Moody's (MCO) 10-Q 1 Nov 19 2019 Q3 Quarterly report Financial data

Cover Page

Cover Page shares in Millions	9 Months Ended
	Sep. 30, 2019shares
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2019
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
Entity Address, Address Line Two	250 Greenwich Street
Entity Address, City or Town	New York
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10007
City Area Code	(212)
Local Phone Number	553-0300
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding (in shares)	188.8
Entity Central Index Key	0001059556
Document Fiscal Period Focus	Q3
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Common Stock, par value $0.01 per share
Entity Information [Line Items]
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	MCO
Security Exchange Name	NYSE
1.75% Senior Notes Due 2027
Entity Information [Line Items]
Title of 12(b) Security	1.75% Senior Notes Due 2027
Trading Symbol	MCO 27
Security Exchange Name	NYSE

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Statement [Abstract]
Revenue	$ 1,240.5	$ 1,080.8	$ 3,596.2	$ 3,382.6
Expenses
Operating	350.2	306.3	1,031.8	941.4
Selling, general and administrative	291.9	260.3	848.1	801.9
Restructuring	(1)	0	58.3	0
Depreciation and amortization	48.6	46.1	149.9	143.6
Acquisition-Related Expenses	0	1.3	3.4	4.1
Impairment pursuant to the planned divestiture of MAKS	2	0	10.7	0
Total expenses	691.7	614	2,102.2	1,891
Operating income	548.8	466.8	1,494	1,491.6
Non-operating (expense) income, net
Interest expense, net	(45.9)	(56.4)	(149)	(160.5)
Other non-operating income, net	9.9	2.4	12.6	18.3
Total non-operating expense, net	(36)	(54)	(136.4)	(142.2)
Income before provisions for income taxes	512.8	412.8	1,357.6	1,349.4
Provision for income taxes	130.4	100.8	289.6	282.7
Net income	382.4	312	1,068	1,066.7
Less: Net income attributable to noncontrolling interests	3	1.8	5.4	7.4
Net income attributable to Moody's	$ 379.4	$ 310.2	$ 1,062.6	$ 1,059.3
Earnings per share attributable to Moody's common shareholders
Basic (in usd per share)	$ 2.01	$ 1.62	$ 5.60	$ 5.53
Diluted (in usd per share)	$ 1.99	$ 1.59	$ 5.54	$ 5.45
Weighted average number of shares outstanding
Basic (in shares)	189	191.8	189.6	191.7
Diluted (in shares)	191.1	194.5	191.8	194.4

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net Income	$ 382.4	$ 312	$ 1,068	$ 1,066.7
Foreign Currency Adjustments:
Foreign currency translation adjustments - Pre Tax	(193.6)	(52.4)	(178.7)	(203.2)
Foreign currency translation adjustment - Tax	0	0	0	0
Foreign currency translation adjustments - Net of Tax	(193.6)	(52.4)	(178.7)	(203.2)
Net gains on net investment hedges - Pre Tax	136.7	5.9	130.1	28
Net gains on net investment hedges, Tax	(34)	(1.8)	(33.1)	(7.4)
Net gains on net investment hedges, Net of Tax	102.7	4.1	97	20.6
Net investment hedges - reclassification of gains included in net income - Pre Tax	(1)	0	(1)	0
Net investment hedges - reclassification of gains included in net income - Tax	0.2	0	0.2	0
Net investment hedges - reclassification of gains included in net income - Net of Tax	(0.8)	0	(0.8)	0
Cash Flow Hedges:
Net realized and unrealized gain (loss) on cash flow hedges - Pre Tax			0	1.9
Net realized and unrealized gain (loss) on cash flow hedges - Tax			0	(0.4)
Net realized and unrealized gain (loss) on cash flow hedges - Net of Tax			0	1.5
Reclassification of (losses) gains included in net income - Pre Tax	0.1	(0.1)	0.2	(0.3)
Reclassification of (losses) gains included in net income - Tax	0.1	0	0.1	0
Reclassification of (losses) gains included in net income - Net of Tax	0	(0.1)	0.1	(0.3)
Pension and Other Retirement Benefits:
Amortization of actuarial losses and prior service costs included in net income - Pre Tax	0.8	1.1	2.4	3.5
Amortization of actuarial losses and prior service costs included in net income - Tax	(0.2)	(0.3)	(0.6)	(1)
Amortization of actuarial losses and prior service costs included in net income - Net of Tax	0.6	0.8	1.8	2.5
Net actuarial (losses) gains and prior service costs - Pre Tax			(1.7)	1.6
Net actuarial (losses) gains and prior service costs - Tax			0.4	(0.4)
Net actuarial (losses) gains and prior service costs - Net of Tax			(1.3)	1.2
Total other comprehensive (loss) income - Pre Tax	(57)	(45.5)	(48.7)	(168.5)
Total other comprehensive (loss)income - Tax	34.1	2.1	33.2	9.2
Other comprehensive income/(loss)	(91.1)	(47.6)	(81.9)	(177.7)
Comprehensive income	291.3	264.4	986.1	889
Less: comprehensive income (loss) attributable to noncontrolling interests	3.1	(8.4)	14.7	(2.7)
Comprehensive Income Attributable to Moody's	$ 288.2	$ 272.8	$ 971.4	$ 891.7

CONSOLIDATED BALANCE SHEETS (UN

CONSOLIDATED BALANCE SHEETS (UNAUDITED) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 1,178	$ 1,685
Short-term investments	95.8	132.5
Accounts receivable, net of allowances of $45.2 in 2019 and $43.5 in 2018	1,228.4	1,287.1
Other current assets	286.1	282.3
Assets held for sale	254	0
Total current assets	3,042.3	3,386.9
Property and equipment, net of accumulated depreciation of $816.8 in 2019 and $790.2 in 2018	292.1	320.4
Operating lease right-of-use assets	464.6
Goodwill	3,610	3,781.3
Intangible assets, net	1,454.1	1,566.1
Deferred tax assets, net	189.4	197.2
Other assets	425.3	274.3
Total assets	9,477.8	9,526.2
Current liabilities:
Accounts payable and accrued liabilities	607.2	695.2
Current portion of operating lease liabilities	89.5
Current portion of long-term debt	501.5	449.9
Deferred revenue	855.7	953.4
Liabilities held for sale	84.1	0
Total current liabilities	2,138	2,098.5
Non-current portion of deferred revenue	115	122.3
Long-term debt	4,736.5	5,226.1
Deferred tax liabilities, net	355.7	351.7
Uncertain tax positions	442	494.6
Operating lease liabilities	495
Other liabilities	492.5	576.5
Total liabilities	8,774.7	8,869.7
Contingencies (Note 20)	0
Redeemable noncontrolling interest	5.8	0
Shareholders' equity:
Preferred stock, par value $0.01 per share and, 10,000,000 shares authorized; no shares issued and outstanding	0	0
Common stock	3.4	3.4
Capital surplus	607.9	600.9
Retained earnings	9,391.6	8,594.4
Treasury stock, at cost; 154,151,437 and 151,598,695 shares of common stock at September 30, 2019 and December 31, 2018, respectively	(8,993)	(8,312.5)
Accumulated other comprehensive loss	(537.3)	(426.3)
Total Moody's shareholders' equity	472.6	459.9
Noncontrolling interests	224.7	196.6
Total shareholders' equity	697.3	656.5
Total liabilities, noncontrolling interests and shareholders' equity	9,477.8	9,526.2
Series Common Stock
Shareholders' equity:
Common stock	$ 0	$ 0

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) (UNAUDITED) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Accounts receivable, allowances	$ 45.2	$ 43.5
Property and equipment, accumulated depreciation	$ 816.8	$ 790.2
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)	154,151,437	151,598,695
Series Common Stock
Common stock, par value (in usd per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	10,000,000	10,000,000
Common stock, shares issued (in shares)	0	0
Common stock, shares outstanding (in shares)	0	0

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities
Net Income	$ 1,068	$ 1,066.7
Reconciliation of net income to net cash provided by operating activities:
Depreciation and amortization	149.9	143.6
Stock-based compensation	103.2	100
Deferred income taxes	(22.2)	(75.3)
ROU Asset impairment & other non-cash restructuring/impairment charges	37.6
Impairment pursuant to the planned divestiture of MAKS	10.7	0
Changes in assets and liabilities:
Accounts receivable	35.9	22.5
Other current assets	(8.2)	36.6
Other assets	(25.6)	(7.4)
Lease obligations	(6.5)
Accounts payable and accrued liabilities	(99.8)	(176.5)
Deferred revenue	(96.4)	(35.3)
Unrecognized tax benefits and other non-current tax liabilities	(17.2)	42.8
Other liabilities	66.1	(33.1)
Net cash provided by operating activities	1,195.5	1,084.6
Cash flows from investing activities
Capital additions	(60.9)	(62.9)
Purchases of investments	(110.6)	(142.5)
Sales and maturities of investments	138.9	120.9
Cash received upon disposal of a subsidiary, net of cash transferred to purchaser	0	5.7
Cash paid for acquisitions, net of cash acquired	(121)	(35)
Receipts from settlements of net investment hedges	4.1	0
Net cash used in investing activities	(149.5)	(113.8)
Cash flows from financing activities
Issuance of notes	0	299.6
Repayment of notes	(450)	(750)
Issuance of commercial paper	1,307.2	434.4
Repayment of commercial paper	(1,310)	(539.2)
Proceeds from stock-based compensation plans	36.4	42.9
Repurchase of shares related to stock-based compensation	(75.9)	(62)
Treasury shares	(728)	(147.2)
Dividends	(283.6)	(252.9)
Dividends to noncontrolling interests	(0.8)	(4)
Payment for noncontrolling interest	(12.3)	0
Debt issuance costs and related fees	0	(1.8)
Net cash used in financing activities	(1,517)	(980.2)
Reclassification of cash to assets held for sale	(11.1)	0
Effect of exchange rate changes on cash and cash equivalents	(24.9)	(27.3)
Decrease in cash and cash equivalents	(507)	(36.7)
Cash and cash equivalents, beginning of period	1,685	1,071.5
Cash and cash equivalents, end of period	$ 1,178	$ 1,034.8

CONSOLIDATED STATEMENT OF SHARE

CONSOLIDATED STATEMENT OF SHAREHOLDERS' EQUITY (UNAUDITED) - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Capital Surplus	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Loss	Total Moody's Shareholders' Equity	Non- Controlling Interests
Beginning Balance (in shares) at Dec. 31, 2017		342.9			151.9
Beginning Balance at Dec. 31, 2017	$ (114.9)	$ 3.4	$ 528.6	$ 7,465.4	$ (8,152.9)	$ (172.2)	$ (327.7)	$ 212.8
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	1,066.7			1,059.3			1,059.3	7.4
Dividends	(258)			(254)			(254)	(4)
Stock-based compensation	100.2		100.2				100.2
Shares issued for stock-based compensation plans at average cost, net	(19.1)		(59.1)		$ 40		(19.1)
Shares issued for stock-based compensation plans at average cost, net (in shares)					1.5
Treasury shares repurchased	(147.2)				$ (147.2)		(147.2)
Treasury shares repurchased (in shares)					(0.9)
Currency translation adjustment and net gain on net investment hedges	(182.6)					(172.4)	(172.4)	(10.2)
Net actuarial gains (losses) and prior service costs	1.2					1.2	1.2
Amortization of prior service costs and actuarial losses	2.5					2.5	2.5
Net realized gain (loss) on cash flow hedges	1.2					1.2	1.2
Ending Balance (in shares) at Sep. 30, 2018		342.9			151.3
Ending Balance at Sep. 30, 2018	606.1	$ 3.4	569.7	8,429.1	$ (8,260.1)	(342)	400.1	206
Beginning Balance (in shares) at Jun. 30, 2018		342.9			151
Beginning Balance at Jun. 30, 2018	460.1	$ 3.4	538.6	8,204.6	$ (8,198.9)	(304.8)	242.9	217.2
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	312			310.2			310.2	1.8
Dividends	(88.3)			(85.7)			(85.7)	(2.6)
Stock-based compensation	30.7		30.7				30.7
Shares issued for stock-based compensation plans at average cost, net	5.4		0.4		$ 5		5.4
Shares issued for stock-based compensation plans at average cost, net (in shares)					0.1
Treasury shares repurchased	(66.2)				$ (66.2)		(66.2)
Treasury shares repurchased (in shares)					(0.4)
Currency translation adjustment and net gain on net investment hedges	(48.3)					(37.9)	(37.9)	(10.4)
Amortization of prior service costs and actuarial losses	0.8					0.8	0.8
Net realized gain (loss) on cash flow hedges	(0.1)					(0.1)	(0.1)
Ending Balance (in shares) at Sep. 30, 2018		342.9			151.3
Ending Balance at Sep. 30, 2018	606.1	$ 3.4	569.7	8,429.1	$ (8,260.1)	(342)	400.1	206
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adoption of new ASU | New Revenue Accounting Standard	156.1			156.1			156.1
Adoption of new ASU | Financial Instruments - Overall (ASU 2016-01)	0			2.3		(2.3)	0
Beginning Balance (in shares) at Dec. 31, 2018		342.9			151.6
Beginning Balance at Dec. 31, 2018	656.5	$ 3.4	600.9	8,594.4	$ (8,312.5)	(426.3)	459.9	196.6
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	1,068			1,062.6			1,062.6	5.4
Dividends	(286.3)			(285.2)			(285.2)	(1.1)
Stock-based compensation	103.5		103.5				103.5
Shares issued for stock-based compensation plans at average cost, net	(39.6)		(71.4)		$ 31.8		(39.6)
Shares issued for stock-based compensation plans at average cost, net (in shares)					1.5
Purchase of noncontrolling interest	(12.3)		(9.4)				(9.4)	(2.9)
Non-controlling interest resulting from majority acquisition of Vigeo Eiris	17.4							17.4
Treasury shares repurchased	(728)		(15.7)		$ (712.3)		(728)
Treasury shares repurchased (in shares)					(4.1)
Currency translation adjustment and net gain on net investment hedges	(82.5)					(91.8)	(91.8)	9.3
Net actuarial gains (losses) and prior service costs	(1.3)					(1.3)	(1.3)
Amortization of prior service costs and actuarial losses	1.8					1.8	1.8
Net realized gain (loss) on cash flow hedges	0.1					0.1	0.1
Ending Balance (in shares) at Sep. 30, 2019		342.9			154.2
Ending Balance at Sep. 30, 2019	697.3	$ 3.4	607.9	9,391.6	$ (8,993)	(537.3)	472.6	224.7
Beginning Balance (in shares) at Jun. 30, 2019		342.9			153.7
Beginning Balance at Jun. 30, 2019	574.7	$ 3.4	574.5	9,107.7	$ (8,886.7)	(446.1)	352.8	221.9
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	382.4			379.4			379.4	3
Dividends	(95.8)			(95.5)			(95.5)	(0.3)
Stock-based compensation	33.4		33.4				33.4
Shares issued for stock-based compensation plans at average cost, net	6.5		0		$ 6.5		6.5
Shares issued for stock-based compensation plans at average cost, net (in shares)					0.2
Treasury shares repurchased	(112.8)		0		$ (112.8)		(112.8)
Treasury shares repurchased (in shares)					(0.7)
Currency translation adjustment and net gain on net investment hedges	(91.7)					(91.8)	(91.8)	0.1
Amortization of prior service costs and actuarial losses	0.6					0.6	0.6
Ending Balance (in shares) at Sep. 30, 2019		342.9			154.2
Ending Balance at Sep. 30, 2019	$ 697.3	$ 3.4	$ 607.9	$ 9,391.6	$ (8,993)	$ (537.3)	$ 472.6	$ 224.7

CONSOLIDATED STATEMENT OF SHA_2

CONSOLIDATED STATEMENT OF SHAREHOLDERS' EQUITY (UNAUDITED) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Stockholders' Equity [Abstract]
Dividends declared per share attributable to Moody's common shareholders	$ 0.50	$ 0.44	$ 1.5	$ 1.32
Currency translation adjustment, tax	$ (33.8)	$ 1.8	$ (32.9)	$ 7.4
Net actuarial losses and prior service costs, tax			(0.4)	0.4
Amortization of actuarial losses and prior service costs included in net income, tax	$ 0.2	$ 0.3	0.6	1
Net unrealized gain on cash flow hedges, tax			$ 0.1	$ 0.4

DESCRIPTION OF BUSINESS AND BAS

DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION	9 Months Ended
	Sep. 30, 2019
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 provider of (i) credit ratings; (ii) credit, capital markets and economic research, data and analytical tools; (iii) software solutions that support financial risk management activities; (iv) quantitatively derived credit scores; (v) learning solutions and certification services; (vi) offshore financial research and analytical services; and (vii) company information and business intelligence products. Moody’s reports in two reportable segments: MIS and MA. MIS, the credit rating agency, publishes credit ratings and provides assessment services on a wide range of debt obligations and the entities that issue such obligations in markets worldwide. Revenue is primarily derived from the originators and issuers of such transactions who use MIS ratings in the distribution of their debt issues to investors. Additionally, MIS earns revenue from certain non-ratings-related operations which consist primarily of financial instrument pricing services in the Asia-Pacific region as well as 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 provides financial intelligence and analytical tools to assist businesses in making decisions. MA’s portfolio of solutions consists of specialized research, data, software, and professional services, which are assembled to support the financial analysis and risk management activities of institutional customers worldwide. Following a strategic review of its business portfolio, the Company initiated a plan to sell MAKS and determined that all of the criteria had been met to classify the assets and liabilities of MAKS as held for sale as of June 30, 2019. On July 16, 2019, the Company entered into an agreement to sell the MAKS business to Equistone Partners Europe Limited, a European private equity firm. The operating results of MAKS will continue to be reported within the MA segment (and PS LOB) until the closing of the transaction, which is expected to occur in the fourth quarter of 2019 . These interim financial statements have been prepared in accordance with the instructions to Form 10-Q and should be read in conjunction with the Company’s consolidated financial statements and related notes in the Company’s 2018 annual report on Form 10-K filed with the SEC on February 25, 2019. The results of interim periods are not necessarily indicative of results for the full year or any subsequent period. In the opinion of management, all adjustments (including normal recurring accruals) considered necessary for a fair presentation of financial position, results of operations and cash flows at the dates and for the periods presented have been included. The year-end consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by accounting principles generally accepted in the United States of America. Certain reclassifications have been made to prior period amounts to conform to the current presentation. Adoption of New Accounting Standards On January 1, 2019, the Company adopted ASU No. 2016-2, “Leases (Topic 842)” and has 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. The New Lease Accounting Standard requires lessees to recognize an ROU Asset and lease liability for all leases with terms of more than 12 months . The Company has elected the package of practical expedients permitted under the transition guidance within the New Lease Accounting Standard, which permits the Company not to reassess the following for any expired or existing contracts: i) whether any contracts contain leases; ii) lease classification (i.e. operating lease or finance/capital lease); and iii) initial direct costs. The adoption of the New Lease Accounting Standard resulted in the recognition of an ROU Assets and lease liabilities of approximately $518 million and $622 million , respectively, at January 1, 2019, consisting primarily of operating leases relating to office space. Pursuant to this transition adjustment, the Company also recognized approximately $150 million and approximately $125 million in additional deferred tax assets and liabilities, respectively. Compared to previous guidance, the New Lease Accounting Standard does not significantly change the method by which a lessee should recognize, measure and present expenses and cash flows arising from a lease. Refer to Note 2 for a more fulsome description of the Company’s accounting policy relating to the New Lease Accounting Standard, which includes a discussion relating to the pattern of operating lease expense recognition (both prior to and subsequent to an impairment of a ROU Asset). In the first quarter of 2019, the Company adopted ASU No. 2018-2, “Income Statement—Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income”. Under current GAAP, adjustments to deferred tax assets and liabilities related to a change in tax laws or rates are included in income from continuing operations, even in situations where the related items were originally recognized in OCI (commonly referred to as a “stranded tax effect”). The provisions of this ASU permit the reclassification of the stranded tax effect related to the Tax Act from AOCI to retained earnings. In the first quarter of 2019, the Company reclassified $19.8 million of tax benefits from AOCI to retained earnings relating to the aforementioned stranded tax effect of the Tax Act. On January 1, 2019, the Company adopted ASU No. 2018-16, “Derivatives and Hedging (Topic 815): Inclusion of the Secured Overnight Financing Rate (SOFR) Overnight Index Swap (OIS) Rate as a Benchmark Interest Rate for Hedge Accounting Purposes”. The amendments in this ASU permit the use of the OIS rate based on SOFR as a U.S. benchmark interest rate for hedge accounting purposes under ASC 815, in addition to the currently permissible benchmark interest rates. This ASU provides the Company the ability to utilize the OIS rate based on SOFR as the benchmark interest rate on certain hedges of interest rate risk. The adoption of this ASU had no impact on the Company’s financial statements upon adoption. Reclassification of Previously Reported Revenue by LOB There were certain organizational/product realignments in both MIS and MA in the first quarter of 2019. Accordingly, in MIS, revenue from REITs, which was previously classified in the SFG LOB, is now classified in the CFG LOB. In MA, revenue relating to the Bureau van Dijk FACT product (a credit assessment and origination solution), which was previously classified in RD&A, is now classified in the ERS LOB. Accordingly, 2018 revenue by LOB was reclassified to conform with this new presentation, as follows: MIS As previously reported Reclassification As Reclassified MA As previously reported Reclassification As Reclassified CFG RD&A Q1 $ 377.7 $ 11.9 $ 389.6 Q1 $ 269.2 $ (2.1 ) $ 267.1 Q2 377.6 13.4 391.0 Q2 279.9 (4.0 ) 275.9 Q3 296.1 11.2 307.3 Q3 282.6 (2.3 ) 280.3 Q4 282.7 8.6 291.3 Q4 302.4 (5.3 ) 297.1 Full year 2018 $ 1,334.1 $ 45.1 $ 1,379.2 Full year 2018 $ 1,134.1 $ (13.7 ) $ 1,120.4 SFG ERS Q1 $ 129.7 $ (11.9 ) $ 117.8 Q1 $ 100.1 $ 2.1 $ 102.2 Q2 141.6 (13.4 ) 128.2 Q2 105.5 4.0 109.5 Q3 125.4 (11.2 ) 114.2 Q3 113.0 2.3 115.3 Q4 129.8 (8.6 ) 121.2 Q4 118.8 5.3 124.1 Full year 2018 $ 526.5 $ (45.1 ) $ 481.4 Full year 2018 $ 437.4 $ 13.7 $ 451.1

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES On January 1, 2019, the Company adopted the New Lease Accounting Standard as more fully discussed in Note 1 . Accordingly, the Company revised its lease accounting policy to reflect the provisions of the new standard, which is discussed below. All other significant accounting policies described in the Form 10-K for the year ended December 31, 2018 remain unchanged. Additionally, refer to Note 19 for additional disclosures relating to the Company’s lease obligations. 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 condensed 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.

