1,455 $ 1,731 9 % 91 % 100 % 15 % 85 % 100 % 16 % 84 % 100 % Total Moody’s Corporation $ 2,374 $ 2,997 $ 5,371 $ 2,102 $ 2,727 $ 4,829 $ 1,962 $ 2,481 $ 4,443 44 % 56 % 100 % 44 % 56 % 100 % 44 % 56 % 100 % (1) Subsequent to the divestiture of MAKS in 2019, the RD&A LOB now includes revenue from MALS beginning in the first quarter of 2020. MALS revenue was previously reported as part of the PS LOB and prior year revenue by LOB has not been reclassified as the amounts were not material. The following table presents the timing of revenue recognition: Year Ended December 31, 2020 Year Ended December 31, 2019 Year Ended December 31, 2018 MIS MA Total MIS MA Total MIS MA Total Revenue recognized at a point in time $ 2,182 $ 121 $ 2,303 $ 1,809 $ 132 $ 1,941 $ 1,686 $ 99 $ 1,785 Revenue recognized over time 1,110 1,958 3,068 1,066 1,822 2,888 1,026 1,632 2,658 Total $ 3,292 $ 2,079 $ 5,371 $ 2,875 $ 1,954 $ 4,829 $ 2,712 $ 1,731 $ 4,443 Unbilled Receivables, Deferred Revenue and Remaining Performance Obligations Unbilled receivables At December 31, 2020 and December 31, 2019, accounts receivable included approximately $361 million and $346 million, respectively, of unbilled receivables related to the MIS segment. Certain MIS arrangements contain contractual terms whereby the customers are billed in arrears for annual monitoring services and rating fees, 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 December 31, 2020 and December 31, 2019, accounts receivable included approximately $98 million and $53 million, respectively, of unbilled receivables 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 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 year ended December 31, 2020 are as follows: Year Ended December 31, 2020 MIS MA Total Balance at December 31, 2019 $ 322 $ 840 $ 1,162 Changes in deferred revenue Revenue recognized that was included in the deferred revenue balance at the beginning of the period (229) (800) (1,029) Increases due to amounts billable excluding amounts recognized as revenue during the period 215 792 1,007 Increases due to acquisitions during the period — 24 24 Effect of exchange rate changes 5 18 23 Total changes in deferred revenue (9) 34 25 Balance at December 31, 2020 $ 313 $ 874 $ 1,187 Deferred revenue - current $ 216 $ 873 $ 1,089 Deferred revenue - noncurrent $ 97 $ 1 $ 98 For the MA segment, for the year ended December 31, 2020, the increase in the deferred revenue balance was primarily due to acquisitions (RDC, Acquire Media, ZMFS, and Catylist) and changes in FX translation rates. Significant changes in the deferred revenue balances during the year ended December 31, 2019 are as follows: Year Ended December 31, 2019 MIS MA Total Balance at December 31, 2018 $ 325 $ 750 $ 1,075 Changes in deferred revenue Revenue recognized that was included in the deferred revenue balance at the beginning of the period (209) (714) (923) Increases due to amounts billable excluding amounts recognized as revenue during the period 202 789 991 Increases due to acquisitions during the period 3 6 9 Effect of exchange rate changes 1 9 10 Total changes in deferred revenue (3) 90 87 Balance at December 31, 2019 $ 322 $ 840 $ 1,162 Deferred revenue—current $ 214 $ 836 $ 1,050 Deferred revenue—noncurrent $ 108 $ 4 $ 112 For the MA segment, for the year ended December 31, 2019, the increase in the deferred revenue balance was primarily due to organic growth. Significant changes in the deferred revenue balances during the year ended December 31, 2018 are as follows: Year Ended December 31, 2018 MIS MA Total Balance at January 1, 2018 (after New Revenue Accounting Standard transition adjustment) $ 334 $ 612 $ 946 Changes in deferred revenue Revenue recognized that was included in the deferred revenue balance at the beginning of the period (218) (590) (808) Increases due to amounts billable excluding amounts recognized as revenue during the period 216 730 946 Increases due to acquisitions during the period — 16 16 Effect of exchange rate changes (7) (18) (25) Total changes in deferred revenue (9) 138 129 Balance at December 31, 2018 $ 325 $ 750 $ 1,075 Deferred revenue—current $ 207 $ 746 $ 953 Deferred revenue—noncurrent $ 118 $ 4 $ 122 For the MA segment, for the year ended December 31, 2018, the increase in the deferred revenue balance was primarily due to organic growth and the Reis acquisition in the fourth quarter of 2018. 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 December 31, 2020, the aggregate amount of the transaction price allocated to remaining performance obligations was approximately $130 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 of unsatisfied performance obligations relating to 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 December 31, 2020 as well as amounts not yet invoiced to customers as of December 31, 2020 largely reflecting future revenue related to signed multi-year arrangements for hosted and installed subscription-based products. As of December 31, 2020, the aggregate amount of the transaction price allocated to remaining performance obligations was approximately $2.2 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.

RECONCILIATION OF WEIGHTED AVER

RECONCILIATION OF WEIGHTED AVERAGE SHARES OUTSTANDING	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
RECONCILIATION OF WEIGHTED AVERAGE SHARES OUTSTANDING	RECONCILIATION OF WEIGHTED AVERAGE SHARES OUTSTANDING Below is a reconciliation of basic to diluted shares outstanding: Year Ended December 31, 2020 2019 2018 Basic 187.6 189.3 191.6 Dilutive effect of shares issuable under stock-based compensation plans 1.7 2.3 2.8 Diluted 189.3 191.6 194.4 Antidilutive options to purchase common shares and restricted stock as well as contingently issuable restricted stock which are excluded from the table above 0.2 0.2 0.4

ACCELERATED SHARE REPURCHASE PR

ACCELERATED SHARE REPURCHASE PROGRAM	12 Months Ended
	Dec. 31, 2020
Other Liabilities Disclosure [Abstract]
Accelerated Share Repurchase	ACCELERATED SHARE REPURCHASE PROGRAMOn February 20, 2019, the Company entered into an ASR agreement with a financial institution counterparty to repurchase $500 million of its outstanding common stock. The Company paid $500 million to the counterparty and received an initial delivery of 2.2 million shares of its common stock. Final settlement of the ASR agreement was completed on April 26, 2019 and the Company received delivery of an additional 0.6 million shares of the Company’s common stock.In total, the Company repurchased 2.8 million shares of the Company’s common stock during the term of the ASR Agreement, based on the volume-weighted average price (net of discount) of $180.33/share over the duration of the program. The initial share repurchase and final share settlement were recorded as a reduction to shareholders’ equity.

CASH EQUIVALENTS AND INVESTMENT

CASH EQUIVALENTS AND INVESTMENTS	12 Months Ended
	Dec. 31, 2020
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 December 31, 2020 Cost Gross Unrealized Gains Fair Value Balance sheet location Cash and cash equivalents Short-term investments Other assets Certificates of deposit and money market deposit accounts (1) $ 1,430 $ — $ 1,430 $ 1,325 $ 99 $ 6 Mutual funds $ 54 $ 6 $ 60 $ — $ — $ 60 As of December 31, 2019 Cost Gross Unrealized Gains Fair Value Balance sheet location Cash and cash equivalents Short-term investments Other assets Certificates of deposit and money market deposit accounts (1) $ 971 $ — $ 971 $ 866 $ 95 $ 10 Mutual funds $ 3 $ — $ 3 $ — $ 3 $ — (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 In addition, the Company invested in Corporate-Owned Life Insurance (COLI) in the first quarter of 2020. As of December 31, 2020, the contract value of the COLI was $17 million.

DERIVATIVE INSTRUMENTS AND HEDG

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES	12 Months Ended
	Dec. 31, 2020
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: Interest Rate Swaps Designated as Fair Value Hedges 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 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: Nature of Swap Notional Amount Floating Interest Rate Hedged Item 2020 2019 2012 Senior Notes due 2022 Pay Floating/Receive Fixed $ 330 $ 330 3-month LIBOR 2017 Senior Notes due 2021 (1) Pay Floating/Receive Fixed $ — $ 500 3-month LIBOR 2017 Senior Notes due 2023 Pay Floating/Receive Fixed $ 250 $ 250 3-month LIBOR 2017 Senior Notes due 2028 (2) Pay Floating/Receive Fixed $ 500 $ — 3-month LIBOR 2020 Senior Notes due 2025 (3) Pay Floating/Receive Fixed $ 300 $ — 6-month LIBOR Total $ 1,380 $ 1,080 (1) These interest rates swaps were terminated in conjunction with the repayment of the 2017 Senior Notes due 2021 in the third quarter of 2020. (2) These interest rate swaps were executed in the first quarter of 2020. (3) These interest rate swaps were executed in the third quarter of 2020. Refer to Note 18 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 Year Ended December 31, 2020 2019 2018 Interest expense, net $ (205) $ (208) $ (215) Location on Consolidated Statements of Operations Net interest settlements and accruals on interest rate swaps Interest expense, net $ 19 $ 3 $ (2) Fair value changes on interest rate swaps Interest expense, net 47 25 2 Fair value changes on hedged debt Interest expense, net $ (47) $ (25) $ (2) 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: 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 December 31, 2019 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 931 Based on 3-month EURIBOR 1,080 Based on 3-month USD LIBOR Total € 2,010 $ 2,300 During the first quarter of 2020, the Company executed €450 million notional value of cross-currency swaps (set to expire in 2026). During the third quarter of 2020, the Company early-terminated €422.5 million notional value of cross-currency swaps (set to expire in 2021), resulting in immaterial cash proceeds. As of December 31, 2020, these hedges will expire and the notional amounts will be settled as follows unless terminated early at the discretion of the Company: Year Ending December 31, 2021 € 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 and GBP 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: December 31, 2020 December 31, 2019 Notional amount of net investment hedges Sell Buy Sell Buy Contract to sell EUR for USD € 524 $ 627 — — Contract to sell GBP for EUR £ 134 € 148 — — These forward contracts both will expire in February 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 AOCI. The loss on the Treasury rate lock will be reclassified from AOCI 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 provides information on the gains/(losses) on the Company’s net investment and cash flow hedges: Amount of Gain/(Loss) Amount of Gain/(Loss) Gain/(Loss) Recognized in Derivative and Non-Derivative Instruments in Net Investment Hedging Relationships Year Ended December 31, Year Ended December 31, Year Ended December 31, 2020 2019 2018 2020 2019 2018 2020 2019 2018 FX forward contracts $ (14) $ 4 $ — $ — $ 2 $ — $ — $ — $ — Cross currency swaps (165) 29 12 — — — 50 52 11 Long-term debt (95) (7) (1) 22 — — — — — — Total net investment hedges $ (274) $ 26 $ 34 $ — $ 2 $ — $ 50 $ 52 $ 11 Derivatives in Cash Flow Hedging Relationships Cross currency swap $ — $ — $ 2 $ — $ — $ — $ — $ — $ — Interest rate contracts (51) — (2) (2) — — — — — Total cash flow hedges (51) — — (2) — — — — — Total $ (325) $ 26 $ 34 $ (2) $ 2 $ — $ 50 $ 52 $ 11 (1) Due to the Company's adoption of ASU 2018-02 during 2019, $3 million related to the tax effect of this net investment hedge was reclassified to retained earnings. The cumulative amount of net investment hedge and cash flow hedge gains (losses) remaining in AOCI is as follows: Cumulative Gains/(Losses), net of tax December 31, 2020 December 31, 2019 Net investment hedges Cross currency swaps $ (124) $ 41 FX forwards 12 26 Long-term debt (108) (13) Total net investment hedges (220) 54 Cash flow hedges Interest Rate Contract (51) (2) Cross-currency swap 2 2 Total cash flow hedges (49) — Total net (loss) gain in AOCI $ (269) $ 54 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 (expense) 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 February 2021. The following table summarizes the notional amounts of the Company’s outstanding foreign exchange forwards: December 31, 2020 December 31, 2019 Notional Amount of Currency Pair: Sell Buy Sell Buy Contracts to sell USD for GBP $ 295 £ 222 $ 235 £ 178 Contracts to sell USD for Japanese Yen $ 15 ¥ 1,600 $ 29 ¥ 3,200 Contracts to sell USD for Canadian dollars $ 107 C$ 140 $ 83 C$ 110 Contracts to sell USD for Singapore dollars $ 59 S$ 79 $ 41 S$ 56 Contracts to sell USD for Euros $ 447 € 376 $ 421 € 378 Contracts to sell Euros for GBP € 135 £ 121 € 25 £ 21 Contracts to sell USD for Russian Ruble $ 13 ₽ 1,000 $ — ₽ — Contracts to sell USD for Indian Rupee $ 18 ₹ 1,350 $ — ₹ — NOTE: € = Euro, £ = British pound, S$ = Singapore dollar, $ = U.S. dollar, ¥ = Japanese yen, C$ = Canadian dollar, ₽ = Russian Ruble, ₹= Indian Rupee The following table summarizes the impact to the consolidated statements of operations relating to the net gain (loss) on the Company’s derivatives which are not designated as hedging instruments: Year Ended December 31, Derivatives Not Designated as Accounting Hedges Location on Statement of Operations 2020 2019 2018 FX forwards Other non-operating expense, net $ 41 $ (11) $ (52) The table below shows the classification between assets and liabilities on the Company’s consolidated balance sheets for the fair value of derivative instruments 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 December 31, 2020 December 31, 2019 Assets: Derivatives designated as accounting hedges: Cross-currency swaps designated as net investment hedges Other assets $ — $ 56 Interest rate swaps designated as fair value hedges Other assets 57 27 Total derivatives designated as accounting hedges 57 83 Derivatives not designated as accounting hedges: FX forwards on certain assets and liabilities Other current assets 31 9 Total assets $ 88 $ 92 Liabilities: Derivatives designated as accounting hedges: FX forwards designated as net investment hedges Accounts payable and accrued liabilities $ 16 $ — Cross-currency swaps designated as net investment hedges Accounts payable and accrued liabilities 23 — Cross-currency swaps designated as net investment hedges Other liabilities 144 — Interest rate swaps Other liabilities 1 — Total derivatives designated as accounting hedges 184 — Non-derivative instrument designated as accounting hedge: Long-term debt designated as net investment hedge Long-term debt 1,530 1,403 Derivatives not designated as accounting hedges: FX forwards on certain assets and liabilities Accounts payable and accrued liabilities 2 — Total liabilities $ 1,716 $ 1,403

PROPERTY AND EQUIPMENT, NET

PROPERTY AND EQUIPMENT, NET	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
PROPERTY AND EQUIPMENT, NET	PROPERTY AND EQUIPMENT, NET Property and equipment, net consisted of: December 31, 2020 2019 Office and computer equipment (3 - 10 year estimated useful life) $ 260 $ 221 Office furniture and fixtures (3 - 10 year estimated useful life) 49 51 Internal-use computer software (1 - 10 year estimated useful life) 666 619 Leasehold improvements and building (1 - 21 year estimated useful life) 231 240 Total property and equipment, at cost 1,206 1,131 Less: accumulated depreciation and amortization (928) (839) Total property and equipment, net $ 278 $ 292 Depreciation and amortization expense related to the above assets was $96 million, $97 million, and $90 million for the years ended December 31, 2020, 2019 and 2018, respectively.

ACQUISITIONS AND DIVESTITURE

ACQUISITIONS AND DIVESTITURE	12 Months Ended
	Dec. 31, 2020
Business Combinations [Abstract]
ACQUISITIONS AND DIVESTITURE	ACQUISITIONS AND DIVESTITUREThe following is a discussion of material acquisitions completed by the Company. 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. Pro forma financial information has not been presented for any of the acquired businesses described below as the financial results of these acquired entities are not material relative to the Company’s financial results. 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: (Amounts in millions) Current assets $ 24 Intangible assets: Customer relationships (25 year weighted average life) $ 174 Database (10 year weighted average life) 86 Product technology (4 year weighted average life) 17 Trade name (3 year weighted average 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. Additionally, current assets include 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. Reis On October 15, 2018, a subsidiary of the Company acquired 100% of Reis, Inc., a provider of commercial real estate market information and analytical tools to real estate professionals. The cash payment of $278 million was funded with cash on hand. The acquisition further expands Moody’s Analytics’ network of data and analytics providers in the commercial real estate space. Shown below is the purchase price allocation, which summarizes the fair value of the assets and liabilities assumed, at the date of acquisition: (Amounts in millions) Current assets $ 32 Property and equipment 4 Intangible assets: Customer relationships (14 year weighted average life) $ 77 Database (5 year weighted average life) 13 Product technology (7 year weighted average life) 10 Trade name (10 year weighted average life) 4 Total intangible assets (12 year weighted average life) 104 Goodwill 183 Deferred tax assets 13 Liabilities: Deferred revenue $ (14) Accounts payable and accrued liabilities (20) Deferred tax liabilities (24) Total liabilities (58) Net assets acquired $ 278 Current assets in the table above include acquired cash of $24 million. Additionally, current assets include accounts receivable of approximately $6 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 Reis, 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. Reis is a separate reporting unit for the purposes of the Company’s annual goodwill impairment assessment. Transaction costs Transaction costs directly related to the Reis acquisition were not material. Other Acquisitions Below is a discussion of acquisitions executed by the Company during the years ended December 31, 2020, 2019 and 2018 for which the purchase prices were not individually material and the near term impact to the Company's financial statements (both individually and in the aggregate) is not expected to be material. The following businesses were acquired in 2019 and operate in the MIS reportable segment: In April 2019, the Company acquired a majority stake in Vigeo Eiris, a provider of Environmental, Social and Governance (ESG) research, data and assessments. The acquisition furthers Moody’s objective of promoting global standards for ESG for use by market participants. During 2020, the Company increased its stake in Vigeo Eiris from 69.2% to 99.8%. Vigeo Eiris revenue is reported in the MIS Other LOB. In July 2019, the Company acquired a majority stake in Four Twenty Seven, Inc., a provider of data, intelligence, and analysis related to physical climate risks. Four Twenty Seven Climate Solutions revenue is reported in the MIS Other LOB. In connection with this transaction, Moody's recognized a Redeemable Non-controlling Interest for the portion of Four Twenty Seven which the Company does not own. This Redeemable Non-controlling interest was not material. The following businesses were acquired in 2020 and operate in the MA reportable segment: During the fourth quarter of 2020, the Company acquired three additional businesses within the MA reportable segment, which were not individually material, but are material in aggregate, to Moody's consolidated financial statements: – In December 2020, the Company acquired 100% of Catylist, Inc., a provider of commercial real estate solutions for brokers. Catylist revenue is reported in the RD&A LOB. – In December 2020, the Company acquired 100% of ZM Financial Systems, a provider of financial management software for the U.S. banking sector. ZMFS revenue is reported in the ERS LOB. – In October 2020, the Company acquired 100% of Acquire Media, an aggregator and distributor of curated real-time news, multimedia, data, and alerts. AM revenue is reported in the RD&A LOB. The aggregate consideration transferred for the aforementioned acquisitions of $205 million was funded by cash on hand, and is subject to customary post-closing completion adjustments that are not expected to be material. The Company has performed preliminary valuation analyses of the fair market value of assets and liabilities of the acquired businesses. The final purchase price allocations will be determined when the Company has completed and fully reviewed the detailed valuations. The final allocations could differ materially from the preliminary allocations. The final allocations may include changes in allocations to acquired intangible assets as well as goodwill and other changes to assets and liabilities including tax liabilities. The estimated useful lives of acquired intangible assets are also preliminary. The following table summarizes the aggregate preliminary estimates of fair value of the assets acquired and liabilities assumed as of the respective closing dates for each acquisition. (Amounts in millions) Current assets $ 5 Intangible assets: Customer relationships (18 year weighted average life) $ 47 Product technology (8 year weighted average life) 23 Database (10 year weighted average life) 8 Trade name (14 year weighted average life) 4 Total intangible assets (14 year weighted average life) 82 Goodwill 131 Other assets 3 Total assets acquired 221 Current liabilities 8 Long-term liabilities 8 Total liabilities assumed 16 Net assets acquired $ 205 The following businesses were acquired in 2019 and 2018 and operate in the MA reportable segment: – In October 2019, the Company acquired the ABS Suite business, which includes a software platform used by issuers and trustees for the administration of asset-backed and mortgage-backed securities programs. ABS Suite revenue is reported in the RD&A LOB. – In July 2019, the Company acquired 100% of RiskFirst, a company providing risk analytic solutions for the asset management and pension fund communities. RiskFirst revenue is reported in the ERS LOB. – In August 2018, the Company acquired 100% of Omega Performance, a provider of online credit training. Revenue for Omega Performance is reported in the PS LOB. Divestiture On November 8, 2019, the Company completed the sale of MAKS to Equistone Partners Europe Limited (Equistone), a European private equity firm for $227 million in net cash proceeds. This divestiture resulted in a loss of $23 million ($9 million in 2020 and $14 million in 2019), which included $32 million of currency translation losses reclassified from AOCI to the statement of operations. Additionally, in connection with this divestiture, the Company has recorded certain indemnification provisions. These provisions totaled $33 million and $43 million as of December 31, 2020 and 2019, respectively. These amounts are included in other liabilities at December 31, 2020 and 2019 in the consolidated balance sheets of the Company.

GOODWILL AND OTHER ACQUIRED INT

GOODWILL AND OTHER ACQUIRED INTANGIBLE ASSETS	12 Months Ended
	Dec. 31, 2020
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: Year Ended December 31, 2020 MIS MA Consolidated Gross Accumulated Net Gross Accumulated Net Gross Accumulated Net Balance at beginning of year $ 315 $ — $ 315 $ 3,419 $ (12) $ 3,407 $ 3,734 $ (12) $ 3,722 Additions/ adjustments (1) (2) — (2) 628 — 628 626 — 626 Foreign currency translation adjustments (2) — (2) 210 — 210 208 — 208 Ending Balance $ 311 $ — $ 311 $ 4,257 $ (12) $ 4,245 $ 4,568 $ (12) $ 4,556 Year Ended December 31, 2019 MIS MA Consolidated Gross Accumulated Net Gross Accumulated Net Gross Accumulated Net Balance at beginning of year $ 258 $ — $ 258 $ 3,535 $ (12) $ 3,523 $ 3,793 $ (12) $ 3,781 Additions/ adjustments (2) 53 — 53 61 — 61 114 — 114 Foreign currency translation adjustments 4 — 4 (14) — (14) (10) — (10) Divestiture of MAKS $ (163) $ (163) $ (163) $ — $ (163) Ending balance $ 315 $ — $ 315 $ 3,419 $ (12) $ 3,407 $ 3,734 $ (12) $ 3,722 (1) The 2020 additions/adjustments for the MA segment in the table above relate to the acquisitions of RDC, AM, ZMFS, and Catylist. (2) The 2019 additions/adjustments for the MIS segment in the table above relate to the acquisitions of Vigeo Eiris and Four Twenty Seven. The 2019 additions/adjustments for the MA segment in the table above relate to the acquisitions of RiskFirst and ABS Suite. Acquired intangible assets and related amortization consisted of: December 31, 2020 2019 Customer relationships $ 1,623 $ 1,325 Accumulated amortization (313) (235) Net customer relationships 1,310 1,090 Trade secrets 30 30 Accumulated amortization (29) (29) Net trade secrets 1 1 Software/product technology 417 372 Accumulated amortization (166) (131) Net software/product technology 251 241 Trade names 161 150 Accumulated amortization (38) (30) Net trade names 123 120 Other (1) 192 80 Accumulated amortization (53) (34) Net other 139 46 Total $ 1,824 $ 1,498 (1) Other intangible assets primarily consist of databases, covenants not to compete, and acquired ratings methodologies and models. Amortization expense relating to acquired intangible assets is as follows: Year Ended December 31, 2020 2019 2018 Amortization expense $ 124 $ 103 $ 102 Estimated future annual amortization expense for intangible assets subject to amortization is as follows: Year Ending December 31, 2021 $ 131 2022 131 2023 126 2024 119 2025 117 Thereafter 1,200 Total estimated future amortization $ 1,824 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 annual report on Form 10-K, 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	12 Months Ended
	Dec. 31, 2020
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. On July 29, 2020, the chief executive officer of Moody’s approved a restructuring program (the “2020 Real Estate Rationalization Restructuring Program”) primarily in response to the COVID-19 pandemic which revolves around the rationalization and exit of certain real estate leases. The exit from certain leased office space began in the third quarter of 2020 and is anticipated to be substantially completed during the first half of 2021. The 2020 Real Estate Rationalization Restructuring Program primarily reflects non-cash charges related to the impairment of operating lease right-of-use assets and leasehold improvements. The 2020 Restructuring Program is expected to result in an estimated annualized savings of approximately $5 to $6 million a year and is substantially complete at December 31, 2020. On October 26, 2018, the chief executive officer of Moody’s approved a restructuring program (the “2018 Restructuring Program”) that the Company estimates will result in annualized savings of approximately $60 million per year. The 2018 Restructuring Program, the scope of which was expanded in the second quarter of 2019, is substantially complete at December 31, 2020. The 2018 Restructuring Program included relocation of certain functions from high-cost to lower-cost jurisdictions, a reduction of staff, including from acquisitions and pursuant to a review of the business criticality of certain positions, and the rationalization and exit of certain real estate due to consolidation of various business activities. The exit from certain leased office space began in the fourth quarter of 2018 and resulted in $50 million of the charges to either terminate or sublease the affected real estate leases. The 2018 Restructuring Program also included $55 million of personnel-related restructuring charges, an amount that includes severance and related costs primarily determined under the Company’s existing severance plans. Cash outlays associated with the employee termination cost component of the 2018 Restructuring Program were $55 million. Total expenses included in the accompanying consolidated statements of operations relating to the Company's restructuring programs are as follows: Year Ended December 31, 2020 2019 2018 2018 Restructuring Program $ (4) $ 60 $ 49 2020 Real Estate Rationalization Restructuring Program 36 — — 2020 MA Strategic Reorganization Restructuring Program 18 — — Total Restructuring $ 50 $ 60 $ 49 Changes to the restructuring liability were as follows: Employee Termination Costs Contract Termination Costs Total Restructuring Liability Balance as of December 31, 2018 $ 30 $ 12 $ 42 2018 Restructuring Program (1) : Adoption of New Lease Accounting Standard (2) — (11) (11) Cost incurred and adjustments 26 5 31 Cash payments and adjustments (35) (3) (38) Balance as of December 31, 2019 $ 21 $ 3 $ 24 2018 Restructuring Program: Cost incurred and adjustments (4) — (4) Cash payments and adjustments (17) (1) (18) 2020 Real Estate Rationalization Restructuring Program (3) : Cost incurred and adjustments — 1 1 2020 MA Strategic Reorganization Restructuring Program: Cost incurred and adjustments 18 — 18 Balance as of December 31, 2020 $ 18 $ 3 $ 21 Cumulative expense incurred to date 2018 Restructuring Program $ 55 $ 50 2020 Real Estate Rationalization Restructuring Program: $ — $ 36 2020 MA Strategic Reorganization Restructuring Program: $ 18 $ — (1) The liability excludes $4 million of non-cash acceleration of amortization of leasehold improvements relating to the rationalization and exit of certain real estate leases as well as $25 million of ROU Asset impairment charges for the year ended December 31, 2019. The fair value of the impaired ROU Assets was determined by utilizing the present value of the estimated future cash flows attributable to the assets. The fair value of those ROU assets subsequent to the impairment was $18 million, and is categorized as Level 3 within the ASC Topic 820 fair value hierarchy. (2) Upon the adoption of the New Lease Accounting Standard (3) The liability excludes $13 million of non-cash acceleration of amortization of leasehold improvements relating to the rationalization and exit of certain real estate leases as well as $21 million of ROU Asset impairment charges for the year ended December 31, 2020. The fair value of the impaired ROU Assets was determined by utilizing the present value of the estimated future cash flows attributable to the assets. The fair value of those ROU assets subsequent to the impairment was $10 million, and is categorized as Level 3 within the ASC Topic 820 fair value hierarchy. As of December 31, 2020, a majority of the remaining $21 million restructuring liability is expected to be paid out through 2022.