REVENUES

REVENUES	9 Months Ended
	Sep. 30, 2019
Revenue from Contract with Customer [Abstract]
REVENUES	REVENUES Revenue by Category The following table presents the Company’s revenues disaggregated by LOB: Three Months Ended Nine Months Ended 2019 2018 2019 2018 MIS: Corporate finance (CFG) (1) Investment-grade $ 105.8 $ 54.7 $ 299.0 $ 214.3 High-yield 56.9 39.1 182.4 155.7 Bank loans 89.3 78.4 245.4 309.8 Other accounts (2) 140.0 135.1 408.0 408.1 Total CFG 392.0 307.3 1,134.8 1,087.9 Structured finance (SFG) (1) Asset-backed securities 25.0 24.6 73.8 80.7 RMBS 22.1 23.7 69.7 74.8 CMBS 17.5 14.7 55.6 54.2 Structured credit 40.0 50.7 116.2 148.6 Other accounts 0.8 0.5 2.9 1.9 Total SFG 105.4 114.2 318.2 360.2 Financial institutions (FIG) Banking 79.9 72.9 244.1 227.2 Insurance 31.3 37.7 88.4 98.9 Managed investments 6.5 5.5 20.0 18.4 Other accounts 2.8 3.4 9.0 9.9 Total FIG 120.5 119.5 361.5 354.4 Public, project and infrastructure finance (PPIF) Public finance / sovereign 57.9 45.3 157.1 143.9 Project and infrastructure 61.9 53.7 164.0 156.4 Total PPIF 119.8 99.0 321.1 300.3 Total ratings revenue 737.7 640.0 2,135.6 2,102.8 MIS Other 8.9 4.8 19.5 14.2 Total external revenue 746.6 644.8 2,155.1 2,117.0 Intersegment royalty 34.3 31.6 99.6 92.0 Total MIS 780.9 676.4 2,254.7 2,209.0 MA: Research, data and analytics (RD&A) (3) 317.5 280.3 940.5 823.3 Enterprise risk solutions (ERS) (3) 133.3 115.3 372.9 327.0 Professional services (PS) 43.1 40.4 127.7 115.3 Total external revenue 493.9 436.0 1,441.1 1,265.6 Intersegment revenue 2.1 2.6 6.7 10.0 Total MA 496.0 438.6 1,447.8 1,275.6 Eliminations (36.4 ) (34.2 ) (106.3 ) (102.0 ) Total MCO $ 1,240.5 $ 1,080.8 $ 3,596.2 $ 3,382.6 (1) Pursuant to certain organizational realignments in 2019 , MIS now reports revenue from REITs, which was previously classified in the SFG LOB, as a component of the CFG LOB. The amounts reclassified were not material and prior year revenue by LOB has been reclassified to conform to this new presentation. (2) 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. (3) Pursuant to organizational/product realignments in 2019 , revenue relating to the Bureau van Dijk FACT product, a credit assessment and origination software solution, is now reported in the ERS LOB. This revenue was previously reported in the RD&A LOB. Prior year revenue by LOB has been reclassified to conform to this new presentation, and the amounts reclassified were not material. The following table presents the Company’s revenues disaggregated by LOB and geographic area: Three Months Ended September 30, 2019 Three Months Ended September 30, 2018 U.S. Non-U.S Total U.S. Non-U.S Total MIS: Corporate finance (CFG) (1) $ 258.9 $ 133.1 $ 392.0 $ 194.7 $ 112.6 $ 307.3 Structured finance (SFG) (1) 67.8 37.6 105.4 70.6 43.6 114.2 Financial institutions (FIG) 53.7 66.8 120.5 59.8 59.7 119.5 Public, project and infrastructure finance (PPIF) 72.8 47.0 119.8 59.4 39.6 99.0 Total ratings revenue 453.2 284.5 737.7 384.5 255.5 640.0 MIS Other 0.2 8.7 8.9 0.2 4.6 4.8 Total MIS 453.4 293.2 746.6 384.7 260.1 644.8 MA: Research, data and analytics (RD&A) (2) 139.8 177.7 317.5 116.7 163.6 280.3 Enterprise risk solutions (ERS) (2) 48.2 85.1 133.3 43.0 72.3 115.3 Professional services (PS) 18.2 24.9 43.1 15.2 25.2 40.4 Total MA 206.2 287.7 493.9 174.9 261.1 436.0 Total MCO $ 659.6 $ 580.9 $ 1,240.5 $ 559.6 $ 521.2 $ 1,080.8 Nine Months Ended September 30, 2019 Nine Months Ended September 30, 2018 U.S. Non-U.S Total U.S. Non-U.S Total MIS: Corporate finance (CFG) (1) $ 744.1 $ 390.7 $ 1,134.8 $ 707.2 $ 380.7 $ 1,087.9 Structured finance (SFG) (1) 201.9 116.3 318.2 225.0 135.2 360.2 Financial institutions (FIG) 151.9 209.6 361.5 162.7 191.7 354.4 Public, project and infrastructure finance (PPIF) 202.4 118.7 321.1 173.9 126.4 300.3 Total ratings revenue 1,300.3 835.3 2,135.6 1,268.8 834.0 2,102.8 MIS Other 0.5 19.0 19.5 0.5 13.7 14.2 Total MIS 1,300.8 854.3 2,155.1 1,269.3 847.7 2,117.0 MA: Research, data and analytics (RD&A) (2) 412.4 528.1 940.5 347.5 475.8 823.3 Enterprise risk solutions (ERS) (2) 142.7 230.2 372.9 124.1 202.9 327.0 Professional services (PS) 53.7 74.0 127.7 41.8 73.5 115.3 Total MA 608.8 832.3 1,441.1 513.4 752.2 1,265.6 Total MCO $ 1,909.6 $ 1,686.6 $ 3,596.2 $ 1,782.7 $ 1,599.9 $ 3,382.6 (1) Pursuant to certain organizational realignments in 2019 , MIS now reports revenue from REITs, which was previously classified in the SFG LOB, as a component of the CFG LOB. The amounts reclassified were not material and prior year revenue by LOB has been reclassified to conform to this new presentation. (2) Pursuant to organizational/product realignments in 2019 , revenue relating to the Bureau van Dijk FACT product, a credit assessment and origination software solution, is now reported in the ERS LOB. This revenue was previously reported in the RD&A LOB. Prior year revenue by LOB has been reclassified to conform to this new presentation, and the amounts reclassified were not material. The following table presents the Company’s reportable segment revenues disaggregated by segment and geographic region: Three Months Ended Nine Months Ended 2019 2018 2019 2018 MIS: U.S. $ 453.4 $ 384.7 $ 1,300.8 $ 1,269.3 Non-U.S.: EMEA 174.9 165.3 501.7 527.5 Asia-Pacific 78.9 72.7 241.7 224.9 Americas 39.4 22.1 110.9 95.3 Total Non-U.S. 293.2 260.1 854.3 847.7 Total MIS 746.6 644.8 2,155.1 2,117.0 MA: U.S. 206.2 174.9 608.8 513.4 Non-U.S.: EMEA 186.6 179.2 555.1 520.4 Asia-Pacific 63.5 50.3 173.7 142.0 Americas 37.6 31.6 103.5 89.8 Total Non-U.S. 287.7 261.1 832.3 752.2 Total MA 493.9 436.0 1,441.1 1,265.6 Total MCO $ 1,240.5 $ 1,080.8 $ 3,596.2 $ 3,382.6 The following tables summarize the split between transaction and relationship revenue. In the MIS segment, excluding MIS Other, transaction revenue represents the initial rating of a new debt issuance as well as other one-time fees while relationship revenue represents the recurring monitoring fees of a rated debt obligation and/or entities that issue such obligations, as well as revenue from programs such as commercial paper, medium-term notes and shelf registrations. In MIS Other, transaction revenue represents revenue from professional services and 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, training and certification services, and outsourced research and analytical engagements. Three Months Ended September 30, 2019 2018 Transaction Relationship Total Transaction Relationship Total Corporate Finance $ 281.8 $ 110.2 $ 392.0 $ 199.4 $ 107.9 $ 307.3 72 % 28 % 100 % 65 % 35 % 100 % Structured Finance $ 58.4 $ 47.0 $ 105.4 $ 73.5 $ 40.7 $ 114.2 55 % 45 % 100 % 64 % 36 % 100 % Financial Institutions $ 55.7 $ 64.8 $ 120.5 $ 56.2 $ 63.3 $ 119.5 46 % 54 % 100 % 47 % 53 % 100 % Public, Project and Infrastructure Finance $ 82.1 $ 37.7 $ 119.8 $ 60.9 $ 38.1 $ 99.0 69 % 31 % 100 % 62 % 38 % 100 % MIS Other $ 0.6 $ 8.3 $ 8.9 $ 0.5 $ 4.3 $ 4.8 7 % 93 % 100 % 10 % 90 % 100 % Total MIS $ 478.6 $ 268.0 $ 746.6 $ 390.5 $ 254.3 $ 644.8 64 % 36 % 100 % 61 % 39 % 100 % Moody's Analytics $ 78.5 (1) $ 415.4 $ 493.9 $ 70.6 (1) $ 365.4 $ 436.0 16 % 84 % 100 % 16 % 84 % 100 % Total Moody's Corporation $ 557.1 $ 683.4 $ 1,240.5 $ 461.1 $ 619.7 $ 1,080.8 45 % 55 % 100 % 43 % 57 % 100 % Nine Months Ended September 30, 2019 2018 Transaction Relationship Total Transaction Relationship Total Corporate Finance $ 807.7 $ 327.1 $ 1,134.8 $ 767.3 $ 320.6 $ 1,087.9 71 % 29 % 100 % 71 % 29 % 100 % Structured Finance $ 183.9 $ 134.3 $ 318.2 $ 233.3 $ 126.9 $ 360.2 58 % 42 % 100 % 65 % 35 % 100 % Financial Institutions $ 164.8 $ 196.7 $ 361.5 $ 162.4 $ 192.0 $ 354.4 46 % 54 % 100 % 46 % 54 % 100 % Public, Project and Infrastructure Finance $ 208.2 $ 112.9 $ 321.1 $ 184.9 $ 115.4 $ 300.3 65 % 35 % 100 % 62 % 38 % 100 % MIS Other $ 1.5 $ 18.0 $ 19.5 $ 1.5 $ 12.7 $ 14.2 8 % 92 % 100 % 11 % 89 % 100 % Total MIS $ 1,366.1 $ 789.0 $ 2,155.1 $ 1,349.4 $ 767.6 $ 2,117.0 63 % 37 % 100 % 64 % 36 % 100 % Moody's Analytics $ 219.2 (1) $ 1,221.9 $ 1,441.1 $ 198.3 (1) $ 1,067.3 $ 1,265.6 15 % 85 % 100 % 16 % 84 % 100 % Total Moody's Corporation $ 1,585.3 $ 2,010.9 $ 3,596.2 $ 1,547.7 $ 1,834.9 $ 3,382.6 44 % 56 % 100 % 46 % 54 % 100 % (1) Revenue from software implementation services and risk management advisory projects, while classified by management as transactional revenue, is recognized over time under the New Revenue Accounting Standard (please also refer to the following table). The following table presents the timing of revenue recognition: Three Months Ended September 30, 2019 Nine Months Ended September 30, 2019 MIS MA Total MIS MA Total Revenue recognized at a point in time $ 478.6 $ 30.7 $ 509.3 $ 1,366.1 $ 82.8 $ 1,448.9 Revenue recognized over time 268.0 463.2 731.2 789.0 1,358.3 2,147.3 Total $ 746.6 $ 493.9 $ 1,240.5 $ 2,155.1 $ 1,441.1 $ 3,596.2 Three Months Ended September 30, 2018 Nine Months Ended September 30, 2018 MIS MA Total MIS MA Total Revenue recognized at a point in time $ 390.5 $ 19.5 $ 410.0 $ 1,349.4 $ 49.0 $ 1,398.4 Revenue recognized over time 254.3 416.5 670.8 767.6 1,216.6 1,984.2 Total $ 644.8 $ 436.0 $ 1,080.8 $ 2,117.0 $ 1,265.6 $ 3,382.6 Unbilled receivables, deferred revenue and remaining performance obligations Unbilled receivables At September 30, 2019 and December 31, 2018 , accounts receivable included $399.3 million and $311.8 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, requiring revenue to be accrued as an unbilled receivable as such services are provided. In addition, for certain MA arrangements, the timing of when the Company has the unconditional right to consideration and recognizes revenue occurs prior to invoicing the customer. Consequently, at September 30, 2019 and December 31, 2018 , accounts receivable included $56.0 million and $59.5 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 related to that contract is recognized. This deferred revenue is relieved when the Company satisfies the related performance obligation and revenue is recognized. Significant changes in the deferred revenue balances during the three and nine months ended September 30, 2019 are as follows: Three Months Ended September 30, 2019 MIS MA Total Balance at June 30, 2019 $ 376.0 $ 694.8 $ 1,070.8 Changes in deferred revenue Revenue recognized that was included in the deferred revenue balance at the beginning of the period (110.8 ) (343.8 ) (454.6 ) Increases due to amounts billable excluding amounts recognized as revenue during the period 82.0 290.1 372.1 Effect of exchange rate changes (3.7 ) (13.9 ) (17.6 ) Total changes in deferred revenue (32.5 ) (67.6 ) (100.1 ) Balance at September 30, 2019 $ 343.5 $ 627.2 $ 970.7 Nine Months Ended September 30, 2019 MIS MA Total Balance at January 1, 2019 $ 325.4 $ 750.3 $ 1,075.7 Changes in deferred revenue Revenue recognized that was included in the deferred revenue balance at the beginning of the period (190.8 ) (687.4 ) (878.2 ) Increases due to amounts billable excluding amounts recognized as revenue during the period 211.6 576.6 788.2 Amount included in liabilities reclassified as held for sale — (2.7 ) (2.7 ) Effect of exchange rate changes (2.7 ) (9.6 ) (12.3 ) Total changes in deferred revenue 18.1 (123.1 ) (105.0 ) Balance at September 30, 2019 $ 343.5 $ 627.2 $ 970.7 Deferred revenue - current $ 233.2 $ 622.5 $ 855.7 Deferred revenue - noncurrent $ 110.3 $ 4.7 $ 115.0 For the MIS segment, the changes in the deferred revenue balance during the three and nine months ended September 30, 2019 were primarily related to the significant portion of contract renewals that occur during the first quarter of 2019 and are generally recognized over a one year period. For the MA segment, the decrease in deferred revenue for the three months ended September 30, 2019 was primarily due to the recognition of annual subscription and maintenance billings from December 2018 and January 2019. For the nine months ended September 30, 2019 , the decrease in the deferred revenue balance was attributable to recognition of revenues related to the aforementioned December 2018 billings, partially offset by the impact of the high concentration of January 2019 billings. Three Months Ended September 30, 2018 MIS MA Total Balance at June 30, 2018 $ 377.5 $ 609.0 $ 986.5 Changes in deferred revenue Revenue recognized that was included in the deferred revenue balance at the beginning of the period (127.4 ) (317.0 ) (444.4 ) Increases due to amounts billable excluding amounts recognized as revenue during the period 101.6 251.9 353.5 Effect of exchange rate changes 1.1 (1.3 ) (0.2 ) Total changes in deferred revenue (24.7 ) (66.4 ) (91.1 ) Balance at September 30, 2018 $ 352.8 $ 542.6 $ 895.4 Nine Months Ended September 30, 2018 MIS MA Total Balance at January 1, 2018 (after New Revenue Accounting Standard transition adjustment) $ 334.7 $ 611.6 $ 946.3 Changes in deferred revenue Revenue recognized that was included in the deferred revenue balance at the beginning of the period (196.2 ) (608.5 ) (804.7 ) Increases due to amounts billable excluding amounts recognized as revenue during the period 217.6 551.3 768.9 Effect of exchange rate changes (3.3 ) (11.8 ) (15.1 ) Total changes in deferred revenue 18.1 (69.0 ) (50.9 ) Balance at September 30, 2018 $ 352.8 $ 542.6 $ 895.4 Deferred revenue - current $ 233.9 $ 537.6 771.5 Deferred revenue - noncurrent $ 118.9 $ 5.0 123.9 For the MIS segment, the changes in the deferred revenue balance during the three and nine months ended September 30, 2018 were primarily related to the significant portion of contract renewals that occur during the first quarter of 2018 and are generally recognized over a one year period. For the MA segment, the decrease in deferred revenue for the three months ended September 30, 2018 was primarily due to the recognition of annual subscription and maintenance billings in December 2017 and January 2018 . For the nine months ended September 30, 2018 , the decrease in the deferred revenue balance was attributable to recognition of revenues related to the aforementioned December 2017 billings, partially offset by the impact of the high concentration of January 2018 billings. Remaining performance obligations The following tables include the expected recognition period for the remaining performance obligations for each reportable segment as of September 30, 2019 : MIS Total Less than 1 year 1 - 5 years 6 - 10 Years 11 - 15 years 16-20 years Over 20 Years $ 146.8 $ 24.3 $ 69.9 $ 37.9 $ 5.8 $ 4.0 $ 4.9 The balances in the MIS table above 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. With respect to the remaining performance obligations for the MIS segment, the Company has applied a practical expedient set forth in ASC Topic 606 permitting the omission from the table above for unsatisfied performance obligations relating to contracts with an original expected length of one year or less. MA Total Less than 1 Year 1 - 2 Years Over 2 Years $ 1,582.8 $ 1,125.6 $ 325.4 $ 131.8 The balances in the MA table above include both amounts recorded as deferred revenue on the balance sheet as of September 30, 2019 as well as amounts not yet invoiced to customers as of September 30, 2019 under non-cancelable multi-year arrangements for hosted and installed subscription based products.

STOCK-BASED COMPENSATION

STOCK-BASED COMPENSATION	9 Months Ended
	Sep. 30, 2019
Share-based Payment Arrangement, Noncash Expense [Abstract]
STOCK-BASED COMPENSATION	STOCK-BASED COMPENSATION Presented below is a summary of the stock-based compensation cost and associated tax benefit included in the accompanying consolidated statements of operations: Three Months Ended Nine Months Ended 2019 2018 2019 2018 Stock-based compensation cost $ 33.3 $ 30.5 $ 103.2 $ 100.0 Tax benefit $ 6.9 $ 11.5 $ 22.0 $ 26.0 During the first nine months of 2019 , the Company granted 0.2 million employee stock options, which had a weighted average grant date fair value of $43.10 per share based on the Black-Scholes option-pricing model. The Company also granted 0.8 million shares of restricted stock in the first nine months of 2019 , which had a weighted average grant date fair value of $173.71 per share. Both the employee stock options and restricted stock generally vest ratably over four years . Additionally, the Company granted 0.1 million shares of performance-based awards whereby the number of shares that ultimately vest are based on the achievement of certain non-market based performance metrics of the Company over three years . The weighted average grant date fair value of these awards was $168.04 per share. The following weighted average assumptions were used in determining the fair value for options granted in 2019 : Expected dividend yield 1.15 % Expected stock volatility 23.61 % Risk-free interest rate 2.59 % Expected holding period 6.2 years Unrecognized stock-based compensation expense at September 30, 2019 was $7.5 million and $175.9 million for stock options and unvested restricted stock, respectively, which is expected to be recognized over a weighted average period of 2.1 years and 2.5 years , respectively. Additionally, there was $29.6 million of unrecognized stock-based compensation expense relating to the aforementioned non-market based performance-based awards, which is expected to be recognized over a weighted average period of 1.9 years . The following tables summarize information relating to stock option exercises and restricted stock vesting: Nine Months Ended 2019 2018 Exercise of stock options: Proceeds from stock option exercises $ 28.9 $ 36.2 Aggregate intrinsic value $ 99.2 $ 94.9 Tax benefit realized upon exercise $ 24.3 $ 23.2 Number of shares exercised 0.7 0.8 Vesting of restricted stock: Fair value of shares vested $ 152.7 $ 150.0 Tax benefit realized upon vesting $ 36.2 $ 34.7 Number of shares vested 0.8 0.9 Vesting of performance-based restricted stock: Fair value of shares vested $ 47.5 $ 23.0 Tax benefit realized upon vesting $ 11.5 $ 5.6 Number of shares vested 0.3 0.1

INCOME TAXES

INCOME TAXES	9 Months Ended
	Sep. 30, 2019
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES Moody’s effective tax rate was 25.4% and 24.4% for the three months ended September 30, 2019 and 2018 , respectively and 21.3% and 21.0% for the nine months ended September 30, 2019 and 2018 , respectively. The Company’s interim tax expense for the three months ended September 30, 2019 differs from the tax computed by applying its estimated annual effective tax rate to this quarter’s pre-tax earnings due to Excess Tax Benefits from stock compensation of $4.7 million and net increases to tax positions of $8.7 million . The Company classifies interest related to UTPs in interest expense, net in its consolidated statements of operations. Penalties, if incurred, would be recognized in other non-operating (expense) income, net. The Company had an increase in its UTPs of $8.8 million ( $8.8 million , net of federal tax) during the third quarter of 2019 and a net decrease in its UTPs during the first nine months of 2019 of $23.9 million ( $24.2 million net of federal tax). 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 2017 is currently under audit and 2016 remains open to examination. The Company’s New York State tax returns for 2011 through 2014 are currently under examination and the Company’s New York City tax return for 2014 is currently under examination. The Company’s U.K. tax return for 2012 is currently under examination and its returns for 2013 through 2017 remain open to examination. For ongoing audits, it is possible the balance of UTPs could decrease in the next twelve months as a result of the settlement of these audits, which might involve the payment of additional taxes, the adjustment of certain deferred taxes and/or the recognition of tax benefits. It is also possible that new issues might be raised by tax authorities which could necessitate increases to the balance of UTPs. As the Company is unable to predict the timing or outcome of these audits, it is therefore unable to estimate the amount of changes to the balance of UTPs at this time. However, the Company believes that it has adequately provided for its financial exposure relating to all open tax years by tax jurisdiction in accordance with the applicable provisions of Topic 740 of the ASC regarding UTPs. The following table shows the amount the Company paid for income taxes: Nine Months Ended September 30, 2019 2018 Income taxes paid $ 302.5 $ 337.0

WEIGHTED AVERAGE SHARES OUTSTAN

WEIGHTED AVERAGE SHARES OUTSTANDING	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
WEIGHTED AVERAGE SHARES OUTSTANDING	WEIGHTED AVERAGE SHARES OUTSTANDING Below is a reconciliation of basic to diluted shares outstanding: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Basic 189.0 191.8 189.6 191.7 Dilutive effect of shares issuable under stock-based compensation plans 2.1 2.7 2.2 2.7 Diluted 191.1 194.5 191.8 194.4 Anti-dilutive options to purchase common shares and restricted stock as well as contingently issuable restricted stock which are excluded from the table above 0.2 0.3 0.3 0.4 The calculation of diluted EPS requires certain assumptions regarding the use of both cash proceeds and assumed proceeds that would be received upon the exercise of stock options and vesting of restricted stock outstanding as of September 30, 2019 and 2018 .

ACCELERATED SHARE REPURCHASE PR

ACCELERATED SHARE REPURCHASE PROGRAM	9 Months Ended
	Sep. 30, 2019
Other Liabilities Disclosure [Abstract]
ACCELERATED SHARE REPURCHASE PROGRAM	ACCELERATED SHARE REPURCHASE PROGRAM On February 20, 2019, the Company entered into an ASR agreement with a financial institution counterparty to repurchase $500.0 million of its outstanding common stock. The Company paid $500.0 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	9 Months Ended
	Sep. 30, 2019
Cash and Cash Equivalents [Abstract]
CASH EQUIVALENTS AND INVESTMENTS	CASH EQUIVALENTS AND INVESTMENTS The table below provides additional information on the Company’s cash equivalents and investments: As of September 30, 2019 Balance sheet location Cost Gross Unrealized Gains Fair Value Cash and cash equivalents Short-term investments Other assets Certificates of deposit and money market deposit accounts (1) $ 436.3 $ — $ 436.3 $ 327.6 $ 88.2 $ 20.5 Open ended mutual funds $ 6.8 $ 0.9 $ 7.7 $ — $ 7.6 $ 0.1 As of December 31, 2018 Balance sheet location Cost Gross Unrealized Gains Fair Value Cash and cash equivalents Short-term investments Other assets Money market mutual funds $ 15.2 $ — $ 15.2 $ 15.2 $ — $ — Certificates of deposit and money market deposit accounts (1) $ 1,022.4 $ — $ 1,022.4 $ 904.3 $ 115.8 $ 2.3 Open ended mutual funds $ 29.5 $ 3.8 $ 33.3 $ — $ 16.7 $ 16.6 (1) Consists of time deposits and money market deposit accounts. The remaining contractual maturities for the certificates of deposits classified as short-term investments were one month to 12 months at both September 30, 2019 and December 31, 2018 . The remaining contractual maturities for the certificates of deposits classified in other assets are 13 to 21 months at September 30, 2019 and 14 to 36 months at December 31, 2018 . Time deposits with a maturity of less than 90 days at time of purchase are classified as cash and cash equivalents.

ACQUISITIONS AND OTHER STRATEGI

ACQUISITIONS AND OTHER STRATEGIC INITIATIVES	9 Months Ended
	Sep. 30, 2019
Business Combinations [Abstract]
ACQUISITIONS AND OTHER STRATEGIC INITIATIVES	ACQUISITIONS AND OTHER STRATEGIC INITIATIVES Below is a discussion of acquisitions and other strategic initiatives executed by the Company. The purchase prices for the acquisitions were not material and the near term impact to the Company's financial statements is not expected to be material. 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. Vigeo Eiris will operate in the MIS reportable segment and its revenue will be reported in the MIS Other LOB. In June 2019, the Company formed a joint venture with Team 8, a cybersecurity think tank and company creation platform, to establish a global standard for evaluating and assessing cyber risk for enterprises. 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 will operate in the MIS reportable segment and its revenue will be 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. In July 2019, the Company acquired RiskFirst, a company providing risk analytic solutions for the asset management and pension fund communities. RiskFirst will operate in the MA reportable segment and its revenue will be reported in the ERS LOB. 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 will operate in the MA reportable segment and its revenue will be reported in the RD&A LOB. In October 2019, the Company acquired a minority stake in SynTao Green Finance (STFG), a provider of ESG data and analytics based in and serving China. STFG will operate in the MIS reportable segment and its revenue will be reported in the MIS Other LOB.

ASSETS AND LIABILITIES HELD FOR

ASSETS AND LIABILITIES HELD FOR SALE	9 Months Ended
	Sep. 30, 2019
Discontinued Operations and Disposal Groups [Abstract]
ASSETS AND LIABILITIES HELD FOR SALE	ASSETS AND LIABILITIES HELD FOR SALE Following a strategic review of its business portfolio, the Company initiated a plan to sell MAKS in the second quarter of 2019 and determined that all of the criteria had been met to classify the assets and liabilities of MAKS as held for sale as of June 30, 2019. On July 16, 2019, the Company entered into a definitive agreement to sell MAKS to Equistone Partners Europe Limited (Equistone), a European private equity firm. The Company expects the transaction to close during the fourth quarter of 2019, and as of September 30, 2019 MAKS continued to be classified as held for sale. In accordance with ASC Topic 360, the Company is required to measure the assets and liabilities of MAKS which are classified as held for sale at the lower of carrying value or fair value less any costs to sell. In addition, the Company will be required to reclassify cumulative currency translation losses associated with MAKS to earnings upon the sale of the business. Accordingly, for the purposes of evaluating the impairment of MAKS, the Company has increased the carrying value of MAKS for $32.6 million of currency translation losses recorded within AOCI at September 30, 2019 . In the three and nine months ended September 30, 2019 , the company recorded a non-cash impairment charge of $2.0 million and $10.7 million to adjust the carrying value of MAKS to fair value. As of September 30, 2019, the estimated fair value of $202.5 million , which is based on an estimate of the selling price, includes a reduction of approximately $43 million for certain indemnification provisions. The fair value of the net assets held for sale is classified as Level 3 within the fair value hierarchy. The following table presents the major classes of the total consolidated assets and liabilities of MAKS that were classified as held for sale on the consolidated balance sheet at September 30, 2019 : September 30, 2019 Assets Current assets: Cash and cash equivalents $ 11.1 Accounts receivable, net 18.7 Other current assets 6.6 Total current assets 36.4 Property and equipment, net 12.7 Goodwill 163.9 Intangible assets, net 44.0 Deferred tax assets, net 4.8 Other assets 2.9 Total assets held for sale prior to impairment $ 264.7 Impairment of assets held for sale (10.7 ) Total assets held for sale $ 254.0 Liabilities Current liabilities: Accounts payable and accrued liabilities $ 21.4 Deferred revenue 1.8 Total current liabilities 23.2 Deferred tax liabilities, net 6.8 Uncertain tax positions 28.6 Other liabilities 25.5 Total liabilities held for sale $ 84.1 Derivation of impairment charge Total net assets held for sale prior to impairment $ 180.6 Currency translation adjustment (1) 32.6 Total net assets held for sale including currency translation adjustment $ 213.2 Estimated fair value less costs to sell 202.5 Impairment of assets held for sale $ 10.7 (1) Primarily due to the depreciation of the Indian rupee to the U.S. dollar

DERIVATIVE INSTRUMENTS AND HEDG

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES	9 Months Ended
	Sep. 30, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES	DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES The Company is exposed to global market risks, including risks from changes in FX rates and changes in interest rates. Accordingly, the Company uses derivatives in certain instances to manage the aforementioned financial exposures that occur in the normal course of business. The Company does not hold or issue derivatives for speculative purposes. Derivatives and non-derivative instruments designated as accounting hedges: Fair Value Hedges Interest Rate Swaps The Company has entered into interest rate swaps to convert the fixed interest rate on certain of its long-term debt to a floating interest rate based on the 3-month LIBOR. The purpose of these hedges is to mitigate the risk associated with changes in the fair value of the long-term debt, thus the Company has designated these swaps as fair value hedges. The fair value of the swaps is adjusted quarterly with a corresponding adjustment to the carrying value of the debt. The changes in the fair value of the swaps and the underlying hedged item generally offset and the net cash settlements on the swaps are recorded each period within interest expense, net in the Company’s consolidated statement of operations. The following table summarizes the Company’s interest rate swaps designated as fair value hedges: Notional Amount Hedged Item Nature of Swap As of As of Floating Interest Rate 2010 Senior Notes due 2020 Pay Floating/Receive Fixed $ 500.0 $ 500.0 3-month USD LIBOR 2012 Senior Notes due 2022 Pay Floating/Receive Fixed 330.0 330.0 3-month USD LIBOR 2017 Senior Notes due 2021 Pay Floating/Receive Fixed 500.0 500.0 3-month USD LIBOR 2017 Senior Notes due 2023 Pay Floating/Receive Fixed 250.0 — 3-month USD LIBOR Total $ 1,580.0 $ 1,330.0 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/(loss) recognized in the consolidated statements of operations Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Interest expense, net $ (45.9 ) $ (56.4 ) $ (149.0 ) $ (160.5 ) Descriptions Location on Consolidated Statements of Operations Net interest settlements and accruals on interest rate swaps Interest expense, net $ 1.0 $ (0.5 ) $ 0.9 $ (1.0 ) Fair value changes on interest rate swaps Interest expense, net $ 2.3 $ (3.3 ) $ 32.9 $ (14.8 ) Fair value changes on hedged debt Interest expense, net $ (2.3 ) $ 3.3 $ (32.9 ) $ 14.8 Net investment hedges The Company has designated €500 million of the 2015 Senior Notes Due 2027 as a net investment hedge 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. This hedge is designated as an accounting hedge under the applicable sections of ASC Topic 815 and will end upon the repayment of the notes in 2027, unless terminated early at the discretion of the Company. The Company enters into cross-currency swaps to mitigate FX exposure related to a portion of the Company’s euro net investment in certain foreign subsidiaries against changes in euro/USD exchange rates. The following table provides information on the cross-currency swaps designated as net investment hedges under ASC Topic 815: September 30, 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 1.43% $ 1,220.0 3.96% Pay Floating/Receive Floating 931.3 Based on 3-month EURIBOR 1,080.0 Based on 3-month USD LIBOR Total € 2,010.4 $ 2,300.0 December 31, 2018 Pay Receive Nature of Swap Notional Amount Weighted Average Interest Rate Notional Amount Weighted Average Interest Rate Pay Floating/Receive Floating € 710.2 Based on 3-month EURIBOR $ 830.0 Based on 3-month USD LIBOR Total € 710.2 $ 830.0 As of September 30, 2019 , these hedges will expire and be settled in 2021, 2022, 2023, and 2024 for €687.7 million , €438.2 million , €441.9 million and €442.6 million of the total notional amount, respectively, unless terminated early at the discretion of the Company. The Company also enters into forward contracts to mitigate FX exposure related to a portion of the Company’s euro net investment in certain foreign subsidiaries against changes in euro/USD exchange rates. The following table summarizes the notional amounts of the Company's outstanding forward contract that was designated as a net investment hedge: September 30, 2019 December 31, 2018 Notional amount of net investment hedges: Sell Buy Sell Buy Contract to sell EUR for USD € 485.0 $ 532.0 — — These forward contracts will expire in October 2019. The following tables provide information on the gains/(losses) on the Company’s net investment and cash flow hedges: Derivative and Non-Derivative Instruments in Net Investment Hedging Relationships Amount of Gain/(Loss) Recognized in AOCI on Derivative, net of Tax Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing) Three Months Ended Three Months Ended Three Months Ended 2019 2018 2019 2018 2019 (2) 2018 FX forward contracts $ 4.9 $ — $ 0.8 $ — $ — $ — Cross currency swaps 79.6 1.8 — — 15.5 4.1 Long-term debt 18.2 (1) 2.2 — — — — Total net investment hedges $ 102.7 $ 4.0 $ 0.8 $ — $ 15.5 $ 4.1 Derivatives in Cash Flow Hedging Relationships Cross currency swap $ — $ — $ 0.1 $ 0.1 $ — $ — Interest rate contracts — — (0.1 ) — — — Total cash flow hedges $ — $ — $ — $ 0.1 $ — $ — Total $ 102.7 $ 4.0 $ 0.8 $ 0.1 $ 15.5 $ 4.1 Derivative and Non-Derivative Instruments in Net Investment Hedging Relationships Amount of Gain/(Loss) Recognized in AOCI on Derivative, net of Tax Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing) Nine Months Ended Nine Months Ended Nine Months Ended 2019 2018 2019 2018 2019 (2) 2018 FX forward contracts $ 4.9 $ — $ 0.8 $ — $ — $ — Cross currency swaps 75.1 5.8 — — 37.3 6.2 Long-term debt 17.0 (1) 14.7 — — — — Total net investment hedges $ 97.0 $ 20.5 $ 0.8 $ — $ 37.3 $ 6.2 Derivatives in Cash Flow Hedging Relationships Cross currency swap $ — $ 1.5 $ — $ 0.3 $ — $ — Interest rate contracts — — (0.1 ) — — — Total cash flow hedges $ — $ 1.5 $ (0.1 ) $ 0.3 $ — $ — Total $ 97.0 $ 22.0 $ 0.7 $ 0.3 $ 37.3 $ 6.2 (1) Due to the Company's adoption of ASU 2018-02 during 2019, $2.5 million related to the tax effect of this net investment hedge was reclassified to retained earnings. Refer to Note 1 for further details. (2) Effective with the adoption of ASU 2017-12, the Company has elected to assess the effectiveness of its net investment hedges based on changes in spot exchange rates. Accordingly, amounts related to cross-currency swaps recognized directly into Net Income during 2019 represent net periodic interest settlements and accruals, which are recognized in interest expense, net. 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 September 30, 2019 December 31, 2018 Net investment hedges Cross currency swaps $ 87.4 $ 12.3 FX forwards 27.6 23.5 Long-term debt 11.4 (3.1 ) Total net investment hedges $ 126.4 $ 32.7 Cash flow hedges Interest rate contracts $ (2.3 ) $ (2.4 ) Cross currency swap 2.5 2.5 Total cash flow hedges 0.2 0.1 Total net gain in AOCI $ 126.6 $ 32.8 Derivatives not designated as accounting hedges: Foreign exchange forwards The Company also enters into foreign exchange forwards 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 November 2019. The following table summarizes the notional amounts of the Company’s outstanding foreign exchange forwards: September 30, 2019 December 31, 2018 Notional amount of currency pair: Sell Buy Sell Buy Contracts to sell USD for GBP $ 144.5 £ 115.4 $ 310.3 £ 241.2 Contracts to sell USD for Japanese Yen $ 30.3 ¥ 3,200.0 $ 14.3 ¥ 1,600.0 Contracts to sell USD for Canadian dollars $ 96.9 C$ 128.0 $ 99.0 C$ 130.0 Contracts to sell USD for Singapore dollars $ 40.5 S$ 56.0 $ — S$ — Contracts to sell USD for Euros $ 532.1 € 485.0 $ 212.8 € 184.6 Contracts to sell EUR for GBP € 180.0 £ 159.5 € — £ — Contracts to sell GBP for USD £ 115.9 $ 143.2 £ — $ — NOTE: € = Euro, £ = British pound, $ = U.S. dollar, ¥ = Japanese Yen, C$ = Canadian dollar, S$= Singapore dollars The following table summarizes the impact to the consolidated statements of operations relating to the net losses on the Company’s derivatives which are not designated as hedging instruments: Derivatives not designated as accounting hedges Location on Statement of Operations Three Months Ended Nine Months Ended 2019 2018 2019 2018 Foreign exchange forwards Other non-operating expense, net $ (26.7 ) $ (11.8 ) $ (35.0 ) $ (29.1 ) The table below shows the classification between assets and liabilities on the Company’s consolidated balance sheets for the fair value of the derivative instrument as well as the carrying value of its non-derivative debt instruments designated and qualifying as net investment hedges: Derivative and Non-Derivative Instruments Balance Sheet Location September 30, 2019 December 31, 2018 Assets: Derivatives designated as accounting hedges: Cross-currency swaps designated as net investment hedges Other assets $ 116.5 $ 19.4 Interest rate swaps designated as fair value hedges Other assets 32.8 7.5 Interest rate swaps designated as fair value hedges Other current assets 2.3 — FX forwards designated as net investment hedges Other current assets 2.4 — Total derivatives designated as accounting hedges $ 154.0 $ 26.9 Derivatives not designated as accounting hedges: FX forwards on certain assets and liabilities Other current assets 0.6 1.4 Total assets $ 154.6 $ 28.3 Liabilities: Derivatives designated as accounting hedges: Cross-currency swaps designated as net investment hedges Other liabilities $ — $ 2.9 Interest rate swaps designated as fair value hedges Other liabilities — 5.3 Total derivatives designated as accounting hedges $ — 8.2 Non-derivatives designated as accounting hedges: Long-term debt designated as net investment hedge Long-term debt 545.1 571.6 Derivatives not designated as accounting hedges: FX forwards on certain assets and liabilities Accounts payable and accrued liabilities 5.7 8.2 Total liabilities $ 550.8 $ 588.0

GOODWILL AND OTHER ACQUIRED INT

GOODWILL AND OTHER ACQUIRED INTANGIBLE ASSETS	9 Months Ended
	Sep. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL AND OTHER ACQUIRED INTANGIBLE ASSETS	GOODWILL AND OTHER ACQUIRED INTANGIBLE ASSETS The following table summarizes the activity in goodwill for the periods indicated: Nine Months Ended September 30, 2019 MIS MA Consolidated Gross goodwill Accumulated impairment charge Net goodwill Gross goodwill Accumulated impairment charge Net goodwill Gross goodwill Accumulated impairment charge Net goodwill Balance at beginning of year $ 257.8 $ — $ 257.8 $ 3,535.7 $ (12.2 ) $ 3,523.5 $ 3,793.5 $ (12.2 ) $ 3,781.3 Additions/ adjustments (1) 52.1 — 52.1 44.9 — 44.9 97.0 — 97.0 Foreign currency translation adjustments 10.1 — 10.1 (114.5 ) — (114.5 ) (104.4 ) — (104.4 ) Reclassification to assets held for sale (See Note 10) (2) — — — (163.9 ) — (163.9 ) (163.9 ) — (163.9 ) Ending balance $ 320.0 $ — $ 320.0 $ 3,302.2 $ (12.2 ) $ 3,290.0 $ 3,622.2 $ (12.2 ) $ 3,610.0 Year Ended December 31, 2018 MIS MA Consolidated Gross goodwill Accumulated impairment Net Gross goodwill Accumulated Net Gross goodwill Accumulated Net Balance at beginning of year $ 285.2 $ — $ 285.2 $ 3,480.2 $ (12.2 ) $ 3,468.0 $ 3,765.4 $ (12.2 ) $ 3,753.2 Additions/ adjustments (3) — — — 211.5 — 211.5 211.5 — 211.5 Foreign currency translation adjustments (27.4 ) — (27.4 ) (156.0 ) — (156.0 ) (183.4 ) — (183.4 ) Ending balance $ 257.8 $ — $ 257.8 $ 3,535.7 $ (12.2 ) $ 3,523.5 $ 3,793.5 $ (12.2 ) $ 3,781.3 (1) 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 acquisition of RiskFirst. (2) The 2019 reclassification to assets held for sale for the MA segment in the table above relate to the planned divestiture of MAKS, more fully discussed in Note 10 . (3) The 2018 additions/adjustments for the MA segment in the table above primarily relate to the acquisitions of Reis and Omega Performance. Acquired intangible assets and related amortization consisted of: September 30, December 31, Customer relationships $ 1,264.9 $ 1,367.5 Accumulated amortization (216.0 ) (214.2 ) Net customer relationships 1,048.9 1,153.3 Trade secrets 29.9 29.8 Accumulated amortization (28.5 ) (28.2 ) Net trade secrets 1.4 1.6 Software/product technology 354.8 353.3 Accumulated amortization (118.4 ) (101.8 ) Net software/product technology 236.4 251.5 Trade names 147.4 155.1 Accumulated amortization (28.0 ) (34.1 ) Net trade names 119.4 121.0 Other (1) 79.2 70.4 Accumulated amortization (31.2 ) (31.7 ) Net other 48.0 38.7 Total acquired intangible assets, net $ 1,454.1 $ 1,566.1 (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: Three Months Ended Nine Months Ended 2019 2018 2019 2018 Amortization expense $ 24.7 $ 24.6 $ 77.3 $ 75.4 Estimated future amortization expense for acquired intangible assets subject to amortization is as follows: Year Ending December 31, 2019 (after September 30) $ 20.1 2020 95.4 2021 95.2 2022 95.1 2023 92.6 Thereafter 1,055.7 Total estimated future amortization $ 1,454.1 ICRA has reported that it is addressing certain matters related to (i) adjudication proceedings initiated by the Securities and Exchange Board of India (SEBI) in connection with credit ratings assigned to one of ICRA’s customers and the customer’s subsidiaries and (ii) anonymous allegations that were forwarded to ICRA by SEBI, as well as certain additional allegations made during the course of the ongoing internal examination into those anonymous allegations. 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. As of the date of this quarterly filing on Form 10-Q, the Company is unable to estimate the financial impact, if any, that may result from a potential unfavorable conclusion of these matters or any related inquiry. An unfavorable resolution of such matters may negatively impact ICRA’s future operating results, which could result in an impairment of goodwill and amortizable intangible assets in future quarters.

RESTRUCTURING

RESTRUCTURING	9 Months Ended
	Sep. 30, 2019
Restructuring and Related Activities [Abstract]
RESTRUCTURING	RESTRUCTURING On October 26, 2018, the chief executive officer of Moody’s approved a restructuring program (the “2018 Restructuring Program”) that the Company currently estimates will result in annualized savings of approximately $60 million per year, a portion of which will benefit 2019. The 2018 Restructuring Program, the scope of which was expanded in the second quarter of 2019, is now estimated to result in total pre-tax charges of $105 to $110 million . The 2018 Restructuring Program includes relocation of certain functions from high-cost to lower-cost jurisdictions, a reduction of staff, including from recent acquisitions and pursuant to a review of the business criticality of certain positions, and the rationalization and exit of certain real estate leases due to consolidation of various business activities. The exit from certain leased office space began in the fourth quarter of 2018 and will entail approximately $50 million of the charges to either terminate or sublease the affected real estate leases. The 2018 Restructuring Program is also anticipated to represent approximately $60 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 are anticipated to be approximately $60 million , which will be paid through 2021. Total expenses included in the accompanying consolidated statements of operations relating to the 2018 Restructuring Program are as follows: Three Months Ended Nine Months Ended 2019 2018 2019 2018 Restructuring $ (1.0 ) $ — $ 58.3 $ — Changes to the restructuring liability during 2019 were as follows: Employee Termination Costs Contract Termination Costs Total Restructuring Liability (2) Balance as of December 31, 2018 $ 29.9 $ 12.4 $ 42.3 2018 Restructuring Program: Adoption of New Lease Accounting Standard (1) — (10.9 ) (10.9 ) Cost incurred and adjustments 25.1 4.3 29.4 Cash payments and adjustments (26.5 ) (3.0 ) (29.5 ) Balance as of September 30, 2019 $ 28.5 $ 2.8 $ 31.3 2018 Restructuring Program: Cumulative expense incurred to date $ 58.0 $ 49.0 (1) Upon the adoption of the New Lease Accounting Standard, the Company recorded a reclassification of $10.9 million of liabilities in the first quarter of 2019 for costs associated with certain real estate leases which were exited in previous years, as a reduction of the ROU Asset capitalized upon adoption. (2) The liability excludes $4.1 million of non-cash acceleration of amortization of leasehold improvements relating to the rationalization and exit of certain real estate leases as well as $24.8 million of ROU Asset impairment charges for the nine months ended September 30, 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 $17.7 million , and is categorized as Level 3 within the ASC Topic 820 fair value hierarchy. As of September 30, 2019 , the remaining $31.3 million restructuring liability is expected to be paid out through 2021.

FAIR VALUE

FAIR VALUE	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
FAIR VALUE	FAIR VALUE The table below presents information about items that are carried at fair value at September 30, 2019 and December 31, 2018 : Fair value Measurement as of September 30, 2019 Description Balance Level 1 Level 2 Assets: Derivatives (1) $ 154.6 $ — $ 154.6 Mutual funds 7.7 7.7 — Total $ 162.3 $ 7.7 $ 154.6 Liabilities: Derivatives (1) $ 5.7 $ — $ 5.7 Total $ 5.7 $ — $ 5.7 Fair value Measurement as of December 31, 2018 Description Balance Level 1 Level 2 Assets: Derivatives (1) $ 28.3 $ — $ 28.3 Money market mutual funds 15.2 15.2 — Mutual funds 33.3 33.3 — Total $ 76.8 $ 48.5 $ 28.3 Liabilities: Derivatives (1) $ 16.4 $ — $ 16.4 Total $ 16.4 $ — $ 16.4 (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 11 to the condensed consolidated financial statements. The following are descriptions of the methodologies utilized by the Company to estimate the fair value of its derivative contracts, mutual funds and money market mutual funds: Derivatives: In determining the fair value of the derivative contracts in the table above, the Company utilizes industry standard valuation models. Where applicable, these models project future cash flows and discount the future amounts to a present value using spot rates, forward points, currency volatilities, interest rates as well as the risk of non-performance of the Company and the counterparties with whom it has derivative contracts. The Company established strict counterparty credit guidelines and only enters into transactions with financial institutions that adhere to these guidelines. Accordingly, the risk of counterparty default is deemed to be minimal. Mutual funds and money market mutual funds: The mutual funds in the table above are deemed to be equity securities with readily determinable fair values with changes in the fair value recognized through net income under ASC Topic 321. The fair value of these instruments is determined using Level 1 inputs as defined in the ASC Topic 820.

OTHER BALANCE SHEET AND STATEME

OTHER BALANCE SHEET AND STATEMENT OF OPERATIONS INFORMATION	9 Months Ended
	Sep. 30, 2019
Other Balance Sheet And Statement Of Operations Information [Abstract]
OTHER BALANCE SHEET AND STATEMENT OF OPERATIONS INFORMATION	OTHER BALANCE SHEET AND STATEMENT OF OPERATIONS INFORMATION The following tables contain additional detail related to certain balance sheet captions: September 30, 2019 December 31, 2018 Other current assets: Prepaid taxes $ 98.3 $ 100.1 Prepaid expenses 64.3 67.0 Capitalized costs to obtain and fulfill sales contracts 67.7 77.2 Other 55.8 38.0 Total other current assets $ 286.1 $ 282.3 Other assets: Investments in non-consolidated affiliates $ 113.0 $ 104.6 Deposits for real-estate leases 12.3 13.5 Indemnification assets related to acquisitions 16.0 16.1 Mutual funds and fixed deposits 20.6 18.9 Costs to obtain sales contracts 90.0 78.0 Cross currency and interest rate swaps 149.3 26.9 Other 24.1 16.3 Total other assets $ 425.3 $ 274.3 September 30, 2019 December 31, 2018 Accounts payable and accrued liabilities: Salaries and benefits $ 95.1 $ 112.5 Incentive compensation 150.3 154.5 Customer credits, advanced payments and advanced billings 25.5 20.4 Self-insurance reserves 13.2 10.5 Dividends 6.0 6.5 Professional service fees 71.0 47.7 Interest accrued on debt 41.2 70.5 Accounts payable 14.8 30.1 Income taxes 56.4 71.4 Pension and other retirement employee benefits 6.5 6.5 Accrued royalties 9.4 25.1 Foreign exchange forwards on certain assets and liabilities 5.7 8.2 Restructuring liability 26.8 9.6 Other 85.3 121.7 Total accounts payable and accrued liabilities $ 607.2 $ 695.2 Other liabilities: Pension and other retirement employee benefits $ 264.2 $ 249.2 Deferred rent - non-current portion (1) — 94.3 Interest accrued on UTPs 61.2 69.6 Income tax liability - non-current portion (2) 125.2 125.3 Cross currency and interest rate swaps — 8.2 Restructuring liability 4.5 6.8 Other 37.4 23.1 Total other liabilities $ 492.5 $ 576.5 (1) Pursuant to the adoption of the New Lease Accounting Standard, deferred rent relating to operating leases was reclassified to operating lease ROU Asset. (2) Primarily reflects the transition tax pursuant to the Tax Act, which was enacted into law in December 2018. Other Non-Operating Income (Expense): The following table summarizes the components of other non-operating income (expense): Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 FX (loss)/gain $ 0.9 $ (3.9 ) $ (14.7 ) $ (3.6 ) Net periodic pension costs - other components 4.5 2.6 13.4 7.8 Income from investments in non-consolidated affiliates 3.9 3.3 10.7 9.2 Other 0.6 0.4 3.2 4.9 Total $ 9.9 $ 2.4 $ 12.6 $ 18.3

COMPREHENSIVE INCOME AND ACCUMU

COMPREHENSIVE INCOME AND ACCUMULATED OTHER COMPREHENSIVE INCOME	9 Months Ended
	Sep. 30, 2019
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: Gains (losses) on cash flow hedges Three Months Ended Nine Months Ended Affected line in the consolidated statement of operations Cross-currency swap $ 0.1 $ — Other non-operating income(expense), net Interest rate contract (0.2 ) (0.2 ) Interest expense, net Total before income taxes (0.1 ) (0.2 ) Income tax effect of items above 0.1 0.1 Provision for income taxes Total net gains (losses) on cash flow hedges — (0.1 ) Gains on net investment hedges FX forwards 1.0 1.0 Other non-operating income(expense), net Income tax effect of item above (0.2 ) (0.2 ) Provision for income taxes Total net gains on net investment hedges 0.8 0.8 Pension and other retirement benefits Amortization of actuarial losses and prior service costs included in net income (0.5 ) (1.5 ) Operating expense Amortization of actuarial losses and prior service costs included in net income (0.3 ) (0.9 ) SG&A expense Total before income taxes (0.8 ) (2.4 ) Income tax effect of item above 0.2 0.6 Provision for income taxes Total pension and other retirement benefits (0.6 ) (1.8 ) Total net gains (losses) included in Net Income attributable to reclassifications out of AOCI $ 0.2 $ (1.1 ) Gains on cash flow hedges Three Months Ended September 30, 2018 Nine Months Ended September 30, 2018 Affected line in the consolidated statement of operations Cross-currency swap $ 0.1 $ 0.3 Other non-operating income (expense), net Income tax effect of item above — — Provision for income taxes Total net gains on cash flow hedges 0.1 0.3 Pension and other retirement benefits Amortization of actuarial losses and prior service costs included in net income (0.6 ) (2.2 ) Operating expense Amortization of actuarial losses and prior service costs included in net income (0.5 ) (1.3 ) SG&A expense Total before income taxes (1.1 ) (3.5 ) Income tax effect of item above 0.3 1.0 Provision for income taxes Total pension and other retirement benefits (0.8 ) (2.5 ) Total net losses included in Net Income attributable to reclassifications out of AOCI $ (0.7 ) $ (2.2 ) The following tables show changes in AOCI by component (net of tax): Three Months Ended September 30, 2019 September 30, 2018 Gains/(Losses) Pension and Other Retirement Benefits Cash Flow Hedges Foreign Currency Translation Adjustments Net Investment Hedges Total Pension and Other Retirement Benefits Cash Flow Hedges Foreign Currency Translation Adjustments Net Investment Hedges Total Balance June 30, $ (70.5 ) $ 0.2 $ (400.3 ) $ 24.5 $ (446.1 ) $ (58.6 ) $ 2.2 $ (263.6 ) $ 15.2 $ (304.8 ) Other comprehensive income/(loss) before reclassifications — — (193.7 ) 102.7 (91.0 ) — — (42.0 ) 4.1 (37.9 ) Amounts reclassified from AOCI 0.6 — — (0.8 ) (0.2 ) 0.8 (0.1 ) — — 0.7 Other comprehensive income/(loss) 0.6 — (193.7 ) 101.9 (91.2 ) 0.8 (0.1 ) (42.0 ) 4.1 (37.2 ) Balance September 30, $ (69.9 ) $ 0.2 $ (594.0 ) $ 126.4 $ (537.3 ) $ (57.8 ) $ 2.1 $ (305.6 ) $ 19.3 $ (342.0 ) Nine Months Ended September 30, 2019 September 30, 2018 Gains/(Losses) Pension and Other Retirement Benefits Cash Flow Hedges Foreign Currency Translation Adjustments Net Investment Hedges Total Pension and Other Retirement Benefits Cash Flow Hedges Foreign Currency Translation Adjustments Net Investment Hedges Gains on Available for Sale Securities Total Balance December 31, $ (53.1 ) $ 0.1 $ (406.0 ) $ 32.7 $ (426.3 ) $ (61.5 ) $ 0.9 $ (112.6 ) $ (1.3 ) $ 2.3 $ (172.2 ) Adoption of ASU 2016-01 relating to financial instruments — — — — — — — — — (2.3 ) (2.3 ) Other comprehensive income/(loss) before reclassifications (1.3 ) — (188.0 ) 97.0 (92.3 ) 1.2 1.5 (193.0 ) 20.6 — (169.7 ) Amounts reclassified from AOCI 1.8 0.1 — (0.8 ) 1.1 2.5 (0.3 ) — — — 2.2 Adoption of ASU 2018-02 (See Note 1) (17.3 ) — — (2.5 ) (19.8 ) — — — — — — Other comprehensive income/(loss) (16.8 ) 0.1 (188.0 ) 93.7 (111.0 ) 3.7 1.2 (193.0 ) 20.6 (2.3 ) (169.8 ) Balance September 30, $ (69.9 ) $ 0.2 $ (594.0 ) $ 126.4 $ (537.3 ) $ (57.8 ) $ 2.1 $ (305.6 ) $ 19.3 $ — $ (342.0 )

PENSION AND OTHER RETIREMENT BE

PENSION AND OTHER RETIREMENT BENEFITS	9 Months Ended
	Sep. 30, 2019
Retirement Benefits [Abstract]
PENSION AND OTHER RETIREMENT BENEFITS	PENSION AND OTHER RETIREMENT BENEFITS Moody’s maintains funded and unfunded noncontributory DBPPs. The U.S. plans provide defined benefits using a cash balance formula based on years of service and career average salary for its employees or final average pay for selected executives. The Company also provides certain healthcare and life insurance benefits for retired U.S. employees. The retirement healthcare plans are contributory; the life insurance plans are noncontributory. Moody’s funded and unfunded U.S. pension plans, the U.S. retirement healthcare plans and the U.S. retirement life insurance plans are collectively referred to herein as the “Retirement Plans”. The U.S. retirement healthcare plans and the U.S. retirement life insurance plans are collectively referred to herein as the “Other Retirement Plans”. The non-U.S. defined benefit pension plan are immaterial. Effective January 1, 2008, the Company no longer offers DBPPs to U.S. employees hired or rehired on or after January 1, 2008. New U.S. employees will instead receive a retirement contribution of similar benefit value under the Company’s Profit Participation Plan. Current participants of the Company’s DBPPs continue to accrue benefits based on existing plan formulas. The components of net periodic benefit expense related to the Retirement Plans are as follows: Three Months Ended September 30, Pension Plans Other Retirement Plans 2019 2018 2019 2018 Components of net periodic expense Service cost $ 4.2 $ 4.6 $ 0.7 $ 0.7 Interest cost 5.1 4.4 0.3 0.3 Expected return on plan assets (5.0 ) (3.8 ) — — Amortization of net actuarial loss from earlier periods 0.9 1.5 — — Amortization of net prior service costs from earlier periods (0.1 ) — (0.1 ) (0.1 ) Net periodic expense $ 5.1 $ 6.7 $ 0.9 $ 0.9 Nine Months Ended September 30, Pension Plans Other Retirement Plans 2019 2018 2019 2018 Components of net periodic expense Service cost $ 12.5 $ 14.0 $ 2.1 $ 2.2 Interest cost 15.4 13.2 0.9 0.8 Expected return on plan assets (15.1 ) (11.4 ) — — Amortization of net actuarial loss from earlier periods 2.8 4.6 — — Amortization of net prior service costs from earlier periods (0.3 ) (0.2 ) (0.2 ) (0.2 ) Net periodic expense $ 15.3 $ 20.2 $ 2.8 $ 2.8 The Company made payments of $3.5 million related to its unfunded U.S. DBPPs and $0.2 million to its U.S. other retirement plans during the nine months ended September 30, 2019 . Additionally, the Company anticipates making payments of $3.1 million and $0.9 million to its unfunded U.S. DBPPs and U.S. other retirement plans, respectively, during the remainder of 2019 .