FAIR VALUE

FAIR VALUE	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
FAIR VALUE	FAIR VALUE The table below presents information about items which are carried at fair value on a recurring basis at December 31, 2020 and 2019: 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 Fair Value Measurement as of December 31, 2019 Description Balance Level 1 Level 2 Assets: Derivatives (1) $ 92 $ — $ 92 Mutual funds 3 3 — Total $ 95 $ 3 $ 92 (1) Represents FX forwards on certain assets and liabilities as well as interest rate swaps and cross-currency swaps as more fully described in Note 7 to the 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: 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 INFORMATION

OTHER BALANCE SHEET INFORMATION	12 Months Ended
	Dec. 31, 2020
Other Balance Sheet Information [Abstract]
OTHER BALANCE SHEET INFORMATION	OTHER BALANCE SHEET INFORMATION The following tables contain additional detail related to certain balance sheet captions: December 31, 2020 2019 Other current assets: Prepaid taxes $ 94 $ 79 Prepaid expenses 91 71 Capitalized costs to obtain and fulfill sales contracts 93 91 Foreign exchange forwards on certain assets and liabilities 31 9 Other 74 80 Total other current assets $ 383 $ 330 December 31, 2020 2019 Other assets: Investments in non-consolidated affiliates $ 135 $ 117 Deposits for real-estate leases 19 13 Indemnification assets related to acquisitions 15 16 Mutual funds and fixed deposits 66 10 Company owned life insurance (at contract value) 17 — Costs to obtain sales contracts 134 119 Derivative instruments designated as accounting hedges 57 83 Pension and other retirement employee benefits 21 — Other 51 31 Total other assets $ 515 $ 389 December 31, 2020 2019 Accounts payable and accrued liabilities: Salaries and benefits $ 197 $ 152 Incentive compensation 226 208 Customer credits, advanced payments and advanced billings 42 28 Dividends 11 7 Professional service fees 53 43 Interest accrued on debt 82 63 Accounts payable 39 38 Income taxes 128 73 Pension and other retirement employee benefits 45 7 Accrued royalties 19 25 Foreign exchange forwards on certain assets and liabilities 2 — Restructuring liability 18 21 Derivative instruments designated as accounting hedges 39 — Other 138 108 Total accounts payable and accrued liabilities $ 1,039 $ 773 December 31, 2020 2019 Other liabilities: Pension and other retirement employee benefits $ 244 $ 299 Interest accrued on UTPs 113 82 MAKS indemnification provisions 33 43 Income tax liability – non-current portion 18 51 Derivative instruments designated as accounting hedges 145 — Restructuring liability 3 3 Other 34 26 Total other liabilities $ 590 $ 504

COMPREHENSIVE INCOME AND ACCUMU

COMPREHENSIVE INCOME AND ACCUMULATED OTHER COMPREHENSIVE INCOME	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
COMPREHENSIVE INCOME AND ACCUMULATED OTHER COMPREHENSIVE INCOME	COMPREHENSIVE INCOME AND ACCUMULATED OTHER COMPREHENSIVE INCOME The following table provides details about the reclassifications out of AOCI: Year Ended December 31, Location in the consolidated 2020 2019 2018 Currency translation adjustment losses Sale of foreign subsidiaries $ — $ (32) $ — Loss pursuant to the divestiture of MAKS Total currency translation adjustment losses — (32) — Losses on cash flow hedges Interest rate contract (3) — — Other non-operating income (expense), net Income tax effect of item above 1 — — Provision for income taxes Total net losses on cash flow hedges (2) — — Gains on net investment hedges Cross currency swaps 1 — — Other non-operating income (expense), net FX forwards — 3 — Other non-operating income (expense), net Total before income taxes 1 3 — Income tax effect of item above — (1) — Provision for income taxes Total net gains on net investment hedges 1 2 — Pension and other retirement benefits Amortization of actuarial losses and prior service costs included in net income (6) (3) (5) Other non-operating income (expense), net Accelerated recognition of loss due to settlement (2) — — Other non-operating income (expense), net Total before income taxes (8) (3) (5) Income tax effect of item above 2 1 1 Provision for income taxes Total pension and other retirement benefits (6) (2) (4) Total losses included in Net Income attributable to reclassifications out of AOCI $ (7) $ (32) $ (4) The following table shows changes in AOCI by component (net of tax): Year Ended December 31, 2020 Pension and Other Retirement Benefits Gains / (Losses) on 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 (32) (51) 356 (273) — Amounts reclassified from AOCI 6 2 — (1) 7 Other comprehensive income/(loss) (26) (49) 356 (274) 7 Balance December 31, 2020 $ (118) $ (49) $ (45) $ (220) $ (432) Year Ended December 31, 2019 Pension and Other Retirement Benefits Gains / (Losses) on Cash Flow Hedges Foreign Currency Translation Adjustments Net Investment Hedges Total Balance December 31, 2018 $ (53) $ — $ (406) $ 33 $ (426) Adoption of ASU 2018-02 (17) — — (3) (20) Other comprehensive income/(loss) before reclassifications (24) — (27) 26 (25) Amounts reclassified from AOCI 2 — 32 (2) 32 Other comprehensive income/(loss) (39) — 5 21 (13) Balance December 31, 2019 $ (92) $ — $ (401) $ 54 $ (439) Year Ended December 31, 2018 Pension and Other Retirement Benefits Gains / (Losses) on Cash Flow Hedges Foreign Currency Translation Adjustments Net Investment Hedges Gains on Available for Sale Securities Total Balance December 31, 2017 $ (61) $ 1 $ (113) $ (1) $ 2 $ (172) Adoption of ASU 2016-01 — — — — (2) (2) Other comprehensive income/(loss) before reclassifications 4 (1) (293) 34 — (256) Amounts reclassified from AOCI 4 — — — — 4 Other comprehensive income/(loss) 8 (1) (293) 34 (2) (254) Balance December 31, 2018 $ (53) $ — $ (406) $ 33 $ — $ (426)

PENSION AND OTHER RETIREMENT BE

PENSION AND OTHER RETIREMENT BENEFITS	12 Months Ended
	Dec. 31, 2020
Retirement Benefits [Abstract]
PENSION AND OTHER RETIREMENT BENEFITS	PENSION AND OTHER RETIREMENT BENEFITS U.S. Plans Moody’s maintains funded and unfunded noncontributory Defined Benefit Pension Plans ("DBPPs"). The DBPPs provide defined benefits using a cash balance formula based on years of service and career average salary 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”. 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 benefit formulas. Following is a summary of changes in benefit obligations and fair value of plan assets for the Retirement Plans for the years ended December 31: Pension Plans Other Retirement Plans 2020 2019 2020 2019 Change in benefit obligation: Benefit obligation, beginning of the period $ (589) $ (508) $ (42) $ (32) Service cost (17) (17) (3) (3) Interest cost (17) (21) (1) (1) Plan participants’ contributions — — (1) (1) Benefits paid 22 21 2 1 Actuarial gain (loss) 6 (3) 2 — Assumption changes (68) (61) (5) (6) Benefit obligation, end of the period $ (663) $ (589) $ (48) $ (42) Change in plan assets: Fair value of plan assets, beginning of the period $ 395 $ 348 $ — $ — Actual return on plan assets 45 60 — — Benefits paid (22) (21) (2) (1) Employer contributions 110 8 1 — Plan participants’ contributions — — 1 1 Fair value of plan assets, end of the period $ 528 $ 395 $ — $ — Funded Status of the plans $ (135) $ (194) $ (48) $ (42) Amounts recorded on the consolidated balance sheets: Pension and retirement benefits asset – non current $ 21 $ — $ — $ — Pension and retirement benefits liability – current (44) (6) (1) (1) Pension and retirement benefits liability – non current (112) (188) (47) (41) Net amount recognized $ (135) $ (194) $ (48) $ (42) Accumulated benefit obligation, end of the period $ (601) $ (529) The increase in the benefit obligation in both 2020 and 2019 primarily resulted from reductions in discount rates, partially offset by a decrease related to lower cash balance conversion interest rates. The following information is for those pension plans with an accumulated benefit obligation in excess of plan assets: December 31, 2020 2019 Aggregate projected benefit obligation $ 156 $ 589 Aggregate accumulated benefit obligation $ 138 $ 529 Aggregate fair value of plan assets $ — $ 395 The following table summarizes the pre-tax net actuarial losses and prior service cost recognized in AOCI for the Company’s Retirement Plans as of December 31: Pension Plans Other Retirement Plans 2020 2019 2020 2019 Net actuarial losses $ (144) $ (116) $ (8) $ (6) Net prior service credits 3 4 — — Total recognized in AOCI – pretax $ (141) $ (112) $ (8) $ (6) Net periodic benefit expenses recognized for the Retirement Plans for years ended December 31: Pension Plans Other Retirement Plans 2020 2019 2018 2020 2019 2018 Components of net periodic expense Service cost $ 17 $ 17 $ 19 $ 3 $ 3 $ 3 Interest cost 17 21 17 1 1 1 Expected return on plan assets (20) (20) (15) — — — Amortization of net actuarial loss and prior service credits from earlier periods 7 4 6 — — — Net periodic expense $ 21 $ 22 $ 27 $ 4 $ 4 $ 4 In addition to the amounts reflected in the above table, during the year ended December 31, 2020, the Company recognized a loss of $2 million on settlement of a pension obligation. The following table summarizes the pre-tax amounts recorded in OCI related to the Company’s Retirement Plans for the years ended December 31: Pension Plans Other Retirement Plans 2020 2019 2018 2020 2019 2018 Amortization of net actuarial losses and prior service credit $ 7 $ 4 $ 6 $ — $ — $ — Settlement loss 2 — — — — — Net actuarial (loss)/gain arising during the period (37) (24) 2 (3) (6) 3 Total recognized in OCI – pre-tax $ (28) $ (20) $ 8 $ (3) $ (6) $ 3 ADDITIONAL INFORMATION: Assumptions—Retirement Plans Weighted-average assumptions used to determine benefit obligations at December 31: Pension Plans Other Retirement Plans 2020 2019 2020 2019 Discount rate 2.24 % 3.04 % 2.30 % 3.05 % Rate of compensation increase 3.62 % 3.64 % — — Weighted-average assumptions used to determine net periodic benefit expense for years ended December 31: Pension Plans Other Retirement Plans 2020 2019 2018 2020 2019 2018 Discount rate 3.04 % 4.07 % 3.46 % 3.05 % 4.10 % 3.45 % Expected return on plan assets 4.45 % 5.65 % 4.50 % — — — Rate of compensation increase 3.64 % 3.69 % 3.71 % — — — Cash balance plan interest crediting rate 4.50 % 4.50 % 4.50 % — — — The expected rate of return on plan assets represents the Company’s best estimate of the long-term return on plan assets and is determined by using a building block approach, which generally weighs the underlying long-term expected rate of return for each major asset class based on their respective allocation target within the plan portfolio, net of plan paid expenses. As the assumption reflects a long-term time horizon, the plan performance in any one particular year does not, by itself, significantly influence the Company’s evaluation. For 2020, the expected rate of return used in calculating the net periodic benefit costs was 4.45%. For 2021, the Company’s expected rate of return assumption is 5.45% to reflect the Company’s current view of long-term capital market outlook. In addition, the Company has updated its mortality assumption by adopting the newly released mortality improvement scale MP-2020 to accompany the Pri2012 mortality tables to reflect the latest information regarding future mortality expectations by the Society of Actuaries. Plan Assets Moody’s investment objective for the assets in the funded pension plan is to earn total returns that will minimize future contribution requirements over the long-term within a prudent level of risk. The Company works with its independent investment consultants to determine asset allocation targets for its pension plan investment portfolio based on its assessment of business and financial conditions, demographic and actuarial data, funding characteristics, and related risk factors. Other relevant factors, including historical and forward looking views of inflation and capital market returns, are also considered. Risk management practices include monitoring plan asset performance, diversification across asset classes and investment styles and periodic rebalancing toward asset allocation targets. The Company’s Asset Management Committee is responsible for overseeing the investment activities of the plan, which includes selecting acceptable asset classes, defining allowable ranges of holdings by asset class and by individual investment managers, defining acceptable securities within each asset class, and establishing investment performance expectations. Ongoing monitoring of the plan includes reviews of investment performance and managers on a regular basis, annual liability measurements, and periodic asset/liability studies. The Company’s investment policy uses risk-controlled investment strategies by increasing the plan’s asset allocation to fixed income securities and specifying ranges of acceptable target allocation by asset class based on different levels of the plan’s accounting funded status. In addition, the investment policy also requires the investment-grade fixed income assets be rebalanced between shorter and longer duration bonds as the interest rate environment changes. This investment policy is designed to help protect the plan’s funded status and to limit volatility of the Company’s contributions. Based on the policy, the Company’s current target asset allocation is approximately 33% (range of 28% to 38%) in equity securities, 62% (range of 57% to 67%) in fixed income securities and 5% (range of 2% to 8%) in other investments and the plan will use a combination of active and passive investment strategies and different investment styles for its investment portfolios within each asset class. The plan’s equity investments are diversified across U.S. and non-U.S. stocks of small, medium and large capitalization. The plan’s fixed income investments are diversified principally across U.S. and non-U.S. government and corporate bonds, which are expected to help reduce plan exposure to interest rate variation and to better align assets with obligations. The plan also invests in other fixed income investments such as debts rated below investment grade, emerging market debt, and convertible securities. The plan’s other investment, which is made through a private real estate debt fund, is expected to provide additional diversification benefits and absolute return enhancement to the plan assets. Fair value of the assets in the Company’s funded pension plan by asset category at December 31, 2020 and 2019 are as follows: Fair Value Measurement as of December 31, 2020 Asset Category Balance Level 1 Level 2 Measured using NAV practical expedient (1) % of total Cash and cash equivalent $ 4 $ — $ 4 $ — 1 % Common/collective trust funds—equity securities U.S. large-cap 143 — 143 — 27 % U.S. small and mid-cap 28 — 28 — 5 % Emerging markets 32 — 32 — 6 % Total equity investments 203 — 203 — 38 % Emerging markets bond fund 32 — — 32 6 % Common/collective trust funds—fixed income securities Intermediate-term investment grade U.S. government/ corporate bonds 214 — 214 — 41 % Mutual funds U.S. Treasury Inflation-Protected Securities (TIPs) 23 23 — — 4 % Convertible securities 16 16 — — 3 % Private investment fund—high yield securities 12 — — 12 2 % Total fixed-income investments 297 39 214 44 56 % Other investment—private real estate fund 24 — — 24 5 % Total Assets $ 528 $ 39 $ 421 $ 68 100 % Fair Value Measurement as of December 31, 2019 Asset Category Balance Level 1 Level 2 Measured using NAV practical expedient (1) % of total Cash and cash equivalent $ 2 $ — $ 2 $ — 1 % Common/collective trust funds—equity securities U.S. large-cap 140 — 140 — 35 % U.S. small and mid-cap 21 — 21 — 5 % Emerging markets 29 — 29 — 7 % Total equity investments 190 — 190 — 48 % Emerging markets bond fund 15 — — 15 4 % Common/collective trust funds—fixed income securities Intermediate-term investment grade U.S. government/ corporate bonds 119 — 119 — 30 % U.S. Treasury Inflation-Protected Securities (TIPs) 22 22 — — 6 % Private investment fund—convertible securities 12 12 — — 3 % Private investment fund—high yield securities 12 — — 12 3 % Total fixed-income investments 180 34 119 27 46 % Other investment—private real estate debt fund 23 — — 23 6 % Total Assets $ 395 $ 34 $ 311 $ 50 100 % (1) Investments are measured using the net asset value per share (or its equivalent) practical expedient and have not been categorized in the fair value hierarchy. The fair value amounts presented in the table are intended to permit a reconciliation of the fair value hierarchy to the value of the total plan assets. Cash and cash equivalents are primarily comprised of investments in money market mutual funds. In determining fair value, Level 1 investments are valued based on quoted market prices in active markets. Investments in common/collective trust funds are valued using the NAV per unit in each fund. The NAV is based on the value of the underlying investments owned by each trust, minus its liabilities, and then divided by the number of shares outstanding. Common/collective trust funds are categorized in Level 2 to the extent that they are considered to have a readily determinable fair value. Investments for which fair value is estimated by using the NAV per share (or its equivalent) as a practical expedient are not categorized in the fair value hierarchy. Except for the Company’s U.S. funded pension plan, all of Moody’s Retirement Plans are unfunded and therefore have no plan assets. Cash Flows The Company contributed $99 million to its U.S. funded pension plan during 2020, but did not contribute to this plan during the year ended December 31, 2019. The Company made payments of $11 million and $8 million related to its U.S. unfunded pension plan obligations during the years ended December 31, 2020 and 2019, respectively. The Company currently does not anticipate making a contribution to its funded pension plan in 2021, and anticipates making payments of $44 million related to its unfunded U.S. pension plans and $1 million related to its other Retirement Plans during the year ended December 31, 2021. Estimated Future Benefits Payable Estimated future benefits payments for the Retirement Plans are as follows as of year ended December 31, 2020: Year Ending December 31, Pension Plans Other Retirement Plans 2021 $ 55 $ 1 2022 17 1 2023 25 2 2024 21 2 2025 24 2 2026 - 2030 $ 139 $ 13 Defined Contribution Plans Moody’s has a Profit Participation Plan covering substantially all U.S. employees. The Profit Participation Plan provides for an employee salary deferral and the Company matches employee contributions, equal to 50% of employee contribution up to a maximum of 3% of the employee’s pay. Effective January 1, 2008, all new hires are automatically enrolled in the Profit Participation Plan when they meet eligibility requirements unless they decline participation. As the Company’s U.S. DBPPs are closed to new entrants effective January 1, 2008, all eligible new hires will instead receive a retirement contribution into the Profit Participation Plan in value similar to the pension benefits. Additionally, effective January 1, 2008, the Company implemented a deferred compensation plan in the U.S., which is unfunded and provides for employee deferral of compensation and Company matching contributions related to compensation in excess of the IRS limitations on benefits and contributions under qualified retirement plans. Total expenses associated with U.S. defined contribution plans were $44 million, $43 million and $27 million in the years ended December 31, 2020, 2019, and 2018, respectively. Effective January 1, 2008, Moody’s has designated the Moody’s Stock Fund, an investment option under the Profit Participation Plan, as an Employee Stock Ownership Plan and, as a result, participants in the Moody’s Stock Fund may receive dividends in cash or may reinvest such dividends into the Moody’s Stock Fund. Moody’s paid approximately $1 million during each of the years ended December 31, 2020, 2019 and 2018, respectively, for the Company’s common shares held by the Moody’s Stock Fund. The Company records the dividends as a reduction of retained earnings in the Consolidated Statements of Shareholders’ Equity (Deficit). The Moody’s Stock Fund held approximately 360,600 and 411,100 shares of Moody’s common stock at December 31, 2020 and 2019, respectively. Non-U.S. Plans Certain of the Company’s non-U.S. operations provide pension benefits to their employees. The non-U.S. defined benefit pension plans are immaterial. For defined contribution plans, company contributions are primarily determined as a percentage of employees’ eligible compensation. Expenses related to these defined contribution plans for the years ended December 31, 2020, 2019 and 2018 were $29 million, $25 million and $26 million, respectively.

STOCK-BASED COMPENSATION PLANS

STOCK-BASED COMPENSATION PLANS	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
STOCK-BASED COMPENSATION PLANS	STOCK-BASED COMPENSATION PLANS Under the 1998 Plan, 33 million shares of the Company’s common stock have been reserved for issuance. The 2001 Plan, which is shareholder approved, permits the granting of up to 50.6 million shares, of which not more than 14.0 million shares are available for grants of awards other than stock options. The Stock Plans also provide for the granting of restricted stock. The Stock Plans provide that options are exercisable not later than ten years from the grant date. The vesting period for awards under the Stock Plans is generally determined by the Board at the date of the grant and has been four years except for employees who are at or near retirement eligibility, as defined, for which vesting is between one The Company maintains the Directors’ Plan for its Board, which permits the granting of awards in the form of non-qualified stock options, restricted stock or performance shares. The Directors’ Plan provides that options are exercisable not later than ten years from the grant date. The vesting period is determined by the Board at the date of the grant and is generally one year for both options and restricted stock. Under the Directors’ Plan, 1.7 million shares of common stock were reserved for issuance. Any director of the Company who is not an employee of the Company or any of its subsidiaries as of the date that an award is granted is eligible to participate in the Directors’ Plan. Presented below is a summary of the stock-based compensation expense and associated tax benefit in the accompanying Consolidated Statements of Operations: Year Ended December 31, 2020 2019 2018 Stock-based compensation expense $ 154 $ 136 $ 130 Tax benefit $ 30 $ 29 $ 32 The fair value of each employee stock option award is estimated on the date of grant using the Black-Scholes option-pricing model that uses the assumptions noted below. The expected dividend yield is derived from the annual dividend rate on the date of grant. The expected stock volatility is based on an assessment of historical weekly stock prices of the Company as well as implied volatility from Moody’s traded options. The risk-free interest rate is based on U.S. government zero coupon bonds with maturities similar to the expected holding period. The expected holding period was determined by examining historical and projected post-vesting exercise behavior activity. The following weighted average assumptions were used for options granted: Year Ended December 31, 2020 2019 2018 Expected dividend yield 0.80 % 1.14 % 1.05 % Expected stock volatility 23 % 24 % 26 % Risk-free interest rate 1.43 % 2.56 % 2.82 % Expected holding period -in years 5.7 6.2 6.2 Grant date fair value $ 60.66 $ 43.29 $ 45.73 A summary of option activity as of December 31, 2020 and changes during the year then ended is presented below: Options Shares Weighted Average Exercise Price Per Share Weighted Average Remaining Contractual Term Aggregate Intrinsic Value Outstanding, December 31, 2019 1.6 $ 93.51 Granted 0.1 280.37 Exercised (0.7) 59.57 Outstanding, December 31, 2020 1.0 133.95 5.6 years $ 160 Vested and expected to vest, December 31, 2020 1.0 132.80 5.6 years $ 158 Exercisable, December 31, 2020 0.7 $ 101.13 4.6 years $ 125 The aggregate intrinsic value in the table above represents the total pre-tax intrinsic value (the difference between Moody’s closing stock price on the last trading day of the year ended December 31, 2020 and the exercise prices, multiplied by the number of in-the-money options) that would have been received by the option holders had all option holders exercised their options as of December 31, 2020. This amount varies based on the fair value of Moody’s stock. As of December 31, 2020, there was $6 million of total unrecognized compensation expense related to options. The expense is expected to be recognized over a weighted average period of 2.3 years. The following table summarizes information relating to stock option exercises: Year Ended December 31, 2020 2019 2018 Proceeds from stock option exercises 39 36 38 Aggregate intrinsic value 132 114 99 Tax benefit realized upon exercise 32 27 24 A summary of nonvested restricted stock activity for the year ended December 31, 2020 is presented below: Nonvested Restricted Stock Shares Weighted Average Grant Date Fair Value Per Share Balance, December 31, 2019 1.8 $ 124.63 Granted 0.5 279.00 Vested (0.8) 132.50 Balance, December 31, 2020 1.5 $ 201.30 As of December 31, 2020, there was $162 million of total unrecognized compensation expense related to nonvested restricted stock. The expense is expected to be recognized over a weighted average period of 2.4 years. The following table summarizes information relating to the vesting of restricted stock awards: Year Ended December 31, 2020 2019 2018 Fair value of shares vested 202 156 151 Tax benefit realized upon vesting 46 36 35 A summary of performance-based restricted stock activity for the year ended December 31, 2020 is presented below: Performance-based restricted stock Shares Weighted Average Grant Date Fair Value Per Share Balance, December 31, 2019 0.5 $ 134.35 Granted 0.1 273.81 Vested (0.3) 109.43 Balance, December 31, 2020 0.3 $ 197.19 The following table summarizes information relating to the vesting of the Company’s performance-based restricted stock awards: Year Ended December 31, 2020 2019 2018 Fair value of shares vested 70 47 23 Tax benefit realized upon vesting 17 11 6 As of December 31, 2020, there was $21 million of total unrecognized compensation expense related to this plan. The expense is expected to be recognized over a weighted average period of 1.8 years. The Company has a policy of issuing treasury stock to satisfy shares issued under stock-based compensation plans. In addition, the Company also sponsors the ESPP. Under the ESPP, 6 million shares of common stock were reserved for issuance. The ESPP allows eligible employees to purchase common stock of the Company on a monthly basis at a discount to the average of the high and the low trading prices on the New York Stock Exchange on the last trading day of each month. This discount was 5% in 2020, 2019, and 2018 resulting in the ESPP qualifying for non-compensatory status under Topic 718 of the ASC. Accordingly, no compensation expense was recognized for the ESPP in 2020, 2019, and 2018. The employee purchases are funded through after-tax payroll deductions, which plan participants can elect from one percent to ten percent of compensation, subject to the annual federal limit.

INCOME TAXES

INCOME TAXES	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES Components of the Company’s income tax provision are as follows: Year Ended December 31, 2020 2019 2018 Current: Federal $ 213 $ 179 $ 168 State and Local 68 59 50 Non-U.S. 215 181 233 Total current 496 419 451 Deferred: Federal 6 (19) (59) State and Local — (3) (2) Non-U.S. (50) (16) (38) Total deferred (44) (38) (99) Total provision for income taxes $ 452 $ 381 $ 352 A reconciliation of the U.S. federal statutory tax rate to the Company’s effective tax rate on income before provision for income taxes is as follows: Year Ended December 31, 2020 2019 2018 U.S. statutory tax rate 21.0 % 21.0 % 21.0 % State and local taxes, net of federal tax benefit 2.3 % 2.2 % 2.2 % Benefit of foreign operations (1.5) % (0.1) % 1.8 % U.S. Tax Act impact — % — % (2.8) % Other (1.5) % (2.1) % (1.1) % Effective tax rate 20.3 % 21.0 % 21.1 % Income tax paid $ 514 $ 458 $ 442 The source of income before provision for income taxes is as follows: Year Ended December 31, 2020 2019 2018 U.S. $ 1,349 $ 1,039 $ 936 Non-U.S. 880 771 736 Income before provision for income taxes $ 2,229 $ 1,810 $ 1,672 The components of deferred tax assets and liabilities are as follows: December 31, 2020 2019 Deferred tax assets: Account receivable allowances $ 9 $ 6 Accumulated depreciation and amortization 2 1 Stock-based compensation 42 46 Accrued compensation and benefits 99 89 Capitalized costs 39 — Operating lease liabilities 122 136 Deferred revenue 30 37 Net operating loss 17 13 Restructuring 3 4 Uncertain tax positions 98 94 Self-insured related reserves 10 8 Loss on net investment hedges - OCI 93 — Other 10 13 Total deferred tax assets 574 447 Deferred tax liabilities: Accumulated depreciation and amortization of intangible assets and capitalized software (468) (389) ROU Assets (90) (107) Capital Gains (23) (23) Self-insured related income (10) (8) Stock-based compensation — (2) Revenue Accounting Standard - ASC 606 (10) (12) Deferred tax on unremitted foreign earnings (16) — Gain on net investment hedges - OCI (8) (22) Other (4) (3) Total deferred tax liabilities (629) (566) Net deferred tax liabilities (55) (119) Valuation allowance (15) (9) Total net deferred tax liabilities $ (70) $ (128) On December 22, 2017, the Tax Act was signed into law, which resulted in significant changes to U.S. corporate tax laws. The Tax Act includes a mandatory one-time deemed repatriation tax (“transition tax”) on previously untaxed accumulated earnings of foreign subsidiaries and beginning in 2018 reduces the statutory federal corporate income tax rate from 35% to 21%. Due to the complexities of the Tax Act, the SEC issued guidance requiring that companies provide a reasonable estimate of the impact of the Tax Act to the extent such reasonable estimate has been determined. Accordingly, as of December 31, 2017, the Company recorded a provisional estimate for the transition tax of $247 million. In September, 2018, the Company filed its 2017 federal income tax return and revised its determination of the transition tax to $236 million, a reduction of $11 million from the estimate at December 31, 2017. The reduction was primarily due to proposed regulations issued by the Internal Revenue Service and the finalization of earnings and profits calculations. A portion of the transition tax will be payable over eight years, starting in 2018, and will not accrue interest. The above revised determination of transition tax may be impacted by a number of additional considerations, including but not limited to the issuance of additional regulations. As a result of the Tax Act, all previously net undistributed foreign earnings have now been subject to U.S. tax. The Company regularly evaluates which entities it will indefinitely reinvest earnings. The Company has provided deferred taxes for those entities whose earnings are not considered indefinitely reinvested. The Company has recorded reductions in its income tax provision of approximately $60 million, or 269 BPS, for the full-year of 2020, and approximately $44 million, or 242 BPS, for the full-year of 2019, relating to Excess Tax Benefits on stock-based compensation. The Company had valuation allowances of $15 million and $9 million at December 31, 2020 and 2019, respectively, related to foreign net operating losses for which realization is uncertain. As of December 31, 2020, the Company had $483 million of UTPs of which $432 million represents the amount that, if recognized, would impact the effective tax rate in future periods. The increase in UTPs primarily resulted from the additional reserves established for non-U.S. tax exposures and an adjustment to the transition tax under U.S. tax reform. In addition, the Company has recorded a deferred tax asset in the amount of $50 million for potential transition tax benefits if certain non-U.S. UTPs are not sustained. A reconciliation of the beginning and ending amount of UTPs is as follows: Year Ended December 31, 2020 2019 2018 Balance as of January 1 $ 477 $ 495 $ 389 Additions for tax positions related to the current year 37 35 80 Additions for tax positions of prior years 17 22 89 Reductions for tax positions of prior years (2) (2) (13) Settlements with taxing authorities (5) (1) (2) Lapse of statute of limitations (41) (44) (48) Reclassification to indemnification liability related to MAKS divestiture — (28) — Balance as of December 31 $ 483 $ 477 $ 495 The Company classifies interest related to UTPs in interest expense in its consolidated statements of operations. Penalties are recognized in other non-operating expenses. During the years ended December 31, 2020 and 2019, the Company incurred a net interest expense of $31 million and $28 million respectively, related to UTPs. As of December 31, 2020 and 2019, the amount of accrued interest recorded in the Company’s consolidated balance sheets related to UTPs was $113 million and $82 million, respectively. 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 returns 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 current ongoing audits related to open tax years, the Company estimates that it is possible that the balance of UTPs could decrease in the next twelve months as a result of the effective 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 might necessitate increases to the balance of UTPs. As the Company is unable to predict the timing of conclusion of these audits, the Company is unable to estimate the amount of changes to the balance of UTPs at this time.

INDEBTEDNESS

INDEBTEDNESS	12 Months Ended
	Dec. 31, 2020
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, 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: December 31, 2020 Principal Amount Fair Value of Interest Rate Swaps (1) Unamortized (Discount) Premium Unamortized Debt Issuance Costs Carrying Value Notes Payable: 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 Note, due 2025 700 (1) (1) (5) 693 3.25% 2020 Senior Note, due 2050 300 — (4) (3) 293 2.55% 2020 Senior Note, due 2060 500 — (4) (5) 491 Total long-term debt $ 6,430 $ 56 $ (24) $ (40) $ 6,422 December 31, 2019 Principal Amount Fair Value of Interest Rate Swaps (1) Unamortized (Discount) Premium Unamortized Debt Issuance Costs Carrying Value Notes Payable: 4.50% 2012 Senior Notes, due 2022 $ 500 $ 9 $ (1) $ (1) $ 507 4.875% 2013 Senior Notes, due 2024 500 — (1) (2) 497 5.25% 2014 Senior Notes, due 2044 600 — 4 (5) 599 1.75% 2015 Senior Notes due 2027 561 — — (3) 558 2.75% 2017 Senior Notes, due 2021 500 11 (1) (2) 508 2.625% 2017 Senior Notes, due 2023 500 7 (1) (2) 504 3.25% 2017 Senior Notes, due 2028 500 — (4) (3) 493 3.25% 2018 Senior Notes, due 2021 300 — — (1) 299 4.25% 2018 Senior Notes, due 2029 400 — (3) (3) 394 4.875% 2018 Senior Notes, due 2048 400 — (7) (4) 389 0.950% 2019 Senior Notes, due 2030 842 — (3) (6) 833 Total long-term debt $ 5,603 $ 27 $ (17) $ (32) $ 5,581 (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. Credit Facility The following summarizes information relating to the Company's revolving credit facility: December 31, 2020 December 31, 2019 Issue Date Capacity Maturity Drawn Undrawn Drawn Undrawn 2018 Credit Facility November 14, 2018 $ 1,000 November 13, 2023 $ — $ 1,000 $ — $ 1,000 Interest on borrowings under the facility may range from 0 BPS to 22.5 BPS per annum for Alternate Base Rate loans (as defined in the 2018 Facility agreement) or payable at rates that are based on the London InterBank Offered Rate (“LIBOR”) plus a premium that can range from 80.5 BPS to 122.5 BPS depending on the Company’s index debt ratings, as set forth in the 2018 Facility agreement. The Company also pays quarterly facility fees, regardless of borrowing activity under the facility. The quarterly fees for the 2018 Facility can range from 7 BPS of the facility amount to 15 BPS, depending on the Company’s index debt ratings. The 2018 Facility contains certain customary covenants including a financial covenant that requires the Company to maintain a total debt to EBITDA ratio of (i) not more than 4 to 1 at the end of any fiscal quarter or (ii) not more than 4.5 to 1 as of the end of the first three consecutive quarters immediately following any acquisition with consideration in excess of $500 million, subject to certain conditions as set forth in the 2018 Facility agreement. Commercial Paper On August 3, 2016, the Company entered into a private placement commercial paper program under which the Company may issue CP notes up to a maximum amount of $1.0 billion. Borrowings under the CP Program are backstopped by the 2018 Facility. Amounts under the CP Program may be re-borrowed. The maturity of the CP Notes will vary, but may not exceed 397 days from the date of issue. The CP Notes are sold at a discount from par, or alternatively, sold at par and bear interest at rates that will vary based upon market conditions. The rates of interest will depend on whether the CP Notes will be a fixed or floating rate. The interest on a floating rate may be based on the following: (a) certificate of deposit rate; (b) commercial paper rate; (c) the federal funds rate; (d) the LIBOR; (e) prime rate; (f) Treasury rate; or (g) such other base rate as may be specified in a supplement to the private placement agreement. The CP Program contains certain events of default including, among other things: non-payment of principal, interest or fees; entrance into any form of moratorium; and bankruptcy and insolvency events, subject in certain instances to cure periods. As of December 31, 2020, the Company has no CP borrowings outstanding. Notes Payable The Company may prepay certain of its senior notes, in whole or in part, but may incur a Make-Whole Amount penalty. During 2020, the Company issued the 2020 Senior Notes, due 2025, the 2020 Senior Notes, due 2050 and the 2020 Senior Notes, due 2060. The key terms of these debt issuances are set forth in the table above. Additionally, in 2020, the Company fully repaid $300 million of the 2018 Senior Notes, due 2021 (along with a Make-Whole Amount of approximately $8 million) and $500 million of the 2017 Senior Notes due 2021 (along with a Make-Whole Amount of approximately $16 million). The Company also recognized in interest expense, net, a $17 million benefit relating to carrying value adjustments pursuant to the early termination of interest rate swaps designated as fair value hedges that were associated with the 2017 Senior Notes due 2021. At December 31, 2020, the Company was in compliance with all covenants contained within all of the debt agreements. All of 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 December 31, 2020, there were no such cross defaults. The repayment schedule for the Company’s borrowings is as follows: Year Ending 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 $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — 2022 500 — — — — — — — — — — — 500 2023 — — — — 500 — — — — — — — 500 2024 — 500 — — — — — — — — — — 500 2025 — — — — — — — — — 700 — — 700 Thereafter — — 600 612 — 500 400 400 918 — 300 500 4,230 Total $ 500 $ 500 $ 600 $ 612 $ 500 $ 500 $ 400 $ 400 $ 918 $ 700 $ 300 $ 500 $ 6,430 Interest expense, net The following table summarizes the components of interest as presented in the consolidated statements of operations: Year Ended December 31, 2020 2019 2018 Income $ 11 $ 17 $ 15 Expense on borrowings (163) (176) (197) Expense on UTPs and other tax related liabilities (34) (28) (15) Net periodic pension costs—interest component (19) (22) (19) Capitalized — 1 1 Total $ (205) $ (208) $ (215) Interest paid (1) $ 132 $ 167 $ 183 (1) Interest paid includes net settlements on interest rate swaps more fully discussed in Note 7. The fair value and carrying value of the Company’s debt as of December 31, 2020 and 2019 are as follows: December 31, 2020 December 31, 2019 Carrying Amount Estimated Fair Carrying Amount Estimated Fair 4.50% 2012 Senior Notes, due 2022 $ 512 $ 530 $ 507 $ 531 4.875% 2013 Senior Notes, due 2024 498 562 497 551 5.25% 2014 Senior Notes, due 2044 598 828 599 757 1.75% 2015 Senior Notes, due 2027 610 674 558 604 2.75% 2017 Senior Notes, due 2021 — — 508 507 2.625% 2017 Senior Notes, due 2023 510 522 504 507 3.25% 2017 Senior Notes, due 2028 524 561 493 523 3.25% 2018 Senior Notes, due 2021 — — 299 306 4.25% 2018 Senior Notes, due 2029 394 480 394 453 4.875% 2018 Senior Notes, due 2048 390 544 389 492 0.950% 2019 Senior Notes, due 2030 909 974 833 847 3.75% 2020 Senior Note, due 2025 693 785 — — 3.25% 2020 Senior Note, due 2050 293 329 — — 2.55% 2020 Senior Note, due 2060 491 467 — — Total $ 6,422 $ 7,256 $ 5,581 $ 6,078 The fair value of the Company’s 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.

CAPITAL STOCK

CAPITAL STOCK	12 Months Ended
	Dec. 31, 2020
Stockholders' Equity Note [Abstract]
CAPITAL STOCK	CAPITAL STOCK Authorized Capital Stock The total number of shares of all classes of stock that the Company has authority to issue under its Restated Certificate of Incorporation is 1.02 billion shares with a par value of $0.01, of which 1.0 billion are shares of common stock, 10.0 million are shares of preferred stock and 10.0 million are shares of series common stock. The preferred stock and series common stock can be issued with varying terms, as determined by the Board. Share Repurchase Program The Company implemented a systematic share repurchase program in the third quarter of 2005 through an SEC Rule 10b5-1 program. Moody’s may also purchase opportunistically when conditions warrant. As a result, Moody’s share repurchase activity will continue to vary from quarter to quarter. The table below summarizes the Company’s remaining authority under its share repurchase program as of December 31, 2020: Date Authorized Amount Authorized Remaining Authority December 16, 2019 $ 1,000 831 During 2020, Moody’s repurchased 2.0 million shares of its common stock under its share repurchase program and issued a net 1.4 million shares under employee stock-based compensation plans. The net amount includes shares withheld for employee payroll taxes. During 2019, the Company entered into an ASR with a financial institution counterparty to repurchase $500 million of its outstanding common stock. Refer to Note 5 for further details. Dividends The Company’s cash dividends were: Dividends Per Share Year ended December 31, 2020 2019 2018 Declared Paid Declared Paid Declared Paid First quarter $ 0.56 $ 0.56 $ 0.50 $ 0.50 $ 0.44 $ 0.44 Second quarter 0.56 0.56 0.50 0.50 0.44 0.44 Third quarter 0.56 0.56 0.50 0.50 0.44 0.44 Fourth quarter 0.56 0.56 0.50 0.50 0.44 0.44 Total $ 2.24 $ 2.24 $ 2.00 $ 2.00 $ 1.76 $ 1.76 On February 9, 2021, the Board approved the declaration of a quarterly dividend of $0.62 per share of Moody’s common stock, payable on March 18, 2021 to shareholders of record at the close of business on February 25, 2021. The continued payment of dividends at the rate noted above, or at all, is subject to the discretion of the Board.

LEASE COMMITMENTS

LEASE COMMITMENTS	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
LEASE COMMITMENTS	LEASE COMMITMENTS The Company has operating leases, substantially all of which relate to the lease of office space. The Company's leases 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 from one The following table presents the components of the Company’s lease cost: Year Ended December 31, 2020 2019 Operating lease cost $ 96 $ 97 Sublease income (5) (2) Variable lease cost 19 17 Total lease cost $ 110 $ 112 During 2020, the Company recorded $21 million of ROU Asset impairment charges related to the exit of certain real estate leases. The impairment charges were recorded within Restructuring expense on the consolidated statement of operations. Refer to Note 11 for further details. The following tables present other information related to the Company’s operating leases: Year Ended December 31, 2020 2019 Cash paid for amounts included in the measurement of operating lease liabilities $ 108 $ 106 Right-of-use assets obtained in exchange for new operating lease liabilities $ 36 $ 41 Year Ended December 31, 2020 2019 Weighted-average remaining lease term (in years) 6.0 6.8 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 December 31, 2020: Year Ending December 31, Operating Leases 2021 $ 110 2022 99 2023 93 2024 84 2025 76 Thereafter 117 Total lease payments (undiscounted) 579 Less: Interest 58 Present value of lease liabilities: 521 Lease liabilities - current 94 Lease liabilities - noncurrent $ 427

CONTINGENCIES

CONTINGENCIES	12 Months Ended
	Dec. 31, 2020
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 17 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	12 Months Ended
	Dec. 31, 2020
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, SFG, FIG and PPIF 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. Beginning in the first quarter of 2020, the MA segment now consists of two LOBs - RD&A and ERS. Subsequent to the divestiture of MAKS in the fourth quarter of 2019, the MALS business, which was historically part of the PS LOB through December 31, 2019, was reclassified to the RD&A LOB. Prior year revenue by LOB has not been reclassified as the amounts relating to the MALS business were not material. Revenue for MIS and expenses for MA include an intersegment royalty charged to MA for the rights to use and distribute content, data and products developed by MIS. The royalty rate charged by MIS approximates the fair value of the aforementioned content, data and products and is generally based on comparable market transactions. Also, 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 fees charged by MA are generally equal to the costs incurred by MA to produce these products and services. 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 and corporate expenses that benefit both segments, in years prior to 2019, the Company generally allocated costs ratably based on each segment’s share of total revenue. Beginning in 2019, the Company refined its methodology such that costs are allocated to each segment based on the segment’s share of full-year 2018 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. The impact of this refined methodology would not have resulted in a material change to previously reported segment results. “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, Adjusted Operating Income and operating income by reportable segment. Adjusted Operating Income is a financial metric utilized by the Company’s chief operating decision maker to assess the profitability of each reportable segment. Refer to Note 3 for further details on the components of the Company’s revenue. Year Ended December 31, 2020 2019 MIS MA Eliminations Consolidated MIS MA Eliminations Consolidated Revenue $ 3,440 $ 2,086 $ (155) $ 5,371 $ 3,009 $ 1,963 $ (143) $ 4,829 Total Expense 1,476 1,662 (155) 2,983 1,376 1,598 (143) 2,831 Operating income 1,964 424 — 2,388 1,633 365 — 1,998 Add: Restructuring 19 31 — 50 31 29 — 60 Depreciation and amortization 70 150 — 220 71 129 — 200 Acquisition-Related Expenses — — — — — 3 — 3 Loss pursuant to the divestiture of MAKS — 9 — 9 — 14 — 14 Captive insurance company settlement — — — — 10 6 — 16 Adjusted Operating Income $ 2,053 $ 614 $ — $ 2,667 $ 1,745 $ 546 $ — $ 2,291 Year Ended December 31, 2018 MIS MA Eliminations Consolidated Revenue $ 2,836 $ 1,743 $ (136) $ 4,443 Total Expense 1,276 1,435 (136) 2,575 Operating Income 1,560 308 — 1,868 Add: Restructuring 32 17 — 49 Depreciation and amortization 65 127 — 192 Acquisition-Related Expenses — 8 — 8 Adjusted Operating income $ 1,657 $ 460 $ — $ 2,117 The cumulative restructuring charges for the MIS and MA reportable segments are $61 million and $44 million, respectively, related to the 2018 Restructuring Program and $21 million and $15 million, respectively, related to the 2020 Restructuring Program. The cumulative restructuring charge for the MA reportable segment related to the 2020 MA Strategic Reorganization Restructuring Program is $18 million. The restructuring programs are more fully discussed in Note 11. CONSOLIDATED REVENUE AND LONG-LIVED ASSETS INFORMATION BY GEOGRAPHIC AREA Year Ended December 31, 2020 2019 2018 Revenue: U.S. $ 2,955 $ 2,544 $ 2,330 Non-U.S.: EMEA 1,545 1,446 1,377 Asia-Pacific 571 551 493 Americas 300 288 243 Total Non-U.S. 2,416 2,285 2,113 Total $ 5,371 $ 4,829 $ 4,443 Long-lived assets at December 31: U.S. $ 2,162 $ 1,290 $ 982 Non-U.S. 4,889 4,678 4,685 Total $ 7,051 $ 5,968 $ 5,667

VALUATION AND QUALIFYING ACCOUN

VALUATION AND QUALIFYING ACCOUNTS	12 Months Ended
	Dec. 31, 2020
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
VALUATION AND QUALIFYING ACCOUNTS	VALUATION AND QUALIFYING ACCOUNTS Accounts receivable allowances represent estimates for uncollectible accounts. The valuation allowance on deferred tax assets relates to foreign net operating tax losses for which realization is uncertain. Below is a summary of activity: Year Ended December 31, Balance at Beginning of the Year Adoption of New Expected Credit Losses Accounting Standard Charged to costs and expenses Deductions (1) Balance at End of the Year 2020 Allowances for credit losses $ (20) $ (2) $ (26) $ 14 $ (34) Deferred tax assets—valuation allowance $ (9) $ — $ (6) $ — $ (15) 2019 Allowances for credit losses $ (20) $ — $ (10) $ 10 $ (20) Deferred tax assets—valuation allowance $ (5) $ — $ (4) $ — $ (9) 2018 Allowances for credit losses $ (14) $ — $ (15) $ 9 $ (20) Deferred tax assets—valuation allowance $ (6) $ — $ — $ 1 $ (5) (1) Reflects write-off of uncollectible accounts receivable or expiration of foreign net operating tax losses.

OTHER NON-OPERATING (EXPENSE) I

OTHER NON-OPERATING (EXPENSE) INCOME, NET	12 Months Ended
	Dec. 31, 2020
Other Income and Expenses [Abstract]
OTHER NON-OPERATING (EXPENSE) INCOME, NET	OTHER NON-OPERATING (EXPENSE) INCOME, NET The following table summarizes the components of other non-operating (expense) income, net as presented in the consolidated statements of operations: Year Ended December 31, 2020 2019 2018 FX gain (loss) $ 2 $ (18) $ (11) Net periodic pension costs—other components 13 18 10 Income from investments in non-consolidated affiliates 6 13 14 Other 25 7 6 Total $ 46 $ 20 $ 19

RELATED PARTY TRANSACTIONS

RELATED PARTY TRANSACTIONS	12 Months Ended
	Dec. 31, 2020
Related Party Transactions [Abstract]
RELATED PARTY TRANSACTIONS	RELATED PARTY TRANSACTIONSMoody’s Corporation made grants of $11 million to The Moody’s Foundation during the year ended December 31, 2020. The Company did not make any grants to the Foundation in the years ended December 31, 2019 and 2018. The Foundation carries out philanthropic activities primarily in the areas of education and health and human services. Certain members of Moody’s senior management are on the board of the Foundation.

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	12 Months Ended
	Dec. 31, 2020
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	SUBSEQUENT EVENTS On February 9, 2021, the Board approved the declaration of a quarterly dividend of $0.62 per share for Moody’s common stock, payable March 18, 2021 to shareholders of record at the close of business on February 25, 2021. Additionally, on February 9, 2021, the Board approved an additional $1 billion of share repurchase authority, which may commence following the completion of the remaining authority disclosed in Note 19. In the first quarter of 2021, the Company reached a settlement and had a lapse of a statute of limitations relating to certain of its UTPs. As a result of these items, in the first quarter of 2021, the Company will release UTPs of $61 million along with accrued interest of $40 million.

SUMMARY OF SIGNIFICANT ACCOUN_2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Basis of Consolidation	Basis of Consolidation The consolidated financial statements include those of Moody’s Corporation and its majority- and wholly-owned subsidiaries. The effects of all intercompany transactions have been eliminated. Investments in companies for which the Company has significant influence over operating and financial policies but not a controlling interest are accounted for on an equity basis whereby the Company records its proportional share of the investment’s net income or loss as part of other non-operating income (expense), net and any dividends received reduce the carrying amount of the investment. The Company applies the guidelines set forth in Topic 810 of the ASC in assessing its interests in variable interest entities to decide whether to consolidate an entity. The Company has reviewed the potential variable interest entities and determined that there are no consolidation requirements under Topic 810 of the ASC. The Company consolidates its ICRA subsidiaries on a three month lag.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash equivalents principally consist of investments in money market mutual funds and money market deposit accounts as well as high-grade commercial paper and certificates of deposit with maturities of three months or less when purchased.
Short-term Investments	Short-term Investments Short-term investments are securities with maturities greater than 90 days at the time of purchase that are available for operations in the next 12 months. The Company’s short-term investments primarily consist of certificates of deposit and their cost approximates fair value due to the short-term nature of the instruments. Interest and dividends on these investments are recorded into income when earned.
Property and Equipment	Property and Equipment Property and equipment are stated at cost and are depreciated using the straight-line method over their estimated useful lives. Expenditures for maintenance and repairs that do not extend the economic useful life of the related assets are charged to expense as incurred.
Computer Software Developed or Obtained for Internal Use	Computer Software Developed or Obtained for Internal Use The Company capitalizes costs related to software developed or obtained for internal use. These assets, included in property and equipment in the consolidated balance sheets, relate to the Company’s financial, website and other systems. Such costs generally consist of direct costs for third-party license fees, professional services provided by third parties and employee compensation, in each case incurred either during the application development stage or in connection with upgrades and enhancements that increase functionality. Such costs are depreciated over their estimated useful lives on a straight-line basis. Costs incurred during the preliminary project stage of development as well as maintenance costs are expensed as incurred.
Goodwill and Other Acquired Intangible Assets	Goodwill and Other Acquired Intangible Assets Moody’s evaluates its goodwill for impairment at the reporting unit level, defined as an operating segment (i.e., MIS and MA), or one level below an operating segment (i.e., a component of an operating segment), annually as of July 31 or more frequently if impairment indicators arise in accordance with ASC Topic 350. The Company evaluates the recoverability of goodwill using a two-step impairment test approach at the reporting unit level. In the first step, the Company assesses various qualitative factors to determine whether the fair value of a reporting unit may be less than its carrying amount. If a determination is made based on the qualitative factors that an impairment does not exist, the Company is not required to perform further testing. If the aforementioned qualitative assessment results in the Company concluding that it is more likely than not that the fair value of a reporting unit may be less than its carrying amount, the fair value of the reporting unit will be quantitatively determined and compared to its carrying value including goodwill. If the fair value of the reporting unit exceeds the carrying value of the net assets assigned to that unit, goodwill is not impaired and the Company is not required to perform further testing. If the fair value of the reporting unit is less than the carrying value, the Company will record a goodwill impairment charge for the amount by which the carrying value exceeds the reporting unit’s fair value. The Company evaluates its reporting units on an annual basis, or more frequently if there are changes in the reporting structure of the Company due to acquisitions, reporting unit realignments or if there are indicators of potential impairment. For the reporting units where the Company is consistently able to conclude that no impairment exists using only a qualitative approach, the Company’s accounting policy is to perform the second step of the aforementioned goodwill impairment assessment at least once every three years. Goodwill is assigned to a reporting unit at the date when an acquisition is integrated into one of the established reporting units, and is based on which reporting unit is expected to benefit from the synergies of the acquisition. For purposes of assessing the recoverability of goodwill, the Company has seven primary reporting units: two within the Company’s ratings business (one for the ICRA business and one that encompasses all of Moody’s other ratings operations) and five reporting units within MA: Content, ERS, MALS, Bureau van Dijk and Reis.
Impairment of long-lived assets and definite-lived intangible assets	Impairment of long-lived assets and definite-lived intangible assets Long-lived assets (including ROU Assets) and amortizable intangible assets are reviewed for recoverability whenever events or changes in circumstances indicate that the carrying amount may not be recoverable.
Stock-Based Compensation	Stock-Based Compensation The Company records compensation expense for all share-based payment award transactions granted to employees based on the fair value of the equity instrument at the time of grant. This includes shares issued under stock option and restricted stock plans.
Derivative Instruments and Hedging Activities	Derivative Instruments and Hedging Activities Based on the Company’s risk management policy, from time to time the Company may use derivative financial instruments to reduce exposure to changes in foreign exchange rates and interest rates. The Company does not enter into derivative financial instruments for speculative purposes. All derivative financial instruments are recorded on the balance sheet at their respective fair values on a gross basis. The changes in the value of derivatives that qualify as fair value hedges are recorded in the same income statement line item in earnings in which the corresponding adjustment to the carrying value of the hedged item is presented. The entire change in the fair value of derivatives that qualify as cash flow hedges is recorded to OCI and such amounts are reclassified from AOCI to the same income statement line in earnings in the same period or periods during which the hedged transaction affects income. Effective with the Company’s early adoption of ASC 2017-12, the Company changed the method by which it assesses effectiveness for net investment hedges from the forward-method to the spot-method. The Company considers the spot-method an improved method of assessing hedge effectiveness, as spot rate changes relating to the hedging instrument’s notional amount perfectly offset the currency translation adjustment on the hedged net investment in the Company’s foreign subsidiaries. The entire change in the fair value of derivatives that qualify as net investment hedges is initially recorded to OCI. Those changes in fair value attributable to components included in the assessment of hedge effectiveness in a net investment hedge are recorded in the currency translation adjustment component of OCI and remain in AOCI until the period in which the hedged item affects earnings. Those changes in fair value attributable to components excluded from the assessment of hedge effectiveness in a net investment hedge are recorded to OCI and amortized to earnings using a systematic and rational method over the duration of the hedge. Any changes in the fair value of derivatives that the Company does not designate as hedging instruments under Topic 815 of the ASC are recorded in the consolidated statements of operations in the period in which they occur.
Revenue Recognition and Costs to Obtain or Fulfill a Contract with a Customer	Revenue Recognition and Costs to Obtain or Fulfill a Contract with a Customer Revenue recognition: Revenue is recognized when control of promised goods or services is transferred to the customer, in an amount that reflects the consideration the Company expects to be entitled to in exchange for those goods or services. When contracts with customers contain multiple performance obligations, the Company accounts for individual performance obligations separately if they are distinct. The transaction price is allocated to each distinct performance obligation on a relative SSP basis. The Company determines the SSP by using the price charged for a deliverable when sold separately or uses management’s best estimate of SSP for goods or services not sold separately using estimation techniques that maximize observable data points, including: internal factors relevant to its pricing practices such as costs and margin objectives; standalone sales prices of similar products; pricing policies; percentage of the fee charged for a primary product or service relative to a related product or service; and customer segment and geography. Additional consideration is also given to market conditions such as competitor pricing strategies and market trends. Sales, usage-based, value added and other taxes are excluded from revenues. MIS Revenue In the MIS segment, revenue arrangements with multiple elements are generally comprised of two distinct performance obligations, a rating and the related monitoring service. Revenue attributed to ratings of issued securities is generally recognized when the rating is delivered to the issuer. Revenue attributed to monitoring of issuers or issued securities is recognized ratably over the period in which the monitoring is performed, generally one year. In the case of certain structured finance products, primarily CMBS, issuers can elect to pay all of the annual monitoring fees upfront. These fees are deferred and recognized over the future monitoring periods based on the expected lives of the rated securities. MIS arrangements generally have standard contractual terms for which the stated payments are due at conclusion of the ratings process for ratings and either upfront or in arrears for monitoring services; and are signed by customers either on a per issue basis or at the beginning of the relationship with the customer. In situations when customer fees for an arrangement may be variable, the Company estimates the variable consideration at inception using the expected value method based on analysis of similar contracts in the same line of business, which is constrained based on the Company’s assessment of the realization of the adjustment amount. The Company allocates the transaction price within arrangements that include multiple performance obligations based upon the relative SSP of each service. The SSP for both rating and monitoring services is generally based upon observable selling prices where the rating or monitoring service is sold separately to similar customers. MA Revenue In the MA segment, products and services offered by the Company include hosted research and data subscriptions, installed software subscriptions, perpetual installed software licenses and related maintenance, or PCS, and professional services. Subscription and PCS contracts are generally invoiced in advance of the contractual coverage period, which is principally one year, but can range from 3-5 years; while perpetual software licenses are generally invoiced upon delivery and professional services are invoiced as those services are provided. Payment terms and conditions vary by contract type, but primarily include a requirement of payment within 30 to 60 days. Revenue from research, data and other hosted subscriptions is recognized ratably over the related subscription period as MA's performance obligation to provide access to these products is progressively fulfilled over the stated term of the contract. A large portion of these services are invoiced in the months of November, December and January. Revenue from the sale of a software license, when considered distinct from the related software implementation services, is generally recognized at the time the product master or first copy is delivered or transferred to the customer. PCS is generally recognized ratably over the contractual period commencing when the software license is fully delivered. Revenue from installed software subscriptions, which includes PCS, is bifurcated into a software license performance obligation and a PCS performance obligation, which follow the patterns of recognition described above. However, in instances where the software license (perpetual or subscription) and related implementation services are considered to be one combined performance obligation, revenue is recognized over time using cost based input methods. Due to the strategic shift in the MA business towards SaaS solutions, revenue generated from these types of arrangements were not material in the years ended December 31, 2020, 2019 and 2018. For implementation services and other service projects within the ERS and ESA businesses for which fees are fixed, the Company determined progress towards completion is most accurately measured on a percentage-of-completion basis (input method) as this approach utilizes the most directly observable data points and is therefore used to recognize the related revenue. For implementation services where price varies based on time expended, a time-based measure of progress towards completion of the performance obligation is utilized. Revenue from professional services rendered is generally recognized as the services are performed over time. Products and services offered within the MA segment are sold either stand-alone or together in various combinations. In instances where an arrangement contains multiple performance obligations, the Company accounts for the individual performance obligations separately if they are considered distinct. Revenue is generally allocated to all performance obligations based upon the relative SSP at contract inception. For certain performance obligations, judgment is required to determine the SSP. Revenue is recognized for each performance obligation based upon the conditions for revenue recognition noted above. In the MA segment, customers usually pay a fixed fee for the products and services based on signed contracts. However, accounting for variable consideration is applied mainly for: i) estimates for cancellation rights and price concessions and ii) T&M based services. The Company estimates the variable consideration associated with cancellation rights and price concessions based on the expected amount to be provided to customers and reduces the amount of revenue to be recognized. T&M based contracts represent about half of MA’s service projects within the ERS and ESA businesses. The Company provides agreed upon services at a contracted daily or hourly rate. The commitment represents a series of goods and services that are substantially the same and have the same pattern of transfer to the customer. As such, if T&M services are sold with other MA products, the Company allocates the variable consideration entirely to the T&M performance obligation if the services are sold at standard pricing or at a similar discount level compared to other performance obligations in the same revenue contract. If these criteria are not met, the Company estimates variable consideration for each performance obligation upfront. Each form of variable consideration is included in the transaction price only to the extent that it is probable that a significant reversal of any incremental revenue will not occur. Costs to Obtain or Fulfill a Contract with a Customer: Costs to obtain a contract with a customer Costs incurred to obtain customer contracts, such as sales commissions, are deferred and recorded within other current assets and other assets when such costs are determined to be incremental to obtaining a contract, would not have been incurred otherwise and the Company expects to recover those costs. These costs are amortized to expense on a systematic basis consistent with the transfer of the products or services to the customer. Depending on the line of business to which the contract relates, this may be based upon the average economic life of the products sold or average period for which services are provided, inclusive of anticipated contract renewals. Determining the estimated economic life of the products sold requires judgment with respect to anticipated future technological changes. The Company had a balance of $180 million and $159 million in such deferred costs as of December 31, 2020 and December 31, 2019, respectively, and recognized $59 million, $53 million and $38 million of related amortization during the years ended December 31, 2020, December 31, 2019 and December 31, 2018, respectively, which is included within SG&A expenses in the consolidated statement of operations. Costs incurred to obtain customer contracts are only in the MA segment. Cost to fulfill a contract with a customer Costs incurred to fulfill customer contracts, are deferred and recorded within other current assets and other assets when such costs relate directly to a contract, generate or enhance resources of the Company that will be used in satisfying performance obligations in the future and the Company expects to recover those costs. The Company capitalizes work-in-process costs for in-progress MIS ratings, which is recognized consistent with the rendering of the related services to the customers, as ratings are issued. The Company had a balance of $12 million and $11 million in such deferred costs as of December 31, 2020 and December 31, 2019, respectively, and recognized $47 million, $42 million and $40 million of amortization of the costs during the years ended December 31, 2020, December 31, 2019 and December 31, 2018, respectively, which is included within operating expenses in the consolidated statement of operations.
Accounts Receivable Allowances	Accounts Receivable Allowances In order to determine an estimate of expected credit losses, receivables are segmented based on similar risk characteristics including historical credit loss patterns and industry or class of customers to calculate reserve rates. The Company uses an aging method for developing its allowance for credit losses by which receivable balances are stratified based on aging category. A reserve rate is calculated for each aging category which is generally based on historical information, and is adjusted, when necessary, for current conditions (e.g., macroeconomic or industry related) and reasonable and supportable forecasts about the future. The Company also considers customer specific information (e.g., bankruptcy or financial difficulty) when estimating its expected credit losses, as well as the economic environment of the customers, both from an industry and geographic perspective, in evaluating the need for allowances. Expected credit losses are reflected as additions to the accounts receivable allowance. Actual uncollectible account write-offs are recorded against the allowance. During the year ended December 31, 2020, the Company recorded a net provision for expected credit losses of $26 million. The increase in the provision for expected credit losses for the current period was primarily attributable to the aforementioned estimated effects of COVID-19.
Leases	Leases The Company has operating leases, of which substantially all 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. The Company determines if an arrangement meets the definition of a lease at contract inception. The Company recognizes in its consolidated balance sheet a lease liability and an ROU Asset for all leases with a lease term greater than 12 months. In determining the length of the lease term, the Company utilizes judgment in assessing the likelihood of whether it is reasonably certain that it will exercise an option to extend or early-terminate a lease, if such options are provided in the lease agreement. ROU Assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. ROU Assets and lease liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. As substantially all of the Company’s leases do not provide an implicit interest rate, the Company uses its estimated secured incremental borrowing rates at the lease commencement date in determining the present value of lease payments. These secured incremental borrowing rates are attributable to the currency in which the lease is denominated. At commencement, the Company’s initial measurement of the ROU Asset is calculated as the present value of the remaining lease payments (i.e., lease liability), with additive adjustments reflecting: initial direct costs (e.g., broker commissions) and prepaid lease payments (if any); and reduced by any lease incentives provided by the lessor if: (i) received before lease commencement or (ii) receipt of the lease incentive is contingent upon future events for which the occurrence is both probable and within the Company’s control. Lease expense for minimum operating lease payments is recognized on a straight-line basis over the lease term. This straight-line lease expense represents a single lease cost which is comprised of both an interest accretion component relating to the lease liability and amortization of the ROU Assets. The Company records this single lease cost in operating and SG&A expenses. However, in situations where an operating lease ROU Asset has been impaired, the subsequent amortization of the ROU Asset is then recorded on a straight-line basis over the remaining lease term and is combined with accretion expense on the lease liability to result in single operating lease cost (which subsequent to impairment will no longer follow a straight-line recognition pattern). The Company has lease agreements which include lease and non-lease components. For the Company’s office space leases, the lease components (e.g., fixed rent payments) and non-lease components (e.g., fixed common-area maintenance costs) are combined and accounted for as a single lease component. Variable lease payments (e.g. variable common-area-maintenance costs) are only included in the initial measurement of the lease liability to the extent those payments depend on an index or a rate. Variable lease payments not included in the lease liability are recognized in net income in the period in which the obligation for those payments is incurred.
Contingencies	Contingencies Moody’s is involved in legal and tax proceedings, governmental, regulatory and legislative investigations and inquiries, claims and litigation that are incidental to the Company’s business, including claims based on ratings assigned by MIS. Moody’s is also subject to ongoing tax audits in the normal course of business. Management periodically assesses the Company’s liabilities and contingencies in connection with these matters based upon the latest information available. Moody’s discloses material pending legal proceedings pursuant to SEC rules and other pending matters as it may determine to be appropriate. 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.
Operating Expenses	Operating Expenses Operating expenses include costs associated with the development and production of the Company’s products and services and their delivery to customers. These expenses principally include employee compensation and benefits and travel costs that are incurred in connection with these activities. Operating expenses are charged to income as incurred.
Selling, General and Administrative Expenses	Selling, General and Administrative Expenses SG&A expenses include such items as compensation and benefits for corporate officers and staff and compensation and other expenses related to sales. They also include items such as office rent, business insurance, professional fees and gains and losses from sales and disposals of assets. SG&A expenses are charged to income as incurred.
Foreign Currency Translation	Foreign Currency Translation For all operations outside the U.S. where the Company has designated the local currency as the functional currency, assets and liabilities are translated into U.S. dollars using end of year exchange rates, and revenue and expenses are translated using average exchange rates for the year. For these foreign operations, currency translation adjustments are recorded to other comprehensive income.
Comprehensive Income	Comprehensive Income Comprehensive income represents the change in net assets of a business enterprise during a period due to transactions and other events and circumstances from non-owner sources including foreign currency translation impacts, net actuarial gains and losses and net prior service costs related to pension and other retirement plans and gains and losses on derivative instruments designated as net investment hedges or cash flow hedges. Comprehensive income items, including cumulative translation adjustments of entities that are less-than-wholly-owned subsidiaries, will be reclassified to noncontrolling interests and thereby, adjusting accumulated other comprehensive income proportionately in accordance with the percentage of ownership interest of the NCI shareholder.
Income Taxes	Income Taxes The Company accounts for income taxes under the asset and liability method in accordance with ASC Topic 740. Therefore, income tax expense is based on reported income before income taxes and deferred income taxes reflect the effect of temporary differences between the amounts of assets and liabilities that are recognized for financial reporting purposes and the amounts that are recognized for income tax purposes. The Company classifies interest related to unrecognized tax benefits as a component of interest expense in its consolidated statements of operations. Penalties are recognized in other non-operating expenses. For UTPs, the Company first determines whether it is more-likely-than-not (defined as a likelihood of more than fifty percent) that a tax position will be sustained based on its technical merits as of the reporting date, assuming that taxing authorities will examine the position and have full knowledge of all relevant information. A tax position that meets this more-likely-than-not threshold is then measured and recognized at the largest amount of benefit that is greater than fifty percent likely to be realized upon effective settlement with a taxing authority. On December 22, 2017, the Tax Act was signed into law, resulting in all previously undistributed foreign earnings being subject to U.S. tax. The Company has provided deferred taxes for those entities whose earnings are not considered indefinitely reinvested.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The Company’s financial instruments include cash, cash equivalents, trade receivables and payables, and certain short-term investments consisting primarily of certificates of deposit and money market deposits, all of which are short-term in nature and, accordingly, approximate fair value. The Company also invests in mutual funds, which are accounted for as equity securities with readily determinable fair values under ASC Topic 321. The Company measures these investments at fair value with both realized gains and losses and unrealized holding gains and losses for these investments included in net income. Also, the Company uses derivative instruments to manage certain financial exposures that occur in the normal course of business. These derivative instruments are carried at fair value in the Company’s consolidated balance sheets. Fair value is defined by the ASC 820 as the price that would be received from selling an asset or paid to transfer a liability (i.e., an exit price) in an orderly transaction between market participants at the measurement date. The determination of this fair value is based on the principal or most advantageous market in which the Company could commence transactions and considers assumptions that market participants would use when pricing the asset or liability, such as inherent risk, transfer restrictions and risk of nonperformance. Also, determination of fair value assumes that market participants will consider the highest and best use of the asset. The ASC establishes a fair value hierarchy whereby the inputs contained in valuation techniques used to measure fair value are categorized into three broad levels as follows: Level 1: quoted market prices in active markets that the reporting entity has the ability to access at the date of the fair value measurement; Level 2: inputs other than quoted market prices described in Level 1 that are observable for the asset or liability, either directly or indirectly, such as quoted prices in active markets for similar assets or liabilities, quoted prices for identical or similar assets or liabilities in markets that are not active or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities; Level 3: unobservable inputs that are supported by little or no market activity and that are significant to the fair value measurement of the assets or liabilities.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments that potentially subject the Company to concentration of credit risk principally consist of cash and cash equivalents, short-term investments, trade receivables and derivatives. The Company manages its credit risk exposure by allocating its cash equivalents among various money market mutual funds, money market deposit accounts, certificates of deposits and high-grade commercial paper. Short-term investments primarily consist of certificates of deposit as of December 31, 2020 and 2019. The Company manages its credit risk exposure on cash equivalents and short-term investments by limiting the amount it can invest with any single entity. No customer accounted for 10% or more of accounts receivable at December 31, 2020 or 2019.
Earnings per Share of Common Stock	Earnings per Share of Common Stock Basic shares outstanding is calculated based on the weighted average number of shares of common stock outstanding during the reporting period. Diluted shares outstanding is calculated giving effect to all potentially dilutive common shares, assuming that such shares were outstanding and dilutive during the reporting period.
Pension and Other Retirement Benefits	Pension and Other Retirement Benefits Moody’s maintains various noncontributory DBPPs as well as other contributory and noncontributory retirement plans. The expense and assets/liabilities that the Company reports for its pension and other retirement benefits are dependent on many assumptions concerning the outcome of future events and circumstances. These assumptions represent the Company’s best estimates and may vary by plan. The differences between the assumptions for the expected long-term rate of return on plan assets and actual experience is spread over a five-year period to the market-related value of plan assets, which is used in determining the expected return on assets component of annual pension expense. All other actuarial gains and losses are generally deferred and amortized over the estimated average future working life of active plan participants. The Company recognizes as an asset or liability in its consolidated balance sheet the funded status of its defined benefit retirement plans, measured on a plan-by-plan basis. Changes in the funded status due to actuarial gains/losses are recorded as part of other comprehensive income during the period the changes occur.
Use of Estimates	Use of EstimatesThe preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenue and expenses during the period. Actual results could differ from those estimates.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In April 2019, the FASB issued 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. This ASU is effective for fiscal years beginning after December 15, 2020, with early adoption permitted. The Company does not anticipate that the adoption of this ASU will have a significant impact on its consolidated financial statements. In December 2019, the FASB issued 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. This ASU is effective for fiscal years beginning after December 15, 2020, with early adoption permitted. The Company does not anticipate that the adoption of this ASU will have a significant impact on its consolidated financial statements. 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.