INDEBTEDNESS

INDEBTEDNESS	9 Months Ended
	Sep. 30, 2019
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 2010 Senior Notes, the 2012 Senior Notes, the 2017 Senior Notes due 2021 and the 2017 Senior Notes due 2023, which are recorded at the carrying amount adjusted for the fair value of an interest rate swap used to hedge the fair value of the note. The following table summarizes total indebtedness: September 30, 2019 Notes Payable: Principal Amount Fair Value of Interest Rate Swaps (1) Unamortized (Discount) Premium Unamortized Debt Issuance Costs Carrying Value 5.50% 2010 Senior Notes, due 2020 $ 500.0 $ 2.3 $ (0.4 ) $ (0.4 ) $ 501.5 4.50% 2012 Senior Notes, due 2022 500.0 11.0 (1.3 ) (1.1 ) 508.6 4.875% 2013 Senior Notes, due 2024 500.0 — (1.4 ) (1.7 ) 496.9 5.25% 2014 Senior Notes (30-Year), due 2044 600.0 — 3.2 (5.3 ) 597.9 1.75% 2015 Senior Notes, due 2027 545.1 — — (2.7 ) 542.4 2.75% 2017 Senior Notes, due 2021 500.0 13.5 (0.7 ) (1.8 ) 511.0 2.625% 2017 Senior Notes, due 2023 500.0 8.3 (0.7 ) (2.4 ) 505.2 3.25% 2017 Senior Notes, due 2028 500.0 — (4.4 ) (3.4 ) 492.2 3.25% 2018 Senior Notes, due 2021 300.0 — (0.3 ) (1.0 ) 298.7 4.25% 2018 Senior Notes, due 2029 400.0 — (2.8 ) (3.0 ) 394.2 4.875% 2018 Senior Notes, due 2048 400.0 — (6.6 ) (4.0 ) 389.4 Total debt $ 5,245.1 $ 35.1 $ (15.4 ) $ (26.8 ) $ 5,238.0 Current portion (501.5 ) Total long-term debt $ 4,736.5 December 31, 2018 Notes Payable: Principal Amount Fair Value of Interest Rate Swaps (1) Unamortized (Discount) Premium Unamortized Debt Issuance Costs Carrying Value 5.50% 2010 Senior Notes, due 2020 $ 500.0 $ (3.7 ) $ (0.6 ) $ (0.7 ) $ 495.0 4.50% 2012 Senior Notes, due 2022 500.0 1.9 (1.6 ) (1.4 ) 498.9 4.875% 2013 Senior Notes, due 2024 500.0 — (1.5 ) (2.0 ) 496.5 2.75% 2014 Senior Notes (5-Year), due 2019 450.0 — (0.1 ) — 449.9 5.25% 2014 Senior Notes (30-Year), due 2044 600.0 — 3.2 (5.5 ) 597.7 1.75% 2015 Senior Notes, due 2027 571.6 — — (3.1 ) 568.5 2.75% 2017 Senior Notes, due 2021 500.0 4.0 (1.0 ) (2.4 ) 500.6 2.625% 2017 Senior Notes, due 2023 500.0 — (0.9 ) (2.8 ) 496.3 3.25% 2017 Senior Notes, due 2028 500.0 — (4.7 ) (3.7 ) 491.6 3.25% 2018 Senior Notes, due 2021 300.0 — (0.4 ) (1.5 ) 298.1 4.25% 2018 Senior Notes, due 2029 400.0 — (3.0 ) (3.3 ) 393.7 4.875% 2018 Senior Notes, due 2048 400.0 — (6.7 ) (4.1 ) 389.2 Total debt $ 5,721.6 $ 2.2 $ (17.3 ) $ (30.5 ) $ 5,676.0 Current portion (449.9 ) Total long-term debt $ 5,226.1 (1) The Company has entered into interest rate swaps on the 2010 Senior Notes, the 2012 Senior Notes, the 2017 Senior Notes due 2021 and the 2017 Senior Notes due 2023 which are more fully discussed in Note 11 above. These amounts represent the cumulative amount of fair value hedging adjustments included in the carrying amount of the hedged debt. Notes Payable On January 3, 2019, the Company fully repaid $ 450.0 million of the 2014 Senior Notes (5-year). At September 30, 2019 , the Company was in compliance with all covenants contained within all of the debt agreements. All the debt agreements contain cross default provisions which state that default under one of the aforementioned debt instruments could in turn permit lenders under other debt instruments to declare borrowings outstanding under those instruments to be immediately due and payable. As of September 30, 2019 , there were no such cross defaults. The repayment schedule for the Company’s borrowings is as follows: Year Ending December 31, 2010 Senior Notes, due 2020 2012 Senior Notes, due 2022 2013 Senior Notes, due 2024 2014 Senior Notes (30-Year), due 2044 2015 Senior Notes, due 2027 2017 Senior Notes, due 2021 2017 Senior Notes, due 2023 2017 Senior Notes, due 2028 2018 Senior Notes, due 2021 2018 Senior Notes, due 2029 2018 Senior Notes, due 2048 Total 2019 (After September 30) $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — 2020 500.0 — — — — — — — — — — $ 500.0 2021 — — — — — 500.0 — — 300.0 — — $ 800.0 2022 — 500.0 — — — — — — — — — $ 500.0 2023 — — — — — — 500.0 — — — — $ 500.0 Thereafter — — 500.0 600.0 545.1 — — 500.0 — 400.0 400.0 $ 2,945.1 Total $ 500.0 $ 500.0 $ 500.0 $ 600.0 $ 545.1 $ 500.0 $ 500.0 $ 500.0 $ 300.0 $ 400.0 $ 400.0 $ 5,245.1 Interest expense, net The following table summarizes the components of interest as presented in the consolidated statements of operations: Three Months Ended Nine Months Ended 2019 2018 2019 2018 Income $ 3.6 $ 4.1 $ 12.5 $ 10.7 Expense on borrowings (37.4 ) (46.4 ) (125.7 ) (147.1 ) UTPs and other tax related liabilities (7.0 ) (9.6 ) (20.2 ) (10.6 ) Net periodic pension costs - interest component (5.6 ) (4.9 ) (16.8 ) (14.5 ) Capitalized 0.5 0.4 1.2 1.0 Total $ (45.9 ) $ (56.4 ) $ (149.0 ) $ (160.5 ) The following table shows the cash paid for interest: Nine Months Ended 2019 2018 Interest paid $ 148.6 $ 169.7 The fair value and carrying value of the Company’s debt as of September 30, 2019 and December 31, 2018 are as follows: September 30, 2019 December 31, 2018 Carrying Amount Estimated Fair Value Carrying Amount Estimated Fair Value 5.50% 2010 Senior Notes, due 2020 $ 501.5 $ 515.0 $ 495.0 $ 517.7 4.50% 2012 Senior Notes, due 2022 508.6 531.7 498.9 513.7 4.875% 2013 Senior Notes, due 2024 496.9 551.8 496.5 522.4 2.75% 2014 Senior Notes (5-Year), due 2019 — — 449.9 449.9 5.25% 2014 Senior Notes (30-Year), due 2044 597.9 768.7 597.7 638.1 1.75% 2015 Senior Notes, due 2027 542.4 596.7 568.5 585.3 2.75% 2017 Senior Notes, due 2021 511.0 506.3 500.6 489.7 2.625% 2017 Senior Notes, due 2023 505.2 506.5 496.3 476.9 3.25% 2017 Senior Notes, due 2028 492.2 526.0 491.6 472.8 3.25% 2018 Senior Notes, due 2021 298.7 305.1 298.1 298.6 4.25% 2018 Senior Notes, due 2029 394.2 451.0 393.7 407.6 4.875% 2018 Senior Notes, due 2048 389.4 496.9 389.2 409.8 Total $ 5,238.0 $ 5,755.7 $ 5,676.0 $ 5,782.5 The fair value of the Company’s long-term debt is estimated based on quoted market prices for similar instruments. Accordingly, the inputs used to estimate the fair value of the Company’s long-term debt are classified as Level 2 inputs within the fair value hierarchy.

LEASES

LEASES	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
LEASES	LEASES The Company has operating leases, substantially all of which relate to the lease of office space. The Company’s leases which are classified as finance leases are not material to the consolidated financial statements. Certain of the Company’s leases include options to renew, with renewal terms that can extend the lease term from one year to 20 years at the Company’s discretion. The following table presents the components of the Company’s lease cost: Three Months Ended Nine Months Ended Operating lease cost $ 24.2 $ 73.3 Short-term lease cost — 0.4 Variable lease cost 5.0 12.7 Total lease cost $ 29.2 $ 86.4 During the second quarter of 2019 , the Company recorded $24.8 million of ROU Asset impairment charges related to the exit of certain real estate leases. The impairment charges were recording within Restructuring expense on the consolidated statement of operations. Refer to Note 13 for further details. The following tables present other information related to the Company’s operating leases: Three Months Ended Nine Months Ended Cash paid for amounts included in the measurement of operating lease liabilities $ 26.6 $ 79.8 Right-of-use assets obtained in exchange for new operating lease liabilities $ 12.0 $ 27.9 September 30, 2019 Weighted-average remaining lease term 6.9 years Weighted-average discount rate applied to operating leases 3.6 % The following table presents a maturity analysis of the future minimum lease payments included within the Company’s operating lease liabilities at September 30, 2019 : Year Ending December 31, Operating Leases 2019 (After September 30) $ 27.2 2020 107.7 2021 102.1 2022 88.7 2023 83.2 After 2023 251.0 Total lease payments (undiscounted) 659.9 Less: Interest 75.4 Present value of lease liabilities: $ 584.5 Lease liabilities - current $ 89.5 Lease liabilities - noncurrent $ 495.0 The minimum rent for operating leases at December 31, 2018 is as follows: Year Ending December 31, Operating Leases 2019 $ 105.9 2020 102.3 2021 95.6 2022 84.4 2023 81.0 After 2023 246.5 Total $ 715.7

CONTINGENCIES

CONTINGENCIES	9 Months Ended
	Sep. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
CONTINGENCIES	CONTINGENCIES Given the nature of their activities, Moody’s and its subsidiaries are subject to legal and tax proceedings, governmental, regulatory and legislative investigations, subpoenas and other inquiries, and claims and litigation by governmental and private parties that are based on ratings assigned by MIS or that are otherwise incidental to the Company’s business. Moody’s and MIS also are subject to periodic reviews, inspections, examinations and investigations by regulators in the U.S. and other jurisdictions, any of which may result in claims, legal proceedings, assessments, fines, penalties or restrictions on business activities. Moody’s also is subject to ongoing tax audits as addressed in Note 5 to the consolidated financial statements. In May 2013, the Company and five subsidiaries (collectively, the “Company Defendants”) were served with a complaint filed by a former employee (“Plaintiff”) in New York Supreme Court (the “Court”) on behalf of New York State (the “State”) and New York City (the “City”) asserting purported claims under the New York False Claims Act (“NYFCA”). Both the State and the City were given an opportunity to intervene as plaintiffs in the action but declined to do so. In August 2013, Plaintiff filed an Amended Complaint adding Marsh & McLennan Companies, Inc. as a defendant. Plaintiff’s central allegation against the Company Defendants is that their treatment of the Company’s wholly-owned captive insurance subsidiary, Moody’s Assurance Company, Inc. (“MAC”), in their State and City tax filings between 2002 and 2014 was contrary to the State and City tax codes. Plaintiff also asserts a cause of action for retaliation under the NYFCA and alleges that his employment was improperly terminated after he reported his concerns regarding MAC’s tax treatment internally. Plaintiff alleges that the Company underpaid State and City taxes by more than $120.0 million (which the Company believes is unsupported as a matter of fact and law), and requests statutory damages of triple that amount, as well as unspecified damages related to the retaliation claim. In December 2016, the Court issued a decision largely denying the Company Defendants’ motion to dismiss. The Company Defendants appealed, and in August 2018, the Appellate Division of the New York Supreme Court upheld the Court’s decision. In October 2019, the Company Defendants reached an agreement with the State, the City and the Plaintiff to settle all claims asserted against the Company Defendants for $15.5 million . Management periodically assesses the Company’s liabilities and contingencies in connection with these matters based upon the latest information available. For claims, litigation and proceedings and governmental investigations and inquiries not related to income taxes, the Company records liabilities in the consolidated financial statements when it is both probable that a liability has been incurred and the amount of loss can be reasonably estimated and periodically adjusts these as appropriate. When the reasonable estimate of the loss is within a range of amounts, the minimum amount of the range is accrued unless some higher amount within the range is a better estimate than another amount within the range. In instances when a loss is reasonably possible but uncertainties exist related to the probable outcome and/or the amount or range of loss, management does not record a liability but discloses the contingency if material. As additional information becomes available, the Company adjusts its assessments and estimates of such matters accordingly. Moody’s also discloses material pending legal proceedings pursuant to SEC rules and other pending matters as it may determine to be appropriate. In view of the inherent difficulty of assessing the potential outcome of legal proceedings, governmental, regulatory and legislative investigations and inquiries, claims and litigation and similar matters and contingencies, particularly when the claimants seek large or indeterminate damages or assert novel legal theories or the matters involve a large number of parties, the Company often cannot predict what the eventual outcome of the pending matters will be or the timing of any resolution of such matters. The Company also may be unable to predict the impact (if any) that any such matters may have on how its business is conducted, on its competitive position or on its financial position, results of operations or cash flows. As the process to resolve any pending matters progresses, management will continue to review the latest information available and assess its ability to predict the outcome of such matters and the effects, if any, on its operations and financial condition and to accrue for and disclose such matters as and when required. However, because such matters are inherently unpredictable and unfavorable developments or resolutions can occur, the ultimate outcome of such matters, including the amount of any loss, may differ from those estimates.

SEGMENT INFORMATION

SEGMENT INFORMATION	9 Months Ended
	Sep. 30, 2019
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 as well as ICRA non-ratings revenue. The MA segment develops a wide range of products and services that support the risk management activities of institutional participants in global financial markets. The MA segment consists of three LOBs - RD&A, ERS and PS. 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 allocated to each segment based on the segment’s share of 2018 actual revenue comprise 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 Company believes that this allocation method will better align the amount of overhead costs consumed by each segment and contribute stability to each segment’s costs over time. 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. Three Months Ended September 30, 2019 2018 MIS MA Eliminations Consolidated MIS MA Eliminations Consolidated Revenue $ 780.9 $ 496.0 $ (36.4 ) $ 1,240.5 $ 676.4 $ 438.6 $ (34.2 ) $ 1,080.8 Total Expense 339.9 388.2 (36.4 ) 691.7 303.5 344.7 (34.2 ) 614.0 Operating income 441.0 107.8 — 548.8 372.9 93.9 — 466.8 Add: Restructuring (0.1 ) (0.9 ) — (1.0 ) — — — — Depreciation and amortization 18.0 30.6 — 48.6 15.8 30.3 — 46.1 Acquisition-Related Expenses — — — — — 1.3 — 1.3 Impairment pursuant to the planned divestiture of MAKS — 2.0 — 2.0 — — — — Captive insurance company settlement 9.4 6.1 — 15.5 — — — — Adjusted Operating Income $ 468.3 $ 145.6 $ — $ 613.9 $ 388.7 $ 125.5 $ — $ 514.2 Nine Months Ended September 30, 2019 2018 MIS MA Eliminations Consolidated MIS MA Eliminations Consolidated Revenue $ 2,254.7 $ 1,447.8 $ (106.3 ) $ 3,596.2 $ 2,209.0 $ 1,275.6 $ (102.0 ) $ 3,382.6 Total Expenses 1,027.9 1,180.6 (106.3 ) 2,102.2 951.0 1,042.0 (102.0 ) 1,891.0 Operating income 1,226.8 267.2 — 1,494.0 1,258.0 233.6 — 1,491.6 Add: Restructuring 29.1 29.2 — 58.3 — — — — Depreciation and amortization 53.0 96.9 — 149.9 49.3 94.3 — 143.6 Acquisition-Related Expenses — 3.4 — 3.4 — 4.1 — 4.1 Impairment pursuant to the planned divestiture of MAKS — 10.7 — 10.7 — — — — Captive insurance company settlement 9.4 6.1 — 15.5 — — — — Adjusted Operating Income $ 1,318.3 $ 413.5 $ — $ 1,731.8 $ 1,307.3 $ 332.0 $ — $ 1,639.3 The cumulative restructuring charges related to the 2018 Restructuring Program, as more fully discussed in Note 13 , for the MIS and MA reportable segments are $61.3 million and $45.7 million, respectively. Consolidated Revenue Information by Geographic Area Consolidated Revenue Information by Geographic Area: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 United States $ 659.6 $ 559.6 $ 1,909.6 $ 1,782.7 Non-U.S.: EMEA 361.5 344.5 1,056.8 1,047.9 Asia-Pacific 142.4 123.0 415.4 366.9 Americas 77.0 53.7 214.4 185.1 Total Non-U.S. 580.9 521.2 1,686.6 1,599.9 Total $ 1,240.5 $ 1,080.8 $ 3,596.2 $ 3,382.6

RECENTLY ISSUED ACCOUNTING STAN

RECENTLY ISSUED ACCOUNTING STANDARDS	9 Months Ended
	Sep. 30, 2019
Accounting Changes and Error Corrections [Abstract]
RECENTLY ISSUED ACCOUNTING STANDARDS	RECENTLY ISSUED ACCOUNTING STANDARDS In June 2016, the FASB issued ASU No. 2016-13, “Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments”. The amendments in this ASU require the use of an “expected credit loss” impairment model for most financial assets reported at amortized cost, which will require entities to estimate expected credit losses over the lifetime of the instrument. This may result in the earlier recognition of allowances for losses. For available-for-sale debt securities with unrealized losses, an allowance for credit losses will be recognized as a contra account to the amortized cost carrying value of the asset rather than a direct reduction to the carrying value, with changes in the allowance impacting earnings. In November 2018, the FASB issued ASU No. 2018-19 “Codification Improvements to Topic 326, Financial Instruments—Credit Losses,” which clarifies that receivables arising from operating leases are not within the scope of Subtopic 326-20, but instead should be accounted for in accordance with Topic 842, Leases. ASU No. 2016-13 is effective for annual and interim reporting periods beginning after December 15, 2019, with early adoption permitted in annual and interim reporting periods beginning after December 15, 2018. Entities will apply the standard’s provisions as a cumulative-effect adjustment to retained earnings as of the beginning of the first effective reporting period. The Company is currently evaluating the impact of this ASU on its financial statements. Currently, the Company believes that the most notable impact of this ASU will relate to its processes around the assessment of its allowance for doubtful accounts relating to accounts receivable. The Company is in the process of updating its policies and procedures in order to implement the “expected credit loss” impairment model, which includes the identification of information that can be used to develop reasonable and supportable forecasts of factors that could affect the collectability of the reported amount of the financial asset. The Company does not currently anticipate that the adoption of this ASU will have a significant impact on its consolidated financial statements. In June 2018, the FASB issued ASU No. 2018-07, “Compensation—Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting”, which simplifies the accounting for nonemployee share-based payment transactions. The amendments specify that ASC Topic 718 applies to all share-based payment transactions in which a grantor acquires goods or services to be used or consumed in a grantor’s own operations by issuing share-based payment awards. The ASU is effective for all entities for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years, 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 August 2018, the FASB issued 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 premises of authoritative guidance for internal-use software, and deferred 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 ASU is effective for all entities for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years, with early adoption permitted. The Company will be 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 is in the process of evaluating the impact of this ASU, but does not anticipate that its adoption will have a significant impact on its consolidated financial statements, other than the aforementioned classification requirements. In August 2018, the FASB issued 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 ASU is effective for all entities for fiscal years beginning after December 15, 2020 on a retrospective basis to all periods presented, with early adoption permitted. The Company is currently evaluating the impact of this ASU on its financial statements. 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.

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	9 Months Ended
	Sep. 30, 2019
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	SUBSEQUENT EVENTS On October 21, 2019 , the Board approved the declaration of a quarterly dividend of $0.50 per share of Moody’s common stock, payable on December 12, 2019 to shareholders of record at the close of business on November 21, 2019 .

SUMMARY OF SIGNIFICANT ACCOUN_2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
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 condensed 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.

DESCRIPTION OF BUSINESS AND B_2

DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION (Tables)	9 Months Ended
	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Reclassification of Revenue Amount	Accordingly, 2018 revenue by LOB was reclassified to conform with this new presentation, as follows: MIS As previously reported Reclassification As Reclassified MA As previously reported Reclassification As Reclassified CFG RD&A Q1 $ 377.7 $ 11.9 $ 389.6 Q1 $ 269.2 $ (2.1 ) $ 267.1 Q2 377.6 13.4 391.0 Q2 279.9 (4.0 ) 275.9 Q3 296.1 11.2 307.3 Q3 282.6 (2.3 ) 280.3 Q4 282.7 8.6 291.3 Q4 302.4 (5.3 ) 297.1 Full year 2018 $ 1,334.1 $ 45.1 $ 1,379.2 Full year 2018 $ 1,134.1 $ (13.7 ) $ 1,120.4 SFG ERS Q1 $ 129.7 $ (11.9 ) $ 117.8 Q1 $ 100.1 $ 2.1 $ 102.2 Q2 141.6 (13.4 ) 128.2 Q2 105.5 4.0 109.5 Q3 125.4 (11.2 ) 114.2 Q3 113.0 2.3 115.3 Q4 129.8 (8.6 ) 121.2 Q4 118.8 5.3 124.1 Full year 2018 $ 526.5 $ (45.1 ) $ 481.4 Full year 2018 $ 437.4 $ 13.7 $ 451.1

REVENUES (Tables)

REVENUES (Tables)	9 Months Ended
	Sep. 30, 2019
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following tables summarize the split between transaction and relationship revenue. In the MIS segment, excluding MIS Other, transaction revenue represents the initial rating of a new debt issuance as well as other one-time fees while relationship revenue represents the recurring monitoring fees of a rated debt obligation and/or entities that issue such obligations, as well as revenue from programs such as commercial paper, medium-term notes and shelf registrations. In MIS Other, transaction revenue represents revenue from professional services and 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, training and certification services, and outsourced research and analytical engagements. Three Months Ended September 30, 2019 2018 Transaction Relationship Total Transaction Relationship Total Corporate Finance $ 281.8 $ 110.2 $ 392.0 $ 199.4 $ 107.9 $ 307.3 72 % 28 % 100 % 65 % 35 % 100 % Structured Finance $ 58.4 $ 47.0 $ 105.4 $ 73.5 $ 40.7 $ 114.2 55 % 45 % 100 % 64 % 36 % 100 % Financial Institutions $ 55.7 $ 64.8 $ 120.5 $ 56.2 $ 63.3 $ 119.5 46 % 54 % 100 % 47 % 53 % 100 % Public, Project and Infrastructure Finance $ 82.1 $ 37.7 $ 119.8 $ 60.9 $ 38.1 $ 99.0 69 % 31 % 100 % 62 % 38 % 100 % MIS Other $ 0.6 $ 8.3 $ 8.9 $ 0.5 $ 4.3 $ 4.8 7 % 93 % 100 % 10 % 90 % 100 % Total MIS $ 478.6 $ 268.0 $ 746.6 $ 390.5 $ 254.3 $ 644.8 64 % 36 % 100 % 61 % 39 % 100 % Moody's Analytics $ 78.5 (1) $ 415.4 $ 493.9 $ 70.6 (1) $ 365.4 $ 436.0 16 % 84 % 100 % 16 % 84 % 100 % Total Moody's Corporation $ 557.1 $ 683.4 $ 1,240.5 $ 461.1 $ 619.7 $ 1,080.8 45 % 55 % 100 % 43 % 57 % 100 % Nine Months Ended September 30, 2019 2018 Transaction Relationship Total Transaction Relationship Total Corporate Finance $ 807.7 $ 327.1 $ 1,134.8 $ 767.3 $ 320.6 $ 1,087.9 71 % 29 % 100 % 71 % 29 % 100 % Structured Finance $ 183.9 $ 134.3 $ 318.2 $ 233.3 $ 126.9 $ 360.2 58 % 42 % 100 % 65 % 35 % 100 % Financial Institutions $ 164.8 $ 196.7 $ 361.5 $ 162.4 $ 192.0 $ 354.4 46 % 54 % 100 % 46 % 54 % 100 % Public, Project and Infrastructure Finance $ 208.2 $ 112.9 $ 321.1 $ 184.9 $ 115.4 $ 300.3 65 % 35 % 100 % 62 % 38 % 100 % MIS Other $ 1.5 $ 18.0 $ 19.5 $ 1.5 $ 12.7 $ 14.2 8 % 92 % 100 % 11 % 89 % 100 % Total MIS $ 1,366.1 $ 789.0 $ 2,155.1 $ 1,349.4 $ 767.6 $ 2,117.0 63 % 37 % 100 % 64 % 36 % 100 % Moody's Analytics $ 219.2 (1) $ 1,221.9 $ 1,441.1 $ 198.3 (1) $ 1,067.3 $ 1,265.6 15 % 85 % 100 % 16 % 84 % 100 % Total Moody's Corporation $ 1,585.3 $ 2,010.9 $ 3,596.2 $ 1,547.7 $ 1,834.9 $ 3,382.6 44 % 56 % 100 % 46 % 54 % 100 % (1) Revenue from software implementation services and risk management advisory projects, while classified by management as transactional revenue, is recognized over time under the New Revenue Accounting Standard (please also refer to the following table). The following table presents the timing of revenue recognition: Three Months Ended September 30, 2019 Nine Months Ended September 30, 2019 MIS MA Total MIS MA Total Revenue recognized at a point in time $ 478.6 $ 30.7 $ 509.3 $ 1,366.1 $ 82.8 $ 1,448.9 Revenue recognized over time 268.0 463.2 731.2 789.0 1,358.3 2,147.3 Total $ 746.6 $ 493.9 $ 1,240.5 $ 2,155.1 $ 1,441.1 $ 3,596.2 Three Months Ended September 30, 2018 Nine Months Ended September 30, 2018 MIS MA Total MIS MA Total Revenue recognized at a point in time $ 390.5 $ 19.5 $ 410.0 $ 1,349.4 $ 49.0 $ 1,398.4 Revenue recognized over time 254.3 416.5 670.8 767.6 1,216.6 1,984.2 Total $ 644.8 $ 436.0 $ 1,080.8 $ 2,117.0 $ 1,265.6 $ 3,382.6 The following table presents the Company’s revenues disaggregated by LOB: Three Months Ended Nine Months Ended 2019 2018 2019 2018 MIS: Corporate finance (CFG) (1) Investment-grade $ 105.8 $ 54.7 $ 299.0 $ 214.3 High-yield 56.9 39.1 182.4 155.7 Bank loans 89.3 78.4 245.4 309.8 Other accounts (2) 140.0 135.1 408.0 408.1 Total CFG 392.0 307.3 1,134.8 1,087.9 Structured finance (SFG) (1) Asset-backed securities 25.0 24.6 73.8 80.7 RMBS 22.1 23.7 69.7 74.8 CMBS 17.5 14.7 55.6 54.2 Structured credit 40.0 50.7 116.2 148.6 Other accounts 0.8 0.5 2.9 1.9 Total SFG 105.4 114.2 318.2 360.2 Financial institutions (FIG) Banking 79.9 72.9 244.1 227.2 Insurance 31.3 37.7 88.4 98.9 Managed investments 6.5 5.5 20.0 18.4 Other accounts 2.8 3.4 9.0 9.9 Total FIG 120.5 119.5 361.5 354.4 Public, project and infrastructure finance (PPIF) Public finance / sovereign 57.9 45.3 157.1 143.9 Project and infrastructure 61.9 53.7 164.0 156.4 Total PPIF 119.8 99.0 321.1 300.3 Total ratings revenue 737.7 640.0 2,135.6 2,102.8 MIS Other 8.9 4.8 19.5 14.2 Total external revenue 746.6 644.8 2,155.1 2,117.0 Intersegment royalty 34.3 31.6 99.6 92.0 Total MIS 780.9 676.4 2,254.7 2,209.0 MA: Research, data and analytics (RD&A) (3) 317.5 280.3 940.5 823.3 Enterprise risk solutions (ERS) (3) 133.3 115.3 372.9 327.0 Professional services (PS) 43.1 40.4 127.7 115.3 Total external revenue 493.9 436.0 1,441.1 1,265.6 Intersegment revenue 2.1 2.6 6.7 10.0 Total MA 496.0 438.6 1,447.8 1,275.6 Eliminations (36.4 ) (34.2 ) (106.3 ) (102.0 ) Total MCO $ 1,240.5 $ 1,080.8 $ 3,596.2 $ 3,382.6 (1) Pursuant to certain organizational realignments in 2019 , MIS now reports revenue from REITs, which was previously classified in the SFG LOB, as a component of the CFG LOB. The amounts reclassified were not material and prior year revenue by LOB has been reclassified to conform to this new presentation. (2) 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. (3) Pursuant to organizational/product realignments in 2019 , revenue relating to the Bureau van Dijk FACT product, a credit assessment and origination software solution, is now reported in the ERS LOB. This revenue was previously reported in the RD&A LOB. Prior year revenue by LOB has been reclassified to conform to this new presentation, and the amounts reclassified were not material. The following table presents the Company’s revenues disaggregated by LOB and geographic area: Three Months Ended September 30, 2019 Three Months Ended September 30, 2018 U.S. Non-U.S Total U.S. Non-U.S Total MIS: Corporate finance (CFG) (1) $ 258.9 $ 133.1 $ 392.0 $ 194.7 $ 112.6 $ 307.3 Structured finance (SFG) (1) 67.8 37.6 105.4 70.6 43.6 114.2 Financial institutions (FIG) 53.7 66.8 120.5 59.8 59.7 119.5 Public, project and infrastructure finance (PPIF) 72.8 47.0 119.8 59.4 39.6 99.0 Total ratings revenue 453.2 284.5 737.7 384.5 255.5 640.0 MIS Other 0.2 8.7 8.9 0.2 4.6 4.8 Total MIS 453.4 293.2 746.6 384.7 260.1 644.8 MA: Research, data and analytics (RD&A) (2) 139.8 177.7 317.5 116.7 163.6 280.3 Enterprise risk solutions (ERS) (2) 48.2 85.1 133.3 43.0 72.3 115.3 Professional services (PS) 18.2 24.9 43.1 15.2 25.2 40.4 Total MA 206.2 287.7 493.9 174.9 261.1 436.0 Total MCO $ 659.6 $ 580.9 $ 1,240.5 $ 559.6 $ 521.2 $ 1,080.8 Nine Months Ended September 30, 2019 Nine Months Ended September 30, 2018 U.S. Non-U.S Total U.S. Non-U.S Total MIS: Corporate finance (CFG) (1) $ 744.1 $ 390.7 $ 1,134.8 $ 707.2 $ 380.7 $ 1,087.9 Structured finance (SFG) (1) 201.9 116.3 318.2 225.0 135.2 360.2 Financial institutions (FIG) 151.9 209.6 361.5 162.7 191.7 354.4 Public, project and infrastructure finance (PPIF) 202.4 118.7 321.1 173.9 126.4 300.3 Total ratings revenue 1,300.3 835.3 2,135.6 1,268.8 834.0 2,102.8 MIS Other 0.5 19.0 19.5 0.5 13.7 14.2 Total MIS 1,300.8 854.3 2,155.1 1,269.3 847.7 2,117.0 MA: Research, data and analytics (RD&A) (2) 412.4 528.1 940.5 347.5 475.8 823.3 Enterprise risk solutions (ERS) (2) 142.7 230.2 372.9 124.1 202.9 327.0 Professional services (PS) 53.7 74.0 127.7 41.8 73.5 115.3 Total MA 608.8 832.3 1,441.1 513.4 752.2 1,265.6 Total MCO $ 1,909.6 $ 1,686.6 $ 3,596.2 $ 1,782.7 $ 1,599.9 $ 3,382.6 (1) Pursuant to certain organizational realignments in 2019 , MIS now reports revenue from REITs, which was previously classified in the SFG LOB, as a component of the CFG LOB. The amounts reclassified were not material and prior year revenue by LOB has been reclassified to conform to this new presentation. (2) Pursuant to organizational/product realignments in 2019 , revenue relating to the Bureau van Dijk FACT product, a credit assessment and origination software solution, is now reported in the ERS LOB. This revenue was previously reported in the RD&A LOB. Prior year revenue by LOB has been reclassified to conform to this new presentation, and the amounts reclassified were not material.
Company's Reportable Segment Revenues Disaggregated by Segment and Geographic Region	The following table presents the Company’s reportable segment revenues disaggregated by segment and geographic region: Three Months Ended Nine Months Ended 2019 2018 2019 2018 MIS: U.S. $ 453.4 $ 384.7 $ 1,300.8 $ 1,269.3 Non-U.S.: EMEA 174.9 165.3 501.7 527.5 Asia-Pacific 78.9 72.7 241.7 224.9 Americas 39.4 22.1 110.9 95.3 Total Non-U.S. 293.2 260.1 854.3 847.7 Total MIS 746.6 644.8 2,155.1 2,117.0 MA: U.S. 206.2 174.9 608.8 513.4 Non-U.S.: EMEA 186.6 179.2 555.1 520.4 Asia-Pacific 63.5 50.3 173.7 142.0 Americas 37.6 31.6 103.5 89.8 Total Non-U.S. 287.7 261.1 832.3 752.2 Total MA 493.9 436.0 1,441.1 1,265.6 Total MCO $ 1,240.5 $ 1,080.8 $ 3,596.2 $ 3,382.6
Schedule of Changes in the Deferred Revenue Balances	Three Months Ended September 30, 2018 MIS MA Total Balance at June 30, 2018 $ 377.5 $ 609.0 $ 986.5 Changes in deferred revenue Revenue recognized that was included in the deferred revenue balance at the beginning of the period (127.4 ) (317.0 ) (444.4 ) Increases due to amounts billable excluding amounts recognized as revenue during the period 101.6 251.9 353.5 Effect of exchange rate changes 1.1 (1.3 ) (0.2 ) Total changes in deferred revenue (24.7 ) (66.4 ) (91.1 ) Balance at September 30, 2018 $ 352.8 $ 542.6 $ 895.4 Nine Months Ended September 30, 2018 MIS MA Total Balance at January 1, 2018 (after New Revenue Accounting Standard transition adjustment) $ 334.7 $ 611.6 $ 946.3 Changes in deferred revenue Revenue recognized that was included in the deferred revenue balance at the beginning of the period (196.2 ) (608.5 ) (804.7 ) Increases due to amounts billable excluding amounts recognized as revenue during the period 217.6 551.3 768.9 Effect of exchange rate changes (3.3 ) (11.8 ) (15.1 ) Total changes in deferred revenue 18.1 (69.0 ) (50.9 ) Balance at September 30, 2018 $ 352.8 $ 542.6 $ 895.4 Deferred revenue - current $ 233.9 $ 537.6 771.5 Deferred revenue - noncurrent $ 118.9 $ 5.0 123.9 Significant changes in the deferred revenue balances during the three and nine months ended September 30, 2019 are as follows: Three Months Ended September 30, 2019 MIS MA Total Balance at June 30, 2019 $ 376.0 $ 694.8 $ 1,070.8 Changes in deferred revenue Revenue recognized that was included in the deferred revenue balance at the beginning of the period (110.8 ) (343.8 ) (454.6 ) Increases due to amounts billable excluding amounts recognized as revenue during the period 82.0 290.1 372.1 Effect of exchange rate changes (3.7 ) (13.9 ) (17.6 ) Total changes in deferred revenue (32.5 ) (67.6 ) (100.1 ) Balance at September 30, 2019 $ 343.5 $ 627.2 $ 970.7 Nine Months Ended September 30, 2019 MIS MA Total Balance at January 1, 2019 $ 325.4 $ 750.3 $ 1,075.7 Changes in deferred revenue Revenue recognized that was included in the deferred revenue balance at the beginning of the period (190.8 ) (687.4 ) (878.2 ) Increases due to amounts billable excluding amounts recognized as revenue during the period 211.6 576.6 788.2 Amount included in liabilities reclassified as held for sale — (2.7 ) (2.7 ) Effect of exchange rate changes (2.7 ) (9.6 ) (12.3 ) Total changes in deferred revenue 18.1 (123.1 ) (105.0 ) Balance at September 30, 2019 $ 343.5 $ 627.2 $ 970.7 Deferred revenue - current $ 233.2 $ 622.5 $ 855.7 Deferred revenue - noncurrent $ 110.3 $ 4.7 $ 115.0
Schedule of Expected Recognition Period for the Remaining Performance Obligations	The following tables include the expected recognition period for the remaining performance obligations for each reportable segment as of September 30, 2019 : MIS Total Less than 1 year 1 - 5 years 6 - 10 Years 11 - 15 years 16-20 years Over 20 Years $ 146.8 $ 24.3 $ 69.9 $ 37.9 $ 5.8 $ 4.0 $ 4.9 MA Total Less than 1 Year 1 - 2 Years Over 2 Years $ 1,582.8 $ 1,125.6 $ 325.4 $ 131.8

STOCK-BASED COMPENSATION (Table

STOCK-BASED COMPENSATION (Tables)	9 Months Ended
	Sep. 30, 2019
Share-based Payment Arrangement, Noncash Expense [Abstract]
Stock-Based Compensation Cost and Associated Tax Benefit	Presented below is a summary of the stock-based compensation cost and associated tax benefit included in the accompanying consolidated statements of operations: Three Months Ended Nine Months Ended 2019 2018 2019 2018 Stock-based compensation cost $ 33.3 $ 30.5 $ 103.2 $ 100.0 Tax benefit $ 6.9 $ 11.5 $ 22.0 $ 26.0
Weighted Average Assumptions used in Determining Fair Value for Options Granted	The following weighted average assumptions were used in determining the fair value for options granted in 2019 : Expected dividend yield 1.15 % Expected stock volatility 23.61 % Risk-free interest rate 2.59 % Expected holding period 6.2 years
Stock Option Exercises and Restricted Stock Vesting	The following tables summarize information relating to stock option exercises and restricted stock vesting: Nine Months Ended 2019 2018 Exercise of stock options: Proceeds from stock option exercises $ 28.9 $ 36.2 Aggregate intrinsic value $ 99.2 $ 94.9 Tax benefit realized upon exercise $ 24.3 $ 23.2 Number of shares exercised 0.7 0.8 Vesting of restricted stock: Fair value of shares vested $ 152.7 $ 150.0 Tax benefit realized upon vesting $ 36.2 $ 34.7 Number of shares vested 0.8 0.9 Vesting of performance-based restricted stock: Fair value of shares vested $ 47.5 $ 23.0 Tax benefit realized upon vesting $ 11.5 $ 5.6 Number of shares vested 0.3 0.1

INCOME TAXES (Tables)

INCOME TAXES (Tables)	9 Months Ended
	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Income Taxes Paid	The following table shows the amount the Company paid for income taxes: Nine Months Ended September 30, 2019 2018 Income taxes paid $ 302.5 $ 337.0

WEIGHTED AVERAGE SHARES OUTST_2

WEIGHTED AVERAGE SHARES OUTSTANDING (Tables)	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Reconciliation of Basic to Diluted Shares Outstanding	Below is a reconciliation of basic to diluted shares outstanding: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Basic 189.0 191.8 189.6 191.7 Dilutive effect of shares issuable under stock-based compensation plans 2.1 2.7 2.2 2.7 Diluted 191.1 194.5 191.8 194.4 Anti-dilutive options to purchase common shares and restricted stock as well as contingently issuable restricted stock which are excluded from the table above 0.2 0.3 0.3 0.4

CASH EQUIVALENTS AND INVESTME_2

CASH EQUIVALENTS AND INVESTMENTS (Tables)	9 Months Ended
	Sep. 30, 2019
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 September 30, 2019 Balance sheet location Cost Gross Unrealized Gains Fair Value Cash and cash equivalents Short-term investments Other assets Certificates of deposit and money market deposit accounts (1) $ 436.3 $ — $ 436.3 $ 327.6 $ 88.2 $ 20.5 Open ended mutual funds $ 6.8 $ 0.9 $ 7.7 $ — $ 7.6 $ 0.1 As of December 31, 2018 Balance sheet location Cost Gross Unrealized Gains Fair Value Cash and cash equivalents Short-term investments Other assets Money market mutual funds $ 15.2 $ — $ 15.2 $ 15.2 $ — $ — Certificates of deposit and money market deposit accounts (1) $ 1,022.4 $ — $ 1,022.4 $ 904.3 $ 115.8 $ 2.3 Open ended mutual funds $ 29.5 $ 3.8 $ 33.3 $ — $ 16.7 $ 16.6 (1) Consists of time deposits and money market deposit accounts. The remaining contractual maturities for the certificates of deposits classified as short-term investments were one month to 12 months at both September 30, 2019 and December 31, 2018 . The remaining contractual maturities for the certificates of deposits classified in other assets are 13 to 21 months at September 30, 2019 and 14 to 36 months at December 31, 2018 . Time deposits with a maturity of less than 90 days at time of purchase are classified as cash and cash equivalents.

ASSETS AND LIABILITIES HELD F_2

ASSETS AND LIABILITIES HELD FOR SALE (Tables)	9 Months Ended
	Sep. 30, 2019
Discontinued Operations and Disposal Groups [Abstract]
Schedule of Assets and Liabilities Held for Sale	The following table presents the major classes of the total consolidated assets and liabilities of MAKS that were classified as held for sale on the consolidated balance sheet at September 30, 2019 : September 30, 2019 Assets Current assets: Cash and cash equivalents $ 11.1 Accounts receivable, net 18.7 Other current assets 6.6 Total current assets 36.4 Property and equipment, net 12.7 Goodwill 163.9 Intangible assets, net 44.0 Deferred tax assets, net 4.8 Other assets 2.9 Total assets held for sale prior to impairment $ 264.7 Impairment of assets held for sale (10.7 ) Total assets held for sale $ 254.0 Liabilities Current liabilities: Accounts payable and accrued liabilities $ 21.4 Deferred revenue 1.8 Total current liabilities 23.2 Deferred tax liabilities, net 6.8 Uncertain tax positions 28.6 Other liabilities 25.5 Total liabilities held for sale $ 84.1 Derivation of impairment charge Total net assets held for sale prior to impairment $ 180.6 Currency translation adjustment (1) 32.6 Total net assets held for sale including currency translation adjustment $ 213.2 Estimated fair value less costs to sell 202.5 Impairment of assets held for sale $ 10.7 (1) Primarily due to the depreciation of the Indian rupee to the U.S. dollar

DERIVATIVE INSTRUMENTS AND HE_2

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES (Tables)	9 Months Ended
	Sep. 30, 2019
Derivative [Line Items]
Schedule of Interest Rate Swap	The following table summarizes the Company’s interest rate swaps designated as fair value hedges: Notional Amount Hedged Item Nature of Swap As of As of Floating Interest Rate 2010 Senior Notes due 2020 Pay Floating/Receive Fixed $ 500.0 $ 500.0 3-month USD LIBOR 2012 Senior Notes due 2022 Pay Floating/Receive Fixed 330.0 330.0 3-month USD LIBOR 2017 Senior Notes due 2021 Pay Floating/Receive Fixed 500.0 500.0 3-month USD LIBOR 2017 Senior Notes due 2023 Pay Floating/Receive Fixed 250.0 — 3-month USD LIBOR Total $ 1,580.0 $ 1,330.0
Gains and Losses on Derivatives Designated as Hedging Instruments	The following table summarizes the impact to the statement of operations of the Company’s interest rate swaps designated as fair value hedges: Total amounts of financial statement line item presented in the statements of operations in which the effects of fair value hedges are recorded Amount of income/(loss) recognized in the consolidated statements of operations Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Interest expense, net $ (45.9 ) $ (56.4 ) $ (149.0 ) $ (160.5 ) Descriptions Location on Consolidated Statements of Operations Net interest settlements and accruals on interest rate swaps Interest expense, net $ 1.0 $ (0.5 ) $ 0.9 $ (1.0 ) Fair value changes on interest rate swaps Interest expense, net $ 2.3 $ (3.3 ) $ 32.9 $ (14.8 ) Fair value changes on hedged debt Interest expense, net $ (2.3 ) $ 3.3 $ (32.9 ) $ 14.8
Summary of Notional Amounts of Outstanding Foreign Exchange Forwards	The following table summarizes the notional amounts of the Company's outstanding forward contract that was designated as a net investment hedge: September 30, 2019 December 31, 2018 Notional amount of net investment hedges: Sell Buy Sell Buy Contract to sell EUR for USD € 485.0 $ 532.0 — — The following table summarizes the notional amounts of the Company’s outstanding foreign exchange forwards: September 30, 2019 December 31, 2018 Notional amount of currency pair: Sell Buy Sell Buy Contracts to sell USD for GBP $ 144.5 £ 115.4 $ 310.3 £ 241.2 Contracts to sell USD for Japanese Yen $ 30.3 ¥ 3,200.0 $ 14.3 ¥ 1,600.0 Contracts to sell USD for Canadian dollars $ 96.9 C$ 128.0 $ 99.0 C$ 130.0 Contracts to sell USD for Singapore dollars $ 40.5 S$ 56.0 $ — S$ — Contracts to sell USD for Euros $ 532.1 € 485.0 $ 212.8 € 184.6 Contracts to sell EUR for GBP € 180.0 £ 159.5 € — £ — Contracts to sell GBP for USD £ 115.9 $ 143.2 £ — $ — NOTE: € = Euro, £ = British pound, $ = U.S. dollar, ¥ = Japanese Yen, C$ = Canadian dollar, S$= Singapore dollars
Amount of Gain/(Loss) Recognized in AOCI on Derivative Net Investment Hedging Relationships (Effectiveness Portion)	The following tables provide information on the gains/(losses) on the Company’s net investment and cash flow hedges: Derivative and Non-Derivative Instruments in Net Investment Hedging Relationships Amount of Gain/(Loss) Recognized in AOCI on Derivative, net of Tax Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing) Three Months Ended Three Months Ended Three Months Ended 2019 2018 2019 2018 2019 (2) 2018 FX forward contracts $ 4.9 $ — $ 0.8 $ — $ — $ — Cross currency swaps 79.6 1.8 — — 15.5 4.1 Long-term debt 18.2 (1) 2.2 — — — — Total net investment hedges $ 102.7 $ 4.0 $ 0.8 $ — $ 15.5 $ 4.1 Derivatives in Cash Flow Hedging Relationships Cross currency swap $ — $ — $ 0.1 $ 0.1 $ — $ — Interest rate contracts — — (0.1 ) — — — Total cash flow hedges $ — $ — $ — $ 0.1 $ — $ — Total $ 102.7 $ 4.0 $ 0.8 $ 0.1 $ 15.5 $ 4.1 Derivative and Non-Derivative Instruments in Net Investment Hedging Relationships Amount of Gain/(Loss) Recognized in AOCI on Derivative, net of Tax Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing) Nine Months Ended Nine Months Ended Nine Months Ended 2019 2018 2019 2018 2019 (2) 2018 FX forward contracts $ 4.9 $ — $ 0.8 $ — $ — $ — Cross currency swaps 75.1 5.8 — — 37.3 6.2 Long-term debt 17.0 (1) 14.7 — — — — Total net investment hedges $ 97.0 $ 20.5 $ 0.8 $ — $ 37.3 $ 6.2 Derivatives in Cash Flow Hedging Relationships Cross currency swap $ — $ 1.5 $ — $ 0.3 $ — $ — Interest rate contracts — — (0.1 ) — — — Total cash flow hedges $ — $ 1.5 $ (0.1 ) $ 0.3 $ — $ — Total $ 97.0 $ 22.0 $ 0.7 $ 0.3 $ 37.3 $ 6.2 (1) Due to the Company's adoption of ASU 2018-02 during 2019, $2.5 million related to the tax effect of this net investment hedge was reclassified to retained earnings. Refer to Note 1 for further details. (2) Effective with the adoption of ASU 2017-12, the Company has elected to assess the effectiveness of its net investment hedges based on changes in spot exchange rates. Accordingly, amounts related to cross-currency swaps recognized directly into Net Income during 2019 represent net periodic interest settlements and accruals, which are recognized in interest expense, net.
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 September 30, 2019 December 31, 2018 Net investment hedges Cross currency swaps $ 87.4 $ 12.3 FX forwards 27.6 23.5 Long-term debt 11.4 (3.1 ) Total net investment hedges $ 126.4 $ 32.7 Cash flow hedges Interest rate contracts $ (2.3 ) $ (2.4 ) Cross currency swap 2.5 2.5 Total cash flow hedges 0.2 0.1 Total net gain in AOCI $ 126.6 $ 32.8 The following tables show changes in AOCI by component (net of tax): Three Months Ended September 30, 2019 September 30, 2018 Gains/(Losses) Pension and Other Retirement Benefits Cash Flow Hedges Foreign Currency Translation Adjustments Net Investment Hedges Total Pension and Other Retirement Benefits Cash Flow Hedges Foreign Currency Translation Adjustments Net Investment Hedges Total Balance June 30, $ (70.5 ) $ 0.2 $ (400.3 ) $ 24.5 $ (446.1 ) $ (58.6 ) $ 2.2 $ (263.6 ) $ 15.2 $ (304.8 ) Other comprehensive income/(loss) before reclassifications — — (193.7 ) 102.7 (91.0 ) — — (42.0 ) 4.1 (37.9 ) Amounts reclassified from AOCI 0.6 — — (0.8 ) (0.2 ) 0.8 (0.1 ) — — 0.7 Other comprehensive income/(loss) 0.6 — (193.7 ) 101.9 (91.2 ) 0.8 (0.1 ) (42.0 ) 4.1 (37.2 ) Balance September 30, $ (69.9 ) $ 0.2 $ (594.0 ) $ 126.4 $ (537.3 ) $ (57.8 ) $ 2.1 $ (305.6 ) $ 19.3 $ (342.0 ) Nine Months Ended September 30, 2019 September 30, 2018 Gains/(Losses) Pension and Other Retirement Benefits Cash Flow Hedges Foreign Currency Translation Adjustments Net Investment Hedges Total Pension and Other Retirement Benefits Cash Flow Hedges Foreign Currency Translation Adjustments Net Investment Hedges Gains on Available for Sale Securities Total Balance December 31, $ (53.1 ) $ 0.1 $ (406.0 ) $ 32.7 $ (426.3 ) $ (61.5 ) $ 0.9 $ (112.6 ) $ (1.3 ) $ 2.3 $ (172.2 ) Adoption of ASU 2016-01 relating to financial instruments — — — — — — — — — (2.3 ) (2.3 ) Other comprehensive income/(loss) before reclassifications (1.3 ) — (188.0 ) 97.0 (92.3 ) 1.2 1.5 (193.0 ) 20.6 — (169.7 ) Amounts reclassified from AOCI 1.8 0.1 — (0.8 ) 1.1 2.5 (0.3 ) — — — 2.2 Adoption of ASU 2018-02 (See Note 1) (17.3 ) — — (2.5 ) (19.8 ) — — — — — — Other comprehensive income/(loss) (16.8 ) 0.1 (188.0 ) 93.7 (111.0 ) 3.7 1.2 (193.0 ) 20.6 (2.3 ) (169.8 ) Balance September 30, $ (69.9 ) $ 0.2 $ (594.0 ) $ 126.4 $ (537.3 ) $ (57.8 ) $ 2.1 $ (305.6 ) $ 19.3 $ — $ (342.0 )
Gains and Losses Recognized in Consolidated Statement of Operations on Derivatives Not Designated as Hedging instruments	The following table summarizes the impact to the consolidated statements of operations relating to the net losses on the Company’s derivatives which are not designated as hedging instruments: Derivatives not designated as accounting hedges Location on Statement of Operations Three Months Ended Nine Months Ended 2019 2018 2019 2018 Foreign exchange forwards Other non-operating expense, net $ (26.7 ) $ (11.8 ) $ (35.0 ) $ (29.1 )
Fair Value of Derivative Instruments	table below shows the classification between assets and liabilities on the Company’s consolidated balance sheets for the fair value of the derivative instrument as well as the carrying value of its non-derivative debt instruments designated and qualifying as net investment hedges: Derivative and Non-Derivative Instruments Balance Sheet Location September 30, 2019 December 31, 2018 Assets: Derivatives designated as accounting hedges: Cross-currency swaps designated as net investment hedges Other assets $ 116.5 $ 19.4 Interest rate swaps designated as fair value hedges Other assets 32.8 7.5 Interest rate swaps designated as fair value hedges Other current assets 2.3 — FX forwards designated as net investment hedges Other current assets 2.4 — Total derivatives designated as accounting hedges $ 154.0 $ 26.9 Derivatives not designated as accounting hedges: FX forwards on certain assets and liabilities Other current assets 0.6 1.4 Total assets $ 154.6 $ 28.3 Liabilities: Derivatives designated as accounting hedges: Cross-currency swaps designated as net investment hedges Other liabilities $ — $ 2.9 Interest rate swaps designated as fair value hedges Other liabilities — 5.3 Total derivatives designated as accounting hedges $ — 8.2 Non-derivatives designated as accounting hedges: Long-term debt designated as net investment hedge Long-term debt 545.1 571.6 Derivatives not designated as accounting hedges: FX forwards on certain assets and liabilities Accounts payable and accrued liabilities 5.7 8.2 Total liabilities $ 550.8 $ 588.0
Designated as Hedging Instrument
Derivative [Line Items]
Schedule of Interest Rate Swap	The following table provides information on the cross-currency swaps designated as net investment hedges under ASC Topic 815: September 30, 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 1.43% $ 1,220.0 3.96% Pay Floating/Receive Floating 931.3 Based on 3-month EURIBOR 1,080.0 Based on 3-month USD LIBOR Total € 2,010.4 $ 2,300.0 December 31, 2018 Pay Receive Nature of Swap Notional Amount Weighted Average Interest Rate Notional Amount Weighted Average Interest Rate Pay Floating/Receive Floating € 710.2 Based on 3-month EURIBOR $ 830.0 Based on 3-month USD LIBOR Total € 710.2 $ 830.0

GOODWILL AND OTHER ACQUIRED I_2

GOODWILL AND OTHER ACQUIRED INTANGIBLE ASSETS (Tables)	9 Months Ended
	Sep. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Activity in Goodwill	The following table summarizes the activity in goodwill for the periods indicated: Nine Months Ended September 30, 2019 MIS MA Consolidated Gross goodwill Accumulated impairment charge Net goodwill Gross goodwill Accumulated impairment charge Net goodwill Gross goodwill Accumulated impairment charge Net goodwill Balance at beginning of year $ 257.8 $ — $ 257.8 $ 3,535.7 $ (12.2 ) $ 3,523.5 $ 3,793.5 $ (12.2 ) $ 3,781.3 Additions/ adjustments (1) 52.1 — 52.1 44.9 — 44.9 97.0 — 97.0 Foreign currency translation adjustments 10.1 — 10.1 (114.5 ) — (114.5 ) (104.4 ) — (104.4 ) Reclassification to assets held for sale (See Note 10) (2) — — — (163.9 ) — (163.9 ) (163.9 ) — (163.9 ) Ending balance $ 320.0 $ — $ 320.0 $ 3,302.2 $ (12.2 ) $ 3,290.0 $ 3,622.2 $ (12.2 ) $ 3,610.0 Year Ended December 31, 2018 MIS MA Consolidated Gross goodwill Accumulated impairment Net Gross goodwill Accumulated Net Gross goodwill Accumulated Net Balance at beginning of year $ 285.2 $ — $ 285.2 $ 3,480.2 $ (12.2 ) $ 3,468.0 $ 3,765.4 $ (12.2 ) $ 3,753.2 Additions/ adjustments (3) — — — 211.5 — 211.5 211.5 — 211.5 Foreign currency translation adjustments (27.4 ) — (27.4 ) (156.0 ) — (156.0 ) (183.4 ) — (183.4 ) Ending balance $ 257.8 $ — $ 257.8 $ 3,535.7 $ (12.2 ) $ 3,523.5 $ 3,793.5 $ (12.2 ) $ 3,781.3 (1) 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 acquisition of RiskFirst. (2) The 2019 reclassification to assets held for sale for the MA segment in the table above relate to the planned divestiture of MAKS, more fully discussed in Note 10 . (3) The 2018 additions/adjustments for the MA segment in the table above primarily relate to the acquisitions of Reis and Omega Performance.
Acquired Intangible Assets and Related Amortization	Acquired intangible assets and related amortization consisted of: September 30, December 31, Customer relationships $ 1,264.9 $ 1,367.5 Accumulated amortization (216.0 ) (214.2 ) Net customer relationships 1,048.9 1,153.3 Trade secrets 29.9 29.8 Accumulated amortization (28.5 ) (28.2 ) Net trade secrets 1.4 1.6 Software/product technology 354.8 353.3 Accumulated amortization (118.4 ) (101.8 ) Net software/product technology 236.4 251.5 Trade names 147.4 155.1 Accumulated amortization (28.0 ) (34.1 ) Net trade names 119.4 121.0 Other (1) 79.2 70.4 Accumulated amortization (31.2 ) (31.7 ) Net other 48.0 38.7 Total acquired intangible assets, net $ 1,454.1 $ 1,566.1 (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: Three Months Ended Nine Months Ended 2019 2018 2019 2018 Amortization expense $ 24.7 $ 24.6 $ 77.3 $ 75.4
Estimated Future Amortization Expense for Acquired Intangible Assets Subject to Amortization	Estimated future amortization expense for acquired intangible assets subject to amortization is as follows: Year Ending December 31, 2019 (after September 30) $ 20.1 2020 95.4 2021 95.2 2022 95.1 2023 92.6 Thereafter 1,055.7 Total estimated future amortization $ 1,454.1

RESTRUCTURING (Tables)

RESTRUCTURING (Tables)	9 Months Ended
	Sep. 30, 2019
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 2018 Restructuring Program are as follows: Three Months Ended Nine Months Ended 2019 2018 2019 2018 Restructuring $ (1.0 ) $ — $ 58.3 $ —
Changes to the Restructuring Liability	Changes to the restructuring liability during 2019 were as follows: Employee Termination Costs Contract Termination Costs Total Restructuring Liability (2) Balance as of December 31, 2018 $ 29.9 $ 12.4 $ 42.3 2018 Restructuring Program: Adoption of New Lease Accounting Standard (1) — (10.9 ) (10.9 ) Cost incurred and adjustments 25.1 4.3 29.4 Cash payments and adjustments (26.5 ) (3.0 ) (29.5 ) Balance as of September 30, 2019 $ 28.5 $ 2.8 $ 31.3 2018 Restructuring Program: Cumulative expense incurred to date $ 58.0 $ 49.0 (1) Upon the adoption of the New Lease Accounting Standard, the Company recorded a reclassification of $10.9 million of liabilities in the first quarter of 2019 for costs associated with certain real estate leases which were exited in previous years, as a reduction of the ROU Asset capitalized upon adoption. (2) The liability excludes $4.1 million of non-cash acceleration of amortization of leasehold improvements relating to the rationalization and exit of certain real estate leases as well as $24.8 million of ROU Asset impairment charges for the nine months ended September 30, 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 $17.7 million , and is categorized as Level 3 within the ASC Topic 820 fair value hierarchy.

FAIR VALUE (Tables)

FAIR VALUE (Tables)	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Financial Instruments Carried at Fair Value on Recurring Basis	The table below presents information about items that are carried at fair value at September 30, 2019 and December 31, 2018 : Fair value Measurement as of September 30, 2019 Description Balance Level 1 Level 2 Assets: Derivatives (1) $ 154.6 $ — $ 154.6 Mutual funds 7.7 7.7 — Total $ 162.3 $ 7.7 $ 154.6 Liabilities: Derivatives (1) $ 5.7 $ — $ 5.7 Total $ 5.7 $ — $ 5.7 Fair value Measurement as of December 31, 2018 Description Balance Level 1 Level 2 Assets: Derivatives (1) $ 28.3 $ — $ 28.3 Money market mutual funds 15.2 15.2 — Mutual funds 33.3 33.3 — Total $ 76.8 $ 48.5 $ 28.3 Liabilities: Derivatives (1) $ 16.4 $ — $ 16.4 Total $ 16.4 $ — $ 16.4 (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 11 to the condensed consolidated financial statements.