REVENUES (Tables)

REVENUES (Tables)	12 Months Ended
	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following table presents the Company’s revenues disaggregated by LOB: Year Ended December 31, 2020 2019 2018 MIS: Corporate finance (CFG) Investment-grade $ 636 $ 379 $ 271 High-yield 352 258 175 Bank loans 287 313 379 Other accounts (CFG) (1) 582 547 554 Total CFG 1,857 1,497 1,379 Structured finance (SFG) Asset-backed securities 98 99 107 RMBS 96 95 98 CMBS 61 81 78 Structured credit 105 148 196 Other accounts (SFG) 2 4 2 Total SFG 362 427 481 Financial institutions (FIG) Banking 355 320 290 Insurance 137 119 114 Managed investments 28 25 25 Other accounts (FIG) 10 12 13 Total FIG 530 476 442 Public, project and infrastructure finance (PPIF) Public finance / sovereign 250 222 185 Project and infrastructure 246 224 206 Total PPIF 496 446 391 Total ratings revenue 3,245 2,846 2,693 MIS Other 47 29 19 Total external revenue 3,292 2,875 2,712 Intersegment royalty 148 134 124 Total MIS 3,440 3,009 2,836 MA: Research, data and analytics (RD&A) 1,514 1,273 1,121 Enterprise risk solutions (ERS) 565 522 451 Professional services (PS) (2) — 159 159 Total external revenue 2,079 1,954 1,731 Intersegment revenue 7 9 12 Total MA 2,086 1,963 1,743 Eliminations (155) (143) (136) Total MCO $ 5,371 $ 4,829 $ 4,443 (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. (2) Subsequent to the divestiture of MAKS in 2019, revenue from the MALS reporting unit, which previous to 2020 was reported in the PS LOB, is now reported as part of the RD&A LOB. Prior periods have not been reclassified as the amounts were not material. The following table presents the Company’s revenues disaggregated by LOB and geographic area: Year Ended December 31, 2020 Year Ended December 31, 2019 Year Ended December 31, 2018 U.S. Non-U.S. Total U.S. Non-U.S. Total U.S. Non-U.S. Total MIS: Corporate finance $ 1,291 $ 566 $ 1,857 $ 968 $ 529 $ 1,497 $ 894 $ 485 $ 1,379 Structured finance 214 148 362 270 157 427 301 180 481 Financial institutions 250 280 530 200 276 476 194 248 442 Public, project and infrastructure finance 311 185 496 282 164 446 229 162 391 Total ratings revenue 2,066 1,179 3,245 1,720 1,126 2,846 1,618 1,075 2,693 MIS Other 2 45 47 1 28 29 1 18 19 Total MIS 2,068 1,224 3,292 1,721 1,154 2,875 1,619 1,093 2,712 MA: Research, data and analytics 668 846 1,514 558 715 1,273 481 640 1,121 Enterprise risk solutions 219 346 565 201 321 522 170 281 451 Professional services (PS) (1) — — — 64 95 159 60 99 159 Total MA 887 1,192 2,079 823 1,131 1,954 711 1,020 1,731 Total MCO $ 2,955 $ 2,416 $ 5,371 $ 2,544 $ 2,285 $ 4,829 $ 2,330 $ 2,113 $ 4,443 (1) Subsequent to the divestiture of MAKS in 2019, revenue from the MALS reporting unit, which previous to 2020 was reported in the PS LOB, is now reported as part of the RD&A LOB. Prior periods have not been reclassified as the amounts were not material. The following table presents the Company's reportable segment revenues disaggregated by segment and geographic region: Year Ended December 31, 2020 2019 2018 MIS: U.S. $ 2,068 $ 1,721 $ 1,619 Non-U.S.: EMEA 727 686 669 Asia-Pacific 345 320 300 Americas 152 148 124 Total Non-U.S. 1,224 1,154 1,093 Total MIS 3,292 2,875 2,712 MA: U.S. 887 823 711 Non-U.S.: EMEA 818 760 708 Asia-Pacific 226 231 193 Americas 148 140 119 Total Non-U.S. 1,192 1,131 1,020 Total MA 2,079 1,954 1,731 Total MCO $ 5,371 $ 4,829 $ 4,443 The tables below 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 outsourcing engagements 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. Year Ended December 31, 2020 2019 2018 Transaction Relationship Total Transaction Relationship Total Transaction Relationship Total Corporate Finance $ 1,401 $ 456 $ 1,857 $ 1,057 $ 440 $ 1,497 $ 949 $ 430 $ 1,379 75 % 25 % 100 % 71 % 29 % 100 % 69 % 31 % 100 % Structured Finance $ 175 $ 187 $ 362 $ 246 $ 181 $ 427 $ 310 $ 171 $ 481 48 % 52 % 100 % 58 % 42 % 100 % 64 % 36 % 100 % Financial Institutions $ 265 $ 265 $ 530 $ 212 $ 264 $ 476 $ 187 $ 255 $ 442 50 % 50 % 100 % 45 % 55 % 100 % 42 % 58 % 100 % Public, Project and Infrastructure Finance $ 337 $ 159 $ 496 $ 292 $ 154 $ 446 $ 238 $ 153 $ 391 68 % 32 % 100 % 65 % 35 % 100 % 61 % 39 % 100 % MIS Other $ 4 $ 43 $ 47 $ 2 $ 27 $ 29 $ 2 $ 17 $ 19 9 % 91 % 100 % 7 % 93 % 100 % 11 % 89 % 100 % Total MIS $ 2,182 $ 1,110 $ 3,292 $ 1,809 $ 1,066 $ 2,875 $ 1,686 $ 1,026 $ 2,712 66 % 34 % 100 % 63 % 37 % 100 % 62 % 38 % 100 % Research, data and analytics $ 74 $ 1,440 $ 1,514 $ 16 $ 1,257 $ 1,273 $ 18 $ 1,103 $ 1,121 5 % 95 % 100 % 1 % 99 % 100 % 2 % 98 % 100 % Enterprise risk solutions $ 118 $ 447 $ 565 $ 118 $ 404 $ 522 $ 99 $ 352 $ 451 21 % 79 % 100 % 23 % 77 % 100 % 22 % 78 % 100 % Professional services (1) $ — $ — $ — $ 159 $ — $ 159 $ 159 $ — $ 159 — % — % — % 100 % — % 100 % 100 % — % 100 % Total MA $ 192 $ 1,887 $ 2,079 $ 293 $ 1,661 $ 1,954 $ 276 $ 1,455 $ 1,731 9 % 91 % 100 % 15 % 85 % 100 % 16 % 84 % 100 % Total Moody’s Corporation $ 2,374 $ 2,997 $ 5,371 $ 2,102 $ 2,727 $ 4,829 $ 1,962 $ 2,481 $ 4,443 44 % 56 % 100 % 44 % 56 % 100 % 44 % 56 % 100 % (1) Subsequent to the divestiture of MAKS in 2019, the RD&A LOB now includes revenue from MALS beginning in the first quarter of 2020. MALS revenue was previously reported as part of the PS LOB and prior year revenue by LOB has not been reclassified as the amounts were not material. The following table presents the timing of revenue recognition: Year Ended December 31, 2020 Year Ended December 31, 2019 Year Ended December 31, 2018 MIS MA Total MIS MA Total MIS MA Total Revenue recognized at a point in time $ 2,182 $ 121 $ 2,303 $ 1,809 $ 132 $ 1,941 $ 1,686 $ 99 $ 1,785 Revenue recognized over time 1,110 1,958 3,068 1,066 1,822 2,888 1,026 1,632 2,658 Total $ 3,292 $ 2,079 $ 5,371 $ 2,875 $ 1,954 $ 4,829 $ 2,712 $ 1,731 $ 4,443
Schedule of Changes in the Deferred Revenue Balances	Significant changes in the deferred revenue balances during the year ended December 31, 2020 are as follows: Year Ended December 31, 2020 MIS MA Total Balance at December 31, 2019 $ 322 $ 840 $ 1,162 Changes in deferred revenue Revenue recognized that was included in the deferred revenue balance at the beginning of the period (229) (800) (1,029) Increases due to amounts billable excluding amounts recognized as revenue during the period 215 792 1,007 Increases due to acquisitions during the period — 24 24 Effect of exchange rate changes 5 18 23 Total changes in deferred revenue (9) 34 25 Balance at December 31, 2020 $ 313 $ 874 $ 1,187 Deferred revenue - current $ 216 $ 873 $ 1,089 Deferred revenue - noncurrent $ 97 $ 1 $ 98 Significant changes in the deferred revenue balances during the year ended December 31, 2019 are as follows: Year Ended December 31, 2019 MIS MA Total Balance at December 31, 2018 $ 325 $ 750 $ 1,075 Changes in deferred revenue Revenue recognized that was included in the deferred revenue balance at the beginning of the period (209) (714) (923) Increases due to amounts billable excluding amounts recognized as revenue during the period 202 789 991 Increases due to acquisitions during the period 3 6 9 Effect of exchange rate changes 1 9 10 Total changes in deferred revenue (3) 90 87 Balance at December 31, 2019 $ 322 $ 840 $ 1,162 Deferred revenue—current $ 214 $ 836 $ 1,050 Deferred revenue—noncurrent $ 108 $ 4 $ 112 Significant changes in the deferred revenue balances during the year ended December 31, 2018 are as follows: Year Ended December 31, 2018 MIS MA Total Balance at January 1, 2018 (after New Revenue Accounting Standard transition adjustment) $ 334 $ 612 $ 946 Changes in deferred revenue Revenue recognized that was included in the deferred revenue balance at the beginning of the period (218) (590) (808) Increases due to amounts billable excluding amounts recognized as revenue during the period 216 730 946 Increases due to acquisitions during the period — 16 16 Effect of exchange rate changes (7) (18) (25) Total changes in deferred revenue (9) 138 129 Balance at December 31, 2018 $ 325 $ 750 $ 1,075 Deferred revenue—current $ 207 $ 746 $ 953 Deferred revenue—noncurrent $ 118 $ 4 $ 122

RECONCILIATION OF WEIGHTED AV_2

RECONCILIATION OF WEIGHTED AVERAGE SHARES OUTSTANDING (Tables)	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Reconciliation of Basic to Diluted Shares Outstanding	Below is a reconciliation of basic to diluted shares outstanding: Year Ended December 31, 2020 2019 2018 Basic 187.6 189.3 191.6 Dilutive effect of shares issuable under stock-based compensation plans 1.7 2.3 2.8 Diluted 189.3 191.6 194.4 Antidilutive options to purchase common shares and restricted stock as well as contingently issuable restricted stock which are excluded from the table above 0.2 0.2 0.4

CASH EQUIVALENTS AND INVESTME_2

CASH EQUIVALENTS AND INVESTMENTS (Tables)	12 Months Ended
	Dec. 31, 2020
Cash and Cash Equivalents [Abstract]
CASH EQUIVALENTS AND INVESTMENTS	The table below provides additional information on the Company’s cash equivalents and investments: As of December 31, 2020 Cost Gross Unrealized Gains Fair Value Balance sheet location Cash and cash equivalents Short-term investments Other assets Certificates of deposit and money market deposit accounts (1) $ 1,430 $ — $ 1,430 $ 1,325 $ 99 $ 6 Mutual funds $ 54 $ 6 $ 60 $ — $ — $ 60 As of December 31, 2019 Cost Gross Unrealized Gains Fair Value Balance sheet location Cash and cash equivalents Short-term investments Other assets Certificates of deposit and money market deposit accounts (1) $ 971 $ — $ 971 $ 866 $ 95 $ 10 Mutual funds $ 3 $ — $ 3 $ — $ 3 $ — (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

DERIVATIVE INSTRUMENTS AND HE_2

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES (Tables)	12 Months Ended
	Dec. 31, 2020
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: Nature of Swap Notional Amount Floating Interest Rate Hedged Item 2020 2019 2012 Senior Notes due 2022 Pay Floating/Receive Fixed $ 330 $ 330 3-month LIBOR 2017 Senior Notes due 2021 (1) Pay Floating/Receive Fixed $ — $ 500 3-month LIBOR 2017 Senior Notes due 2023 Pay Floating/Receive Fixed $ 250 $ 250 3-month LIBOR 2017 Senior Notes due 2028 (2) Pay Floating/Receive Fixed $ 500 $ — 3-month LIBOR 2020 Senior Notes due 2025 (3) Pay Floating/Receive Fixed $ 300 $ — 6-month LIBOR Total $ 1,380 $ 1,080 (1) These interest rates swaps were terminated in conjunction with the repayment of the 2017 Senior Notes due 2021 in the third quarter of 2020. (2) These interest rate swaps were executed in the first quarter of 2020. (3) These interest rate swaps were executed in the third quarter of 2020. 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 December 31, 2019 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 931 Based on 3-month EURIBOR 1,080 Based on 3-month USD LIBOR Total € 2,010 $ 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 Year Ended December 31, 2020 2019 2018 Interest expense, net $ (205) $ (208) $ (215) Location on Consolidated Statements of Operations Net interest settlements and accruals on interest rate swaps Interest expense, net $ 19 $ 3 $ (2) Fair value changes on interest rate swaps Interest expense, net 47 25 2 Fair value changes on hedged debt Interest expense, net $ (47) $ (25) $ (2)
Schedule of Net Investment Hedges, Notional Amount That Will Be Settled At Expiry	As of December 31, 2020, these hedges will expire and the notional amounts will be settled as follows unless terminated early at the discretion of the Company: Year Ending December 31, 2021 € 265 2022 € 438 2023 € 442 2024 € 443 2026 € 450 Total € 2,038
Summary of Notional Amounts of Outstanding Derivative Positions	The following table summarizes the notional amounts of the Company's outstanding forward contracts that were designated as net investment hedges: December 31, 2020 December 31, 2019 Notional amount of net investment hedges Sell Buy Sell Buy Contract to sell EUR for USD € 524 $ 627 — — Contract to sell GBP for EUR £ 134 € 148 — — The following table summarizes the notional amounts of the Company’s outstanding foreign exchange forwards: December 31, 2020 December 31, 2019 Notional Amount of Currency Pair: Sell Buy Sell Buy Contracts to sell USD for GBP $ 295 £ 222 $ 235 £ 178 Contracts to sell USD for Japanese Yen $ 15 ¥ 1,600 $ 29 ¥ 3,200 Contracts to sell USD for Canadian dollars $ 107 C$ 140 $ 83 C$ 110 Contracts to sell USD for Singapore dollars $ 59 S$ 79 $ 41 S$ 56 Contracts to sell USD for Euros $ 447 € 376 $ 421 € 378 Contracts to sell Euros for GBP € 135 £ 121 € 25 £ 21 Contracts to sell USD for Russian Ruble $ 13 ₽ 1,000 $ — ₽ — Contracts to sell USD for Indian Rupee $ 18 ₹ 1,350 $ — ₹ — NOTE: € = Euro, £ = British pound, S$ = Singapore dollar, $ = U.S. dollar, ¥ = Japanese yen, C$ = Canadian dollar, ₽ = Russian Ruble, ₹= Indian Rupee
Amount of Gain/(Loss) Recognized in AOCI on Derivative Net Investment Hedging Relationships	The following table provides information on the gains/(losses) on the Company’s net investment and cash flow hedges: Amount of Gain/(Loss) Amount of Gain/(Loss) Gain/(Loss) Recognized in Derivative and Non-Derivative Instruments in Net Investment Hedging Relationships Year Ended December 31, Year Ended December 31, Year Ended December 31, 2020 2019 2018 2020 2019 2018 2020 2019 2018 FX forward contracts $ (14) $ 4 $ — $ — $ 2 $ — $ — $ — $ — Cross currency swaps (165) 29 12 — — — 50 52 11 Long-term debt (95) (7) (1) 22 — — — — — — Total net investment hedges $ (274) $ 26 $ 34 $ — $ 2 $ — $ 50 $ 52 $ 11 Derivatives in Cash Flow Hedging Relationships Cross currency swap $ — $ — $ 2 $ — $ — $ — $ — $ — $ — Interest rate contracts (51) — (2) (2) — — — — — Total cash flow hedges (51) — — (2) — — — — — Total $ (325) $ 26 $ 34 $ (2) $ 2 $ — $ 50 $ 52 $ 11 (1) Due to the Company's adoption of ASU 2018-02 during 2019, $3 million related to the tax effect of this net investment hedge was reclassified to retained earnings.
Components of Accumulated Other Comprehensive Income	The cumulative amount of net investment hedge and cash flow hedge gains (losses) remaining in AOCI is as follows: Cumulative Gains/(Losses), net of tax December 31, 2020 December 31, 2019 Net investment hedges Cross currency swaps $ (124) $ 41 FX forwards 12 26 Long-term debt (108) (13) Total net investment hedges (220) 54 Cash flow hedges Interest Rate Contract (51) (2) Cross-currency swap 2 2 Total cash flow hedges (49) — Total net (loss) gain in AOCI $ (269) $ 54 The following table shows changes in AOCI by component (net of tax): Year Ended December 31, 2020 Pension and Other Retirement Benefits Gains / (Losses) on 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 (32) (51) 356 (273) — Amounts reclassified from AOCI 6 2 — (1) 7 Other comprehensive income/(loss) (26) (49) 356 (274) 7 Balance December 31, 2020 $ (118) $ (49) $ (45) $ (220) $ (432) Year Ended December 31, 2019 Pension and Other Retirement Benefits Gains / (Losses) on Cash Flow Hedges Foreign Currency Translation Adjustments Net Investment Hedges Total Balance December 31, 2018 $ (53) $ — $ (406) $ 33 $ (426) Adoption of ASU 2018-02 (17) — — (3) (20) Other comprehensive income/(loss) before reclassifications (24) — (27) 26 (25) Amounts reclassified from AOCI 2 — 32 (2) 32 Other comprehensive income/(loss) (39) — 5 21 (13) Balance December 31, 2019 $ (92) $ — $ (401) $ 54 $ (439) Year Ended December 31, 2018 Pension and Other Retirement Benefits Gains / (Losses) on Cash Flow Hedges Foreign Currency Translation Adjustments Net Investment Hedges Gains on Available for Sale Securities Total Balance December 31, 2017 $ (61) $ 1 $ (113) $ (1) $ 2 $ (172) Adoption of ASU 2016-01 — — — — (2) (2) Other comprehensive income/(loss) before reclassifications 4 (1) (293) 34 — (256) Amounts reclassified from AOCI 4 — — — — 4 Other comprehensive income/(loss) 8 (1) (293) 34 (2) (254) Balance December 31, 2018 $ (53) $ — $ (406) $ 33 $ — $ (426)
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 gain (loss) on the Company’s derivatives which are not designated as hedging instruments: Year Ended December 31, Derivatives Not Designated as Accounting Hedges Location on Statement of Operations 2020 2019 2018 FX forwards Other non-operating expense, net $ 41 $ (11) $ (52)
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 derivative instruments 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 December 31, 2020 December 31, 2019 Assets: Derivatives designated as accounting hedges: Cross-currency swaps designated as net investment hedges Other assets $ — $ 56 Interest rate swaps designated as fair value hedges Other assets 57 27 Total derivatives designated as accounting hedges 57 83 Derivatives not designated as accounting hedges: FX forwards on certain assets and liabilities Other current assets 31 9 Total assets $ 88 $ 92 Liabilities: Derivatives designated as accounting hedges: FX forwards designated as net investment hedges Accounts payable and accrued liabilities $ 16 $ — Cross-currency swaps designated as net investment hedges Accounts payable and accrued liabilities 23 — Cross-currency swaps designated as net investment hedges Other liabilities 144 — Interest rate swaps Other liabilities 1 — Total derivatives designated as accounting hedges 184 — Non-derivative instrument designated as accounting hedge: Long-term debt designated as net investment hedge Long-term debt 1,530 1,403 Derivatives not designated as accounting hedges: FX forwards on certain assets and liabilities Accounts payable and accrued liabilities 2 — Total liabilities $ 1,716 $ 1,403

PROPERTY AND EQUIPMENT, NET (Ta

PROPERTY AND EQUIPMENT, NET (Tables)	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Property and Equipment, Net	Property and equipment, net consisted of: December 31, 2020 2019 Office and computer equipment (3 - 10 year estimated useful life) $ 260 $ 221 Office furniture and fixtures (3 - 10 year estimated useful life) 49 51 Internal-use computer software (1 - 10 year estimated useful life) 666 619 Leasehold improvements and building (1 - 21 year estimated useful life) 231 240 Total property and equipment, at cost 1,206 1,131 Less: accumulated depreciation and amortization (928) (839) Total property and equipment, net $ 278 $ 292

ACQUISITIONS AND DIVESTITURE (T

ACQUISITIONS AND DIVESTITURE (Tables)	12 Months Ended
	Dec. 31, 2020
Business Combinations [Abstract]
Schedule of Business Acquisitions, by Acquisition	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: (Amounts in millions) Current assets $ 32 Property and equipment 4 Intangible assets: Customer relationships (14 year weighted average life) $ 77 Database (5 year weighted average life) 13 Product technology (7 year weighted average life) 10 Trade name (10 year weighted average life) 4 Total intangible assets (12 year weighted average life) 104 Goodwill 183 Deferred tax assets 13 Liabilities: Deferred revenue $ (14) Accounts payable and accrued liabilities (20) Deferred tax liabilities (24) Total liabilities (58) Net assets acquired $ 278 The following table summarizes the aggregate preliminary estimates of fair value of the assets acquired and liabilities assumed as of the respective closing dates for each acquisition. (Amounts in millions) Current assets $ 5 Intangible assets: Customer relationships (18 year weighted average life) $ 47 Product technology (8 year weighted average life) 23 Database (10 year weighted average life) 8 Trade name (14 year weighted average life) 4 Total intangible assets (14 year weighted average life) 82 Goodwill 131 Other assets 3 Total assets acquired 221 Current liabilities 8 Long-term liabilities 8 Total liabilities assumed 16 Net assets acquired $ 205
Summary of Fair Values of Assets Acquired and Liabilities Assumed	Shown below is the purchase price allocation, which summarizes the fair value of the assets and liabilities assumed, at the date of acquisition: (Amounts in millions) Current assets $ 24 Intangible assets: Customer relationships (25 year weighted average life) $ 174 Database (10 year weighted average life) 86 Product technology (4 year weighted average life) 17 Trade name (3 year weighted average 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

GOODWILL AND OTHER ACQUIRED I_2

GOODWILL AND OTHER ACQUIRED INTANGIBLE ASSETS (Tables)	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Activity in Goodwill	The following table summarizes the activity in goodwill: Year Ended December 31, 2020 MIS MA Consolidated Gross Accumulated Net Gross Accumulated Net Gross Accumulated Net Balance at beginning of year $ 315 $ — $ 315 $ 3,419 $ (12) $ 3,407 $ 3,734 $ (12) $ 3,722 Additions/ adjustments (1) (2) — (2) 628 — 628 626 — 626 Foreign currency translation adjustments (2) — (2) 210 — 210 208 — 208 Ending Balance $ 311 $ — $ 311 $ 4,257 $ (12) $ 4,245 $ 4,568 $ (12) $ 4,556 Year Ended December 31, 2019 MIS MA Consolidated Gross Accumulated Net Gross Accumulated Net Gross Accumulated Net Balance at beginning of year $ 258 $ — $ 258 $ 3,535 $ (12) $ 3,523 $ 3,793 $ (12) $ 3,781 Additions/ adjustments (2) 53 — 53 61 — 61 114 — 114 Foreign currency translation adjustments 4 — 4 (14) — (14) (10) — (10) Divestiture of MAKS $ (163) $ (163) $ (163) $ — $ (163) Ending balance $ 315 $ — $ 315 $ 3,419 $ (12) $ 3,407 $ 3,734 $ (12) $ 3,722 (1) The 2020 additions/adjustments for the MA segment in the table above relate to the acquisitions of RDC, AM, ZMFS, and Catylist. (2) The 2019 additions/adjustments for the MIS segment in the table above relate to the acquisitions of Vigeo Eiris and Four Twenty Seven. The 2019 additions/adjustments for the MA segment in the table above relate to the acquisitions of RiskFirst and ABS Suite.
Acquired Intangible Assets and Related Amortization	Acquired intangible assets and related amortization consisted of: December 31, 2020 2019 Customer relationships $ 1,623 $ 1,325 Accumulated amortization (313) (235) Net customer relationships 1,310 1,090 Trade secrets 30 30 Accumulated amortization (29) (29) Net trade secrets 1 1 Software/product technology 417 372 Accumulated amortization (166) (131) Net software/product technology 251 241 Trade names 161 150 Accumulated amortization (38) (30) Net trade names 123 120 Other (1) 192 80 Accumulated amortization (53) (34) Net other 139 46 Total $ 1,824 $ 1,498 (1) Other intangible assets primarily consist of databases, 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: Year Ended December 31, 2020 2019 2018 Amortization expense $ 124 $ 103 $ 102
Estimated Future Amortization Expense for Acquired Intangible Assets Subject to Amortization	Estimated future annual amortization expense for intangible assets subject to amortization is as follows: Year Ending December 31, 2021 $ 131 2022 131 2023 126 2024 119 2025 117 Thereafter 1,200 Total estimated future amortization $ 1,824

RESTRUCTURING (Tables)

RESTRUCTURING (Tables)	12 Months Ended
	Dec. 31, 2020
Restructuring and Related Activities [Abstract]
Restructuring Expenses Included in Consolidated Statements of Operations	Total expenses included in the accompanying consolidated statements of operations relating to the Company's restructuring programs are as follows: Year Ended December 31, 2020 2019 2018 2018 Restructuring Program $ (4) $ 60 $ 49 2020 Real Estate Rationalization Restructuring Program 36 — — 2020 MA Strategic Reorganization Restructuring Program 18 — — Total Restructuring $ 50 $ 60 $ 49
Changes to the Restructuring Liability	Changes to the restructuring liability were as follows: Employee Termination Costs Contract Termination Costs Total Restructuring Liability Balance as of December 31, 2018 $ 30 $ 12 $ 42 2018 Restructuring Program (1) : Adoption of New Lease Accounting Standard (2) — (11) (11) Cost incurred and adjustments 26 5 31 Cash payments and adjustments (35) (3) (38) Balance as of December 31, 2019 $ 21 $ 3 $ 24 2018 Restructuring Program: Cost incurred and adjustments (4) — (4) Cash payments and adjustments (17) (1) (18) 2020 Real Estate Rationalization Restructuring Program (3) : Cost incurred and adjustments — 1 1 2020 MA Strategic Reorganization Restructuring Program: Cost incurred and adjustments 18 — 18 Balance as of December 31, 2020 $ 18 $ 3 $ 21 Cumulative expense incurred to date 2018 Restructuring Program $ 55 $ 50 2020 Real Estate Rationalization Restructuring Program: $ — $ 36 2020 MA Strategic Reorganization Restructuring Program: $ 18 $ — (1) The liability excludes $4 million of non-cash acceleration of amortization of leasehold improvements relating to the rationalization and exit of certain real estate leases as well as $25 million of ROU Asset impairment charges for the year ended December 31, 2019. The fair value of the impaired ROU Assets was determined by utilizing the present value of the estimated future cash flows attributable to the assets. The fair value of those ROU assets subsequent to the impairment was $18 million, and is categorized as Level 3 within the ASC Topic 820 fair value hierarchy. (2) Upon the adoption of the New Lease Accounting Standard (3) The liability excludes $13 million of non-cash acceleration of amortization of leasehold improvements relating to the rationalization and exit of certain real estate leases as well as $21 million of ROU Asset impairment charges for the year ended December 31, 2020. The fair value of the impaired ROU Assets was determined by utilizing the present value of the estimated future cash flows attributable to the assets. The fair value of those ROU assets subsequent to the impairment was $10 million, and is categorized as Level 3 within the ASC Topic 820 fair value hierarchy.

FAIR VALUE (Tables)

FAIR VALUE (Tables)	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Financial Instruments Carried at Fair Value on Recurring Basis	The table below presents information about items which are carried at fair value on a recurring basis at December 31, 2020 and 2019: 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 Fair Value Measurement as of December 31, 2019 Description Balance Level 1 Level 2 Assets: Derivatives (1) $ 92 $ — $ 92 Mutual funds 3 3 — Total $ 95 $ 3 $ 92 (1) Represents FX forwards on certain assets and liabilities as well as interest rate swaps and cross-currency swaps as more fully described in Note 7 to the consolidated financial statements.

OTHER BALANCE SHEET INFORMATI_2

OTHER BALANCE SHEET INFORMATION (Tables)	12 Months Ended
	Dec. 31, 2020
Other Balance Sheet Information [Abstract]
Additional Details Related to Certain Balance Sheet Captions	The following tables contain additional detail related to certain balance sheet captions: December 31, 2020 2019 Other current assets: Prepaid taxes $ 94 $ 79 Prepaid expenses 91 71 Capitalized costs to obtain and fulfill sales contracts 93 91 Foreign exchange forwards on certain assets and liabilities 31 9 Other 74 80 Total other current assets $ 383 $ 330 December 31, 2020 2019 Other assets: Investments in non-consolidated affiliates $ 135 $ 117 Deposits for real-estate leases 19 13 Indemnification assets related to acquisitions 15 16 Mutual funds and fixed deposits 66 10 Company owned life insurance (at contract value) 17 — Costs to obtain sales contracts 134 119 Derivative instruments designated as accounting hedges 57 83 Pension and other retirement employee benefits 21 — Other 51 31 Total other assets $ 515 $ 389 December 31, 2020 2019 Accounts payable and accrued liabilities: Salaries and benefits $ 197 $ 152 Incentive compensation 226 208 Customer credits, advanced payments and advanced billings 42 28 Dividends 11 7 Professional service fees 53 43 Interest accrued on debt 82 63 Accounts payable 39 38 Income taxes 128 73 Pension and other retirement employee benefits 45 7 Accrued royalties 19 25 Foreign exchange forwards on certain assets and liabilities 2 — Restructuring liability 18 21 Derivative instruments designated as accounting hedges 39 — Other 138 108 Total accounts payable and accrued liabilities $ 1,039 $ 773 December 31, 2020 2019 Other liabilities: Pension and other retirement employee benefits $ 244 $ 299 Interest accrued on UTPs 113 82 MAKS indemnification provisions 33 43 Income tax liability – non-current portion 18 51 Derivative instruments designated as accounting hedges 145 — Restructuring liability 3 3 Other 34 26 Total other liabilities $ 590 $ 504

COMPREHENSIVE INCOME AND ACCU_2

COMPREHENSIVE INCOME AND ACCUMULATED OTHER COMPREHENSIVE INCOME (Tables)	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Reclassifications out of AOCI	The following table provides details about the reclassifications out of AOCI: Year Ended December 31, Location in the consolidated 2020 2019 2018 Currency translation adjustment losses Sale of foreign subsidiaries $ — $ (32) $ — Loss pursuant to the divestiture of MAKS Total currency translation adjustment losses — (32) — Losses on cash flow hedges Interest rate contract (3) — — Other non-operating income (expense), net Income tax effect of item above 1 — — Provision for income taxes Total net losses on cash flow hedges (2) — — Gains on net investment hedges Cross currency swaps 1 — — Other non-operating income (expense), net FX forwards — 3 — Other non-operating income (expense), net Total before income taxes 1 3 — Income tax effect of item above — (1) — Provision for income taxes Total net gains on net investment hedges 1 2 — Pension and other retirement benefits Amortization of actuarial losses and prior service costs included in net income (6) (3) (5) Other non-operating income (expense), net Accelerated recognition of loss due to settlement (2) — — Other non-operating income (expense), net Total before income taxes (8) (3) (5) Income tax effect of item above 2 1 1 Provision for income taxes Total pension and other retirement benefits (6) (2) (4) Total losses included in Net Income attributable to reclassifications out of AOCI $ (7) $ (32) $ (4)
Components of Accumulated Other Comprehensive Income	The cumulative amount of net investment hedge and cash flow hedge gains (losses) remaining in AOCI is as follows: Cumulative Gains/(Losses), net of tax December 31, 2020 December 31, 2019 Net investment hedges Cross currency swaps $ (124) $ 41 FX forwards 12 26 Long-term debt (108) (13) Total net investment hedges (220) 54 Cash flow hedges Interest Rate Contract (51) (2) Cross-currency swap 2 2 Total cash flow hedges (49) — Total net (loss) gain in AOCI $ (269) $ 54 The following table shows changes in AOCI by component (net of tax): Year Ended December 31, 2020 Pension and Other Retirement Benefits Gains / (Losses) on 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 (32) (51) 356 (273) — Amounts reclassified from AOCI 6 2 — (1) 7 Other comprehensive income/(loss) (26) (49) 356 (274) 7 Balance December 31, 2020 $ (118) $ (49) $ (45) $ (220) $ (432) Year Ended December 31, 2019 Pension and Other Retirement Benefits Gains / (Losses) on Cash Flow Hedges Foreign Currency Translation Adjustments Net Investment Hedges Total Balance December 31, 2018 $ (53) $ — $ (406) $ 33 $ (426) Adoption of ASU 2018-02 (17) — — (3) (20) Other comprehensive income/(loss) before reclassifications (24) — (27) 26 (25) Amounts reclassified from AOCI 2 — 32 (2) 32 Other comprehensive income/(loss) (39) — 5 21 (13) Balance December 31, 2019 $ (92) $ — $ (401) $ 54 $ (439) Year Ended December 31, 2018 Pension and Other Retirement Benefits Gains / (Losses) on Cash Flow Hedges Foreign Currency Translation Adjustments Net Investment Hedges Gains on Available for Sale Securities Total Balance December 31, 2017 $ (61) $ 1 $ (113) $ (1) $ 2 $ (172) Adoption of ASU 2016-01 — — — — (2) (2) Other comprehensive income/(loss) before reclassifications 4 (1) (293) 34 — (256) Amounts reclassified from AOCI 4 — — — — 4 Other comprehensive income/(loss) 8 (1) (293) 34 (2) (254) Balance December 31, 2018 $ (53) $ — $ (406) $ 33 $ — $ (426)

PENSION AND OTHER RETIREMENT _2

PENSION AND OTHER RETIREMENT BENEFITS (Tables)	12 Months Ended
	Dec. 31, 2020
Retirement Benefits [Abstract]
Summary of Changes in Benefit Obligations and Fair Value of Plan Assets for Retirement Plans	Following is a summary of changes in benefit obligations and fair value of plan assets for the Retirement Plans for the years ended December 31: Pension Plans Other Retirement Plans 2020 2019 2020 2019 Change in benefit obligation: Benefit obligation, beginning of the period $ (589) $ (508) $ (42) $ (32) Service cost (17) (17) (3) (3) Interest cost (17) (21) (1) (1) Plan participants’ contributions — — (1) (1) Benefits paid 22 21 2 1 Actuarial gain (loss) 6 (3) 2 — Assumption changes (68) (61) (5) (6) Benefit obligation, end of the period $ (663) $ (589) $ (48) $ (42) Change in plan assets: Fair value of plan assets, beginning of the period $ 395 $ 348 $ — $ — Actual return on plan assets 45 60 — — Benefits paid (22) (21) (2) (1) Employer contributions 110 8 1 — Plan participants’ contributions — — 1 1 Fair value of plan assets, end of the period $ 528 $ 395 $ — $ — Funded Status of the plans $ (135) $ (194) $ (48) $ (42) Amounts recorded on the consolidated balance sheets: Pension and retirement benefits asset – non current $ 21 $ — $ — $ — Pension and retirement benefits liability – current (44) (6) (1) (1) Pension and retirement benefits liability – non current (112) (188) (47) (41) Net amount recognized $ (135) $ (194) $ (48) $ (42) Accumulated benefit obligation, end of the period $ (601) $ (529)
Accumulated Benefit Obligation in Excess of Plan Assets	The following information is for those pension plans with an accumulated benefit obligation in excess of plan assets: December 31, 2020 2019 Aggregate projected benefit obligation $ 156 $ 589 Aggregate accumulated benefit obligation $ 138 $ 529 Aggregate fair value of plan assets $ — $ 395
Summary of Pre-Tax Net Actuarial Losses and Prior Service Cost Recognized in AOCI	The following table summarizes the pre-tax net actuarial losses and prior service cost recognized in AOCI for the Company’s Retirement Plans as of December 31: Pension Plans Other Retirement Plans 2020 2019 2020 2019 Net actuarial losses $ (144) $ (116) $ (8) $ (6) Net prior service credits 3 4 — — Total recognized in AOCI – pretax $ (141) $ (112) $ (8) $ (6)
Components of Net Periodic Benefit Expense Related to Retirement Plans	Net periodic benefit expenses recognized for the Retirement Plans for years ended December 31: Pension Plans Other Retirement Plans 2020 2019 2018 2020 2019 2018 Components of net periodic expense Service cost $ 17 $ 17 $ 19 $ 3 $ 3 $ 3 Interest cost 17 21 17 1 1 1 Expected return on plan assets (20) (20) (15) — — — Amortization of net actuarial loss and prior service credits from earlier periods 7 4 6 — — — Net periodic expense $ 21 $ 22 $ 27 $ 4 $ 4 $ 4
Summary of Pre-Tax Amounts Recorded in OCI	The following table summarizes the pre-tax amounts recorded in OCI related to the Company’s Retirement Plans for the years ended December 31: Pension Plans Other Retirement Plans 2020 2019 2018 2020 2019 2018 Amortization of net actuarial losses and prior service credit $ 7 $ 4 $ 6 $ — $ — $ — Settlement loss 2 — — — — — Net actuarial (loss)/gain arising during the period (37) (24) 2 (3) (6) 3 Total recognized in OCI – pre-tax $ (28) $ (20) $ 8 $ (3) $ (6) $ 3
Weighted-average Assumptions Used to Determine Benefit Obligations and Net Periodic Benefit Expenses	Weighted-average assumptions used to determine benefit obligations at December 31: Pension Plans Other Retirement Plans 2020 2019 2020 2019 Discount rate 2.24 % 3.04 % 2.30 % 3.05 % Rate of compensation increase 3.62 % 3.64 % — — Weighted-average assumptions used to determine net periodic benefit expense for years ended December 31: Pension Plans Other Retirement Plans 2020 2019 2018 2020 2019 2018 Discount rate 3.04 % 4.07 % 3.46 % 3.05 % 4.10 % 3.45 % Expected return on plan assets 4.45 % 5.65 % 4.50 % — — — Rate of compensation increase 3.64 % 3.69 % 3.71 % — — — Cash balance plan interest crediting rate 4.50 % 4.50 % 4.50 % — — —
Summary of Pension Plan Assets by Category Based on Hierarchy of Fair Value Measurements	Fair value of the assets in the Company’s funded pension plan by asset category at December 31, 2020 and 2019 are as follows: Fair Value Measurement as of December 31, 2020 Asset Category Balance Level 1 Level 2 Measured using NAV practical expedient (1) % of total Cash and cash equivalent $ 4 $ — $ 4 $ — 1 % Common/collective trust funds—equity securities U.S. large-cap 143 — 143 — 27 % U.S. small and mid-cap 28 — 28 — 5 % Emerging markets 32 — 32 — 6 % Total equity investments 203 — 203 — 38 % Emerging markets bond fund 32 — — 32 6 % Common/collective trust funds—fixed income securities Intermediate-term investment grade U.S. government/ corporate bonds 214 — 214 — 41 % Mutual funds U.S. Treasury Inflation-Protected Securities (TIPs) 23 23 — — 4 % Convertible securities 16 16 — — 3 % Private investment fund—high yield securities 12 — — 12 2 % Total fixed-income investments 297 39 214 44 56 % Other investment—private real estate fund 24 — — 24 5 % Total Assets $ 528 $ 39 $ 421 $ 68 100 % Fair Value Measurement as of December 31, 2019 Asset Category Balance Level 1 Level 2 Measured using NAV practical expedient (1) % of total Cash and cash equivalent $ 2 $ — $ 2 $ — 1 % Common/collective trust funds—equity securities U.S. large-cap 140 — 140 — 35 % U.S. small and mid-cap 21 — 21 — 5 % Emerging markets 29 — 29 — 7 % Total equity investments 190 — 190 — 48 % Emerging markets bond fund 15 — — 15 4 % Common/collective trust funds—fixed income securities Intermediate-term investment grade U.S. government/ corporate bonds 119 — 119 — 30 % U.S. Treasury Inflation-Protected Securities (TIPs) 22 22 — — 6 % Private investment fund—convertible securities 12 12 — — 3 % Private investment fund—high yield securities 12 — — 12 3 % Total fixed-income investments 180 34 119 27 46 % Other investment—private real estate debt fund 23 — — 23 6 % Total Assets $ 395 $ 34 $ 311 $ 50 100 % (1) Investments are measured using the net asset value per share (or its equivalent) practical expedient and have not been categorized in the fair value hierarchy. The fair value amounts presented in the table are intended to permit a reconciliation of the fair value hierarchy to the value of the total plan assets.
Estimated Future Benefits Payments for Retirement Plans	Estimated future benefits payments for the Retirement Plans are as follows as of year ended December 31, 2020: Year Ending December 31, Pension Plans Other Retirement Plans 2021 $ 55 $ 1 2022 17 1 2023 25 2 2024 21 2 2025 24 2 2026 - 2030 $ 139 $ 13

STOCK-BASED COMPENSATION PLANS

STOCK-BASED COMPENSATION PLANS (Tables)	12 Months Ended
	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-Based Compensation Cost and Associated Tax Benefit	Presented below is a summary of the stock-based compensation expense and associated tax benefit in the accompanying Consolidated Statements of Operations: Year Ended December 31, 2020 2019 2018 Stock-based compensation expense $ 154 $ 136 $ 130 Tax benefit $ 30 $ 29 $ 32
Weighted Average Assumptions used in Determining Fair Value for Options Granted	The following weighted average assumptions were used for options granted: Year Ended December 31, 2020 2019 2018 Expected dividend yield 0.80 % 1.14 % 1.05 % Expected stock volatility 23 % 24 % 26 % Risk-free interest rate 1.43 % 2.56 % 2.82 % Expected holding period -in years 5.7 6.2 6.2 Grant date fair value $ 60.66 $ 43.29 $ 45.73
Share-based Payment Arrangement, Option and Stock Appreciation Rights, Activity	A summary of option activity as of December 31, 2020 and changes during the year then ended is presented below: Options Shares Weighted Average Exercise Price Per Share Weighted Average Remaining Contractual Term Aggregate Intrinsic Value Outstanding, December 31, 2019 1.6 $ 93.51 Granted 0.1 280.37 Exercised (0.7) 59.57 Outstanding, December 31, 2020 1.0 133.95 5.6 years $ 160 Vested and expected to vest, December 31, 2020 1.0 132.80 5.6 years $ 158 Exercisable, December 31, 2020 0.7 $ 101.13 4.6 years $ 125
Stock Option Exercises and Restricted Stock Vesting	The following table summarizes information relating to stock option exercises: Year Ended December 31, 2020 2019 2018 Proceeds from stock option exercises 39 36 38 Aggregate intrinsic value 132 114 99 Tax benefit realized upon exercise 32 27 24
Non Vested Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity	A summary of nonvested restricted stock activity for the year ended December 31, 2020 is presented below: Nonvested Restricted Stock Shares Weighted Average Grant Date Fair Value Per Share Balance, December 31, 2019 1.8 $ 124.63 Granted 0.5 279.00 Vested (0.8) 132.50 Balance, December 31, 2020 1.5 $ 201.30
Share-based Compensation Arrangements by Share-based Payment Award, Restricted Stock Units, Vested and Expected to Vest	The following table summarizes information relating to the vesting of restricted stock awards: Year Ended December 31, 2020 2019 2018 Fair value of shares vested 202 156 151 Tax benefit realized upon vesting 46 36 35
Performance Based Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity	A summary of performance-based restricted stock activity for the year ended December 31, 2020 is presented below: Performance-based restricted stock Shares Weighted Average Grant Date Fair Value Per Share Balance, December 31, 2019 0.5 $ 134.35 Granted 0.1 273.81 Vested (0.3) 109.43 Balance, December 31, 2020 0.3 $ 197.19
Share-based Compensation Arrangements by Share-based Payment Award, Restricted Stock Units, Vested and Expected to Vest	The following table summarizes information relating to the vesting of the Company’s performance-based restricted stock awards: Year Ended December 31, 2020 2019 2018 Fair value of shares vested 70 47 23 Tax benefit realized upon vesting 17 11 6

INCOME TAXES (Tables)

INCOME TAXES (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Provision for Income Taxes	Components of the Company’s income tax provision are as follows: Year Ended December 31, 2020 2019 2018 Current: Federal $ 213 $ 179 $ 168 State and Local 68 59 50 Non-U.S. 215 181 233 Total current 496 419 451 Deferred: Federal 6 (19) (59) State and Local — (3) (2) Non-U.S. (50) (16) (38) Total deferred (44) (38) (99) Total provision for income taxes $ 452 $ 381 $ 352
Reconciliation of United States Federal Statutory Tax Rate to Effective Tax Rate on Income before Provision for Income Taxes	A reconciliation of the U.S. federal statutory tax rate to the Company’s effective tax rate on income before provision for income taxes is as follows: Year Ended December 31, 2020 2019 2018 U.S. statutory tax rate 21.0 % 21.0 % 21.0 % State and local taxes, net of federal tax benefit 2.3 % 2.2 % 2.2 % Benefit of foreign operations (1.5) % (0.1) % 1.8 % U.S. Tax Act impact — % — % (2.8) % Other (1.5) % (2.1) % (1.1) % Effective tax rate 20.3 % 21.0 % 21.1 % Income tax paid $ 514 $ 458 $ 442
Source of Income before Provision for Income Taxes	The source of income before provision for income taxes is as follows: Year Ended December 31, 2020 2019 2018 U.S. $ 1,349 $ 1,039 $ 936 Non-U.S. 880 771 736 Income before provision for income taxes $ 2,229 $ 1,810 $ 1,672
Components of Deferred Tax Assets and Liabilities	The components of deferred tax assets and liabilities are as follows: December 31, 2020 2019 Deferred tax assets: Account receivable allowances $ 9 $ 6 Accumulated depreciation and amortization 2 1 Stock-based compensation 42 46 Accrued compensation and benefits 99 89 Capitalized costs 39 — Operating lease liabilities 122 136 Deferred revenue 30 37 Net operating loss 17 13 Restructuring 3 4 Uncertain tax positions 98 94 Self-insured related reserves 10 8 Loss on net investment hedges - OCI 93 — Other 10 13 Total deferred tax assets 574 447 Deferred tax liabilities: Accumulated depreciation and amortization of intangible assets and capitalized software (468) (389) ROU Assets (90) (107) Capital Gains (23) (23) Self-insured related income (10) (8) Stock-based compensation — (2) Revenue Accounting Standard - ASC 606 (10) (12) Deferred tax on unremitted foreign earnings (16) — Gain on net investment hedges - OCI (8) (22) Other (4) (3) Total deferred tax liabilities (629) (566) Net deferred tax liabilities (55) (119) Valuation allowance (15) (9) Total net deferred tax liabilities $ (70) $ (128)
Reconciliation of Uncertain Tax Positions	A reconciliation of the beginning and ending amount of UTPs is as follows: Year Ended December 31, 2020 2019 2018 Balance as of January 1 $ 477 $ 495 $ 389 Additions for tax positions related to the current year 37 35 80 Additions for tax positions of prior years 17 22 89 Reductions for tax positions of prior years (2) (2) (13) Settlements with taxing authorities (5) (1) (2) Lapse of statute of limitations (41) (44) (48) Reclassification to indemnification liability related to MAKS divestiture — (28) — Balance as of December 31 $ 483 $ 477 $ 495

INDEBTEDNESS (Tables)

INDEBTEDNESS (Tables)	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Summary of Total Indebtedness	The following table summarizes total indebtedness: December 31, 2020 Principal Amount Fair Value of Interest Rate Swaps (1) Unamortized (Discount) Premium Unamortized Debt Issuance Costs Carrying Value Notes Payable: 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 Note, due 2025 700 (1) (1) (5) 693 3.25% 2020 Senior Note, due 2050 300 — (4) (3) 293 2.55% 2020 Senior Note, due 2060 500 — (4) (5) 491 Total long-term debt $ 6,430 $ 56 $ (24) $ (40) $ 6,422 December 31, 2019 Principal Amount Fair Value of Interest Rate Swaps (1) Unamortized (Discount) Premium Unamortized Debt Issuance Costs Carrying Value Notes Payable: 4.50% 2012 Senior Notes, due 2022 $ 500 $ 9 $ (1) $ (1) $ 507 4.875% 2013 Senior Notes, due 2024 500 — (1) (2) 497 5.25% 2014 Senior Notes, due 2044 600 — 4 (5) 599 1.75% 2015 Senior Notes due 2027 561 — — (3) 558 2.75% 2017 Senior Notes, due 2021 500 11 (1) (2) 508 2.625% 2017 Senior Notes, due 2023 500 7 (1) (2) 504 3.25% 2017 Senior Notes, due 2028 500 — (4) (3) 493 3.25% 2018 Senior Notes, due 2021 300 — — (1) 299 4.25% 2018 Senior Notes, due 2029 400 — (3) (3) 394 4.875% 2018 Senior Notes, due 2048 400 — (7) (4) 389 0.950% 2019 Senior Notes, due 2030 842 — (3) (6) 833 Total long-term debt $ 5,603 $ 27 $ (17) $ (32) $ 5,581 (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.
Schedule of Credit Facilities	The following summarizes information relating to the Company's revolving credit facility: December 31, 2020 December 31, 2019 Issue Date Capacity Maturity Drawn Undrawn Drawn Undrawn 2018 Credit Facility November 14, 2018 $ 1,000 November 13, 2023 $ — $ 1,000 $ — $ 1,000
Principal Payments Due on Long-term Borrowings	The repayment schedule for the Company’s borrowings is as follows: Year Ending 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 $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — 2022 500 — — — — — — — — — — — 500 2023 — — — — 500 — — — — — — — 500 2024 — 500 — — — — — — — — — — 500 2025 — — — — — — — — — 700 — — 700 Thereafter — — 600 612 — 500 400 400 918 — 300 500 4,230 Total $ 500 $ 500 $ 600 $ 612 $ 500 $ 500 $ 400 $ 400 $ 918 $ 700 $ 300 $ 500 $ 6,430
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: Year Ended December 31, 2020 2019 2018 Income $ 11 $ 17 $ 15 Expense on borrowings (163) (176) (197) Expense on UTPs and other tax related liabilities (34) (28) (15) Net periodic pension costs—interest component (19) (22) (19) Capitalized — 1 1 Total $ (205) $ (208) $ (215) Interest paid (1) $ 132 $ 167 $ 183 (1) Interest paid includes net settlements on interest rate swaps more fully discussed in Note 7.
Fair Value and Carrying Value of Long-term Debt	The fair value and carrying value of the Company’s debt as of December 31, 2020 and 2019 are as follows: December 31, 2020 December 31, 2019 Carrying Amount Estimated Fair Carrying Amount Estimated Fair 4.50% 2012 Senior Notes, due 2022 $ 512 $ 530 $ 507 $ 531 4.875% 2013 Senior Notes, due 2024 498 562 497 551 5.25% 2014 Senior Notes, due 2044 598 828 599 757 1.75% 2015 Senior Notes, due 2027 610 674 558 604 2.75% 2017 Senior Notes, due 2021 — — 508 507 2.625% 2017 Senior Notes, due 2023 510 522 504 507 3.25% 2017 Senior Notes, due 2028 524 561 493 523 3.25% 2018 Senior Notes, due 2021 — — 299 306 4.25% 2018 Senior Notes, due 2029 394 480 394 453 4.875% 2018 Senior Notes, due 2048 390 544 389 492 0.950% 2019 Senior Notes, due 2030 909 974 833 847 3.75% 2020 Senior Note, due 2025 693 785 — — 3.25% 2020 Senior Note, due 2050 293 329 — — 2.55% 2020 Senior Note, due 2060 491 467 — — Total $ 6,422 $ 7,256 $ 5,581 $ 6,078

CAPITAL STOCK (Tables)

CAPITAL STOCK (Tables)	12 Months Ended
	Dec. 31, 2020
Stockholders' Equity Note [Abstract]
Share Repurchase Programs	The table below summarizes the Company’s remaining authority under its share repurchase program as of December 31, 2020: Date Authorized Amount Authorized Remaining Authority December 16, 2019 $ 1,000 831
Dividends Paid	The Company’s cash dividends were: Dividends Per Share Year ended December 31, 2020 2019 2018 Declared Paid Declared Paid Declared Paid First quarter $ 0.56 $ 0.56 $ 0.50 $ 0.50 $ 0.44 $ 0.44 Second quarter 0.56 0.56 0.50 0.50 0.44 0.44 Third quarter 0.56 0.56 0.50 0.50 0.44 0.44 Fourth quarter 0.56 0.56 0.50 0.50 0.44 0.44 Total $ 2.24 $ 2.24 $ 2.00 $ 2.00 $ 1.76 $ 1.76

LEASE COMMITMENTS (Tables)

LEASE COMMITMENTS (Tables)	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Components of Lease Cost	The following table presents the components of the Company’s lease cost: Year Ended December 31, 2020 2019 Operating lease cost $ 96 $ 97 Sublease income (5) (2) Variable lease cost 19 17 Total lease cost $ 110 $ 112
Schedule of Operating Leases Information	The following tables present other information related to the Company’s operating leases: Year Ended December 31, 2020 2019 Cash paid for amounts included in the measurement of operating lease liabilities $ 108 $ 106 Right-of-use assets obtained in exchange for new operating lease liabilities $ 36 $ 41 Year Ended December 31, 2020 2019 Weighted-average remaining lease term (in years) 6.0 6.8 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 December 31, 2020: Year Ending December 31, Operating Leases 2021 $ 110 2022 99 2023 93 2024 84 2025 76 Thereafter 117 Total lease payments (undiscounted) 579 Less: Interest 58 Present value of lease liabilities: 521 Lease liabilities - current 94 Lease liabilities - noncurrent $ 427

SEGMENT INFORMATION (Tables)

SEGMENT INFORMATION (Tables)	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Financial Information by Segment	The table below shows revenue, Adjusted Operating Income and operating income by reportable segment. Adjusted Operating Income is a financial metric utilized by the Company’s chief operating decision maker to assess the profitability of each reportable segment. Refer to Note 3 for further details on the components of the Company’s revenue. Year Ended December 31, 2020 2019 MIS MA Eliminations Consolidated MIS MA Eliminations Consolidated Revenue $ 3,440 $ 2,086 $ (155) $ 5,371 $ 3,009 $ 1,963 $ (143) $ 4,829 Total Expense 1,476 1,662 (155) 2,983 1,376 1,598 (143) 2,831 Operating income 1,964 424 — 2,388 1,633 365 — 1,998 Add: Restructuring 19 31 — 50 31 29 — 60 Depreciation and amortization 70 150 — 220 71 129 — 200 Acquisition-Related Expenses — — — — — 3 — 3 Loss pursuant to the divestiture of MAKS — 9 — 9 — 14 — 14 Captive insurance company settlement — — — — 10 6 — 16 Adjusted Operating Income $ 2,053 $ 614 $ — $ 2,667 $ 1,745 $ 546 $ — $ 2,291 Year Ended December 31, 2018 MIS MA Eliminations Consolidated Revenue $ 2,836 $ 1,743 $ (136) $ 4,443 Total Expense 1,276 1,435 (136) 2,575 Operating Income 1,560 308 — 1,868 Add: Restructuring 32 17 — 49 Depreciation and amortization 65 127 — 192 Acquisition-Related Expenses — 8 — 8 Adjusted Operating income $ 1,657 $ 460 $ — $ 2,117
Company's Reportable Segment Revenues Disaggregated by Segment and Geographic Region	CONSOLIDATED REVENUE AND LONG-LIVED ASSETS INFORMATION BY GEOGRAPHIC AREA Year Ended December 31, 2020 2019 2018 Revenue: U.S. $ 2,955 $ 2,544 $ 2,330 Non-U.S.: EMEA 1,545 1,446 1,377 Asia-Pacific 571 551 493 Americas 300 288 243 Total Non-U.S. 2,416 2,285 2,113 Total $ 5,371 $ 4,829 $ 4,443 Long-lived assets at December 31: U.S. $ 2,162 $ 1,290 $ 982 Non-U.S. 4,889 4,678 4,685 Total $ 7,051 $ 5,968 $ 5,667

VALUATION AND QUALIFYING ACCO_2

VALUATION AND QUALIFYING ACCOUNTS (Tables)	12 Months Ended
	Dec. 31, 2020
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Summary of Activity for Valuation Allowances	Below is a summary of activity: Year Ended December 31, Balance at Beginning of the Year Adoption of New Expected Credit Losses Accounting Standard Charged to costs and expenses Deductions (1) Balance at End of the Year 2020 Allowances for credit losses $ (20) $ (2) $ (26) $ 14 $ (34) Deferred tax assets—valuation allowance $ (9) $ — $ (6) $ — $ (15) 2019 Allowances for credit losses $ (20) $ — $ (10) $ 10 $ (20) Deferred tax assets—valuation allowance $ (5) $ — $ (4) $ — $ (9) 2018 Allowances for credit losses $ (14) $ — $ (15) $ 9 $ (20) Deferred tax assets—valuation allowance $ (6) $ — $ — $ 1 $ (5) (1) Reflects write-off of uncollectible accounts receivable or expiration of foreign net operating tax losses.

OTHER NON-OPERATING (EXPENSE)_2

OTHER NON-OPERATING (EXPENSE) INCOME, NET (Tables)	12 Months Ended
	Dec. 31, 2020
Other Income and Expenses [Abstract]
Components of Other Non-Operating Income	The following table summarizes the components of other non-operating (expense) income, net as presented in the consolidated statements of operations: Year Ended December 31, 2020 2019 2018 FX gain (loss) $ 2 $ (18) $ (11) Net periodic pension costs—other components 13 18 10 Income from investments in non-consolidated affiliates 6 13 14 Other 25 7 6 Total $ 46 $ 20 $ 19

Description of Business and B_2

Description of Business and Basis of Presentation - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)segment	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of reportable segments | segment	2
Shareholders' equity	$ 1,763	$ 831	$ 656	$ (115)
COVID-19
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase in long-term debt	700
Cumulative Effect, Period of Adoption, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Shareholders' equity		(2)	0
Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Shareholders' equity	$ 11,011	9,656	8,594	$ 7,465
Retained Earnings | Cumulative Effect, Period of Adoption, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Shareholders' equity		$ (2)	$ 20

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)reportingUnitcustomer	Dec. 31, 2019USD ($)customer	Dec. 31, 2018USD ($)
Capitalized Contract Cost [Line Items]
Number of reporting units | reportingUnit	7
Provision for credit losses	$ 26	$ 10	$ 15
Number of customers greater than 10% or more of accounts receivable | customer	0	0
MIS
Capitalized Contract Cost [Line Items]
Number of reporting units | reportingUnit	2
MA
Capitalized Contract Cost [Line Items]
Number of reporting units | reportingUnit	5
Deferred cost balance	$ 180	$ 159
MA | Selling, General and Administrative Expenses
Capitalized Contract Cost [Line Items]
Capitalized contract cost, amortization	59	53	38
Capitalization of Work-In-Process for In-Progress Ratings | MIS
Capitalized Contract Cost [Line Items]
Deferred cost balance	12	11
Capitalization of Work-In-Process for In-Progress Ratings | MIS | Operating Expense
Capitalized Contract Cost [Line Items]
Capitalized contract cost, amortization	47	42	40
Royalty Cost | MA
Capitalized Contract Cost [Line Items]
Deferred cost balance	35	40
Royalty Cost | MA | Selling, General and Administrative Expenses
Capitalized Contract Cost [Line Items]
Capitalized contract cost, amortization	$ 66	$ 56	$ 54
Subscription and Maintenance Contracts | MA | Minimum
Capitalized Contract Cost [Line Items]
Revenue, contractual coverage period (years)	3 years
General customer contract payment condition (days)	30 days
Subscription and Maintenance Contracts | MA | Maximum
Capitalized Contract Cost [Line Items]
Revenue, contractual coverage period (years)	5 years
General customer contract payment condition (days)	60 days

Revenues - Revenue by Category

Revenues - Revenue by Category (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Revenue	$ 5,371	$ 4,829	$ 4,443
Eliminations
Disaggregation of Revenue [Line Items]
Revenue	(155)	(143)	(136)
MIS
Disaggregation of Revenue [Line Items]
Revenue	3,292	2,875	2,712
MIS | Eliminations
Disaggregation of Revenue [Line Items]
Revenue	148	134	124
MIS | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	3,440	3,009	2,836
MIS | Corporate finance (CFG)
Disaggregation of Revenue [Line Items]
Revenue	1,857	1,497	1,379
MIS | Corporate finance (CFG) | Investment-grade
Disaggregation of Revenue [Line Items]
Revenue	636	379	271
MIS | Corporate finance (CFG) | High-yield
Disaggregation of Revenue [Line Items]
Revenue	352	258	175
MIS | Corporate finance (CFG) | Bank loans
Disaggregation of Revenue [Line Items]
Revenue	287	313	379
MIS | Corporate finance (CFG) | Other accounts
Disaggregation of Revenue [Line Items]
Revenue	582	547	554
MIS | Structured finance (SFG)
Disaggregation of Revenue [Line Items]
Revenue	362	427	481
MIS | Structured finance (SFG) | Asset-backed securities
Disaggregation of Revenue [Line Items]
Revenue	98	99	107
MIS | Structured finance (SFG) | RMBS
Disaggregation of Revenue [Line Items]
Revenue	96	95	98
MIS | Structured finance (SFG) | CMBS
Disaggregation of Revenue [Line Items]
Revenue	61	81	78
MIS | Structured finance (SFG) | Structured credit
Disaggregation of Revenue [Line Items]
Revenue	105	148	196
MIS | Structured finance (SFG) | Other accounts
Disaggregation of Revenue [Line Items]
Revenue	2	4	2
MIS | Financial institutions (FIG)
Disaggregation of Revenue [Line Items]
Revenue	530	476	442
MIS | Financial institutions (FIG) | Banking
Disaggregation of Revenue [Line Items]
Revenue	355	320	290
MIS | Financial institutions (FIG) | Insurance
Disaggregation of Revenue [Line Items]
Revenue	137	119	114
MIS | Financial institutions (FIG) | Managed investments
Disaggregation of Revenue [Line Items]
Revenue	28	25	25
MIS | Financial institutions (FIG) | Other accounts
Disaggregation of Revenue [Line Items]
Revenue	10	12	13
MIS | Public, project and infrastructure finance (PPIF)
Disaggregation of Revenue [Line Items]
Revenue	496	446	391
MIS | Public, project and infrastructure finance (PPIF) | Public finance / sovereign
Disaggregation of Revenue [Line Items]
Revenue	250	222	185
MIS | Public, project and infrastructure finance (PPIF) | Project and infrastructure
Disaggregation of Revenue [Line Items]
Revenue	246	224	206
MIS | Rating Revenue
Disaggregation of Revenue [Line Items]
Revenue	3,245	2,846	2,693
MIS | MIS Other
Disaggregation of Revenue [Line Items]
Revenue	47	29	19
MA
Disaggregation of Revenue [Line Items]
Revenue	2,079	1,954	1,731
MA | Eliminations
Disaggregation of Revenue [Line Items]
Revenue	7	9	12
MA | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	2,086	1,963	1,743
MA | Research, data and analytics (RD&A)
Disaggregation of Revenue [Line Items]
Revenue	1,514	1,273	1,121
MA | Enterprise risk solutions (ERS)
Disaggregation of Revenue [Line Items]
Revenue	565	522	451
MA | Professional Services
Disaggregation of Revenue [Line Items]
Revenue	$ 0	$ 159	$ 159