OTHER BALANCE SHEET AND STATE_2

OTHER BALANCE SHEET AND STATEMENT OF OPERATIONS INFORMATION (Tables)	9 Months Ended
	Sep. 30, 2019
Other Balance Sheet And Statement Of Operations Information [Abstract]
Additional Details Related to Certain Balance Sheet Captions	The following tables contain additional detail related to certain balance sheet captions: September 30, 2019 December 31, 2018 Other current assets: Prepaid taxes $ 98.3 $ 100.1 Prepaid expenses 64.3 67.0 Capitalized costs to obtain and fulfill sales contracts 67.7 77.2 Other 55.8 38.0 Total other current assets $ 286.1 $ 282.3 Other assets: Investments in non-consolidated affiliates $ 113.0 $ 104.6 Deposits for real-estate leases 12.3 13.5 Indemnification assets related to acquisitions 16.0 16.1 Mutual funds and fixed deposits 20.6 18.9 Costs to obtain sales contracts 90.0 78.0 Cross currency and interest rate swaps 149.3 26.9 Other 24.1 16.3 Total other assets $ 425.3 $ 274.3 September 30, 2019 December 31, 2018 Accounts payable and accrued liabilities: Salaries and benefits $ 95.1 $ 112.5 Incentive compensation 150.3 154.5 Customer credits, advanced payments and advanced billings 25.5 20.4 Self-insurance reserves 13.2 10.5 Dividends 6.0 6.5 Professional service fees 71.0 47.7 Interest accrued on debt 41.2 70.5 Accounts payable 14.8 30.1 Income taxes 56.4 71.4 Pension and other retirement employee benefits 6.5 6.5 Accrued royalties 9.4 25.1 Foreign exchange forwards on certain assets and liabilities 5.7 8.2 Restructuring liability 26.8 9.6 Other 85.3 121.7 Total accounts payable and accrued liabilities $ 607.2 $ 695.2 Other liabilities: Pension and other retirement employee benefits $ 264.2 $ 249.2 Deferred rent - non-current portion (1) — 94.3 Interest accrued on UTPs 61.2 69.6 Income tax liability - non-current portion (2) 125.2 125.3 Cross currency and interest rate swaps — 8.2 Restructuring liability 4.5 6.8 Other 37.4 23.1 Total other liabilities $ 492.5 $ 576.5 (1) Pursuant to the adoption of the New Lease Accounting Standard, deferred rent relating to operating leases was reclassified to operating lease ROU Asset. (2) Primarily reflects the transition tax pursuant to the Tax Act, which was enacted into law in December 2018.
Other Non-Operating	The following table summarizes the components of other non-operating income (expense): Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 FX (loss)/gain $ 0.9 $ (3.9 ) $ (14.7 ) $ (3.6 ) Net periodic pension costs - other components 4.5 2.6 13.4 7.8 Income from investments in non-consolidated affiliates 3.9 3.3 10.7 9.2 Other 0.6 0.4 3.2 4.9 Total $ 9.9 $ 2.4 $ 12.6 $ 18.3

COMPREHENSIVE INCOME AND ACCU_2

COMPREHENSIVE INCOME AND ACCUMULATED OTHER COMPREHENSIVE INCOME (Tables)	9 Months Ended
	Sep. 30, 2019
Equity [Abstract]
Reclassifications out of AOCI	The following table provides details about the reclassifications out of AOCI: Gains (losses) on cash flow hedges Three Months Ended Nine Months Ended Affected line in the consolidated statement of operations Cross-currency swap $ 0.1 $ — Other non-operating income(expense), net Interest rate contract (0.2 ) (0.2 ) Interest expense, net Total before income taxes (0.1 ) (0.2 ) Income tax effect of items above 0.1 0.1 Provision for income taxes Total net gains (losses) on cash flow hedges — (0.1 ) Gains on net investment hedges FX forwards 1.0 1.0 Other non-operating income(expense), net Income tax effect of item above (0.2 ) (0.2 ) Provision for income taxes Total net gains on net investment hedges 0.8 0.8 Pension and other retirement benefits Amortization of actuarial losses and prior service costs included in net income (0.5 ) (1.5 ) Operating expense Amortization of actuarial losses and prior service costs included in net income (0.3 ) (0.9 ) SG&A expense Total before income taxes (0.8 ) (2.4 ) Income tax effect of item above 0.2 0.6 Provision for income taxes Total pension and other retirement benefits (0.6 ) (1.8 ) Total net gains (losses) included in Net Income attributable to reclassifications out of AOCI $ 0.2 $ (1.1 ) Gains on cash flow hedges Three Months Ended September 30, 2018 Nine Months Ended September 30, 2018 Affected line in the consolidated statement of operations Cross-currency swap $ 0.1 $ 0.3 Other non-operating income (expense), net Income tax effect of item above — — Provision for income taxes Total net gains on cash flow hedges 0.1 0.3 Pension and other retirement benefits Amortization of actuarial losses and prior service costs included in net income (0.6 ) (2.2 ) Operating expense Amortization of actuarial losses and prior service costs included in net income (0.5 ) (1.3 ) SG&A expense Total before income taxes (1.1 ) (3.5 ) Income tax effect of item above 0.3 1.0 Provision for income taxes Total pension and other retirement benefits (0.8 ) (2.5 ) Total net losses included in Net Income attributable to reclassifications out of AOCI $ (0.7 ) $ (2.2 )
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 September 30, 2019 December 31, 2018 Net investment hedges Cross currency swaps $ 87.4 $ 12.3 FX forwards 27.6 23.5 Long-term debt 11.4 (3.1 ) Total net investment hedges $ 126.4 $ 32.7 Cash flow hedges Interest rate contracts $ (2.3 ) $ (2.4 ) Cross currency swap 2.5 2.5 Total cash flow hedges 0.2 0.1 Total net gain in AOCI $ 126.6 $ 32.8 The following tables show changes in AOCI by component (net of tax): Three Months Ended September 30, 2019 September 30, 2018 Gains/(Losses) Pension and Other Retirement Benefits Cash Flow Hedges Foreign Currency Translation Adjustments Net Investment Hedges Total Pension and Other Retirement Benefits Cash Flow Hedges Foreign Currency Translation Adjustments Net Investment Hedges Total Balance June 30, $ (70.5 ) $ 0.2 $ (400.3 ) $ 24.5 $ (446.1 ) $ (58.6 ) $ 2.2 $ (263.6 ) $ 15.2 $ (304.8 ) Other comprehensive income/(loss) before reclassifications — — (193.7 ) 102.7 (91.0 ) — — (42.0 ) 4.1 (37.9 ) Amounts reclassified from AOCI 0.6 — — (0.8 ) (0.2 ) 0.8 (0.1 ) — — 0.7 Other comprehensive income/(loss) 0.6 — (193.7 ) 101.9 (91.2 ) 0.8 (0.1 ) (42.0 ) 4.1 (37.2 ) Balance September 30, $ (69.9 ) $ 0.2 $ (594.0 ) $ 126.4 $ (537.3 ) $ (57.8 ) $ 2.1 $ (305.6 ) $ 19.3 $ (342.0 ) Nine Months Ended September 30, 2019 September 30, 2018 Gains/(Losses) Pension and Other Retirement Benefits Cash Flow Hedges Foreign Currency Translation Adjustments Net Investment Hedges Total Pension and Other Retirement Benefits Cash Flow Hedges Foreign Currency Translation Adjustments Net Investment Hedges Gains on Available for Sale Securities Total Balance December 31, $ (53.1 ) $ 0.1 $ (406.0 ) $ 32.7 $ (426.3 ) $ (61.5 ) $ 0.9 $ (112.6 ) $ (1.3 ) $ 2.3 $ (172.2 ) Adoption of ASU 2016-01 relating to financial instruments — — — — — — — — — (2.3 ) (2.3 ) Other comprehensive income/(loss) before reclassifications (1.3 ) — (188.0 ) 97.0 (92.3 ) 1.2 1.5 (193.0 ) 20.6 — (169.7 ) Amounts reclassified from AOCI 1.8 0.1 — (0.8 ) 1.1 2.5 (0.3 ) — — — 2.2 Adoption of ASU 2018-02 (See Note 1) (17.3 ) — — (2.5 ) (19.8 ) — — — — — — Other comprehensive income/(loss) (16.8 ) 0.1 (188.0 ) 93.7 (111.0 ) 3.7 1.2 (193.0 ) 20.6 (2.3 ) (169.8 ) Balance September 30, $ (69.9 ) $ 0.2 $ (594.0 ) $ 126.4 $ (537.3 ) $ (57.8 ) $ 2.1 $ (305.6 ) $ 19.3 $ — $ (342.0 )

PENSION AND OTHER RETIREMENT _2

PENSION AND OTHER RETIREMENT BENEFITS (Tables)	9 Months Ended
	Sep. 30, 2019
Retirement Benefits [Abstract]
Components of Net Periodic Benefit Expense Related to Post-Retirement Plans	The components of net periodic benefit expense related to the Retirement Plans are as follows: Three Months Ended September 30, Pension Plans Other Retirement Plans 2019 2018 2019 2018 Components of net periodic expense Service cost $ 4.2 $ 4.6 $ 0.7 $ 0.7 Interest cost 5.1 4.4 0.3 0.3 Expected return on plan assets (5.0 ) (3.8 ) — — Amortization of net actuarial loss from earlier periods 0.9 1.5 — — Amortization of net prior service costs from earlier periods (0.1 ) — (0.1 ) (0.1 ) Net periodic expense $ 5.1 $ 6.7 $ 0.9 $ 0.9 Nine Months Ended September 30, Pension Plans Other Retirement Plans 2019 2018 2019 2018 Components of net periodic expense Service cost $ 12.5 $ 14.0 $ 2.1 $ 2.2 Interest cost 15.4 13.2 0.9 0.8 Expected return on plan assets (15.1 ) (11.4 ) — — Amortization of net actuarial loss from earlier periods 2.8 4.6 — — Amortization of net prior service costs from earlier periods (0.3 ) (0.2 ) (0.2 ) (0.2 ) Net periodic expense $ 15.3 $ 20.2 $ 2.8 $ 2.8

INDEBTEDNESS (Tables)

INDEBTEDNESS (Tables)	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Summary of Total Indebtedness	The following table summarizes total indebtedness: September 30, 2019 Notes Payable: Principal Amount Fair Value of Interest Rate Swaps (1) Unamortized (Discount) Premium Unamortized Debt Issuance Costs Carrying Value 5.50% 2010 Senior Notes, due 2020 $ 500.0 $ 2.3 $ (0.4 ) $ (0.4 ) $ 501.5 4.50% 2012 Senior Notes, due 2022 500.0 11.0 (1.3 ) (1.1 ) 508.6 4.875% 2013 Senior Notes, due 2024 500.0 — (1.4 ) (1.7 ) 496.9 5.25% 2014 Senior Notes (30-Year), due 2044 600.0 — 3.2 (5.3 ) 597.9 1.75% 2015 Senior Notes, due 2027 545.1 — — (2.7 ) 542.4 2.75% 2017 Senior Notes, due 2021 500.0 13.5 (0.7 ) (1.8 ) 511.0 2.625% 2017 Senior Notes, due 2023 500.0 8.3 (0.7 ) (2.4 ) 505.2 3.25% 2017 Senior Notes, due 2028 500.0 — (4.4 ) (3.4 ) 492.2 3.25% 2018 Senior Notes, due 2021 300.0 — (0.3 ) (1.0 ) 298.7 4.25% 2018 Senior Notes, due 2029 400.0 — (2.8 ) (3.0 ) 394.2 4.875% 2018 Senior Notes, due 2048 400.0 — (6.6 ) (4.0 ) 389.4 Total debt $ 5,245.1 $ 35.1 $ (15.4 ) $ (26.8 ) $ 5,238.0 Current portion (501.5 ) Total long-term debt $ 4,736.5 December 31, 2018 Notes Payable: Principal Amount Fair Value of Interest Rate Swaps (1) Unamortized (Discount) Premium Unamortized Debt Issuance Costs Carrying Value 5.50% 2010 Senior Notes, due 2020 $ 500.0 $ (3.7 ) $ (0.6 ) $ (0.7 ) $ 495.0 4.50% 2012 Senior Notes, due 2022 500.0 1.9 (1.6 ) (1.4 ) 498.9 4.875% 2013 Senior Notes, due 2024 500.0 — (1.5 ) (2.0 ) 496.5 2.75% 2014 Senior Notes (5-Year), due 2019 450.0 — (0.1 ) — 449.9 5.25% 2014 Senior Notes (30-Year), due 2044 600.0 — 3.2 (5.5 ) 597.7 1.75% 2015 Senior Notes, due 2027 571.6 — — (3.1 ) 568.5 2.75% 2017 Senior Notes, due 2021 500.0 4.0 (1.0 ) (2.4 ) 500.6 2.625% 2017 Senior Notes, due 2023 500.0 — (0.9 ) (2.8 ) 496.3 3.25% 2017 Senior Notes, due 2028 500.0 — (4.7 ) (3.7 ) 491.6 3.25% 2018 Senior Notes, due 2021 300.0 — (0.4 ) (1.5 ) 298.1 4.25% 2018 Senior Notes, due 2029 400.0 — (3.0 ) (3.3 ) 393.7 4.875% 2018 Senior Notes, due 2048 400.0 — (6.7 ) (4.1 ) 389.2 Total debt $ 5,721.6 $ 2.2 $ (17.3 ) $ (30.5 ) $ 5,676.0 Current portion (449.9 ) Total long-term debt $ 5,226.1 (1) The Company has entered into interest rate swaps on the 2010 Senior Notes, the 2012 Senior Notes, the 2017 Senior Notes due 2021 and the 2017 Senior Notes due 2023 which are more fully discussed in Note 11 above. These amounts represent the cumulative amount of fair value hedging adjustments included in the carrying amount of the hedged debt.
Principal Payments Due on Long-Term Borrowings	The repayment schedule for the Company’s borrowings is as follows: Year Ending December 31, 2010 Senior Notes, due 2020 2012 Senior Notes, due 2022 2013 Senior Notes, due 2024 2014 Senior Notes (30-Year), due 2044 2015 Senior Notes, due 2027 2017 Senior Notes, due 2021 2017 Senior Notes, due 2023 2017 Senior Notes, due 2028 2018 Senior Notes, due 2021 2018 Senior Notes, due 2029 2018 Senior Notes, due 2048 Total 2019 (After September 30) $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — 2020 500.0 — — — — — — — — — — $ 500.0 2021 — — — — — 500.0 — — 300.0 — — $ 800.0 2022 — 500.0 — — — — — — — — — $ 500.0 2023 — — — — — — 500.0 — — — — $ 500.0 Thereafter — — 500.0 600.0 545.1 — — 500.0 — 400.0 400.0 $ 2,945.1 Total $ 500.0 $ 500.0 $ 500.0 $ 600.0 $ 545.1 $ 500.0 $ 500.0 $ 500.0 $ 300.0 $ 400.0 $ 400.0 $ 5,245.1
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: Three Months Ended Nine Months Ended 2019 2018 2019 2018 Income $ 3.6 $ 4.1 $ 12.5 $ 10.7 Expense on borrowings (37.4 ) (46.4 ) (125.7 ) (147.1 ) UTPs and other tax related liabilities (7.0 ) (9.6 ) (20.2 ) (10.6 ) Net periodic pension costs - interest component (5.6 ) (4.9 ) (16.8 ) (14.5 ) Capitalized 0.5 0.4 1.2 1.0 Total $ (45.9 ) $ (56.4 ) $ (149.0 ) $ (160.5 )
Interest Paid	The following table shows the cash paid for interest: Nine Months Ended 2019 2018 Interest paid $ 148.6 $ 169.7
Fair Value and Carrying Value of Long-Term Debt	The fair value and carrying value of the Company’s debt as of September 30, 2019 and December 31, 2018 are as follows: September 30, 2019 December 31, 2018 Carrying Amount Estimated Fair Value Carrying Amount Estimated Fair Value 5.50% 2010 Senior Notes, due 2020 $ 501.5 $ 515.0 $ 495.0 $ 517.7 4.50% 2012 Senior Notes, due 2022 508.6 531.7 498.9 513.7 4.875% 2013 Senior Notes, due 2024 496.9 551.8 496.5 522.4 2.75% 2014 Senior Notes (5-Year), due 2019 — — 449.9 449.9 5.25% 2014 Senior Notes (30-Year), due 2044 597.9 768.7 597.7 638.1 1.75% 2015 Senior Notes, due 2027 542.4 596.7 568.5 585.3 2.75% 2017 Senior Notes, due 2021 511.0 506.3 500.6 489.7 2.625% 2017 Senior Notes, due 2023 505.2 506.5 496.3 476.9 3.25% 2017 Senior Notes, due 2028 492.2 526.0 491.6 472.8 3.25% 2018 Senior Notes, due 2021 298.7 305.1 298.1 298.6 4.25% 2018 Senior Notes, due 2029 394.2 451.0 393.7 407.6 4.875% 2018 Senior Notes, due 2048 389.4 496.9 389.2 409.8 Total $ 5,238.0 $ 5,755.7 $ 5,676.0 $ 5,782.5

LEASES (Tables)

LEASES (Tables)	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Components of Lease Cost	The following table presents the components of the Company’s lease cost: Three Months Ended Nine Months Ended Operating lease cost $ 24.2 $ 73.3 Short-term lease cost — 0.4 Variable lease cost 5.0 12.7 Total lease cost $ 29.2 $ 86.4
Schedule of Operating Leases Information	The following tables present other information related to the Company’s operating leases: Three Months Ended Nine Months Ended Cash paid for amounts included in the measurement of operating lease liabilities $ 26.6 $ 79.8 Right-of-use assets obtained in exchange for new operating lease liabilities $ 12.0 $ 27.9 September 30, 2019 Weighted-average remaining lease term 6.9 years Weighted-average discount rate applied to operating leases 3.6 %
Lessee, Operating Lease, Liability, Maturity	The following table presents a maturity analysis of the future minimum lease payments included within the Company’s operating lease liabilities at September 30, 2019 : Year Ending December 31, Operating Leases 2019 (After September 30) $ 27.2 2020 107.7 2021 102.1 2022 88.7 2023 83.2 After 2023 251.0 Total lease payments (undiscounted) 659.9 Less: Interest 75.4 Present value of lease liabilities: $ 584.5 Lease liabilities - current $ 89.5 Lease liabilities - noncurrent $ 495.0
Operating Leases, Future Minimum Payment	The minimum rent for operating leases at December 31, 2018 is as follows: Year Ending December 31, Operating Leases 2019 $ 105.9 2020 102.3 2021 95.6 2022 84.4 2023 81.0 After 2023 246.5 Total $ 715.7

SEGMENT INFORMATION (Tables)

SEGMENT INFORMATION (Tables)	9 Months Ended
	Sep. 30, 2019
Segment Reporting Information [Line Items]
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. Three Months Ended September 30, 2019 2018 MIS MA Eliminations Consolidated MIS MA Eliminations Consolidated Revenue $ 780.9 $ 496.0 $ (36.4 ) $ 1,240.5 $ 676.4 $ 438.6 $ (34.2 ) $ 1,080.8 Total Expense 339.9 388.2 (36.4 ) 691.7 303.5 344.7 (34.2 ) 614.0 Operating income 441.0 107.8 — 548.8 372.9 93.9 — 466.8 Add: Restructuring (0.1 ) (0.9 ) — (1.0 ) — — — — Depreciation and amortization 18.0 30.6 — 48.6 15.8 30.3 — 46.1 Acquisition-Related Expenses — — — — — 1.3 — 1.3 Impairment pursuant to the planned divestiture of MAKS — 2.0 — 2.0 — — — — Captive insurance company settlement 9.4 6.1 — 15.5 — — — — Adjusted Operating Income $ 468.3 $ 145.6 $ — $ 613.9 $ 388.7 $ 125.5 $ — $ 514.2 Nine Months Ended September 30, 2019 2018 MIS MA Eliminations Consolidated MIS MA Eliminations Consolidated Revenue $ 2,254.7 $ 1,447.8 $ (106.3 ) $ 3,596.2 $ 2,209.0 $ 1,275.6 $ (102.0 ) $ 3,382.6 Total Expenses 1,027.9 1,180.6 (106.3 ) 2,102.2 951.0 1,042.0 (102.0 ) 1,891.0 Operating income 1,226.8 267.2 — 1,494.0 1,258.0 233.6 — 1,491.6 Add: Restructuring 29.1 29.2 — 58.3 — — — — Depreciation and amortization 53.0 96.9 — 149.9 49.3 94.3 — 143.6 Acquisition-Related Expenses — 3.4 — 3.4 — 4.1 — 4.1 Impairment pursuant to the planned divestiture of MAKS — 10.7 — 10.7 — — — — Captive insurance company settlement 9.4 6.1 — 15.5 — — — — Adjusted Operating Income $ 1,318.3 $ 413.5 $ — $ 1,731.8 $ 1,307.3 $ 332.0 $ — $ 1,639.3
Company's Reportable Segment Revenues Disaggregated by Segment and Geographic Region	The following table presents the Company’s reportable segment revenues disaggregated by segment and geographic region: Three Months Ended Nine Months Ended 2019 2018 2019 2018 MIS: U.S. $ 453.4 $ 384.7 $ 1,300.8 $ 1,269.3 Non-U.S.: EMEA 174.9 165.3 501.7 527.5 Asia-Pacific 78.9 72.7 241.7 224.9 Americas 39.4 22.1 110.9 95.3 Total Non-U.S. 293.2 260.1 854.3 847.7 Total MIS 746.6 644.8 2,155.1 2,117.0 MA: U.S. 206.2 174.9 608.8 513.4 Non-U.S.: EMEA 186.6 179.2 555.1 520.4 Asia-Pacific 63.5 50.3 173.7 142.0 Americas 37.6 31.6 103.5 89.8 Total Non-U.S. 287.7 261.1 832.3 752.2 Total MA 493.9 436.0 1,441.1 1,265.6 Total MCO $ 1,240.5 $ 1,080.8 $ 3,596.2 $ 3,382.6
Operating Segments
Segment Reporting Information [Line Items]
Company's Reportable Segment Revenues Disaggregated by Segment and Geographic Region	Consolidated Revenue Information by Geographic Area: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 United States $ 659.6 $ 559.6 $ 1,909.6 $ 1,782.7 Non-U.S.: EMEA 361.5 344.5 1,056.8 1,047.9 Asia-Pacific 142.4 123.0 415.4 366.9 Americas 77.0 53.7 214.4 185.1 Total Non-U.S. 580.9 521.2 1,686.6 1,599.9 Total $ 1,240.5 $ 1,080.8 $ 3,596.2 $ 3,382.6

DESCRIPTION OF BUSINESS AND B_3

DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION - Additional Information (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2019USD ($)segment	Jan. 01, 2019USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of reportable segments | segment	2
Operating lease right-of-use assets	$ 464.6
Operating lease liabilities	$ 495
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets		$ 518
Operating lease liabilities		622
Deferred tax assets		150
Deferred tax liabilities		125
Accounting Standards Update 2018-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Effect of adoption adjustment reduction to retained earnings		0
Accumulated Other Comprehensive Loss | Accounting Standards Update 2018-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Effect of adoption adjustment reduction to retained earnings		(19.8)
Retained Earnings | Accounting Standards Update 2018-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Effect of adoption adjustment reduction to retained earnings		$ 19.8

DESCRIPTION OF BUSINESS AND B_4

DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION - Adjustment to Retained Earnings (Detail) - USD ($) $ in Millions	3 Months Ended					9 Months Ended		12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue	$ 1,240.5		$ 1,080.8			$ 3,596.2	$ 3,382.6
MIS
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue	746.6		644.8			2,155.1	2,117
MIS | Corporate Finance (CFG)
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue	392	$ 291.3	307.3	$ 391	$ 389.6	1,134.8	1,087.9	$ 1,379.2
MIS | Structured Finance (SFG)
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue	105.4	121.2	114.2	128.2	117.8	318.2	360.2	481.4
MIS | As previously reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue			296.1
MIS | As previously reported | Corporate Finance (CFG)
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue		282.7		377.6	377.7			1,334.1
MIS | As previously reported | Structured Finance (SFG)
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue		129.8	125.4	141.6	129.7			526.5
MIS | Reclassification | Corporate Finance (CFG)
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue		8.6	11.2	13.4	11.9			45.1
MIS | Reclassification | Structured Finance (SFG)
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue		(8.6)	(11.2)	(13.4)	(11.9)			(45.1)
MA
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue	493.9		436			1,441.1	1,265.6
MA | Research, Data And Analytics (RD&A)
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue	317.5	297.1	280.3	275.9	267.1	940.5	823.3	1,120.4
MA | Enterprise Risk Solutions (ERS)
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue	$ 133.3	124.1	115.3	109.5	102.2	$ 372.9	$ 327	451.1
MA | As previously reported | Research, Data And Analytics (RD&A)
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue		302.4	282.6	279.9	269.2			1,134.1
MA | As previously reported | Enterprise Risk Solutions (ERS)
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue		118.8	113	105.5	100.1			437.4
MA | Reclassification | Research, Data And Analytics (RD&A)
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue		(5.3)	(2.3)	(4)	(2.1)			(13.7)
MA | Reclassification | Enterprise Risk Solutions (ERS)
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenue		$ 5.3	$ 2.3	$ 4	$ 2.1			$ 13.7

REVENUES - Revenue by Category

REVENUES - Revenue by Category (Detail) - USD ($) $ in Millions	3 Months Ended					9 Months Ended		12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Revenue	$ 1,240.5		$ 1,080.8			$ 3,596.2	$ 3,382.6
Eliminations
Disaggregation of Revenue [Line Items]
Revenue	(36.4)		(34.2)			(106.3)	(102)
MIS
Disaggregation of Revenue [Line Items]
Revenue	746.6		644.8			2,155.1	2,117
MIS | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	780.9		676.4			2,254.7	2,209
MIS | Eliminations
Disaggregation of Revenue [Line Items]
Revenue	34.3		31.6			99.6	92
MIS | Corporate Finance (CFG)
Disaggregation of Revenue [Line Items]
Revenue	392	$ 291.3	307.3	$ 391	$ 389.6	1,134.8	1,087.9	$ 1,379.2
MIS | Corporate Finance (CFG) | Investment-grade
Disaggregation of Revenue [Line Items]
Revenue	105.8		54.7			299	214.3
MIS | Corporate Finance (CFG) | High-yield
Disaggregation of Revenue [Line Items]
Revenue	56.9		39.1			182.4	155.7
MIS | Corporate Finance (CFG) | Bank loans
Disaggregation of Revenue [Line Items]
Revenue	89.3		78.4			245.4	309.8
MIS | Corporate Finance (CFG) | Other accounts
Disaggregation of Revenue [Line Items]
Revenue	140		135.1			408	408.1
MIS | Structured Finance (SFG)
Disaggregation of Revenue [Line Items]
Revenue	105.4	121.2	114.2	128.2	117.8	318.2	360.2	481.4
MIS | Structured Finance (SFG) | Other accounts
Disaggregation of Revenue [Line Items]
Revenue	0.8		0.5			2.9	1.9
MIS | Structured Finance (SFG) | Asset-backed securities
Disaggregation of Revenue [Line Items]
Revenue	25		24.6			73.8	80.7
MIS | Structured Finance (SFG) | RMBS
Disaggregation of Revenue [Line Items]
Revenue	22.1		23.7			69.7	74.8
MIS | Structured Finance (SFG) | CMBS
Disaggregation of Revenue [Line Items]
Revenue	17.5		14.7			55.6	54.2
MIS | Structured Finance (SFG) | Structured credit
Disaggregation of Revenue [Line Items]
Revenue	40		50.7			116.2	148.6
MIS | Financial Institutions (FIG)
Disaggregation of Revenue [Line Items]
Revenue	120.5		119.5			361.5	354.4
MIS | Financial Institutions (FIG) | Other accounts
Disaggregation of Revenue [Line Items]
Revenue	2.8		3.4			9	9.9
MIS | Financial Institutions (FIG) | Banking
Disaggregation of Revenue [Line Items]
Revenue	79.9		72.9			244.1	227.2
MIS | Financial Institutions (FIG) | Insurance
Disaggregation of Revenue [Line Items]
Revenue	31.3		37.7			88.4	98.9
MIS | Financial Institutions (FIG) | Managed investments
Disaggregation of Revenue [Line Items]
Revenue	6.5		5.5			20	18.4
MIS | Public, Project And Infrastructure Finance (PPIF)
Disaggregation of Revenue [Line Items]
Revenue	119.8		99			321.1	300.3
MIS | Public, Project And Infrastructure Finance (PPIF) | Public finance / sovereign
Disaggregation of Revenue [Line Items]
Revenue	57.9		45.3			157.1	143.9
MIS | Public, Project And Infrastructure Finance (PPIF) | Project and infrastructure
Disaggregation of Revenue [Line Items]
Revenue	61.9		53.7			164	156.4
MIS | Rating Revenue
Disaggregation of Revenue [Line Items]
Revenue	737.7		640			2,135.6	2,102.8
MIS | MIS Other
Disaggregation of Revenue [Line Items]
Revenue	8.9		4.8			19.5	14.2
MA
Disaggregation of Revenue [Line Items]
Revenue	493.9		436			1,441.1	1,265.6
MA | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	496		438.6			1,447.8	1,275.6
MA | Eliminations
Disaggregation of Revenue [Line Items]
Revenue	2.1		2.6			6.7	10
MA | Research, Data And Analytics (RD&A)
Disaggregation of Revenue [Line Items]
Revenue	317.5	297.1	280.3	275.9	267.1	940.5	823.3	1,120.4
MA | Enterprise Risk Solutions (ERS)
Disaggregation of Revenue [Line Items]
Revenue	133.3	$ 124.1	115.3	$ 109.5	$ 102.2	372.9	327	$ 451.1
MA | Professional Services (PS)
Disaggregation of Revenue [Line Items]
Revenue	$ 43.1		$ 40.4			$ 127.7	$ 115.3