Revenues - Revenues Disaggregat

Revenues - Revenues Disaggregated by Line of Business and Geographical Area (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Revenue	$ 5,371	$ 4,829	$ 4,443
U.S.
Disaggregation of Revenue [Line Items]
Revenue	2,955	2,544	2,330
Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	2,416	2,285	2,113
MIS
Disaggregation of Revenue [Line Items]
Revenue	3,292	2,875	2,712
MIS | U.S.
Disaggregation of Revenue [Line Items]
Revenue	2,068	1,721	1,619
MIS | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	1,224	1,154	1,093
MIS | Corporate finance (CFG)
Disaggregation of Revenue [Line Items]
Revenue	1,857	1,497	1,379
MIS | Corporate finance (CFG) | U.S.
Disaggregation of Revenue [Line Items]
Revenue	1,291	968	894
MIS | Corporate finance (CFG) | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	566	529	485
MIS | Structured finance (SFG)
Disaggregation of Revenue [Line Items]
Revenue	362	427	481
MIS | Structured finance (SFG) | U.S.
Disaggregation of Revenue [Line Items]
Revenue	214	270	301
MIS | Structured finance (SFG) | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	148	157	180
MIS | Financial institutions (FIG)
Disaggregation of Revenue [Line Items]
Revenue	530	476	442
MIS | Financial institutions (FIG) | U.S.
Disaggregation of Revenue [Line Items]
Revenue	250	200	194
MIS | Financial institutions (FIG) | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	280	276	248
MIS | Public, project and infrastructure finance (PPIF)
Disaggregation of Revenue [Line Items]
Revenue	496	446	391
MIS | Public, project and infrastructure finance (PPIF) | U.S.
Disaggregation of Revenue [Line Items]
Revenue	311	282	229
MIS | Public, project and infrastructure finance (PPIF) | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	185	164	162
MIS | Rating Revenue
Disaggregation of Revenue [Line Items]
Revenue	3,245	2,846	2,693
MIS | Rating Revenue | U.S.
Disaggregation of Revenue [Line Items]
Revenue	2,066	1,720	1,618
MIS | Rating Revenue | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	1,179	1,126	1,075
MIS | MIS Other
Disaggregation of Revenue [Line Items]
Revenue	47	29	19
MIS | MIS Other | U.S.
Disaggregation of Revenue [Line Items]
Revenue	2	1	1
MIS | MIS Other | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	45	28	18
MA
Disaggregation of Revenue [Line Items]
Revenue	2,079	1,954	1,731
MA | U.S.
Disaggregation of Revenue [Line Items]
Revenue	887	823	711
MA | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	1,192	1,131	1,020
MA | Research, data and analytics (RD&A)
Disaggregation of Revenue [Line Items]
Revenue	1,514	1,273	1,121
MA | Research, data and analytics (RD&A) | U.S.
Disaggregation of Revenue [Line Items]
Revenue	668	558	481
MA | Research, data and analytics (RD&A) | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	846	715	640
MA | Enterprise risk solutions (ERS)
Disaggregation of Revenue [Line Items]
Revenue	565	522	451
MA | Enterprise risk solutions (ERS) | U.S.
Disaggregation of Revenue [Line Items]
Revenue	219	201	170
MA | Enterprise risk solutions (ERS) | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	346	321	281
MA | Professional Services
Disaggregation of Revenue [Line Items]
Revenue	0	159	159
MA | Professional Services | U.S.
Disaggregation of Revenue [Line Items]
Revenue	0	64	60
MA | Professional Services | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	$ 0	$ 95	$ 99

Revenues - Consolidated Revenue

Revenues - Consolidated Revenue Information by Geographic Area (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Revenue	$ 5,371	$ 4,829	$ 4,443
MIS
Segment Reporting Information [Line Items]
Revenue	3,292	2,875	2,712
MA
Segment Reporting Information [Line Items]
Revenue	2,079	1,954	1,731
U.S.
Segment Reporting Information [Line Items]
Revenue	2,955	2,544	2,330
U.S. | MIS
Segment Reporting Information [Line Items]
Revenue	2,068	1,721	1,619
U.S. | MA
Segment Reporting Information [Line Items]
Revenue	887	823	711
EMEA
Segment Reporting Information [Line Items]
Revenue	1,545	1,446	1,377
EMEA | MIS
Segment Reporting Information [Line Items]
Revenue	727	686	669
EMEA | MA
Segment Reporting Information [Line Items]
Revenue	818	760	708
Asia-Pacific
Segment Reporting Information [Line Items]
Revenue	571	551	493
Asia-Pacific | MIS
Segment Reporting Information [Line Items]
Revenue	345	320	300
Asia-Pacific | MA
Segment Reporting Information [Line Items]
Revenue	226	231	193
Americas
Segment Reporting Information [Line Items]
Revenue	300	288	243
Americas | MIS
Segment Reporting Information [Line Items]
Revenue	152	148	124
Americas | MA
Segment Reporting Information [Line Items]
Revenue	148	140	119
Non-U.S.
Segment Reporting Information [Line Items]
Revenue	2,416	2,285	2,113
Non-U.S. | MIS
Segment Reporting Information [Line Items]
Revenue	1,224	1,154	1,093
Non-U.S. | MA
Segment Reporting Information [Line Items]
Revenue	$ 1,192	$ 1,131	$ 1,020

Revenues - Transaction and Rela

Revenues - Transaction and Relationship Revenue (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Revenue	$ 5,371	$ 4,829	$ 4,443
Percentage of Revenues	100.00%	100.00%	100.00%
MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 3,292	$ 2,875	$ 2,712
Percentage of Revenues	100.00%	100.00%	100.00%
MA
Disaggregation of Revenue [Line Items]
Revenue	$ 2,079	$ 1,954	$ 1,731
Percentage of Revenues	100.00%	100.00%	100.00%
Corporate finance (CFG) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 1,857	$ 1,497	$ 1,379
Percentage of Revenues	100.00%	100.00%	100.00%
Structured finance (SFG) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 362	$ 427	$ 481
Percentage of Revenues	100.00%	100.00%	100.00%
Financial institutions (FIG) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 530	$ 476	$ 442
Percentage of Revenues	100.00%	100.00%	100.00%
Public, project and infrastructure finance (PPIF) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 496	$ 446	$ 391
Percentage of Revenues	100.00%	100.00%	100.00%
MIS Other | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 47	$ 29	$ 19
Percentage of Revenues	100.00%	100.00%	100.00%
Research, data and analytics (RD&A) | MA
Disaggregation of Revenue [Line Items]
Revenue	$ 1,514	$ 1,273	$ 1,121
Percentage of Revenues	100.00%	100.00%	100.00%
Enterprise risk solutions (ERS) | MA
Disaggregation of Revenue [Line Items]
Revenue	$ 565	$ 522	$ 451
Percentage of Revenues	100.00%	100.00%	100.00%
Professional Services | MA
Disaggregation of Revenue [Line Items]
Revenue	$ 0	$ 159	$ 159
Percentage of Revenues	0.00%	100.00%	100.00%
Transaction Revenue
Disaggregation of Revenue [Line Items]
Revenue	$ 2,374	$ 2,102	$ 1,962
Percentage of Revenues	44.00%	44.00%	44.00%
Transaction Revenue | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 2,182	$ 1,809	$ 1,686
Percentage of Revenues	66.00%	63.00%	62.00%
Transaction Revenue | MA
Disaggregation of Revenue [Line Items]
Revenue	$ 192	$ 293	$ 276
Percentage of Revenues	9.00%	15.00%	16.00%
Transaction Revenue | Corporate finance (CFG) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 1,401	$ 1,057	$ 949
Percentage of Revenues	75.00%	71.00%	69.00%
Transaction Revenue | Structured finance (SFG) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 175	$ 246	$ 310
Percentage of Revenues	48.00%	58.00%	64.00%
Transaction Revenue | Financial institutions (FIG) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 265	$ 212	$ 187
Percentage of Revenues	50.00%	45.00%	42.00%
Transaction Revenue | Public, project and infrastructure finance (PPIF) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 337	$ 292	$ 238
Percentage of Revenues	68.00%	65.00%	61.00%
Transaction Revenue | MIS Other | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 4	$ 2	$ 2
Percentage of Revenues	9.00%	7.00%	11.00%
Transaction Revenue | Research, data and analytics (RD&A) | MA
Disaggregation of Revenue [Line Items]
Revenue	$ 74	$ 16	$ 18
Percentage of Revenues	5.00%	1.00%	2.00%
Transaction Revenue | Enterprise risk solutions (ERS) | MA
Disaggregation of Revenue [Line Items]
Revenue	$ 118	$ 118	$ 99
Percentage of Revenues	21.00%	23.00%	22.00%
Transaction Revenue | Professional Services | MA
Disaggregation of Revenue [Line Items]
Revenue	$ 0	$ 159	$ 159
Percentage of Revenues	0.00%	100.00%	100.00%
Relationship Revenue
Disaggregation of Revenue [Line Items]
Revenue	$ 2,997	$ 2,727	$ 2,481
Percentage of Revenues	56.00%	56.00%	56.00%
Relationship Revenue | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 1,110	$ 1,066	$ 1,026
Percentage of Revenues	34.00%	37.00%	38.00%
Relationship Revenue | MA
Disaggregation of Revenue [Line Items]
Revenue	$ 1,887	$ 1,661	$ 1,455
Percentage of Revenues	91.00%	85.00%	84.00%
Relationship Revenue | Corporate finance (CFG) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 456	$ 440	$ 430
Percentage of Revenues	25.00%	29.00%	31.00%
Relationship Revenue | Structured finance (SFG) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 187	$ 181	$ 171
Percentage of Revenues	52.00%	42.00%	36.00%
Relationship Revenue | Financial institutions (FIG) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 265	$ 264	$ 255
Percentage of Revenues	50.00%	55.00%	58.00%
Relationship Revenue | Public, project and infrastructure finance (PPIF) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 159	$ 154	$ 153
Percentage of Revenues	32.00%	35.00%	39.00%
Relationship Revenue | MIS Other | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 43	$ 27	$ 17
Percentage of Revenues	91.00%	93.00%	89.00%
Relationship Revenue | Research, data and analytics (RD&A) | MA
Disaggregation of Revenue [Line Items]
Revenue	$ 1,440	$ 1,257	$ 1,103
Percentage of Revenues	95.00%	99.00%	98.00%
Relationship Revenue | Enterprise risk solutions (ERS) | MA
Disaggregation of Revenue [Line Items]
Revenue	$ 447	$ 404	$ 352
Percentage of Revenues	79.00%	77.00%	78.00%
Relationship Revenue | Professional Services | MA
Disaggregation of Revenue [Line Items]
Revenue	$ 0	$ 0	$ 0
Percentage of Revenues	0.00%	0.00%	0.00%

Revenues - Revenue Recognition

Revenues - Revenue Recognition Timing (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Revenue recognized	$ 5,371	$ 4,829	$ 4,443
At Point in Time
Disaggregation of Revenue [Line Items]
Revenue recognized	2,303	1,941	1,785
Over Time
Disaggregation of Revenue [Line Items]
Revenue recognized	3,068	2,888	2,658
MIS
Disaggregation of Revenue [Line Items]
Revenue recognized	3,292	2,875	2,712
MIS | At Point in Time
Disaggregation of Revenue [Line Items]
Revenue recognized	2,182	1,809	1,686
MIS | Over Time
Disaggregation of Revenue [Line Items]
Revenue recognized	1,110	1,066	1,026
MA
Disaggregation of Revenue [Line Items]
Revenue recognized	2,079	1,954	1,731
MA | At Point in Time
Disaggregation of Revenue [Line Items]
Revenue recognized	121	132	99
MA | Over Time
Disaggregation of Revenue [Line Items]
Revenue recognized	$ 1,958	$ 1,822	$ 1,632

Revenues - Additional Informati

Revenues - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Increases due to acquisitions during the period	$ 24	$ 9	$ 16
MIS
Disaggregation of Revenue [Line Items]
Unbilled Receivables	361	346
Increases due to acquisitions during the period	0	3	0
MA
Disaggregation of Revenue [Line Items]
Unbilled Receivables	98	53
Increases due to acquisitions during the period	$ 24	$ 6	$ 16

Revenues - Schedule of Changes

Revenues - Schedule of Changes in the Deferred Revenue Balances (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Change in Contract with Customer, Liability [Abstract]
Beginning Balance	$ 1,162	$ 1,075	$ 946
Revenue recognized that was included in the deferred revenue balance at the beginning of the period	(1,029)	(923)	(808)
Increases due to amounts billable excluding amounts recognized as revenue during the period	1,007	991	946
Increases due to acquisitions during the period	24	9	16
Effect of exchange rate changes	23	10	(25)
Total changes in deferred revenue	25	87	129
Ending Balance	1,187	1,162	1,075
Deferred revenue - current	1,089	1,050	953
Deferred revenue - noncurrent	98	112	122
MIS
Change in Contract with Customer, Liability [Abstract]
Beginning Balance	322	325	334
Revenue recognized that was included in the deferred revenue balance at the beginning of the period	(229)	(209)	(218)
Increases due to amounts billable excluding amounts recognized as revenue during the period	215	202	216
Increases due to acquisitions during the period	0	3	0
Effect of exchange rate changes	5	1	(7)
Total changes in deferred revenue	(9)	(3)	(9)
Ending Balance	313	322	325
Deferred revenue - current	216	214	207
Deferred revenue - noncurrent	97	108	118
MA
Change in Contract with Customer, Liability [Abstract]
Beginning Balance	840	750	612
Revenue recognized that was included in the deferred revenue balance at the beginning of the period	(800)	(714)	(590)
Increases due to amounts billable excluding amounts recognized as revenue during the period	792	789	730
Increases due to acquisitions during the period	24	6	16
Effect of exchange rate changes	18	9	(18)
Total changes in deferred revenue	34	90	138
Ending Balance	874	840	750
Deferred revenue - current	873	836	746
Deferred revenue - noncurrent	$ 1	$ 4	$ 4

Revenues - Expected Recognition

Revenues - Expected Recognition Period for Remaining Performance Obligations (Detail) $ in Millions	Dec. 31, 2020USD ($)
MIS
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 130
MIS | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
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]: 2022-01-01
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	$ 2,200
MA | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
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]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, percentage	20.00%
Revenue, remaining performance obligation, period	1 year

Reconciliation of Weighted Av_3

Reconciliation of Weighted Average Shares Outstanding - Reconciliation of Basic to Diluted Shares Outstanding (Detail) - shares shares in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Earnings Per Share [Abstract]
Basic (in shares)	187.6	189.3	191.6
Dilutive effect of shares issuable under stock-based compensation plans (in shares)	1.7	2.3	2.8
Diluted (in shares)	189.3	191.6	194.4
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)	0.2	0.2	0.4

Accelerated Share Repurchase _2

Accelerated Share Repurchase Program - Additional Information (Details) - USD ($) $ / shares in Units, shares in Millions	Apr. 26, 2019	Feb. 20, 2019	Dec. 31, 2020
Accelerated Share Repurchases [Line Items]
Accelerated share repurchases, final price paid per share (in usd per share)			$ 180.33
Accelerated Share Repurchases
Accelerated Share Repurchases [Line Items]
Treasury stock, shares, acquired (in shares)			2.8
February 20, 2019
Accelerated Share Repurchases [Line Items]
Accelerated share repurchases payment		$ 500,000,000
February 20, 2019 | Accelerated Share Repurchases
Accelerated Share Repurchases [Line Items]
Treasury stock, shares, acquired (in shares)		2.2
April 26, 2019 | Accelerated Share Repurchases
Accelerated Share Repurchases [Line Items]
Treasury stock, shares, acquired (in shares)	0.6

Cash Equivalents and Investme_3

Cash Equivalents and Investments (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Cash and Cash Equivalents [Line Items]
Fair Value	$ 60	$ 3
Cash and cash equivalents	2,597	1,832
Short-term investments	99	98
Certificates of deposit and money market deposit accounts
Cash and Cash Equivalents [Line Items]
Cost	1,430	971
Gross Unrealized Gains	0	0
Fair Value	1,430	971
Cash and cash equivalents	1,325	866
Short-term investments	99	95
Other assets	6	10
Mutual funds
Cash and Cash Equivalents [Line Items]
Cost	54	3
Gross Unrealized Gains	6	0
Fair Value	60	3
Cash and cash equivalents	0	0
Short-term investments	0	3
Other assets	$ 60	$ 0

Cash Equivalents and Investme_4

Cash Equivalents and Investments (Footnote) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Cash and Cash Equivalents [Line Items]
Company owned life insurance (at contract value)	$ 17	$ 0
Short-term Investments | Certificates of deposit and money market deposit accounts | Minimum
Cash and Cash Equivalents [Line Items]
Securities maturity period	1 month	1 month
Short-term Investments | Certificates of deposit and money market deposit accounts | Maximum
Cash and Cash Equivalents [Line Items]
Securities maturity period	12 months	12 months
Other assets | Certificates of deposit and money market deposit accounts | Minimum
Cash and Cash Equivalents [Line Items]
Securities maturity period	13 months	13 months
Other assets | Certificates of deposit and money market deposit accounts | Maximum
Cash and Cash Equivalents [Line Items]
Securities maturity period	23 months	18 months
Cash and cash equivalent | Certificates of deposit and money market deposit accounts | Maximum
Cash and Cash Equivalents [Line Items]
Securities maturity period	90 days

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	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Derivative [Line Items]
Notional Amount	$ 1,380	$ 1,080
2012 Senior Notes due 2022
Derivative [Line Items]
Nature of Swap	Pay Floating/Receive Fixed
Notional Amount	$ 330	330
Floating Interest Rate	3-month LIBOR
2017 Senior Notes due 2021
Derivative [Line Items]
Nature of Swap	Pay Floating/Receive Fixed
Notional Amount	$ 0	500
Floating Interest Rate	3-month 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 LIBOR
2017 Senior Notes due 2028
Derivative [Line Items]
Nature of Swap	Pay Floating/Receive Fixed
Notional Amount	$ 500	0
Floating Interest Rate	3-month LIBOR
2020 Senior Notes due 2025
Derivative [Line Items]
Nature of Swap	Pay Floating/Receive Fixed
Notional Amount	$ 300	$ 0
Floating Interest Rate	6-month 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	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Interest expense, net	$ (205)	$ (208)	$ (215)
Designated as Hedging Instrument | Interest Rate Swap | Interest Expense
Derivative Instruments, Gain (Loss) [Line Items]
Fair value changes on interest rate swaps	47	25	2
Fair value changes on hedged debt	(47)	(25)	(2)
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	$ 19	$ 3	$ (2)

Derivative Instruments And He_5

Derivative Instruments And Hedging Activities - Additional Information (Detail)	1 Months Ended
	Jan. 31, 2020USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2020EUR (€)	Sep. 30, 2020EUR (€)	Apr. 30, 2020USD ($)	Mar. 31, 2020EUR (€)	Dec. 31, 2019USD ($)
Derivative [Line Items]
Accumulated other comprehensive loss		$ 432,000,000					$ 439,000,000
Designated as Hedging Instrument
Derivative [Line Items]
Accumulated other comprehensive loss		269,000,000					(54,000,000)
Net Investment Hedging | Designated as Hedging Instrument
Derivative [Line Items]
Accumulated other comprehensive loss		220,000,000					(54,000,000)
Net Investment Hedging | Designated as Hedging Instrument | Cross currency swaps
Derivative [Line Items]
Notional Amount | €						€ 2,038,000,000
Accumulated other comprehensive loss		124,000,000					(41,000,000)
Cash Flow Hedging | Forward Contracts
Derivative [Line Items]
Accumulated other comprehensive loss					$ 68,000,000
Cash Flow Hedging | Designated as Hedging Instrument
Derivative [Line Items]
Accumulated other comprehensive loss		49,000,000					0
Cash Flow Hedging | Designated as Hedging Instrument | Cross currency swaps
Derivative [Line Items]
Accumulated other comprehensive loss		$ (2,000,000)					$ (2,000,000)
Cash Flow Hedging | Designated as Hedging Instrument | Forward Contracts
Derivative [Line Items]
Notional Amount	$ 300,000,000
Derivative, forward interest rate	2.0103%
Term of notes	30 years
2015 Senior Notes, due 2027
Derivative [Line Items]
Senior unsecured notes, interest		1.75%	1.75%				1.75%
2015 Senior Notes, due 2027 | Net Investment Hedging | Designated as Hedging Instrument | Cross currency swaps
Derivative [Line Items]
Notional Amount | €			€ 500,000,000
2019 Senior Notes, due 2030 | Net Investment Hedging | Designated as Hedging Instrument | Cross currency swaps
Derivative [Line Items]
Notional Amount | €			€ 750,000,000
2017 Senior Notes due 2021 | Net Investment Hedging | Designated as Hedging Instrument | Cross currency swaps
Derivative [Line Items]
Notional Amount | €				€ 422,500,000
3.25% 2020 Senior Note, due 2050
Derivative [Line Items]
Senior unsecured notes, interest		3.25%	3.25%

Derivative Instruments And He_6

Derivative Instruments And Hedging Activities - Summary of Notional Amounts of Outstanding Cross Currency Swap (Detail) - Cross currency swaps - Net Investment Hedging € in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2020EUR (€)	Dec. 31, 2019EUR (€)
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	€ 2,010
Currency Paid | 1.43%
Derivative [Line Items]
Notional Amount | €			€ 1,079	€ 1,079
Weighted Average Interest Rate	1.43%	1.43%	1.43%	1.43%
Currency Paid | 3-month EURIBOR
Derivative [Line Items]
Notional Amount | €			€ 959	€ 931
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 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 - Cross currency swaps - EUR (€)	Dec. 31, 2020	Mar. 31, 2020
Net Investment Hedging
Derivative [Line Items]
Notional Amount		€ 2,038,000,000
2021
Derivative [Line Items]
Notional Amount	€ 265,000,000
2022
Derivative [Line Items]
Notional Amount	438,000,000
2023
Derivative [Line Items]
Notional Amount	442,000,000
2024
Derivative [Line Items]
Notional Amount	€ 443,000,000
2026
Derivative [Line Items]
Notional Amount		€ 450,000,000

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) - Dec. 31, 2020 - Net Investment Hedging - Designated as Hedging Instrument € in Millions, £ in Millions, $ in Millions	USD ($)	EUR (€)	GBP (£)
Contract to sell EUR for USD
Derivative [Line Items]
Notional Amount	$ 627	€ 524
Contract to sell GBP for EUR
Derivative [Line Items]
Notional Amount		€ 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	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Hedging Relationships, Amount of Gain/(Loss) Recognized in AOCI on Derivative, net of Tax	$ (51)	$ 0	$ (1)
Total, Amount of Gain/(Loss) Recognized in AOCI on Derivative, net of Tax	(325)	26	34
Net Investment Hedging Relationships, Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax	1	2	0
Cash Flow Hedging Relationships, Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax	(2)	0	0
Total, Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax	(2)	2	0
Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	50	52	11
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	(274)	26	34
Net Investment Hedging Relationships, Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax	0	2	0
Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	50	52	11
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	(51)	0	0
Cash Flow Hedging Relationships, Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax	(2)	0	0
Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	0	0	0
FX forwards | Net Investment Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Net Investment Hedging Relationships, Amount of Gain/(Loss) Recognized in AOCI on Derivative, net of Tax	(14)	4	0
Net Investment Hedging Relationships, Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax	0	2	0
Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	0	0	0
Cross currency swaps | 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	(165)	29	12
Net Investment Hedging Relationships, Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax	0	0	0
Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	50	52	11
Cross currency swaps | 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	0	2
Cash Flow Hedging Relationships, Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax	0	0	0
Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	0	0	0
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	(95)	(7)	22
Net Investment Hedging Relationships, Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax	0	0	0
Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	0	0	0
Interest rate contract | Cash Flow Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Hedging Relationships, Amount of Gain/(Loss) Recognized in AOCI on Derivative, net of Tax	(51)	0	(2)
Cash Flow Hedging Relationships, Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax	(2)	0	0
Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	$ 0	$ 0	$ 0

Derivative Instruments And H_10

Derivative Instruments And Hedging Activities - Gains (Losses) Recognized in AOCI and Reclassified from AOCI on Derivatives (Footnote) (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)
Net Investment Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Shareholders' equity	$ 3

Derivative Instruments And H_11

Derivative Instruments And Hedging Activities - Cumulative Amount of Unrecognized Hedge Losses Recorded in AOCI (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Derivative [Line Items]
Cumulative Gains/(Losses), net of tax	$ (432)	$ (439)
Designated as Hedging Instrument
Derivative [Line Items]
Cumulative Gains/(Losses), net of tax	(269)	54
Net Investment Hedging | Designated as Hedging Instrument
Derivative [Line Items]
Cumulative Gains/(Losses), net of tax	(220)	54
Net Investment Hedging | Cross currency swaps | Designated as Hedging Instrument
Derivative [Line Items]
Cumulative Gains/(Losses), net of tax	(124)	41
Net Investment Hedging | FX forwards | Designated as Hedging Instrument
Derivative [Line Items]
Cumulative Gains/(Losses), net of tax	12	26
Net Investment Hedging | Long-term debt | Designated as Hedging Instrument
Derivative [Line Items]
Cumulative Gains/(Losses), net of tax	(108)	(13)
Cash Flow Hedging | Designated as Hedging Instrument
Derivative [Line Items]
Cumulative Gains/(Losses), net of tax	(49)	0
Cash Flow Hedging | Cross currency swaps | Designated as Hedging Instrument
Derivative [Line Items]
Cumulative Gains/(Losses), net of tax	2	2
Cash Flow Hedging | Interest rate contract | Designated as Hedging Instrument
Derivative [Line Items]
Cumulative Gains/(Losses), net of tax	$ (51)	$ (2)

Derivative Instruments And H_12

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

Dec. 31, 2020USD ($)

Dec. 31, 2020EUR (€)

Dec. 31, 2020GBP (£)

Dec. 31, 2020JPY (¥)

Dec. 31, 2020CAD ($)

Dec. 31, 2020SGD ($)

Dec. 31, 2020RUB (₽)

Dec. 31, 2020INR (₨)

Dec. 31, 2019USD ($)

Dec. 31, 2019EUR (€)

Dec. 31, 2019GBP (£)

Dec. 31, 2019JPY (¥)

Dec. 31, 2019CAD ($)

Dec. 31, 2019SGD ($)

Contracts to sell USD for GBP

Derivative [Line Items]

Notional Amount

$ 295

£ 222

$ 235

£ 178

Contracts to sell USD for Japanese Yen

Derivative [Line Items]

Notional Amount

15

¥ 1,600

29

¥ 3,200

Contracts to sell USD for Canadian dollars

Derivative [Line Items]

Notional Amount

107

$ 140

83

$ 110

Contracts to sell USD for Singapore dollars

Derivative [Line Items]

Notional Amount

59

$ 79

41

$ 56

Contracts to sell USD for Euros

Derivative [Line Items]

Notional Amount

447

€ 376

$ 421

€ 378

Contracts to sell Euros for GBP

Derivative [Line Items]

Notional Amount

€ 135

£ 121

€ 25

£ 21

Contracts to sell USD for Russian Ruble

Derivative [Line Items]

Notional Amount

13

₽ 1,000

Contracts to sell USD for Indian Rupee

Derivative [Line Items]

Notional Amount

$ 18

₨ 1,350

Derivative Instruments And H_13

Derivative Instruments And Hedging Activities - Summary of Net Gain (Loss) on Foreign Exchange Forwards Not Designated as Hedging Instruments (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
FX forwards | Other non-operating expense, net
Derivative Instruments, Gain (Loss) [Line Items]
Foreign exchange forwards amount of gain (loss) recognized in income	$ 41	$ (11)	$ (52)

Derivative Instruments And H_14

Derivative Instruments And Hedging Activities - Fair Value of Derivative Instruments (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Assets	$ 88	$ 92
Liabilities	1,716	1,403
Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Assets	57	83
Liabilities	184	0
Designated as Hedging Instrument | Long-term debt | Net Investment Hedging
Derivatives, Fair Value [Line Items]
Liabilities	1,530	1,403
Designated as Hedging Instrument | Cross currency swaps | Other assets | Net Investment Hedging
Derivatives, Fair Value [Line Items]
Assets	0	56
Designated as Hedging Instrument | Cross currency swaps | Accounts payable and accrued liabilities | Net Investment Hedging
Derivatives, Fair Value [Line Items]
Liabilities	23	0
Designated as Hedging Instrument | Cross currency swaps | Other liabilities | Net Investment Hedging
Derivatives, Fair Value [Line Items]
Liabilities	144	0
Designated as Hedging Instrument | Interest Rate Swap | Other assets | Fair Value Hedging
Derivatives, Fair Value [Line Items]
Assets	57	27
Designated as Hedging Instrument | Interest Rate Swap | Other liabilities | Fair Value Hedging
Derivatives, Fair Value [Line Items]
Liabilities	1	0
Designated as Hedging Instrument | FX forwards | Accounts payable and accrued liabilities | Net Investment Hedging
Derivatives, Fair Value [Line Items]
Liabilities	16	0
Not Designated as Accounting Hedges | FX forwards | Other current assets
Derivatives, Fair Value [Line Items]
Assets	31	9
Not Designated as Accounting Hedges | FX forwards | Accounts payable and accrued liabilities
Derivatives, Fair Value [Line Items]
Liabilities	$ 2	$ 0

Property and Equipment, Net (De

Property and Equipment, Net (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Total property and equipment, at cost	$ 1,206	$ 1,131
Less: accumulated depreciation and amortization	(928)	(839)
Total property and equipment, net	278	292
Office and Computer Equipment
Property, Plant and Equipment [Line Items]
Total property and equipment, at cost	$ 260	221
Office and Computer Equipment | Minimum
Property, Plant and Equipment [Line Items]
Property plant and equipment useful life	3 years
Office and Computer Equipment | Maximum
Property, Plant and Equipment [Line Items]
Property plant and equipment useful life	10 years
Office Furniture and Fixtures
Property, Plant and Equipment [Line Items]
Total property and equipment, at cost	$ 49	51
Office Furniture and Fixtures | Minimum
Property, Plant and Equipment [Line Items]
Property plant and equipment useful life	3 years
Office Furniture and Fixtures | Maximum
Property, Plant and Equipment [Line Items]
Property plant and equipment useful life	10 years
Internal-use Computer Software
Property, Plant and Equipment [Line Items]
Total property and equipment, at cost	$ 666	619
Internal-use Computer Software | Minimum
Property, Plant and Equipment [Line Items]
Property plant and equipment useful life	1 year
Internal-use Computer Software | Maximum
Property, Plant and Equipment [Line Items]
Property plant and equipment useful life	10 years
Leasehold Improvements and Building
Property, Plant and Equipment [Line Items]
Total property and equipment, at cost	$ 231	$ 240
Leasehold Improvements and Building | Minimum
Property, Plant and Equipment [Line Items]
Property plant and equipment useful life	1 year
Leasehold Improvements and Building | Maximum
Property, Plant and Equipment [Line Items]
Property plant and equipment useful life	21 years

Property and Equipment, Net - A

Property and Equipment, Net - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Depreciation and amortization expense related to property and equipment	$ 96	$ 97	$ 90

Acquisitions and Divestiture -

Acquisitions and Divestiture - Acquisitions Narrative (Detail) - USD ($) $ in Millions	Feb. 13, 2020	Oct. 15, 2018	Dec. 31, 2020	Oct. 31, 2020	Dec. 31, 2019	Jul. 31, 2019	Aug. 31, 2018
Regulatory DataCorp
Business Acquisition [Line Items]
Business acquisition interests acquired	100.00%
Cash and equivalents	$ 6
Receivables	14
Cash paid for business acquisition	700
Consideration transferred	$ 702
Reis Inc
Business Acquisition [Line Items]
Business acquisition interests acquired		100.00%
Cash and equivalents		$ 24
Receivables		6
Cash paid for business acquisition		$ 278
Vigeo Eiris
Business Acquisition [Line Items]
Business acquisition interests acquired			99.80%		69.20%
Acquire Media, ZM Financial Systems & Catylist Inc.
Business Acquisition [Line Items]
Consideration transferred			$ 205
Catylist Inc.
Business Acquisition [Line Items]
Business acquisition interests acquired			100.00%
ZM Financial Systems
Business Acquisition [Line Items]
Business acquisition interests acquired			100.00%
Acquire Media
Business Acquisition [Line Items]
Business acquisition interests acquired				100.00%
RiskFirst
Business Acquisition [Line Items]
Business acquisition interests acquired						100.00%
Omega Performance
Business Acquisition [Line Items]
Business acquisition interests acquired							100.00%

Acquisitions and Divestiture _2

Acquisitions and Divestiture - Total Consideration Relating to Acquisition (Detail) - Regulatory DataCorp $ in Millions	Feb. 13, 2020USD ($)
Business Acquisition [Line Items]
Cash paid at closing	$ 700
Additional consideration paid to sellers in 2020	2
Total consideration	$ 702

Acquisitions and Divestiture _3

Acquisitions and Divestiture - Purchase Price Allocation (Detail) - USD ($) $ in Millions	Feb. 13, 2020	Oct. 15, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Goodwill			$ 4,556	$ 3,722	$ 3,781
Liabilities:
Weighted average life of intangible assets acquired (in years)			14 years
Customer relationships
Liabilities:
Weighted average life of intangible assets acquired (in years)			18 years
Database
Liabilities:
Weighted average life of intangible assets acquired (in years)			10 years
Product Technology
Liabilities:
Weighted average life of intangible assets acquired (in years)			8 years
Trade names
Liabilities:
Weighted average life of intangible assets acquired (in years)			14 years
Regulatory DataCorp
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
Weighted average life of intangible assets acquired (in years)	19 years
Regulatory DataCorp | Customer relationships
Business Acquisition [Line Items]
Total intangible assets	$ 174
Liabilities:
Weighted average life of intangible assets acquired (in years)	25 years
Regulatory DataCorp | Database
Business Acquisition [Line Items]
Total intangible assets	$ 86
Liabilities:
Weighted average life of intangible assets acquired (in years)	10 years
Regulatory DataCorp | Product Technology
Business Acquisition [Line Items]
Total intangible assets	$ 17
Liabilities:
Weighted average life of intangible assets acquired (in years)	4 years
Regulatory DataCorp | Trade names
Business Acquisition [Line Items]
Total intangible assets	$ 3
Liabilities:
Weighted average life of intangible assets acquired (in years)	3 years
Reis Inc
Business Acquisition [Line Items]
Current assets		$ 32
Property and equipment		4
Total intangible assets		104
Goodwill		183
Deferred tax assets		13
Liabilities:
Accounts payable and accrued liabilities		(20)
Deferred revenue		(14)
Deferred tax liabilities		(24)
Total liabilities		(58)
Net assets acquired		$ 278
Weighted average life of intangible assets acquired (in years)		12 years
Reis Inc | Customer relationships
Business Acquisition [Line Items]
Total intangible assets		$ 77
Liabilities:
Weighted average life of intangible assets acquired (in years)		14 years
Reis Inc | Database
Business Acquisition [Line Items]
Total intangible assets		$ 13
Liabilities:
Weighted average life of intangible assets acquired (in years)		5 years
Reis Inc | Product Technology
Business Acquisition [Line Items]
Total intangible assets		$ 10
Liabilities:
Weighted average life of intangible assets acquired (in years)		7 years
Reis Inc | Trade names
Business Acquisition [Line Items]
Total intangible assets		$ 4
Liabilities:
Weighted average life of intangible assets acquired (in years)		10 years
Acquire Media, ZM Financial Systems & Catylist Inc.
Business Acquisition [Line Items]
Current assets			$ 5
Total intangible assets			82
Goodwill			131
Other assets			3
Total assets acquired			221
Liabilities:
Current liabilities			8
Long-term liabilities			8
Total liabilities			(16)
Net assets acquired			205
Acquire Media, ZM Financial Systems & Catylist Inc. | Customer relationships
Business Acquisition [Line Items]
Total intangible assets			47
Acquire Media, ZM Financial Systems & Catylist Inc. | Database
Business Acquisition [Line Items]
Total intangible assets			8
Acquire Media, ZM Financial Systems & Catylist Inc. | Product Technology
Business Acquisition [Line Items]
Total intangible assets			23
Acquire Media, ZM Financial Systems & Catylist Inc. | Trade names
Business Acquisition [Line Items]
Total intangible assets			$ 4

Acquisitions and Divestiture _4

Acquisitions and Divestiture - Divestiture Narrative (Detail) - USD ($) $ in Millions	Nov. 08, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2020
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash received upon disposal of a business, net of cash transferred to purchaser		$ 0	$ 226	$ 6
Loss pursuant to the divestiture of MAKS		9	14	$ 0
Indemnification provision liability		33	43		$ 33
MAKS | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash received upon disposal of a business, net of cash transferred to purchaser	$ 227
Loss pursuant to the divestiture of MAKS		9	14		23
Disposal group, including discontinued operation, foreign currency translation losses			32
Indemnification provision liability		$ 33	$ 43		$ 33

Goodwill And Other Acquired I_3

Goodwill And Other Acquired Intangible Assets - Activity in Goodwill (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Goodwill [Roll Forward]
Beginning balance, Goodwill gross	$ 3,734	$ 3,793
Beginning balance, Accumulated impairment charge	(12)	(12)
Beginning balance, goodwill net	3,722	3,781
Additions/adjustments	626	114
Foreign currency translation adjustments	208	(10)
Divestiture of MAKS		(163)
Ending balance, Goodwill gross	4,568	3,734
Ending balance, Accumulated impairment charge	(12)	(12)
Ending balance, goodwill net	4,556	3,722
MIS
Goodwill [Roll Forward]
Beginning balance, Goodwill gross	315	258
Beginning balance, Accumulated impairment charge	0	0
Beginning balance, goodwill net	315	258
Additions/adjustments	(2)	53
Foreign currency translation adjustments	(2)	4
Ending balance, Goodwill gross	311	315
Ending balance, Accumulated impairment charge	0	0
Ending balance, goodwill net	311	315
MA
Goodwill [Roll Forward]
Beginning balance, Goodwill gross	3,419	3,535
Beginning balance, Accumulated impairment charge	(12)	(12)
Beginning balance, goodwill net	3,407	3,523
Additions/adjustments	628	61
Foreign currency translation adjustments	210	(14)
Divestiture of MAKS		(163)
Ending balance, Goodwill gross	4,257	3,419
Ending balance, Accumulated impairment charge	(12)	(12)
Ending balance, goodwill net	$ 4,245	$ 3,407

Goodwill And Other Acquired I_4

Goodwill And Other Acquired Intangible Assets - Acquired Intangible Assets and Related Amortization (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, net	$ 1,824	$ 1,498
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, gross	1,623	1,325
Accumulated amortization	(313)	(235)
Acquired intangible assets, net	1,310	1,090
Trade secrets
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, gross	30	30
Accumulated amortization	(29)	(29)
Acquired intangible assets, net	1	1
Software/product technology
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, gross	417	372
Accumulated amortization	(166)	(131)
Acquired intangible assets, net	251	241
Trade names
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, gross	161	150
Accumulated amortization	(38)	(30)
Acquired intangible assets, net	123	120
Other
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, gross	192	80
Accumulated amortization	(53)	(34)
Acquired intangible assets, net	$ 139	$ 46

Goodwill And Other Acquired I_5

Goodwill And Other Acquired Intangible Assets - Amortization Expense Relating to Acquired Intangible Assets (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense	$ 124	$ 103	$ 102

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	Dec. 31, 2020USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2021	$ 131
2022	131
2023	126
2024	119
2025	117
Thereafter	1,200
Total estimated future amortization	$ 1,824

Goodwill And Other Acquired I_7

Goodwill And Other Acquired Intangible Assets - Narrative (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	Jul. 29, 2020	Oct. 26, 2018	Dec. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2022	Dec. 31, 2020
Restructuring Cost and Reserve [Line Items]
Restructuring					$ 50	$ 60	$ 49
Remaining restructuring liability				$ 42	21	24	42		$ 21
2020 MA Strategic Reorganization Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring					18	0	0
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
2020 Real Estate Rationalization Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring					36	0	0
2020 Real Estate Rationalization Restructuring Program | Minimum | Estimated Annual Savings
Restructuring Cost and Reserve [Line Items]
Effect on future earnings, amount		$ 5
2020 Real Estate Rationalization Restructuring Program | Maximum | Estimated Annual Savings
Restructuring Cost and Reserve [Line Items]
Effect on future earnings, amount		$ 6
2018 Restructuring Program
Restructuring Cost and Reserve [Line Items]
Payments for restructuring					18	38
Restructuring					(4)	60	49
2018 Restructuring Program | Estimated Annual Savings
Restructuring Cost and Reserve [Line Items]
Effect on future earnings, amount			$ 60
Real Estate | 2018 Restructuring Program | Maximum
Restructuring Cost and Reserve [Line Items]
Restructuring				50
Employee Termination Costs
Restructuring Cost and Reserve [Line Items]
Remaining restructuring liability				$ 30	18	21	$ 30		18
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
Employee Termination Costs | 2018 Restructuring Program
Restructuring Cost and Reserve [Line Items]
Payments for restructuring					$ 17	$ 35			55
Restructuring									$ 55

Restructuring - Restructuring E

Restructuring - Restructuring Expenses Included in Consolidated Statements of Operations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring	$ 50	$ 60	$ 49
2018 Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring	(4)	60	49
2020 Real Estate Rationalization Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring	36	0	0
2020 MA Strategic Reorganization Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring	$ 18	$ 0	$ 0

Restructuring - Changes in Rest

Restructuring - Changes in Restructuring Liability (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended				26 Months Ended
	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2020
Restructuring Reserve [Roll Forward]
Restructuring liability, Beginning Balance	$ 42	$ 24	$ 42
Restructuring liability, Ending Balance		21	$ 24	$ 42		$ 21
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201602Member		us-gaap:AccountingStandardsUpdate201613Member	us-gaap:AccountingStandardsUpdate201802Member
Cumulative Effect, Period of Adoption, Adjustment
Restructuring Reserve [Roll Forward]
Accounting Standards Update [Extensible List]				us-gaap:AccountingStandardsUpdate201802Member	us-gaap:AccountingStandardsUpdate201602Member
Employee Termination Costs
Restructuring Reserve [Roll Forward]
Restructuring liability, Beginning Balance	$ 30	21	$ 30
Restructuring liability, Ending Balance		18	21	$ 30		18
Contract Termination Costs
Restructuring Reserve [Roll Forward]
Restructuring liability, Beginning Balance	12	3	12
Restructuring liability, Ending Balance		3	3	12		3
2018 Restructuring Program
Restructuring Reserve [Roll Forward]
Cost incurred and adjustments		(4)	31
Cash payments and adjustments		(18)	(38)
2018 Restructuring Program | Cumulative Effect, Period of Adoption, Adjustment
Restructuring Reserve [Roll Forward]
Restructuring liability, Beginning Balance	(11)		(11)
Restructuring liability, Ending Balance				(11)
2018 Restructuring Program | Employee Termination Costs
Restructuring Reserve [Roll Forward]
Cost incurred and adjustments		(4)	26
Cash payments and adjustments		(17)	(35)			(55)
Cumulative expense incurred to date		55				55
2018 Restructuring Program | Employee Termination Costs | Cumulative Effect, Period of Adoption, Adjustment
Restructuring Reserve [Roll Forward]
Restructuring liability, Beginning Balance	0		0
Restructuring liability, Ending Balance				0
2018 Restructuring Program | Contract Termination Costs
Restructuring Reserve [Roll Forward]
Cost incurred and adjustments		0	5
Cash payments and adjustments		(1)	(3)
Cumulative expense incurred to date		50				50
2018 Restructuring Program | Contract Termination Costs | Cumulative Effect, Period of Adoption, Adjustment
Restructuring Reserve [Roll Forward]
Restructuring liability, Beginning Balance	$ (11)		$ (11)
Restructuring liability, Ending Balance				$ (11)
2020 Real Estate Rationalization Restructuring Program
Restructuring Reserve [Roll Forward]
Cost incurred and adjustments		1
2020 Real Estate Rationalization Restructuring Program | Employee Termination Costs
Restructuring Reserve [Roll Forward]
Cost incurred and adjustments		0
Cumulative expense incurred to date		0				0
2020 Real Estate Rationalization Restructuring Program | Contract Termination Costs
Restructuring Reserve [Roll Forward]
Cost incurred and adjustments		1
Cumulative expense incurred to date		36				36
2020 MA Strategic Reorganization Restructuring Program
Restructuring Reserve [Roll Forward]
Cost incurred and adjustments		18
2020 MA Strategic Reorganization Restructuring Program | Employee Termination Costs
Restructuring Reserve [Roll Forward]
Cost incurred and adjustments		18
Cumulative expense incurred to date		18				18
2020 MA Strategic Reorganization Restructuring Program | Contract Termination Costs
Restructuring Reserve [Roll Forward]
Cost incurred and adjustments		0
Cumulative expense incurred to date		$ 0				$ 0

Restructuring - Changes in Re_2

Restructuring - Changes in Restructuring Liability (Footnote) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Restructuring Cost and Reserve [Line Items]
Impairment of right-of-use		$ 21
Operating lease right-of-use assets		393	$ 456
Restructuring liability		21	$ 24	$ 42
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201602Member		us-gaap:AccountingStandardsUpdate201613Member	us-gaap:AccountingStandardsUpdate201802Member
Cumulative Effect, Period of Adoption, Adjustment
Restructuring Cost and Reserve [Line Items]
Accounting Standards Update [Extensible List]				us-gaap:AccountingStandardsUpdate201802Member	us-gaap:AccountingStandardsUpdate201602Member
Cumulative Effect, Period of Adoption, Adjustment | 2018 Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring liability				$ (11)
Real Estate
Restructuring Cost and Reserve [Line Items]
Impairment of right-of-use		21	$ 25
Real Estate | Level 3
Restructuring Cost and Reserve [Line Items]
Operating lease right-of-use assets		10	18
Contract Termination Costs
Restructuring Cost and Reserve [Line Items]
Restructuring liability		3	3	12
Contract Termination Costs | Cumulative Effect, Period of Adoption, Adjustment | 2018 Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring liability				(11)
Contract Termination Costs | Real Estate
Restructuring Cost and Reserve [Line Items]
Non-cash acceleration of amortization		$ 13	$ 4
Contract Termination Costs | Real Estate | Cumulative Effect, Period of Adoption, Adjustment | 2018 Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring liability				$ (11)

Fair Value - Financial Instrume

Fair Value - Financial Instruments Carried at Fair Value on Recurring Basis (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Assets:
Derivatives	$ 88	$ 92
Mutual funds	60	3
Total	148	95
Liabilities:
Derivatives	186
Total	186
Level 1
Assets:
Derivatives	0	0
Mutual funds	60	3
Total	60	3
Liabilities:
Derivatives	0
Total	0
Level 2
Assets:
Derivatives	88	92
Mutual funds	0	0
Total	88	$ 92
Liabilities:
Derivatives	186
Total	$ 186

Other Balance Sheet Informati_3

Other Balance Sheet Information - Additional Details Related to Certain Balance Sheet Captions (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Other current assets:
Prepaid taxes	$ 94	$ 79
Prepaid expenses	91	71
Capitalized costs to obtain and fulfill sales contracts	93	91
Foreign exchange forwards on certain assets and liabilities	31	9
Other	74	80
Total other current assets	383	330
Other assets:
Investments in non-consolidated affiliates	135	117
Deposits for real-estate leases	19	13
Indemnification assets related to acquisitions	15	16
Mutual funds and fixed deposits	66	10
Company owned life insurance (at contract value)	17	0
Costs to obtain sales contracts	134	119
Derivative instruments designated as accounting hedges	57	83
Pension and other retirement employee benefits	21	0
Other	51	31
Total other assets	515	389
Accounts payable and accrued liabilities:
Salaries and benefits	197	152
Incentive compensation	226	208
Customer credits, advanced payments and advanced billings	42	28
Dividends	11	7
Professional service fees	53	43
Interest accrued on debt	82	63
Accounts payable	39	38
Income taxes	128	73
Pension and other retirement employee benefits	45	7
Accrued royalties	19	25
Foreign exchange forwards on certain assets and liabilities	2	0
Restructuring liability	18	21
Derivative instruments designated as accounting hedges	39	0
Other	138	108
Total accounts payable and accrued liabilities	1,039	773
Other liabilities:
Pension and other retirement employee benefits	244	299
Interest accrued on UTPs	113	82
MAKS indemnification provisions	33	43
Income tax liability – non-current portion	18	51
Derivative instruments designated as accounting hedges	145	0
Restructuring liability	3	3
Other	34	26
Total other liabilities	$ 590	$ 504

Comprehensive Income And Accu_3

Comprehensive Income And Accumulated Other Comprehensive Income - Reclassification out of AOCI (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Loss pursuant to the divestiture of MAKS	$ (9)	$ (14)	$ 0
Other non-operating income (expense), net	46	20	19
Total before income taxes	2,229	1,810	1,672
Provision for income taxes	(452)	(381)	(352)
Net income	1,777	1,429	1,320
Reclassification out of Accumulated Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Net income	(7)	(32)	(4)
Currency translation adjustment losses | Reclassification out of Accumulated Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Loss pursuant to the divestiture of MAKS	0	(32)	0
Net income	0	(32)	0
Losses on cash flow hedges | Reclassification out of Accumulated Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Provision for income taxes	1	0	0
Net income	(2)	0	0
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 (expense), net	(3)	0	0
Gains on net investment hedges | Reclassification out of Accumulated Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Total before income taxes	1	3	0
Provision for income taxes	0	(1)	0
Net income	1	2	0
Gains on net investment hedges | Reclassification out of Accumulated Other Comprehensive Income | Cross currency swaps
Derivative Instruments, Gain (Loss) [Line Items]
Other non-operating income (expense), net	1	0	0
Gains on net investment hedges | Reclassification out of Accumulated Other Comprehensive Income | FX forwards
Derivative Instruments, Gain (Loss) [Line Items]
Other non-operating income (expense), net	0	3	0
Pension and other retirement benefits | Reclassification out of Accumulated Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Total before income taxes	(8)	(3)	(5)
Provision for income taxes	2	1	1
Net income	(6)	(2)	(4)
Amortization of actuarial losses and prior service costs included in net income | Reclassification out of Accumulated Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Other non-operating income (expense), net	(6)	(3)	(5)
Accelerated recognition of loss due to settlement | Reclassification out of Accumulated Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Other non-operating income (expense), net	$ (2)	$ 0	$ 0

Comprehensive Income And Accu_4

Comprehensive Income And Accumulated Other Comprehensive Income - Changes in Components of Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance		$ 612
Other comprehensive income/(loss) before reclassifications		0	$ (25)	$ (256)
Amounts reclassified from AOCI		7	32	4
Other comprehensive income/(loss)		7	(13)	$ (254)
Ending balance		1,569	$ 612
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201602Member		us-gaap:AccountingStandardsUpdate201613Member	us-gaap:AccountingStandardsUpdate201802Member
Cumulative Effect, Period of Adoption, Adjustment
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Accounting Standards Update [Extensible List]				us-gaap:AccountingStandardsUpdate201802Member	us-gaap:AccountingStandardsUpdate201602Member
Total
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	$ (426)	(439)	$ (426)	$ (172)
Ending balance		(432)	(439)	(426)	$ (172)
Total | Cumulative Effect, Period of Adoption, Adjustment
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(20)		(20)	(2)
Ending balance				(20)	(2)
Pension and Other Retirement Benefits
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(53)	(92)	(53)	(61)
Other comprehensive income/(loss) before reclassifications		(32)	(24)	4
Amounts reclassified from AOCI		6	2	4
Other comprehensive income/(loss)		(26)	(39)	8
Ending balance		(118)	(92)	(53)	(61)
Pension and Other Retirement Benefits | Cumulative Effect, Period of Adoption, Adjustment
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(17)		(17)
Ending balance				(17)
Gains / (Losses) on Cash Flow Hedges
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	0	0	0	1
Other comprehensive income/(loss) before reclassifications		(51)	0	(1)
Amounts reclassified from AOCI		2	0	0
Other comprehensive income/(loss)		(49)	0	(1)
Ending balance		(49)	0	0	1
Foreign Currency Translation Adjustments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(406)	(401)	(406)	(113)
Other comprehensive income/(loss) before reclassifications		356	(27)	(293)
Amounts reclassified from AOCI		0	32	0
Other comprehensive income/(loss)		356	5	(293)
Ending balance		(45)	(401)	(406)	(113)
Net Investment Hedges
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	33	54	33	(1)
Other comprehensive income/(loss) before reclassifications		(273)	26	34
Amounts reclassified from AOCI		(1)	(2)	0
Other comprehensive income/(loss)		(274)	21	34
Ending balance		$ (220)	54	33	(1)
Net Investment Hedges | Cumulative Effect, Period of Adoption, Adjustment
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(3)		(3)
Ending balance				(3)
Gains on Available for Sale Securities
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	$ 0		$ 0	2
Other comprehensive income/(loss) before reclassifications				0
Amounts reclassified from AOCI				0
Other comprehensive income/(loss)				(2)
Ending balance				0	2
Gains on Available for Sale Securities | Cumulative Effect, Period of Adoption, Adjustment
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance				$ (2)
Ending balance					$ (2)

Pension And Other Retirement _3

Pension And Other Retirement Benefits - Summary of Changes in Benefit Obligations and Fair Value of Plan Assets for Post-Retirement Plans (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Change in benefit obligation:
Interest cost	$ (19)	$ (22)	$ (19)
Amounts recorded on the consolidated balance sheets:
Pension and retirement benefits asset – non current	21	0
Pension and retirement benefits liability – current	(45)	(7)
Pension and retirement benefits liability – non current	(244)	(299)
U.S. Plans | Pension Plans
Change in benefit obligation:
Benefit obligation, beginning of the period	(589)	(508)
Service cost	(17)	(17)	(19)
Interest cost	(17)	(21)	(17)
Plan participants’ contributions	0	0
Benefits paid	22	21
Actuarial gain (loss)	6	(3)
Assumption changes	(68)	(61)
Benefit obligation, end of the period	(663)	(589)	(508)
Change in plan assets:
Fair value of plan assets, beginning of the period	395	348
Actual return on plan assets	45	60
Benefits paid	(22)	(21)
Employer contributions	110	8
Plan participants’ contributions	0	0
Fair value of plan assets, end of the period	528	395	348
Funded Status of the plans	(135)	(194)
Amounts recorded on the consolidated balance sheets:
Pension and retirement benefits asset – non current	21	0
Pension and retirement benefits liability – current	(44)	(6)
Pension and retirement benefits liability – non current	(112)	(188)
Net amount recognized	(135)	(194)
Accumulated benefit obligation, end of the period	(601)	(529)
U.S. Plans | Other Retirement Plans
Change in benefit obligation:
Benefit obligation, beginning of the period	(42)	(32)
Service cost	(3)	(3)	(3)
Interest cost	(1)	(1)	(1)
Plan participants’ contributions	(1)	(1)
Benefits paid	2	1
Actuarial gain (loss)	2	0
Assumption changes	(5)	(6)
Benefit obligation, end of the period	(48)	(42)	(32)
Change in plan assets:
Fair value of plan assets, beginning of the period	0	0
Actual return on plan assets	0	0
Benefits paid	(2)	(1)
Employer contributions	1	0
Plan participants’ contributions	1	1
Fair value of plan assets, end of the period	0	0	$ 0
Funded Status of the plans	(48)	(42)
Amounts recorded on the consolidated balance sheets:
Pension and retirement benefits asset – non current	0	0
Pension and retirement benefits liability – current	(1)	(1)
Pension and retirement benefits liability – non current	(47)	(41)
Net amount recognized	$ (48)	$ (42)

Pension and Other Retirement _4

Pension and Other Retirement Benefits - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plans and Other Postretirement Benefit Plans [Abstract]
Dividends paid on ESOP		$ 1	$ 1	$ 1
Moody's shares held in ESOP		360,600	411,100
Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans [Abstract]
Loss on settlement of pension obligation		$ 2
U.S. Plans
Defined Benefit Plans and Other Postretirement Benefit Plans [Abstract]
Employee contribution percentage of employee contribution in participation		50.00%
Maximum employee contribution in profit participation plan		3.00%
Defined contribution compensation expense		$ 44	$ 43	$ 27
U.S. Plans | Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans [Abstract]
Expected rate of return		4.45%	5.65%	4.50%
Employer contributions		$ 110	$ 8
U.S. Plans | Other Retirement Plans
Defined Benefit Plans and Other Postretirement Benefit Plans [Abstract]
Expected rate of return		0.00%	0.00%	0.00%
Employer contributions		$ 1	$ 0
Anticipated contribution to plans		$ 1
U.S. Plans | Equity Securities | Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans [Abstract]
Plan asset, target asset allocation percentage		33.00%
U.S. Plans | Equity Securities | Pension Plans | Minimum
Defined Benefit Plans and Other Postretirement Benefit Plans [Abstract]
Plan asset, target asset allocation percentage		28.00%
U.S. Plans | Equity Securities | Pension Plans | Maximum
Defined Benefit Plans and Other Postretirement Benefit Plans [Abstract]
Plan asset, target asset allocation percentage		38.00%
U.S. Plans | Fixed Income Securities | Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans [Abstract]
Plan asset, target asset allocation percentage		62.00%
U.S. Plans | Fixed Income Securities | Pension Plans | Minimum
Defined Benefit Plans and Other Postretirement Benefit Plans [Abstract]
Plan asset, target asset allocation percentage		57.00%
U.S. Plans | Fixed Income Securities | Pension Plans | Maximum
Defined Benefit Plans and Other Postretirement Benefit Plans [Abstract]
Plan asset, target asset allocation percentage		67.00%
U.S. Plans | Other Investments | Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans [Abstract]
Plan asset, target asset allocation percentage		5.00%
U.S. Plans | Other Investments | Pension Plans | Minimum
Defined Benefit Plans and Other Postretirement Benefit Plans [Abstract]
Plan asset, target asset allocation percentage		2.00%
U.S. Plans | Other Investments | Pension Plans | Maximum
Defined Benefit Plans and Other Postretirement Benefit Plans [Abstract]
Plan asset, target asset allocation percentage		8.00%
Non-U.S. Plans
Defined Benefit Plans and Other Postretirement Benefit Plans [Abstract]
Defined contribution compensation expense		$ 29	25	$ 26
Funded Plan | U.S. Plans | Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans [Abstract]
Employer contributions		99
Unfunded Plan | U.S. Plans | Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans [Abstract]
Employer contributions		11	$ 8
Anticipated contribution to plans		$ 44
Forecast | U.S. Plans | Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans [Abstract]
Expected rate of return	5.45%

Pension And Other Retirement _5

Pension And Other Retirement Benefits - Accumulated Benefit Obligation in Excess of Plan Assets (Detail) - Pension Plans - U.S. Plans - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Aggregate projected benefit obligation	$ 156	$ 589
Aggregate accumulated benefit obligation	138	529
Aggregate fair value of plan assets	$ 0	$ 395

Pension And Other Retirement _6

Pension And Other Retirement Benefits - Summary of Pre-Tax Net Actuarial Losses and Prior Service Cost Recognized in Accumulated Other Comprehensive Income (Loss) (Detail) - U.S. Plans - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Pension Plans
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Net actuarial losses	$ (144)	$ (116)
Net prior service credits	3	4
Total recognized in AOCI – pretax	(141)	(112)
Other Retirement Plans
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Net actuarial losses	(8)	(6)
Net prior service credits	0	0
Total recognized in AOCI – pretax	$ (8)	$ (6)

Pension And Other Retirement _7

Pension And Other Retirement Benefits - Components of Net Periodic Benefit Expense Related to Retirement Plans (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 19	$ 22	$ 19
U.S. Plans | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	17	17	19
Interest cost	17	21	17
Expected return on plan assets	(20)	(20)	(15)
Amortization of net actuarial loss and prior service credits from earlier periods	7	4	6
Net periodic expense	21	22	27
U.S. Plans | Other Retirement Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	3	3	3
Interest cost	1	1	1
Expected return on plan assets	0	0	0
Amortization of net actuarial loss and prior service credits from earlier periods	0	0	0
Net periodic expense	$ 4	$ 4	$ 4

Pension And Other Retirement _8

Pension And Other Retirement Benefits - Summary Of Pre Tax Amounts Recognized In Other Comprehensive Income (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Net actuarial (loss)/gain arising during the period	$ (42)	$ (32)	$ 6
U.S. Plans | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Amortization of net actuarial losses and prior service credit	(7)	(4)	(6)
Settlement loss	2	0	0
Net actuarial (loss)/gain arising during the period	(37)	(24)	2
Total recognized in OCI – pre-tax	(28)	(20)	8
U.S. Plans | Other Retirement Plans
Defined Benefit Plan Disclosure [Line Items]
Amortization of net actuarial losses and prior service credit	0	0	0
Settlement loss	0	0	0
Net actuarial (loss)/gain arising during the period	(3)	(6)	3
Total recognized in OCI – pre-tax	$ (3)	$ (6)	$ 3

Pension And Other Retirement _9

Pension And Other Retirement Benefits - Weighted-Average Assumptions Used to Determine Benefit Obligations (Detail) - U.S. Plans	Dec. 31, 2020	Dec. 31, 2019
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Discount rate	2.24%	3.04%
Rate of compensation increase	3.62%	3.64%
Other Retirement Plans
Defined Benefit Plan Disclosure [Line Items]
Discount rate	2.30%	3.05%
Rate of compensation increase	0.00%	0.00%

Pension And Other Retirement_10

Pension And Other Retirement Benefits - Weighted-Average Assumptions Used to Determine Net Periodic Benefit Expense (Detail) - U.S. Plans	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.04%	4.07%	3.46%
Expected return on plan assets	4.45%	5.65%	4.50%
Rate of compensation increase	3.64%	3.69%	3.71%
Cash balance plan interest crediting rate	4.50%	4.50%	4.50%
Other Retirement Plans
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.05%	4.10%	3.45%
Expected return on plan assets	0.00%	0.00%	0.00%
Rate of compensation increase	0.00%	0.00%	0.00%
Cash balance plan interest crediting rate	0.00%	0.00%	0.00%

Pension And Other Retirement_11

Pension And Other Retirement Benefits - Summary of Pension Plan Assets by Category Based on Hierarchy of Fair Value Measurements (Detail) - Pension Plans - U.S. Plans - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 528	$ 395	$ 348
Percent of total assets	100.00%	100.00%
Level 1
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 39	$ 34
Level 2
Defined Benefit Plan Disclosure [Line Items]
Total assets	421	311
Measured using NAV practical expedient
Defined Benefit Plan Disclosure [Line Items]
Total assets	68	50
Cash and cash equivalent
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 4	$ 2
Percent of total assets	1.00%	1.00%
Cash and cash equivalent | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 4	$ 2
Total equity investments
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 203	$ 190
Percent of total assets	38.00%	48.00%
Total equity investments | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 203	$ 190
U.S. large-cap
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 143	$ 140
Percent of total assets	27.00%	35.00%
U.S. large-cap | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 143	$ 140
U.S. small and mid-cap
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 28	$ 21
Percent of total assets	5.00%	5.00%
U.S. small and mid-cap | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 28	$ 21
Emerging markets
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 32	$ 29
Percent of total assets	6.00%	7.00%
Emerging markets | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 32	$ 29
Total fixed-income investments
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 297	$ 180
Percent of total assets	56.00%	46.00%
Total fixed-income investments | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 39	$ 34
Total fixed-income investments | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total assets	214	119
Total fixed-income investments | Measured using NAV practical expedient
Defined Benefit Plan Disclosure [Line Items]
Total assets	44	27
Emerging markets bond fund
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 32	$ 15
Percent of total assets	6.00%	4.00%
Emerging markets bond fund | Measured using NAV practical expedient
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 32	$ 15
Intermediate-term investment grade U.S. government/ corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 214	$ 119
Percent of total assets	41.00%	30.00%
Intermediate-term investment grade U.S. government/ corporate bonds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 214	$ 119
U.S. Treasury Inflation-Protected Securities (TIPs)
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 23	$ 22
Percent of total assets	4.00%	6.00%
U.S. Treasury Inflation-Protected Securities (TIPs) | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 23	$ 22
Convertible securities
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 16
Percent of total assets	3.00%
Convertible securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 16
Private investment fund—convertible securities
Defined Benefit Plan Disclosure [Line Items]
Total assets		$ 12
Percent of total assets		3.00%
Private investment fund—convertible securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total assets		$ 12
Private investment fund—high yield securities
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 12	$ 12
Percent of total assets	2.00%	3.00%
Private investment fund—high yield securities | Measured using NAV practical expedient
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 12	$ 12
Other investment—private real estate fund
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 24	$ 23
Percent of total assets	5.00%	6.00%
Other investment—private real estate fund | Measured using NAV practical expedient
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 24	$ 23