REVENUES - Revenues disaggregat

REVENUES - Revenues disaggregated by Line of Business and Geographical Area (Detail) - USD ($) $ in Millions	3 Months Ended					9 Months Ended		12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Revenue	$ 1,240.5		$ 1,080.8			$ 3,596.2	$ 3,382.6
United States
Disaggregation of Revenue [Line Items]
Revenue	659.6		559.6			1,909.6	1,782.7
Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	580.9		521.2			1,686.6	1,599.9
MIS
Disaggregation of Revenue [Line Items]
Revenue	746.6		644.8			2,155.1	2,117
MIS | United States
Disaggregation of Revenue [Line Items]
Revenue	453.4		384.7			1,300.8	1,269.3
MIS | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	293.2		260.1			854.3	847.7
MIS | Corporate Finance (CFG)
Disaggregation of Revenue [Line Items]
Revenue	392	$ 291.3	307.3	$ 391	$ 389.6	1,134.8	1,087.9	$ 1,379.2
MIS | Corporate Finance (CFG) | United States
Disaggregation of Revenue [Line Items]
Revenue	258.9		194.7			744.1	707.2
MIS | Corporate Finance (CFG) | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	133.1		112.6			390.7	380.7
MIS | Structured Finance (SFG)
Disaggregation of Revenue [Line Items]
Revenue	105.4	121.2	114.2	128.2	117.8	318.2	360.2	481.4
MIS | Structured Finance (SFG) | United States
Disaggregation of Revenue [Line Items]
Revenue	67.8		70.6			201.9	225
MIS | Structured Finance (SFG) | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	37.6		43.6			116.3	135.2
MIS | Financial Institutions (FIG)
Disaggregation of Revenue [Line Items]
Revenue	120.5		119.5			361.5	354.4
MIS | Financial Institutions (FIG) | United States
Disaggregation of Revenue [Line Items]
Revenue	53.7		59.8			151.9	162.7
MIS | Financial Institutions (FIG) | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	66.8		59.7			209.6	191.7
MIS | Public, Project And Infrastructure Finance (PPIF)
Disaggregation of Revenue [Line Items]
Revenue	119.8		99			321.1	300.3
MIS | Public, Project And Infrastructure Finance (PPIF) | United States
Disaggregation of Revenue [Line Items]
Revenue	72.8		59.4			202.4	173.9
MIS | Public, Project And Infrastructure Finance (PPIF) | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	47		39.6			118.7	126.4
MIS | Rating Revenue
Disaggregation of Revenue [Line Items]
Revenue	737.7		640			2,135.6	2,102.8
MIS | Rating Revenue | United States
Disaggregation of Revenue [Line Items]
Revenue	453.2		384.5			1,300.3	1,268.8
MIS | Rating Revenue | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	284.5		255.5			835.3	834
MIS | MIS Other
Disaggregation of Revenue [Line Items]
Revenue	8.9		4.8			19.5	14.2
MIS | MIS Other | United States
Disaggregation of Revenue [Line Items]
Revenue	0.2		0.2			0.5	0.5
MIS | MIS Other | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	8.7		4.6			19	13.7
MA
Disaggregation of Revenue [Line Items]
Revenue	493.9		436			1,441.1	1,265.6
MA | United States
Disaggregation of Revenue [Line Items]
Revenue	206.2		174.9			608.8	513.4
MA | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	287.7		261.1			832.3	752.2
MA | Research, Data And Analytics (RD&A)
Disaggregation of Revenue [Line Items]
Revenue	317.5	297.1	280.3	275.9	267.1	940.5	823.3	1,120.4
MA | Research, Data And Analytics (RD&A) | United States
Disaggregation of Revenue [Line Items]
Revenue	139.8		116.7			412.4	347.5
MA | Research, Data And Analytics (RD&A) | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	177.7		163.6			528.1	475.8
MA | Enterprise Risk Solutions (ERS)
Disaggregation of Revenue [Line Items]
Revenue	133.3	$ 124.1	115.3	$ 109.5	$ 102.2	372.9	327	$ 451.1
MA | Enterprise Risk Solutions (ERS) | United States
Disaggregation of Revenue [Line Items]
Revenue	48.2		43			142.7	124.1
MA | Enterprise Risk Solutions (ERS) | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	85.1		72.3			230.2	202.9
MA | Professional Services
Disaggregation of Revenue [Line Items]
Revenue	43.1		40.4			127.7	115.3
MA | Professional Services | United States
Disaggregation of Revenue [Line Items]
Revenue	18.2		15.2			53.7	41.8
MA | Professional Services | Non-U.S.
Disaggregation of Revenue [Line Items]
Revenue	$ 24.9		$ 25.2			$ 74	$ 73.5

REVENUES - Consolidated Revenue

REVENUES - Consolidated Revenue Information by Geographic Area (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Revenue	$ 1,240.5	$ 1,080.8	$ 3,596.2	$ 3,382.6
MIS
Segment Reporting Information [Line Items]
Revenue	746.6	644.8	2,155.1	2,117
MA
Segment Reporting Information [Line Items]
Revenue	493.9	436	1,441.1	1,265.6
United States
Segment Reporting Information [Line Items]
Revenue	659.6	559.6	1,909.6	1,782.7
United States | MIS
Segment Reporting Information [Line Items]
Revenue	453.4	384.7	1,300.8	1,269.3
United States | MA
Segment Reporting Information [Line Items]
Revenue	206.2	174.9	608.8	513.4
EMEA
Segment Reporting Information [Line Items]
Revenue	361.5	344.5	1,056.8	1,047.9
EMEA | MIS
Segment Reporting Information [Line Items]
Revenue	174.9	165.3	501.7	527.5
EMEA | MA
Segment Reporting Information [Line Items]
Revenue	186.6	179.2	555.1	520.4
Asia-Pacific
Segment Reporting Information [Line Items]
Revenue	142.4	123	415.4	366.9
Asia-Pacific | MIS
Segment Reporting Information [Line Items]
Revenue	78.9	72.7	241.7	224.9
Asia-Pacific | MA
Segment Reporting Information [Line Items]
Revenue	63.5	50.3	173.7	142
Americas
Segment Reporting Information [Line Items]
Revenue	77	53.7	214.4	185.1
Americas | MIS
Segment Reporting Information [Line Items]
Revenue	39.4	22.1	110.9	95.3
Americas | MA
Segment Reporting Information [Line Items]
Revenue	37.6	31.6	103.5	89.8
Non-U.S.
Segment Reporting Information [Line Items]
Revenue	580.9	521.2	1,686.6	1,599.9
Non-U.S. | MIS
Segment Reporting Information [Line Items]
Revenue	293.2	260.1	854.3	847.7
Non-U.S. | MA
Segment Reporting Information [Line Items]
Revenue	$ 287.7	$ 261.1	$ 832.3	$ 752.2

REVENUES - Transaction and Rela

REVENUES - Transaction and Relationship Revenue (Detail) - USD ($) $ in Millions	3 Months Ended					9 Months Ended		12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Revenue	$ 1,240.5		$ 1,080.8			$ 3,596.2	$ 3,382.6
Percentage of Revenues	100.00%		100.00%			100.00%	100.00%
MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 746.6		$ 644.8			$ 2,155.1	$ 2,117
Percentage of Revenues	100.00%		100.00%			100.00%	100.00%
MA
Disaggregation of Revenue [Line Items]
Revenue	$ 493.9		$ 436			$ 1,441.1	$ 1,265.6
Percentage of Revenues	100.00%		100.00%			100.00%	100.00%
Corporate Finance (CFG) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 392	$ 291.3	$ 307.3	$ 391	$ 389.6	$ 1,134.8	$ 1,087.9	$ 1,379.2
Percentage of Revenues	100.00%		100.00%			100.00%	100.00%
Structured Finance (SFG) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 105.4	$ 121.2	$ 114.2	$ 128.2	$ 117.8	$ 318.2	$ 360.2	$ 481.4
Percentage of Revenues	100.00%		100.00%			100.00%	100.00%
Financial Institutions (FIG) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 120.5		$ 119.5			$ 361.5	$ 354.4
Percentage of Revenues	100.00%		100.00%			100.00%	100.00%
Public, Project And Infrastructure Finance (PPIF) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 119.8		$ 99			$ 321.1	$ 300.3
Percentage of Revenues	100.00%		100.00%			100.00%	100.00%
MIS Other | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 8.9		$ 4.8			$ 19.5	$ 14.2
Percentage of Revenues	100.00%		100.00%			100.00%	100.00%
Transaction Revenue
Disaggregation of Revenue [Line Items]
Revenue	$ 557.1		$ 461.1			$ 1,585.3	$ 1,547.7
Percentage of Revenues	45.00%		43.00%			44.00%	46.00%
Transaction Revenue | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 478.6		$ 390.5			$ 1,366.1	$ 1,349.4
Percentage of Revenues	64.00%		61.00%			63.00%	64.00%
Transaction Revenue | MA
Disaggregation of Revenue [Line Items]
Revenue	$ 78.5		$ 70.6			$ 219.2	$ 198.3
Percentage of Revenues	16.00%		16.00%			15.00%	16.00%
Transaction Revenue | Corporate Finance (CFG) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 281.8		$ 199.4			$ 807.7	$ 767.3
Percentage of Revenues	72.00%		65.00%			71.00%	71.00%
Transaction Revenue | Structured Finance (SFG) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 58.4		$ 73.5			$ 183.9	$ 233.3
Percentage of Revenues	55.00%		64.00%			58.00%	65.00%
Transaction Revenue | Financial Institutions (FIG) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 55.7		$ 56.2			$ 164.8	$ 162.4
Percentage of Revenues	46.00%		47.00%			46.00%	46.00%
Transaction Revenue | Public, Project And Infrastructure Finance (PPIF) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 82.1		$ 60.9			$ 208.2	$ 184.9
Percentage of Revenues	69.00%		62.00%			65.00%	62.00%
Transaction Revenue | MIS Other | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 0.6		$ 0.5			$ 1.5	$ 1.5
Percentage of Revenues	7.00%		10.00%			8.00%	11.00%
Relationship Revenue
Disaggregation of Revenue [Line Items]
Revenue	$ 683.4		$ 619.7			$ 2,010.9	$ 1,834.9
Percentage of Revenues	55.00%		57.00%			56.00%	54.00%
Relationship Revenue | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 268		$ 254.3			$ 789	$ 767.6
Percentage of Revenues	36.00%		39.00%			37.00%	36.00%
Relationship Revenue | MA
Disaggregation of Revenue [Line Items]
Revenue	$ 415.4		$ 365.4			$ 1,221.9	$ 1,067.3
Percentage of Revenues	84.00%		84.00%			85.00%	84.00%
Relationship Revenue | Corporate Finance (CFG) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 110.2		$ 107.9			$ 327.1	$ 320.6
Percentage of Revenues	28.00%		35.00%			29.00%	29.00%
Relationship Revenue | Structured Finance (SFG) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 47		$ 40.7			$ 134.3	$ 126.9
Percentage of Revenues	45.00%		36.00%			42.00%	35.00%
Relationship Revenue | Financial Institutions (FIG) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 64.8		$ 63.3			$ 196.7	$ 192
Percentage of Revenues	54.00%		53.00%			54.00%	54.00%
Relationship Revenue | Public, Project And Infrastructure Finance (PPIF) | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 37.7		$ 38.1			$ 112.9	$ 115.4
Percentage of Revenues	31.00%		38.00%			35.00%	38.00%
Relationship Revenue | MIS Other | MIS
Disaggregation of Revenue [Line Items]
Revenue	$ 8.3		$ 4.3			$ 18	$ 12.7
Percentage of Revenues	93.00%		90.00%			92.00%	89.00%

REVENUES - Revenue Recognition

REVENUES - Revenue Recognition Timing (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Revenue recognized	$ 1,240.5	$ 1,080.8	$ 3,596.2	$ 3,382.6
At Point in Time
Disaggregation of Revenue [Line Items]
Revenue recognized	509.3	410	1,448.9	1,398.4
Over Time
Disaggregation of Revenue [Line Items]
Revenue recognized	731.2	670.8	2,147.3	1,984.2
MIS
Disaggregation of Revenue [Line Items]
Revenue recognized	746.6	644.8	2,155.1	2,117
MIS | At Point in Time
Disaggregation of Revenue [Line Items]
Revenue recognized	478.6	390.5	1,366.1	1,349.4
MIS | Over Time
Disaggregation of Revenue [Line Items]
Revenue recognized	268	254.3	789	767.6
MA
Disaggregation of Revenue [Line Items]
Revenue recognized	493.9	436	1,441.1	1,265.6
MA | At Point in Time
Disaggregation of Revenue [Line Items]
Revenue recognized	30.7	19.5	82.8	49
MA | Over Time
Disaggregation of Revenue [Line Items]
Revenue recognized	$ 463.2	$ 416.5	$ 1,358.3	$ 1,216.6

REVENUES - Additional Informati

REVENUES - Additional Information (Detail) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
MIS
Disaggregation of Revenue [Line Items]
Unbilled Receivables	$ 399.3	$ 311.8
MA
Disaggregation of Revenue [Line Items]
Unbilled Receivables	$ 56	$ 59.5

REVENUES - Schedule of Changes

REVENUES - Schedule of Changes in the Deferred Revenue Balances (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Change in Contract with Customer, Liability [Abstract]
Beginning Balance	$ 1,070.8	$ 986.5	$ 1,075.7	$ 946.3
Revenue recognized that was included in the deferred revenue balance at the beginning of the period	(454.6)	(444.4)	(878.2)	(804.7)
Increases due to amounts billable excluding amounts recognized as revenue during the period	372.1	353.5	788.2	768.9
Amount included in liabilities reclassified as held for sale			(2.7)
Effect of exchange rate changes	(17.6)	(0.2)	(12.3)	(15.1)
Total changes in deferred revenue	(100.1)	(91.1)	(105)	(50.9)
Ending Balance	970.7	895.4	970.7	895.4
Deferred revenue - current	855.7	771.5	855.7	771.5	$ 953.4
Deferred revenue - noncurrent	115	123.9	115	123.9	$ 122.3
MIS
Change in Contract with Customer, Liability [Abstract]
Beginning Balance	376	377.5	325.4	334.7
Revenue recognized that was included in the deferred revenue balance at the beginning of the period	(110.8)	(127.4)	(190.8)	(196.2)
Increases due to amounts billable excluding amounts recognized as revenue during the period	82	101.6	211.6	217.6
Amount included in liabilities reclassified as held for sale			0
Effect of exchange rate changes	(3.7)	1.1	(2.7)	(3.3)
Total changes in deferred revenue	(32.5)	(24.7)	18.1	18.1
Ending Balance	343.5	352.8	343.5	352.8
Deferred revenue - current	233.2	233.9	233.2	233.9
Deferred revenue - noncurrent	110.3	118.9	110.3	118.9
MA
Change in Contract with Customer, Liability [Abstract]
Beginning Balance	694.8	609	750.3	611.6
Revenue recognized that was included in the deferred revenue balance at the beginning of the period	(343.8)	(317)	(687.4)	(608.5)
Increases due to amounts billable excluding amounts recognized as revenue during the period	290.1	251.9	576.6	551.3
Amount included in liabilities reclassified as held for sale			(2.7)
Effect of exchange rate changes	(13.9)	(1.3)	(9.6)	(11.8)
Total changes in deferred revenue	(67.6)	(66.4)	(123.1)	(69)
Ending Balance	627.2	542.6	627.2	542.6
Deferred revenue - current	622.5	537.6	622.5	537.6
Deferred revenue - noncurrent	$ 4.7	$ 5	$ 4.7	$ 5

REVENUES - Expected Recognition

REVENUES - Expected Recognition Period for Remaining Performance Obligations (Detail) $ in Millions	Sep. 30, 2019USD ($)
MIS | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 24.3
Revenue, remaining performance obligation, period	1 year
MIS | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 69.9
MIS | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	37.9
MIS | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2030-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	5.8
MIS | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2035-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	4
MIS | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2039-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 4.9
Revenue, remaining performance obligation, period
MIS | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 146.8
MA | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 1,125.6
Revenue, remaining performance obligation, period	1 year
MA | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 325.4
Revenue, remaining performance obligation, period	1 year
MA | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 131.8
Revenue, remaining performance obligation, period
MA | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 1,582.8
Minimum | MIS | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, period	1 year
Minimum | MIS | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, period	1 year
Minimum | MIS | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2030-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, period	1 year
Minimum | MIS | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2035-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, period	1 year
Maximum | MIS | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, period	5 years
Maximum | MIS | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, period	5 years
Maximum | MIS | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2030-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, period	5 years
Maximum | MIS | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2035-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, period	5 years

STOCK-BASED COMPENSATION - Stoc

STOCK-BASED COMPENSATION - Stock-Based Compensation Cost and Associated Tax Benefit (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Share-based Payment Arrangement, Noncash Expense [Abstract]
Stock-based compensation cost	$ 33.3	$ 30.5	$ 103.2	$ 100
Tax benefit	$ 6.9	$ 11.5	$ 22	$ 26

STOCK-BASED COMPENSATION - Addi

STOCK-BASED COMPENSATION - Additional Information (Detail) $ / shares in Units, shares in Millions, $ in Millions	9 Months Ended
	Sep. 30, 2019USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee stock options, granted (in shares) | shares	0.2
Employee stock options, weighted average grant date fair value (in usd per share) | $ / shares	$ 43.10
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Other than options, shares granted (in shares) | shares	0.8
Other than options, weighted average grant date fair value (in usd per share) | $ / shares	$ 173.71
Award vesting period (in years)	4 years
Unrecognized compensation expense | $	$ 175.9
Weighted average period to recognize expense	2 years 6 months
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)	4 years
Unrecognized compensation expense | $	$ 7.5
Weighted average period to recognize expense	2 years 1 month 6 days
Performance Based Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Other than options, shares granted (in shares) | shares	0.1
Other than options, weighted average grant date fair value (in usd per share) | $ / shares	$ 168.04
Award vesting period (in years)	3 years
Unrecognized compensation expense | $	$ 29.6
Weighted average period to recognize expense	1 year 10 months 24 days

STOCK-BASED COMPENSATION - Weig

STOCK-BASED COMPENSATION - Weighted Average Assumptions used in Determining Fair Value for Options Granted (Detail)	9 Months Ended
	Sep. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected dividend yield	1.15%
Expected stock volatility	23.61%
Risk-free interest rate	2.59%
Expected holding period	6 years 2 months 12 days

STOCK-BASED COMPENSATION - St_2

STOCK-BASED COMPENSATION - Stock Option Exercises and Restricted Stock Vesting (Detail) - USD ($) shares in Millions, $ in Millions	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Proceeds from stock option exercises	$ 28.9	$ 36.2
Aggregate intrinsic value	99.2	94.9
Tax benefit realized upon exercise	$ 24.3	$ 23.2
Number of shares exercised (shares)	0.7	0.8
Restricted Stock
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Fair value of shares vested	$ 152.7	$ 150
Tax benefit realized upon vesting	$ 36.2	$ 34.7
Number of shares vested (shares)	0.8	0.9
Performance Based Restricted Stock
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Fair value of shares vested	$ 47.5	$ 23
Tax benefit realized upon vesting	$ 11.5	$ 5.6
Number of shares vested (shares)	0.3	0.1

INCOME TAXES - Additional Infor

INCOME TAXES - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Tax Contingency [Line Items]
Effective tax rate (percent)	25.40%	24.40%	21.30%	21.00%
Excess tax benefits from stock compensation	$ 4.7
Increases to tax positions	8.7
Overall increase (decrease) in unrecognized tax benefits (UTPs)	8.8		$ (23.9)
Net of Federal Tax
Income Tax Contingency [Line Items]
Overall increase (decrease) in unrecognized tax benefits (UTPs)	$ 8.8		$ (24.2)

INCOME TAXES - Income Taxes Pai

INCOME TAXES - Income Taxes Paid (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Income taxes paid	$ 302.5	$ 337

WEIGHTED AVERAGE SHARES OUTST_3

WEIGHTED AVERAGE SHARES OUTSTANDING - Reconciliation of Basic to Diluted Shares Outstanding (Detail) - shares shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Earnings Per Share [Abstract]
Basic (in shares)	189	191.8	189.6	191.7
Dilutive effect of shares issuable under stock-based compensation plans (in shares)	2.1	2.7	2.2	2.7
Diluted (in shares)	191.1	194.5	191.8	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	0.3	0.3	0.4

ACCELERATED SHARE REPURCHASE _2

ACCELERATED SHARE REPURCHASE PROGRAM - Additional Information (Detail) - USD ($) $ / shares in Units, shares in Millions	Apr. 26, 2019	Feb. 20, 2019	Sep. 30, 2019
Accelerated Share Repurchases [Line Items]
Accelerated share repurchases, final price paid per share (in usd per share)			$ 180.33
February 20, 2019
Accelerated Share Repurchases [Line Items]
Accelerated share repurchase payment		$ 500,000,000
February 20, 2019 | Accelerated Share Repurchases
Accelerated Share Repurchases [Line Items]
Treasury shares repurchased (in shares)		2.2
April 26, 2019 | Accelerated Share Repurchases
Accelerated Share Repurchases [Line Items]
Treasury shares repurchased (in shares)	0.6		2.8

Cash Equivalents and Investme_3

Cash Equivalents and Investments (Detail) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Cash and Cash Equivalents [Line Items]
Fair Value	$ 7.7	$ 33.3
Cash and cash equivalents	1,178	1,685
Short-term investments	95.8	132.5
Money market mutual funds
Cash and Cash Equivalents [Line Items]
Cost		15.2
Gross Unrealized Gains		0
Fair Value		15.2
Cash and cash equivalents		15.2
Short-term investments		0
Other assets		0
Certificates of deposit and money market deposit accounts
Cash and Cash Equivalents [Line Items]
Cost	436.3	1,022.4
Gross Unrealized Gains	0	0
Fair Value	436.3	1,022.4
Cash and cash equivalents	327.6	904.3
Short-term investments	88.2	115.8
Other assets	20.5	2.3
Open ended mutual funds
Cash and Cash Equivalents [Line Items]
Cost	6.8	29.5
Gross Unrealized Gains	0.9	3.8
Fair Value	7.7	33.3
Cash and cash equivalents	0	0
Short-term investments	7.6	16.7
Other assets	$ 0.1	$ 16.6

Cash Equivalents and Investme_4

Cash Equivalents and Investments (Footnote) (Detail)	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
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	14 months
Other assets | Certificates of deposit and money market deposit accounts | Maximum
Cash and Cash Equivalents [Line Items]
Securities maturity period	21 months	36 months
Cash and Cash Equivalents | Open ended mutual funds | Maximum
Cash and Cash Equivalents [Line Items]
Securities maturity period	90 days

Assets And Liabilities Held F_3

Assets And Liabilities Held For Sale - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of assets held for sale	$ 2	$ 0	$ 10.7	$ 0
MAKS
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Currency translation adjustments, net of tax	(32.6)		(32.6)
Estimated fair value less costs to sell	202.5		202.5
Adjustment to fair value of disposal group relating to certain indemnification provisions	43		43
MAKS | Disposal Group, Held-for-sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of assets held for sale	$ 2		$ 10.7

Assets And Liabilities Held F_4

Assets And Liabilities Held For Sale - Schedule of Assets and Liabilities Held For Sale (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Current assets:
Impairment of assets held for sale	$ (2)	$ 0	$ (10.7)	$ 0
Total assets held for sale	254		254		$ 0
Current liabilities:
Total liabilities held for sale	84.1		84.1		$ 0
Disposal Group, Held-for-sale, Not Discontinued Operations | MAKS
Current assets:
Cash and cash equivalents	11.1		11.1
Accounts receivable, net	18.7		18.7
Other current assets	6.6		6.6
Total current assets	36.4		36.4
Property and equipment, net	12.7		12.7
Goodwill	163.9		163.9
Intangible assets, net	44		44
Deferred tax assets, net	4.8		4.8
Other assets	2.9		2.9
Total assets held for sale prior to impairment	264.7		264.7
Impairment of assets held for sale	(2)		(10.7)
Total assets held for sale	254		254
Current liabilities:
Accounts payable and accrued liabilities	21.4		21.4
Deferred revenue	1.8		1.8
Total current liabilities	23.2		23.2
Deferred tax liabilities, net	6.8		6.8
Uncertain tax positions	28.6		28.6
Other liabilities	25.5		25.5
Total liabilities held for sale	$ 84.1		$ 84.1

Assets And Liabilities Held F_5

Assets And Liabilities Held For Sale - Schedule of Impairement of Held for Sale Assets (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Derivation of impairment charge
Impairment of assets held for sale	$ 2	$ 0	$ 10.7	$ 0
MAKS
Derivation of impairment charge
Total net assets held for sale prior to impairment	180.6		180.6
Currency translation adjustments	32.6		32.6
Total net assets held for sale including currency translation adjustment	213.2		213.2
Estimated fair value less costs to sell	$ 202.5		$ 202.5

Derivative Instruments And He_3

Derivative Instruments And Hedging Activities - Schedule of Interest Rate Swap (Details) - Fair Value Hedging - Interest Rate Swap - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Derivative [Line Items]
Notional Amount	$ 1,580	$ 1,330
5.50% 2010 Senior Notes, due 2020
Derivative [Line Items]
Nature of Swap	Pay Floating/Receive Fixed
Notional Amount	$ 500	500
Floating Interest Rate	3-month USD LIBOR
4.50% 2012 Senior Notes, due 2022
Derivative [Line Items]
Nature of Swap	Pay Floating/Receive Fixed
Notional Amount	$ 330	330
Floating Interest Rate	3-month USD LIBOR
2.75% 2017 Senior Notes, due 2021
Derivative [Line Items]
Nature of Swap	Pay Floating/Receive Fixed
Notional Amount	$ 500	500
Floating Interest Rate	3-month USD LIBOR
2.625% 2017 Senior Notes, due 2023
Derivative [Line Items]
Nature of Swap	Pay Floating/Receive Fixed
Notional Amount	$ 250	$ 0
Floating Interest Rate	3-month USD LIBOR

Derivative Instruments And He_4

Derivative Instruments And Hedging Activities - Summary of Net Gain (Loss) on Interest Rate Swaps Designated in Fair Value Hedge (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Interest expense, net	$ (45.9)	$ (56.4)	$ (149)	$ (160.5)
Designated as Hedging Instrument | Interest Rate Swap | Interest Expense
Derivative Instruments, Gain (Loss) [Line Items]
Fair value changes on interest rate swaps	2.3	(3.3)	32.9	(14.8)
Fair value changes on hedged debt	(2.3)	3.3	(32.9)	14.8
Designated as Hedging Instrument | Interest Rate Swap | Interest Expense | Fair Value hedge Net Interest Settlements and Accruals
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in income	$ 1	$ (0.5)	$ 0.9	$ (1)