Pension And Other Retirement_12

Pension And Other Retirement Benefits - Estimated Future Benefits Payments for Retirement Plans (Detail) - U.S. Plans $ in Millions	Dec. 31, 2020USD ($)
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
2021	$ 55
2022	17
2023	25
2024	21
2025	24
2026 - 2030	139
Other Retirement Plans
Defined Benefit Plan Disclosure [Line Items]
2021	1
2022	1
2023	2
2024	2
2025	2
2026 - 2030	$ 13

Stock-Based Compensation Plan_2

Stock-Based Compensation Plans - Additional Information (Detail) - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Equity Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)	4 years
Unrecognized compensation expense	$ 6
Weighted average period to recognize expense	2 years 3 months 18 days
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense	$ 162
Weighted average period to recognize expense	2 years 4 months 24 days
Performance Based Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)	3 years
Unrecognized compensation expense	$ 21
Weighted average period to recognize expense	1 year 9 months 18 days
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserve for issuance or grant (shares)	6
Discount allowed to employees on purchase of shares under ESPP plan	5.00%	5.00%	5.00%
1998 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserve for issuance or grant (shares)	33
2001 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserve for issuance or grant (shares)	50.6
2001 Plan | Instruments Other Than Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserve for issuance or grant (shares)	14
Directors' Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserve for issuance or grant (shares)	1.7
Award vesting period (in years)	1 year
Minimum | Equity Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)	1 year
Minimum | Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee subscription rate as a percentage of compensation	1.00%
Maximum | Equity Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)	4 years
Maximum | Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee subscription rate as a percentage of compensation	10.00%
Maximum | 1998 and 2001 Plan | Equity Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)	10 years
Maximum | Directors' Plan | Equity Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)	10 years

Stock-Based Compensation Plan_3

Stock-Based Compensation Plans - Stock-Based Compensation Cost and Associated Tax Benefit (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Payment Arrangement [Abstract]
Stock-based compensation expense	$ 154	$ 136	$ 130
Tax benefit	$ 30	$ 29	$ 32

Stock-Based Compensation Plan_4

Stock-Based Compensation Plans - Weighted Average Assumptions used in Determining Fair Value for Options Granted (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Payment Arrangement [Abstract]
Expected dividend yield	0.80%	1.14%	1.05%
Expected stock volatility	23.00%	24.00%	26.00%
Risk-free interest rate	1.43%	2.56%	2.82%
Expected holding period -in years	5 years 8 months 12 days	6 years 2 months 12 days	6 years 2 months 12 days
Grant date fair value	$ 60.66	$ 43.29	$ 45.73

Stock-Based Compensation Plan_5

Stock-Based Compensation Plans - Summary of Option Activity (Details) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)$ / sharesshares
Shares
Shares, Outstanding, Beginning Balance (in shares) | shares	1.6
Shares, Granted (in shares) | shares	0.1
Shares, Exercised (in shares) | shares	(0.7)
Shares, Outstanding, Ending Balance (in shares) | shares	1
Shares, Vested and expected to vest (in shares) | shares	1
Shares, Exercisable (in shares) | shares	0.7
Weighted Average Exercise Price Per Share
Weighted Average Exercise Price Per Share, Beginning Balance (in usd per share) | $ / shares	$ 93.51
Weighted Average Exercise Price Per Share, Granted (in usd per share) | $ / shares	280.37
Weighted Average Exercise Price Per Share, Exercised (in usd per share) | $ / shares	59.57
Weighted Average Exercise Price Per Share, Ending Balance (in usd per share) | $ / shares	133.95
Weighted Average Exercise Price Per Share, Vested and expected to vest (in usd per share) | $ / shares	132.80
Weighted Average Exercise Price Per Share, Exercisable (in usd per share) | $ / shares	$ 101.13
Weighted Average Remaining Contractual Term
Weighted Average Remaining Contractual Term, Outstanding (in years)	5 years 7 months 6 days
Weighted Average Remaining Contractual Term, Vested and expected to vest (in years)	5 years 7 months 6 days
Weighted Average Remaining Contractual Term (in years)	4 years 7 months 6 days
Aggregate Intrinsic Value
Aggregate Intrinsic Value, Outstanding | $	$ 160
Aggregate Intrinsic Value, Vested and expected to vest | $	158
Aggregate Intrinsic Value, Exercisable | $	$ 125

Stock-Based Compensation Plan_6

Stock-Based Compensation Plans - Stock Option Exercises and Restricted Stock Vesting (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Proceeds from stock option exercises	$ 39	$ 36	$ 38
Aggregate intrinsic value	132	114	99
Tax benefit realized upon exercise	32	27	24
Restricted Stock
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Fair value of shares vested	202	156	151
Tax benefit realized upon vesting	46	36	35
Performance Based Restricted Stock
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Fair value of shares vested	70	47	23
Tax benefit realized upon vesting	$ 17	$ 11	$ 6

Stock-Based Compensation Plan_7

Stock-Based Compensation Plans - Summary of Nonvested Restricted Stock (Details) - Non Vested Restricted Stock shares in Millions	12 Months Ended
	Dec. 31, 2020$ / sharesshares
Shares
Shares, Beginning Balance (in shares) | shares	1.8
Shares, Granted (in shares) | shares	0.5
Shares, Vested (in shares) | shares	(0.8)
Shares, Ending Balance (in shares) | shares	1.5
Weighted Average Grant Date Fair Value Per Share
Weighted Average Grant Date Fair Value Per Share, Beginning Balance (in usd per share) | $ / shares	$ 124.63
Weighted Average Grant Date Fair Value Per Share, Granted (in usd per share) | $ / shares	279
Weighted Average Grant Date Fair Value Per Share, Vested (in usd per share) | $ / shares	132.50
Weighted Average Grant Date Fair Value Per Share, Ending Balance (in usd per share) | $ / shares	$ 201.30

Stock-Based Compensation Plan_8

Stock-Based Compensation Plans - Summary of Performance Based Restricted Stock (Details) - Performance Based Restricted Stock shares in Millions	12 Months Ended
	Dec. 31, 2020$ / sharesshares
Performance-Based Restricted Stock
Shares, Beginning Balance (in shares) | shares	0.5
Shares, Granted (in shares) | shares	0.1
Shares, Vested (in shares) | shares	(0.3)
Shares, Ending Balance (in shares) | shares	0.3
Performance based restricted stock, Weighted Average Grant Date Fair Value Per Share
Weighted Average Grant Date Fair Value Per Share, Beginning Balance (in usd per share) | $ / shares	$ 134.35
Weighted Average Grant Date Fair Value Per Share, Granted (in usd per share) | $ / shares	273.81
Weighted Average Grant Date Fair Value Per Share, Vested (in usd per share) | $ / shares	109.43
Weighted Average Grant Date Fair Value Per Share, Ending Balance (in usd per share) | $ / shares	$ 197.19

Income Taxes - Provision for In

Income Taxes - Provision for Income Taxes (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current:
Federal	$ 213	$ 179	$ 168
State and Local	68	59	50
Non-U.S.	215	181	233
Total current	496	419	451
Deferred:
Federal	6	(19)	(59)
State and Local	0	(3)	(2)
Non-U.S.	(50)	(16)	(38)
Total deferred	(44)	(38)	(99)
Total provision for income taxes	$ 452	$ 381	$ 352

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of United States Federal Statutory Tax Rate to Effective Tax Rate on Income Before Provision for Income Taxes (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
U.S. statutory tax rate	21.00%	21.00%	21.00%
State and local taxes, net of federal tax benefit	2.30%	2.20%	2.20%
Benefit of foreign operations	(1.50%)	(0.10%)	1.80%
U.S. Tax Act Impact	0	0	(0.028)
Other	(1.50%)	(2.10%)	(1.10%)
Effective tax rate	20.30%	21.00%	21.10%
Income tax paid	$ 514	$ 458	$ 442

Income Taxes - Source of income

Income Taxes - Source of income Before Provision for Income Taxes (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
U.S.	$ 1,349	$ 1,039	$ 936
Non-U.S.	880	771	736
Income before provision for income taxes	$ 2,229	$ 1,810	$ 1,672

Income Taxes - Components of De

Income Taxes - Components of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets:
Account receivable allowances	$ 9	$ 6
Accumulated depreciation and amortization	2	1
Stock-based compensation	42	46
Accrued compensation and benefits	99	89
Capitalized costs	39	0
Operating lease liabilities	122	136
Deferred revenue	30	37
Net operating loss	17	13
Restructuring	3	4
Uncertain tax positions	98	94
Self-insured related reserves	10	8
Loss on net investment hedges - OCI	93	0
Other	10	13
Total deferred tax assets	574	447
Deferred tax liabilities:
Accumulated depreciation and amortization of intangible assets and capitalized software	(468)	(389)
ROU Assets	(90)	(107)
Capital Gains	(23)	(23)
Self-insured related income	(10)	(8)
Stock-based compensation	0	(2)
Revenue Accounting Standard - ASC 606	(10)	(12)
Deferred tax on unremitted foreign earnings	(16)	0
Gain on net investment hedges - OCI	(8)	(22)
Other	(4)	(3)
Total deferred tax liabilities	(629)	(566)
Net deferred tax liabilities	(55)	(119)
Valuation allowance	(15)	(9)	$ (5)	$ (6)
Total net deferred tax liabilities	$ (70)	$ (128)

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Sep. 30, 2018	Sep. 30, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Revision of estimated repatriation tax liability resulting from tax reform legislation	$ 247	$ 236
Reduction in estimated repatriation tax liability resulting from tax act			$ 11
Estimated repatriation tax liability resulting from the tax act, pay period						8 years
Excess tax benefits from stock compensation				$ 60	$ 44
Excess tax benefits from stock compensation (percent)				2.69%	2.42%
Valuation allowance	6			$ 15	$ 9	$ 5
Unrecognized tax benefits	$ 389			483	477	495
Uncertain tax positions if recognized would impact the effective tax rate				432
Deferred tax asset for potential transition tax benefit						$ 50
Net interest expense on UTPs				31	28
Interest accrued on UTPs				$ 113	$ 82

Income Taxes - Reconciliation_2

Income Taxes - Reconciliation of Uncertain Tax Positions (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of Unrecognized Tax Benefits
Unrecognized tax positions, beginning balance	$ 477	$ 495	$ 389
Additions for tax positions related to the current year	37	35	80
Additions for tax positions of prior years	17	22	89
Reductions for tax positions of prior years	(2)	(2)	(13)
Settlements with taxing authorities	(5)	(1)	(2)
Lapse of statute of limitations	(41)	(44)	(48)
Reclassification to indemnification liability related to MAKS divestiture	0	(28)	0
Unrecognized tax positions, ending balance	$ 483	$ 477	$ 495

Indebtedness - Summary of Total

Indebtedness - Summary of Total Indebtedness (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Principal Amount	$ 6,430	$ 5,603
Fair Value of Interest Rate Swap	56	27
Unamortized (Discount) Premium	(24)	(17)
Unamortized Debt Issuance Costs	(40)	(32)
Carrying Amount	$ 6,422	$ 5,581
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	14	9
Unamortized (Discount) Premium	(1)	(1)
Unamortized Debt Issuance Costs	(1)	(1)
Carrying Amount	$ 512	$ 507
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)	(2)
Carrying Amount	$ 498	$ 497
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	4
Unamortized Debt Issuance Costs	(5)	(5)
Carrying Amount	$ 598	$ 599
1.75% 2015 Senior Notes, due 2027
Debt Instrument [Line Items]
Notes payable, interest rate	1.75%	1.75%
Principal Amount	$ 612	$ 561
Fair Value of Interest Rate Swap	0	0
Unamortized (Discount) Premium	0	0
Unamortized Debt Issuance Costs	(2)	(3)
Carrying Amount	$ 610	$ 558
2.75% 2017 Senior Notes, due 2021
Debt Instrument [Line Items]
Notes payable, interest rate		2.75%
Principal Amount		$ 500
Fair Value of Interest Rate Swap		11
Unamortized (Discount) Premium		(1)
Unamortized Debt Issuance Costs		(2)
Carrying Amount		$ 508
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	12	7
Unamortized (Discount) Premium	0	(1)
Unamortized Debt Issuance Costs	(2)	(2)
Carrying Amount	$ 510	$ 504
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	31	0
Unamortized (Discount) Premium	(4)	(4)
Unamortized Debt Issuance Costs	(3)	(3)
Carrying Amount	$ 524	$ 493
3.25% 2018 Senior Notes, due 2021
Debt Instrument [Line Items]
Notes payable, interest rate		3.25%
Principal Amount		$ 300
Fair Value of Interest Rate Swap		0
Unamortized (Discount) Premium		0
Unamortized Debt Issuance Costs		(1)
Carrying Amount		$ 299
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	(3)	(3)
Unamortized Debt Issuance Costs	(3)	(3)
Carrying Amount	$ 394	$ 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)	(7)
Unamortized Debt Issuance Costs	(4)	(4)
Carrying Amount	$ 390	$ 389
0.950% 2019 Senior Note, due 2030
Debt Instrument [Line Items]
Notes payable, interest rate	0.95%	0.95%
Principal Amount	$ 918	$ 842
Fair Value of Interest Rate Swap	0	0
Unamortized (Discount) Premium	(3)	(3)
Unamortized Debt Issuance Costs	(6)	(6)
Carrying Amount	$ 909	$ 833
3.75% 2020 Senior Note, due 2025
Debt Instrument [Line Items]
Notes payable, interest rate	3.75%
Principal Amount	$ 700
Fair Value of Interest Rate Swap	(1)
Unamortized (Discount) Premium	(1)
Unamortized Debt Issuance Costs	(5)
Carrying Amount	$ 693
3.25% 2020 Senior Note, due 2050
Debt Instrument [Line Items]
Notes payable, interest rate	3.25%
Principal Amount	$ 300
Fair Value of Interest Rate Swap	0
Unamortized (Discount) Premium	(4)
Unamortized Debt Issuance Costs	(3)
Carrying Amount	$ 293
2.55% 2020 Senior Note, due 2060
Debt Instrument [Line Items]
Notes payable, interest rate	2.55%
Principal Amount	$ 500
Fair Value of Interest Rate Swap	0
Unamortized (Discount) Premium	(4)
Unamortized Debt Issuance Costs	(5)
Carrying Amount	$ 491

Indebtedness - Schedule of Cred

Indebtedness - Schedule of Credit Facilities (Details) - 2018 Credit Facility - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Nov. 14, 2018
Line of Credit Facility [Line Items]
Maximum Borrowing Capacity			$ 1,000,000,000
Drawn	$ 0	$ 0
Undrawn	$ 1,000,000,000	$ 1,000,000,000

Indebtedness - Additional Infor

Indebtedness - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Nov. 14, 2018
3.25% 2018 Senior Notes, due 2021
Debt Instrument [Line Items]
Repayments of debt	$ 300,000,000
Make-whole amount	8,000,000
2017 Senior Notes due 2021
Debt Instrument [Line Items]
Repayments of debt	500,000,000
Make-whole amount	16,000,000
Accretion expense	$ 17,000,000
2018 Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 1,000,000,000
2018 Credit Facility | Term Loan Facility Any Fiscal Quarter
Debt Instrument [Line Items]
Debt/EBITDA ratio	4
2018 Credit Facility | First Three Consecutive Quarters immediately following Any Acquisition
Debt Instrument [Line Items]
Debt/EBITDA ratio	4.5
2018 Credit Facility | Minimum
Debt Instrument [Line Items]
Facility fee basis points	0.07%
Contingent consideration arising from acquisitions, payment or settlement	$ 500,000,000
2018 Credit Facility | Maximum
Debt Instrument [Line Items]
Facility fee basis points	0.15%
Commercial Paper
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 1,000,000,000
Commercial paper	$ 0
Commercial Paper | Maximum
Debt Instrument [Line Items]
Term of notes	397 days
Alternate Base Rate | 2018 Credit Facility | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate (percent)	0.00%
Alternate Base Rate | 2018 Credit Facility | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate (percent)	0.225%
Adjusted LIBOR | 2018 Credit Facility | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate (percent)	0.805%
Adjusted LIBOR | 2018 Credit Facility | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate (percent)	1.225%

Indebtedness - Principal Paymen

Indebtedness - Principal Payments Due on Long-Term Borrowings (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
2021	$ 0
2022	500
2023	500
2024	500
2025	700
Thereafter	4,230
Total principal payment	6,430	$ 5,603
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	612
Total principal payment	612	561
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
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% 2019 Senior Note, due 2030
Debt Instrument [Line Items]
Thereafter	918
Total principal payment	918
3.75% 2020 Senior Note, due 2025
Debt Instrument [Line Items]
2025	700
Total principal payment	700
3.25% 2020 Senior Note, due 2050
Debt Instrument [Line Items]
Thereafter	300
Total principal payment	300
2.55% 2020 Senior Note, due 2060
Debt Instrument [Line Items]
Thereafter	500
Total principal payment	$ 500

Indebtedness - Summary of Compo

Indebtedness - Summary of Components of Interest as Presented in Consolidated Statements of Operations (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Debt Disclosure [Abstract]
Income	$ 11	$ 17	$ 15
Expense on borrowings	(163)	(176)	(197)
Expense on UTPs and other tax related liabilities	(34)	(28)	(15)
Net periodic pension costs--interest component	(19)	(22)	(19)
Capitalized	0	1	1
Total	(205)	(208)	(215)
Interest paid	$ 132	$ 167	$ 183

Indebtedness - Fair Value and C

Indebtedness - Fair Value and Carrying Value of Long-Term Debt (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Carrying Amount	$ 6,422	$ 5,581
4.50% 2012 Senior Notes, due 2022
Debt Instrument [Line Items]
Notes payable, interest rate	4.50%	4.50%
Carrying Amount	$ 512	$ 507
4.875% 2013 Senior Notes, due 2024
Debt Instrument [Line Items]
Notes payable, interest rate	4.875%	4.875%
Carrying Amount	$ 498	$ 497
5.25% 2014 Senior Notes, due 2044
Debt Instrument [Line Items]
Notes payable, interest rate	5.25%	5.25%
Carrying Amount	$ 598	$ 599
1.75% 2015 Senior Notes, due 2027
Debt Instrument [Line Items]
Notes payable, interest rate	1.75%	1.75%
Carrying Amount	$ 610	$ 558
2.75% 2017 Senior Notes, due 2021
Debt Instrument [Line Items]
Notes payable, interest rate		2.75%
Carrying Amount		$ 508
2.625% 2017 Senior Notes, due 2023
Debt Instrument [Line Items]
Notes payable, interest rate	2.625%	2.625%
Carrying Amount	$ 510	$ 504
3.25% 2017 Senior Notes, due 2028
Debt Instrument [Line Items]
Notes payable, interest rate	3.25%	3.25%
Carrying Amount	$ 524	$ 493
3.25% 2018 Senior Notes, due 2021
Debt Instrument [Line Items]
Notes payable, interest rate		3.25%
Carrying Amount		$ 299
4.25% 2018 Senior Notes, due 2029
Debt Instrument [Line Items]
Notes payable, interest rate	4.25%	4.25%
Carrying Amount	$ 394	$ 394
4.875% 2018 Senior Notes, due 2048
Debt Instrument [Line Items]
Notes payable, interest rate	4.875%	4.875%
Carrying Amount	$ 390	$ 389
0.950% 2019 Senior Note, due 2030
Debt Instrument [Line Items]
Carrying Amount	$ 909
3.75% 2020 Senior Note, due 2025
Debt Instrument [Line Items]
Notes payable, interest rate	3.75%
Carrying Amount	$ 693
3.25% 2020 Senior Note, due 2050
Debt Instrument [Line Items]
Notes payable, interest rate	3.25%
Carrying Amount	$ 293
2.55% 2020 Senior Note, due 2060
Debt Instrument [Line Items]
Notes payable, interest rate	2.55%
Carrying Amount	$ 491
Level 2
Debt Instrument [Line Items]
Estimated Fair Value	7,256	6,078
Level 2 | 4.50% 2012 Senior Notes, due 2022
Debt Instrument [Line Items]
Estimated Fair Value	530	531
Level 2 | 4.875% 2013 Senior Notes, due 2024
Debt Instrument [Line Items]
Estimated Fair Value	562	551
Level 2 | 5.25% 2014 Senior Notes, due 2044
Debt Instrument [Line Items]
Estimated Fair Value	828	757
Level 2 | 1.75% 2015 Senior Notes, due 2027
Debt Instrument [Line Items]
Estimated Fair Value	674	604
Level 2 | 2.75% 2017 Senior Notes, due 2021
Debt Instrument [Line Items]
Estimated Fair Value		507
Level 2 | 2.625% 2017 Senior Notes, due 2023
Debt Instrument [Line Items]
Estimated Fair Value	522	507
Level 2 | 3.25% 2017 Senior Notes, due 2028
Debt Instrument [Line Items]
Estimated Fair Value	561	523
Level 2 | 3.25% 2018 Senior Notes, due 2021
Debt Instrument [Line Items]
Estimated Fair Value		306
Level 2 | 4.25% 2018 Senior Notes, due 2029
Debt Instrument [Line Items]
Estimated Fair Value	480	453
Level 2 | 4.875% 2018 Senior Notes, due 2048
Debt Instrument [Line Items]
Estimated Fair Value	544	492
Level 2 | 0.950% 2019 Senior Note, due 2030
Debt Instrument [Line Items]
Estimated Fair Value	974	$ 847
Level 2 | 3.75% 2020 Senior Note, due 2025
Debt Instrument [Line Items]
Estimated Fair Value	785
Level 2 | 3.25% 2020 Senior Note, due 2050
Debt Instrument [Line Items]
Estimated Fair Value	329
Level 2 | 2.55% 2020 Senior Note, due 2060
Debt Instrument [Line Items]
Estimated Fair Value	$ 467

Capital Stock - Additional Info

Capital Stock - Additional Information (Detail) - USD ($)	Feb. 09, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Feb. 20, 2019
Class of Stock [Line Items]
All classes of stock, shares authorized (in shares)		1,020,000,000
Shares of all classes of stock, par value (in usd per share)		$ 0.01
Common stock, shares authorized (in shares)		1,000,000,000	1,000,000,000
Preferred stock, shares authorized (in shares)		10,000,000	10,000,000
Shares issued during the period for stock-based compensation plans (in shares)		1,400,000
Series Common Stock
Class of Stock [Line Items]
Common stock, shares authorized (in shares)		10,000,000
Treasury Stock
Class of Stock [Line Items]
Treasury stock, shares, acquired (in shares)		2,000,000	5,200,000	1,200,000
Accelerated Share Repurchase Initial Date
Class of Stock [Line Items]
Accelerated share repurchases payment					$ (500,000,000)
Subsequent Event
Class of Stock [Line Items]
Share repurchase program, amount	$ 1,000,000,000
Dividend declared, declaration date	Feb. 9, 2021
Quarterly dividend declared (in dollars per share)	$ 0.62
Dividend declared, payable date	Mar. 18, 2021
Dividend declared, record date	Feb. 25, 2021

Capital Stock - Share Repurchas

Capital Stock - Share Repurchase Programs (Detail) - December 16, 2019	Dec. 31, 2020USD ($)
Equity, Class of Treasury Stock [Line Items]
Amount Authorized	$ 1,000,000,000
Remaining Authority	$ 831,000,000

Capital Stock - Dividends Paid

Capital Stock - Dividends Paid (Detail) - $ / shares	3 Months Ended												12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Stockholders' Equity Note [Abstract]
Dividends declared per share (in USD per share)	$ 0.56	$ 0.56	$ 0.56	$ 0.56	$ 0.50	$ 0.50	$ 0.50	$ 0.50	$ 0.44	$ 0.44	$ 0.44	$ 0.44	$ 2.24	$ 2	$ 1.76
Dividends per share paid (in USD per share)	$ 0.56	$ 0.56	$ 0.56	$ 0.56	$ 0.50	$ 0.50	$ 0.50	$ 0.50	$ 0.44	$ 0.44	$ 0.44	$ 0.44	$ 2.24	$ 2	$ 1.76

Lease Commitments - Additional

Lease Commitments - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)
Operating Leased Assets [Line Items]
Impairment of right-of-use	$ 21
Minimum
Operating Leased Assets [Line Items]
Operating lease, renewal term	1 year
Maximum
Operating Leased Assets [Line Items]
Operating lease, renewal term	20 years

Lease Commitments - Components

Lease Commitments - Components of Lease Cost (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Lease, Cost [Abstract]
Operating lease cost	$ 96	$ 97
Sublease income	(5)	(2)
Variable lease cost	19	17
Total lease cost	$ 110	$ 112

Lease Commitments - Operating L

Lease Commitments - Operating Leases Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Cash paid for amounts included in the measurement of operating lease liabilities	$ 108	$ 106
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 36	$ 41
Weighted-average remaining lease term (years)	6 years	6 years 9 months 18 days
Weighted-average discount rate applied to operating leases (percent)	3.60%	3.60%

Lease Commitments - Operating_2

Lease Commitments - Operating Leases, Future Minimum Payment (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
2021	$ 110
2022	99
2023	93
2024	84
2025	76
Thereafter	117
Total minimum lease payments	579
Less: Interest	58
Present value of lease liabilities:	521
Lease liabilities - current	94	$ 89
Lease liabilities - noncurrent	$ 427	$ 485

Segment Information - Additiona

Segment Information - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)segmentlineOfBusiness
Segment Reporting Information [Line Items]
Number of operating segments | segment	2
Number of reportable segments | segment	2
MIS
Segment Reporting Information [Line Items]
Number of lines of business | lineOfBusiness	5
MA
Segment Reporting Information [Line Items]
Number of lines of business | lineOfBusiness	2
2018 Restructuring Program | MIS
Segment Reporting Information [Line Items]
Cumulative expense incurred to date	$ 61
2018 Restructuring Program | MA
Segment Reporting Information [Line Items]
Cumulative expense incurred to date	44
2020 Real Estate Rationalization Restructuring Program | MIS
Segment Reporting Information [Line Items]
Cumulative expense incurred to date	21
2020 Real Estate Rationalization Restructuring Program | MA
Segment Reporting Information [Line Items]
Cumulative expense incurred to date	15
2020 MA Strategic Reorganization Restructuring Program | MA
Segment Reporting Information [Line Items]
Cumulative expense incurred to date	$ 18

Segment Information - Financial

Segment Information - Financial Information by Segment (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information, Operating Income (Loss) [Abstract]
Revenue	$ 5,371	$ 4,829	$ 4,443
Total Expense	2,983	2,831	2,575
Operating income	2,388	1,998	1,868
Restructuring	50	60	49
Depreciation and amortization	220	200	192
Acquisition-Related Expenses	0	3	8
Loss pursuant to the divestiture of MAKS	9	14	0
Captive insurance company settlement	0	16
Adjusted Operating Income	2,667	2,291	2,117
Eliminations
Segment Reporting Information, Operating Income (Loss) [Abstract]
Revenue	(155)	(143)	(136)
Total Expense	(155)	(143)	(136)
Operating income	0	0	0
Restructuring	0	0	0
Depreciation and amortization	0	0	0
Acquisition-Related Expenses	0	0	0
Loss pursuant to the divestiture of MAKS	0	0
Captive insurance company settlement	0	0
Adjusted Operating Income	0	0	0
MIS
Segment Reporting Information, Operating Income (Loss) [Abstract]
Revenue	3,292	2,875	2,712
MIS | Operating Segments
Segment Reporting Information, Operating Income (Loss) [Abstract]
Revenue	3,440	3,009	2,836
Total Expense	1,476	1,376	1,276
Operating income	1,964	1,633	1,560
Restructuring	19	31	32
Depreciation and amortization	70	71	65
Acquisition-Related Expenses	0	0	0
Loss pursuant to the divestiture of MAKS	0	0
Captive insurance company settlement	0	10
Adjusted Operating Income	2,053	1,745	1,657
MA
Segment Reporting Information, Operating Income (Loss) [Abstract]
Revenue	2,079	1,954	1,731
MA | Operating Segments
Segment Reporting Information, Operating Income (Loss) [Abstract]
Revenue	2,086	1,963	1,743
Total Expense	1,662	1,598	1,435
Operating income	424	365	308
Restructuring	31	29	17
Depreciation and amortization	150	129	127
Acquisition-Related Expenses	0	3	8
Loss pursuant to the divestiture of MAKS	9	14
Captive insurance company settlement	0	6
Adjusted Operating Income	$ 614	$ 546	$ 460

Segment Information - Consolida

Segment Information - Consolidated Revenue Information by Geographic Area (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Revenue	$ 5,371	$ 4,829	$ 4,443
Long-lived assets	7,051	5,968	5,667
U.S.
Segment Reporting Information [Line Items]
Revenue	2,955	2,544	2,330
Long-lived assets	2,162	1,290	982
Non-U.S.
Segment Reporting Information [Line Items]
Revenue	2,416	2,285	2,113
Long-lived assets	4,889	4,678	4,685
EMEA
Segment Reporting Information [Line Items]
Revenue	1,545	1,446	1,377
Asia-Pacific
Segment Reporting Information [Line Items]
Revenue	571	551	493
Americas
Segment Reporting Information [Line Items]
Revenue	$ 300	$ 288	$ 243

Valuation and Qualifying Acco_3

Valuation and Qualifying Accounts - Summary of Activity for Valuation Allowances (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance, Accounts receivable allowance	$ (20)	$ (20)	$ (20)	$ (14)
Charged to costs and expenses, Accounts receivable allowance		(26)	(10)	(15)
Deductions, Accounts receivable allowance		14	10	9
Ending balance, Accounts receivable allowance		(34)	(20)	(20)	$ (14)
Beginning balance, Deferred tax assets valuation allowance	$ (5)	(9)	(5)	(6)
Charged to costs and expenses, Deferred tax assets valuation allowance		(6)	(4)	0
Deductions, Deferred tax assets valuation allowance		0	0	1
Ending balance, Deferred tax assets valuation allowance		(15)	$ (9)	$ (5)	$ (6)
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201602Member		us-gaap:AccountingStandardsUpdate201613Member	us-gaap:AccountingStandardsUpdate201802Member
Cumulative Effect, Period of Adoption, Adjustment
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance, Accounts receivable allowance		$ 2
Ending balance, Accounts receivable allowance			$ 2
Accounting Standards Update [Extensible List]				us-gaap:AccountingStandardsUpdate201802Member	us-gaap:AccountingStandardsUpdate201602Member

Components of Other Non-Operati

Components of Other Non-Operating Income (Expense), Net (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Other Income and Expenses [Abstract]
FX gain (loss)	$ 2	$ (18)	$ (11)
Net periodic pension costs - other components	13	18	10
Income from investments in non-consolidated affiliates	6	13	14
Other	25	7	6
Total	$ 46	$ 20	$ 19

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)
The Moody's Foundation
Related Party Transaction [Line Items]
Grants made by Moody's Corporation	$ 11

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - Subsequent Event - USD ($) $ / shares in Units, $ in Millions	Feb. 09, 2021	Mar. 31, 2021
Subsequent Event [Line Items]
Share repurchase program, amount	$ 1,000
Dividend declared, declaration date	Feb. 9, 2021
Dividend declared, per share (in dollars per share)	$ 0.62
Dividend declared, payable date	Mar. 18, 2021
Dividend declared, record date	Feb. 25, 2021
Forecast
Subsequent Event [Line Items]
Lapse of statute of limitations		$ 61
Interest accrued on UTPs		$ 40