Derivative Instruments And He_5

Derivative Instruments And Hedging Activities - Additional Information (Detail) - Designated as Hedging Instrument - Cross-currency swap € in Millions	Sep. 30, 2019EUR (€)
Net Investment Hedging
Derivative [Line Items]
Notional Amount	€ 500
2021
Derivative [Line Items]
Notional Amount	687.7
2022
Derivative [Line Items]
Notional Amount	438.2
2023
Derivative [Line Items]
Notional Amount	441.9
2024
Derivative [Line Items]
Notional Amount	€ 442.6

Derivative Instruments And He_6

Derivative Instruments And Hedging Activities - Summary of Notional Amounts of Outstanding Cross Currency Swap (Detail) - Cross-currency swap - Net Investment Hedging € in Millions, $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2019USD ($)	Dec. 31, 2018USD ($)	Sep. 30, 2019EUR (€)	Dec. 31, 2018EUR (€)
1.51%
Derivative [Line Items]
Nature of Swap	Pay Fixed/Receive Fixed
3-month EURIBOR
Derivative [Line Items]
Nature of Swap	Pay Floating/Receive Floating	Pay Floating/Receive Floating
4.13%
Derivative [Line Items]
Nature of Swap	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 | €			€ 2,010.4	€ 710.2
Currency Paid | 1.51%
Derivative [Line Items]
Notional Amount | €			€ 1,079.1
Weighted Average Fixed Interest Rate	1.43%		1.43%
Currency Paid | 3-month EURIBOR
Derivative [Line Items]
Notional Amount | €			€ 931.3	€ 710.2
Weighted Average Floating Interest Rate	Based on 3-month EURIBOR	Based on 3-month EURIBOR
Currency Received
Derivative [Line Items]
Notional Amount | $	$ 2,300	$ 830
Currency Received | 4.13%
Derivative [Line Items]
Notional Amount | $	$ 1,220
Weighted Average Fixed Interest Rate	3.96%		3.96%
Currency Received | 3-month U.S. LIBOR
Derivative [Line Items]
Notional Amount | $	$ 1,080	$ 830
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 - Summary of Notional Amounts of Outstanding Foreign Exchange Forwards (Detail) € in Millions, ¥ in Millions, £ in Millions, $ in Millions, $ in Millions, $ in Millions	Sep. 30, 2019USD ($)	Sep. 30, 2019EUR (€)	Sep. 30, 2019SGD ($)	Sep. 30, 2019GBP (£)	Sep. 30, 2019JPY (¥)	Sep. 30, 2019CAD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2018EUR (€)	Dec. 31, 2018GBP (£)	Dec. 31, 2018JPY (¥)	Dec. 31, 2018CAD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2018EUR (€)
Net Investment Hedging | Contract to sell EUR for USD
Derivative [Line Items]
Notional Amount	$ 532	€ 485										$ 0	€ 0
Not Designated as Accounting Hedges | Contracts to sell USD for GBP
Derivative [Line Items]
Notional Amount	144.5			£ 115.4			$ 310.3		£ 241.2
Not Designated as Accounting Hedges | Contracts to sell USD for Japanese Yen
Derivative [Line Items]
Notional Amount	30.3				¥ 3,200		14.3			¥ 1,600
Not Designated as Accounting Hedges | Contracts to sell USD for Canadian dollars
Derivative [Line Items]
Notional Amount	96.9					$ 128	99				$ 130
Not Designated as Accounting Hedges | Contracts to sell USD for Singapore dollars
Derivative [Line Items]
Notional Amount	40.5		$ 56
Not Designated as Accounting Hedges | Contracts to sell USD for Euros
Derivative [Line Items]
Notional Amount	532.1	485					$ 212.8	€ 184.6
Not Designated as Accounting Hedges | Contracts to sell EUR for GBP
Derivative [Line Items]
Notional Amount		€ 180		159.5
Not Designated as Accounting Hedges | Contracts to sell GBP for USD
Derivative [Line Items]
Notional Amount	$ 143.2			£ 115.9

Derivative Instruments And He_8

Derivative Instruments And Hedging Activities - Gains (Losses) Recognized in AOCI and Reclassified from AOCI on Derivatives (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Hedging Relationships, Amount of Gain/(Loss) Recognized in AOCI on Derivative, net of Tax			$ 0	$ 1.5
Total, Amount of Gain/(Loss) Recognized in AOCI on Derivative, net of Tax	$ 102.7	$ 4	97	22
Net Investment Hedging Relationships, Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax	0.8	0	0.8	0
Cash Flow Hedging Relationships, Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax	0	0.1	(0.1)	0.3
Total, Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax	0.8	0.1	0.7	0.3
Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	15.5	4.1	37.3	6.2
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	102.7	4	97	20.5
Net Investment Hedging Relationships, Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax	0.8	0	0.8	0
Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	15.5	4.1	37.3	6.2
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	0	1.5
Cash Flow Hedging Relationships, Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax	0	0.1	(0.1)	0.3
Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	0	0	0	0
FX forwards | Net Investment Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Net Investment Hedging Relationships, Amount of Gain/(Loss) Recognized in AOCI on Derivative, net of Tax	4.9	0	4.9	0
Net Investment Hedging Relationships, Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax	0.8	0	0.8	0
Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	0	0	0	0
Cross-currency swap | Net Investment Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Net Investment Hedging Relationships, Amount of Gain/(Loss) Recognized in AOCI on Derivative, net of Tax	79.6	1.8	75.1	5.8
Net Investment Hedging Relationships, Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax	0	0	0	0
Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	15.5	4.1	37.3	6.2
Cross-currency swap | 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	0	1.5
Cash Flow Hedging Relationships, Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax	0.1	0.1	0	0.3
Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	0	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	18.2	2.2	17	14.7
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	0
Interest rate contract | Cash Flow Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Hedging Relationships, Amount of Gain/(Loss) Recognized in AOCI on Derivative, net of Tax	0	0	0	0
Cash Flow Hedging Relationships, Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax	(0.1)	0	(0.1)	0
Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	$ 0	$ 0	$ 0	$ 0

Derivative Instruments And He_9

Derivative Instruments And Hedging Activities - Gains (Losses) Recognized in AOCI and Reclassified from AOCI on Derivatives (Effective Portion) (Detail) - Accounting Standards Update 2018-02 - USD ($) $ in Millions	Sep. 30, 2019	Jan. 01, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Effect of adoption adjustment reduction to retained earnings		$ 0
Retained Earnings
Derivative Instruments, Gain (Loss) [Line Items]
Effect of adoption adjustment reduction to retained earnings		19.8
Retained Earnings | Net Investment Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Effect of adoption adjustment reduction to retained earnings	$ 2.5
Accumulated Other Comprehensive Loss
Derivative Instruments, Gain (Loss) [Line Items]
Effect of adoption adjustment reduction to retained earnings		$ (19.8)
Accumulated Other Comprehensive Loss | Net Investment Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Effect of adoption adjustment reduction to retained earnings	$ (2.5)

Derivative Instruments And H_10

Derivative Instruments And Hedging Activities - Cumulative Amount of Unrecognized Hedge Losses Recorded in AOCI (Detail) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Derivative [Line Items]
Accumulated other comprehensive loss	$ (537.3)	$ (426.3)
Designated as Hedging Instrument
Derivative [Line Items]
Accumulated other comprehensive loss	126.6	32.8
Net Investment Hedging
Derivative [Line Items]
Accumulated other comprehensive loss	126.4	32.7
Net Investment Hedging | FX forwards
Derivative [Line Items]
Accumulated other comprehensive loss	27.6	23.5
Net Investment Hedging | Long-term debt
Derivative [Line Items]
Accumulated other comprehensive loss	11.4	(3.1)
Net Investment Hedging | Cross-currency swap
Derivative [Line Items]
Accumulated other comprehensive loss	87.4	12.3
Cash Flow Hedging
Derivative [Line Items]
Accumulated other comprehensive loss	0.2	0.1
Cash Flow Hedging | Interest rate contract
Derivative [Line Items]
Accumulated other comprehensive loss	(2.3)	(2.4)
Cash Flow Hedging | Cross-currency swap
Derivative [Line Items]
Accumulated other comprehensive loss	$ 2.5	$ 2.5

Derivative Instruments And H_11

Derivative Instruments And Hedging Activities - Summary of Net Gain (Loss) on Foreign Exchange Forwards Not Designated as Hedging Instruments (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Other non-operating expense, net
Derivative Instruments, Gain (Loss) [Line Items]
Foreign exchange forwards amount of gain (loss) recognized in income	$ (26.7)	$ (11.8)	$ (35)	$ (29.1)

Derivative Instruments And H_12

Derivative Instruments And Hedging Activities - Fair Value of Derivative Instruments (Detail) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Assets	$ 154.6	$ 28.3
Liabilities	550.8	588
Long-term debt | Net Investment Hedging
Derivatives, Fair Value [Line Items]
Liabilities	545.1	571.6
Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Assets	154	26.9
Liabilities	0	8.2
Designated as Hedging Instrument | Cross-currency swap | Other assets | Net Investment Hedging
Derivatives, Fair Value [Line Items]
Assets	116.5	19.4
Designated as Hedging Instrument | Cross-currency swap | Other liabilities | Net Investment Hedging
Derivatives, Fair Value [Line Items]
Liabilities	0	2.9
Designated as Hedging Instrument | Interest Rate Swap | Other assets | Fair Value Hedging
Derivatives, Fair Value [Line Items]
Assets	32.8	7.5
Designated as Hedging Instrument | Interest Rate Swap | Other current assets | Fair Value Hedging
Derivatives, Fair Value [Line Items]
Assets	2.3	0
Designated as Hedging Instrument | Interest Rate Swap | Other liabilities | Fair Value Hedging
Derivatives, Fair Value [Line Items]
Liabilities	0	5.3
Designated as Hedging Instrument | FX forwards | Other current assets | Net Investment Hedging
Derivatives, Fair Value [Line Items]
Assets	2.4	0
Not Designated as Accounting Hedges | FX forwards | Other current assets
Derivatives, Fair Value [Line Items]
Assets	0.6	1.4
Not Designated as Accounting Hedges | FX forwards | Accounts payable and accrued liabilities
Derivatives, Fair Value [Line Items]
Liabilities	$ 5.7	$ 8.2

Goodwill And Other Acquired I_3

Goodwill And Other Acquired Intangible Assets - Activity in Goodwill (Detail) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Goodwill [Roll Forward]
Beginning balance, Goodwill gross	$ 3,793.5	$ 3,765.4
Beginning balance, Accumulated impairment charge	(12.2)	(12.2)
Beginning balance, goodwill net	3,781.3	3,753.2
Additions/adjustments	97	211.5
Foreign currency translation adjustments	(104.4)	(183.4)
Ending balance, Goodwill gross	3,622.2	3,793.5
Ending balance, Accumulated impairment charge	(12.2)	(12.2)
Ending balance, goodwill net	3,610	3,781.3
Disposal Group, Held-for-sale, Not Discontinued Operations
Goodwill [Roll Forward]
Reclassification to assets held-for-sale	(163.9)
MIS
Goodwill [Roll Forward]
Beginning balance, Goodwill gross	257.8	285.2
Beginning balance, Accumulated impairment charge	0	0
Beginning balance, goodwill net	257.8	285.2
Additions/adjustments	52.1	0
Foreign currency translation adjustments	10.1	(27.4)
Ending balance, Goodwill gross	320	257.8
Ending balance, Accumulated impairment charge	0	0
Ending balance, goodwill net	320	257.8
MIS | Disposal Group, Held-for-sale, Not Discontinued Operations
Goodwill [Roll Forward]
Reclassification to assets held-for-sale	0
MA
Goodwill [Roll Forward]
Beginning balance, Goodwill gross	3,535.7	3,480.2
Beginning balance, Accumulated impairment charge	(12.2)	(12.2)
Beginning balance, goodwill net	3,523.5	3,468
Additions/adjustments	44.9	211.5
Foreign currency translation adjustments	(114.5)	(156)
Ending balance, Goodwill gross	3,302.2	3,535.7
Ending balance, Accumulated impairment charge	(12.2)	(12.2)
Ending balance, goodwill net	3,290	$ 3,523.5
MA | Disposal Group, Held-for-sale, Not Discontinued Operations
Goodwill [Roll Forward]
Reclassification to assets held-for-sale	$ (163.9)

Goodwill And Other Acquired I_4

Goodwill And Other Acquired Intangible Assets - Acquired Intangible Assets and Related Amortization (Detail) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, net	$ 1,454.1	$ 1,566.1
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, gross	1,264.9	1,367.5
Accumulated amortization	(216)	(214.2)
Acquired intangible assets, net	1,048.9	1,153.3
Trade secrets
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, gross	29.9	29.8
Accumulated amortization	(28.5)	(28.2)
Acquired intangible assets, net	1.4	1.6
Software/product technology
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, gross	354.8	353.3
Accumulated amortization	(118.4)	(101.8)
Acquired intangible assets, net	236.4	251.5
Trade names
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, gross	147.4	155.1
Accumulated amortization	(28)	(34.1)
Acquired intangible assets, net	119.4	121
Other
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, gross	79.2	70.4
Accumulated amortization	(31.2)	(31.7)
Acquired intangible assets, net	$ 48	$ 38.7

Goodwill And Other Acquired I_5

Goodwill And Other Acquired Intangible Assets - Amortization Expense Relating to Acquired Intangible Assets (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense	$ 24.7	$ 24.6	$ 77.3	$ 75.4

Goodwill And Other Acquired I_6

Goodwill And Other Acquired Intangible Assets - Estimated Future Amortization Expense for Acquired Intangible Assets Subject to Amortization (Detail) $ in Millions	Sep. 30, 2019USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2019 (after September 30)	$ 20.1
2020	95.4
2021	95.2
2022	95.1
2023	92.6
Thereafter	1,055.7
Total estimated future amortization	$ 1,454.1

Restructuring - Additional Info

Restructuring - Additional Information (Detail) - USD ($) $ in Millions	Oct. 26, 2018	Jun. 30, 2019	Sep. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Restructuring Cost and Reserve [Line Items]
Payments for restructuring			$ 29.5
Reclassification of liabilities as a reduction of the ROU Asset capitalized upon adoption			(10.9)
Impairment of right-of-use		$ 24.8
Operating lease right-of-use assets			464.6
Remaining restructuring liability			31.3		$ 42.3
Contract Termination Costs
Restructuring Cost and Reserve [Line Items]
Payments for restructuring			3
Reclassification of liabilities as a reduction of the ROU Asset capitalized upon adoption			(10.9)
Remaining restructuring liability			$ 2.8		$ 12.4
2018 Restructuring Program | Minimum
Restructuring Cost and Reserve [Line Items]
Effect on future earnings, amount	$ 60
Restructuring expected cost	105
2018 Restructuring Program | Maximum
Restructuring Cost and Reserve [Line Items]
Restructuring expected cost	110
2018 Restructuring Program | Employee Termination Costs | Minimum
Restructuring Cost and Reserve [Line Items]
Restructuring expected cost	60
2018 Restructuring Program | Employee Termination Costs | Maximum
Restructuring Cost and Reserve [Line Items]
Payments for restructuring	50
2018 Restructuring Program | Real Estate | Minimum
Restructuring Cost and Reserve [Line Items]
Restructuring expected cost	$ 60
Accounting Standards Update 2016-02
Restructuring Cost and Reserve [Line Items]
Operating lease right-of-use assets				$ 518

Restructuring - Restructuring E

Restructuring - Restructuring Expenses Included in Consolidated Statements of Operations (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Restructuring and Related Activities [Abstract]
Restructuring	$ (1)	$ 0	$ 58.3	$ 0

Restructuring - Changes in Rest

Restructuring - Changes in Restructuring Liability (Details) $ in Millions	9 Months Ended
	Sep. 30, 2019USD ($)
Restructuring Reserve [Roll Forward]
Restructuring liability, Beginning Balance	$ 42.3
Adoption of New Lease Accounting Standard	(10.9)
Cost incurred and adjustments	29.4
Cash payments and adjustments	(29.5)
Restructuring liability, Ending Balance	31.3
Employee Termination Costs
Restructuring Reserve [Roll Forward]
Restructuring liability, Beginning Balance	29.9
Adoption of New Lease Accounting Standard	0
Cost incurred and adjustments	25.1
Cash payments and adjustments	(26.5)
Restructuring liability, Ending Balance	28.5
Cumulative expense incurred to date	58
Contract Termination Costs
Restructuring Reserve [Roll Forward]
Restructuring liability, Beginning Balance	12.4
Adoption of New Lease Accounting Standard	(10.9)
Cost incurred and adjustments	4.3
Cash payments and adjustments	(3)
Restructuring liability, Ending Balance	2.8
Cumulative expense incurred to date	$ 49

Restructuring - Changes in Re_2

Restructuring - Changes in Restructuring Liability (Footnote) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Jun. 30, 2019	Sep. 30, 2019	Jan. 01, 2019
Restructuring Cost and Reserve [Line Items]
Reclassification of liabilities as a reduction of the ROU Asset capitalized upon adoption		$ (10.9)
Impairment of right-of-use	$ 24.8
Operating lease right-of-use assets		464.6
Accounting Standards Update 2016-02
Restructuring Cost and Reserve [Line Items]
Operating lease right-of-use assets			$ 518
Real Estate
Restructuring Cost and Reserve [Line Items]
Impairment of right-of-use		24.8
Real Estate | Level 3
Restructuring Cost and Reserve [Line Items]
Operating lease right-of-use assets		17.7
Contract Termination Costs
Restructuring Cost and Reserve [Line Items]
Reclassification of liabilities as a reduction of the ROU Asset capitalized upon adoption		(10.9)
Contract Termination Costs | Real Estate
Restructuring Cost and Reserve [Line Items]
Non-cash acceleration of amortization		4.1
Contract Termination Costs | Real Estate | Accounting Standards Update 2016-02
Restructuring Cost and Reserve [Line Items]
Reclassification of liabilities as a reduction of the ROU Asset capitalized upon adoption		$ 10.9

Fair Value - Financial Instrume

Fair Value - Financial Instruments Carried at Fair Value on Recurring Basis (Detail) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Assets:
Derivatives	$ 154.6	$ 28.3
Money market mutual funds		15.2
Mutual funds	7.7	33.3
Total	162.3	76.8
Liabilities:
Derivatives	5.7	16.4
Total	5.7	16.4
Level 1
Assets:
Derivatives	0	0
Money market mutual funds		15.2
Mutual funds	7.7	33.3
Total	7.7	48.5
Liabilities:
Derivatives	0	0
Total	0	0
Level 2
Assets:
Derivatives	154.6	28.3
Money market mutual funds		0
Mutual funds	0	0
Total	154.6	28.3
Liabilities:
Derivatives	5.7	16.4
Total	$ 5.7	$ 16.4

Other Balance Sheet and State_3

Other Balance Sheet and Statement of Operations Information - Additional Details Related to Certain Balance Sheet Captions (Detail) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Other current assets:
Prepaid taxes	$ 98.3	$ 100.1
Prepaid expenses	64.3	67
Capitalized costs to obtain and fulfill sales contracts	67.7	77.2
Other	55.8	38
Total other current assets	286.1	282.3
Other assets:
Investments in non-consolidated affiliates	113	104.6
Deposits for real-estate leases	12.3	13.5
Indemnification assets related to acquisitions	16	16.1
Mutual funds and fixed deposits	20.6	18.9
Costs to obtain sales contracts	90	78
Cross currency and interest rate swaps	149.3	26.9
Other	24.1	16.3
Total other assets	425.3	274.3
Accounts payable and accrued liabilities:
Salaries and benefits	95.1	112.5
Incentive compensation	150.3	154.5
Customer credits, advanced payments and advanced billings	25.5	20.4
Self-insurance reserves	13.2	10.5
Dividends	6	6.5
Professional service fees	71	47.7
Interest accrued on debt	41.2	70.5
Accounts payable	14.8	30.1
Income taxes	56.4	71.4
Pension and other retirement employee benefits	6.5	6.5
Accrued royalties	9.4	25.1
Foreign exchange forwards on certain assets and liabilities	5.7	8.2
Restructuring liability	26.8	9.6
Other	85.3	121.7
Total accounts payable and accrued liabilities	607.2	695.2
Other liabilities:
Pension and other retirement employee benefits	264.2	249.2
Deferred rent-non-current portion		94.3
Interest accrued on UTPs	61.2	69.6
Income tax liability - non-current	125.2	125.3
Cross currency and interest rate swaps	0	8.2
Restructuring liability	4.5	6.8
Other	37.4	23.1
Total other liabilities	$ 492.5	$ 576.5

Other Balance Sheet and State_4

Other Balance Sheet and Statement of Operations Information - Other Non-Operating Interest (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Other Balance Sheet And Statement Of Operations Information [Abstract]
FX (loss)/gain	$ 0.9	$ (3.9)	$ (14.7)	$ (3.6)
Net periodic pension costs - other components	4.5	2.6	13.4	7.8
Income from investments in non-consolidated affiliates	3.9	3.3	10.7	9.2
Other	0.6	0.4	3.2	4.9
Total	$ 9.9	$ 2.4	$ 12.6	$ 18.3

Comprehensive Income And Accu_3

Comprehensive Income And Accumulated Other Comprehensive Income - Reclassification out of AOCI (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Other non-operating income (expense), net	$ 9.9	$ 2.4	$ 12.6	$ 18.3
Interest expense, net	(45.9)	(56.4)	(149)	(160.5)
Operating expense	691.7	614	2,102.2	1,891
Selling, general and administrative	291.9	260.3	848.1	801.9
Total before income taxes	512.8	412.8	1,357.6	1,349.4
Provision for income taxes	(130.4)	(100.8)	(289.6)	(282.7)
Net income	382.4	312	1,068	1,066.7
Reclassification out of Accumulated Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Net income	0.2	(0.7)	(1.1)	(2.2)
Gains (losses) on cash flow hedges | Reclassification out of Accumulated Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Total before income taxes	(0.1)		(0.2)
Provision for income taxes	0.1		0.1
Net income	0	0.1	(0.1)	0.3
Gains (losses) on cash flow hedges | Reclassification out of Accumulated Other Comprehensive Income | Cross-currency swap
Derivative Instruments, Gain (Loss) [Line Items]
Other non-operating income (expense), net	0.1	0.1	0	0.3
Provision for income taxes		0		0
Gains (losses) on cash flow hedges | Reclassification out of Accumulated Other Comprehensive Income | Interest rate contract
Derivative Instruments, Gain (Loss) [Line Items]
Interest expense, net	(0.2)		(0.2)
Gains on net investment hedges | Reclassification out of Accumulated Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Provision for income taxes	(0.2)		(0.2)
Net income	0.8		0.8
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	1		1
Amortization of actuarial losses and prior service costs included in net income | Reclassification out of Accumulated Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Operating expense	(0.5)	(0.6)	(1.5)	(2.2)
Selling, general and administrative	(0.3)	(0.5)	(0.9)	(1.3)
Pension and other retirement benefits | Reclassification out of Accumulated Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Total before income taxes	(0.8)	(1.1)	(2.4)	(3.5)
Provision for income taxes	0.2	0.3	0.6	1
Net income	$ (0.6)	$ (0.8)	$ (1.8)	$ (2.5)

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		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Jan. 01, 2019
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance	$ 574.7	$ 460.1	$ 656.5	$ (114.9)
Other comprehensive income/(loss)	(91.1)	(47.6)	(81.9)	(177.7)
Ending Balance	697.3	606.1	697.3	606.1
Pension and Other Retirement Benefits
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance	(70.5)	(58.6)	(53.1)	(61.5)
Other comprehensive income/(loss) before reclassifications	0	0	(1.3)	1.2
Amounts reclassified from AOCI	0.6	0.8	1.8	2.5
Other comprehensive income/(loss)	0.6	0.8	(16.8)	3.7
Ending Balance	(69.9)	(57.8)	(69.9)	(57.8)
Cash Flow Hedges
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance	0.2	2.2	0.1	0.9
Other comprehensive income/(loss) before reclassifications	0	0	0	1.5
Amounts reclassified from AOCI	0	(0.1)	0.1	(0.3)
Other comprehensive income/(loss)	0	(0.1)	0.1	1.2
Ending Balance	0.2	2.1	0.2	2.1
Foreign Currency Translation Adjustments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance	(400.3)	(263.6)	(406)	(112.6)
Other comprehensive income/(loss) before reclassifications	(193.7)	(42)	(188)	(193)
Amounts reclassified from AOCI	0	0	0	0
Other comprehensive income/(loss)	(193.7)	(42)	(188)	(193)
Ending Balance	(594)	(305.6)	(594)	(305.6)
Net Investment Hedges
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance	24.5	15.2	32.7	(1.3)
Other comprehensive income/(loss) before reclassifications	102.7	4.1	97	20.6
Amounts reclassified from AOCI	(0.8)	0	(0.8)	0
Other comprehensive income/(loss)	101.9	4.1	93.7	20.6
Ending Balance	126.4	19.3	126.4	19.3
Gains on Available for Sale Securities
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance				2.3
Other comprehensive income/(loss) before reclassifications				0
Amounts reclassified from AOCI				0
Other comprehensive income/(loss)				(2.3)
Ending Balance		0		0
Total
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance	(446.1)	(304.8)	(426.3)	(172.2)
Other comprehensive income/(loss) before reclassifications	(91)	(37.9)	(92.3)	(169.7)
Amounts reclassified from AOCI	(0.2)	0.7	1.1	2.2
Other comprehensive income/(loss)	(91.2)	(37.2)	(111)	(169.8)
Ending Balance	$ (537.3)	(342)	$ (537.3)	(342)
Financial Instruments - Overall (ASU 2016-01) | Gains on Available for Sale Securities
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Cumulative Effect of New Accounting Principle in Period of Adoption		(2.3)		(2.3)
Financial Instruments - Overall (ASU 2016-01) | Total
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Cumulative Effect of New Accounting Principle in Period of Adoption		$ (2.3)		$ (2.3)
Accounting Standards Update 2018-02 | Pension and Other Retirement Benefits
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Cumulative Effect of New Accounting Principle in Period of Adoption					$ (17.3)
Accounting Standards Update 2018-02 | Cash Flow Hedges
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Cumulative Effect of New Accounting Principle in Period of Adoption					0
Accounting Standards Update 2018-02 | Foreign Currency Translation Adjustments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Cumulative Effect of New Accounting Principle in Period of Adoption					0
Accounting Standards Update 2018-02 | Net Investment Hedges
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Cumulative Effect of New Accounting Principle in Period of Adoption					(2.5)
Accounting Standards Update 2018-02 | Total
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Cumulative Effect of New Accounting Principle in Period of Adoption					$ (19.8)

Pension and Other Retirement _3

Pension and Other Retirement Benefits - Components of Net Periodic Benefit Expense Related to Post-Retirement Plans (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Components of net periodic expense
Interest cost	$ 5.6	$ 4.9	$ 16.8	$ 14.5
Pension Plans
Components of net periodic expense
Service cost	4.2	4.6	12.5	14
Interest cost	5.1	4.4	15.4	13.2
Expected return on plan assets	(5)	(3.8)	(15.1)	(11.4)
Amortization of net actuarial loss from earlier periods	0.9	1.5	2.8	4.6
Amortization of net prior service costs from earlier periods	(0.1)	0	(0.3)	(0.2)
Net periodic expense	5.1	6.7	15.3	20.2
Other Retirement Plans
Components of net periodic expense
Service cost	0.7	0.7	2.1	2.2
Interest cost	0.3	0.3	0.9	0.8
Expected return on plan assets	0	0	0	0
Amortization of net actuarial loss from earlier periods	0	0	0	0
Amortization of net prior service costs from earlier periods	(0.1)	(0.1)	(0.2)	(0.2)
Net periodic expense	$ 0.9	$ 0.9	$ 2.8	$ 2.8

Pension and Other Retirement _4

Pension and Other Retirement Benefits - Additional Information (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2019USD ($)
Other Retirement Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit payment amount	$ 0.2
Estimated additional payments in 2019	0.9
Unfunded Plan | Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit payment amount	3.5
Estimated additional payments in 2019	$ 3.1

Indebtedness - Summary of Total

Indebtedness - Summary of Total Indebtedness (Detail) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Debt, Long-term and Short-term, Combined Amount [Abstract]
Principal Amount	$ 5,245.1	$ 5,721.6
Fair Value of Interest Rate Swap	35.1	2.2
Unamortized (Discount) Premium	(15.4)	(17.3)
Unamortized Debt Issuance Costs	(26.8)	(30.5)
Carrying Value	5,238	5,676
Current portion	(501.5)	(449.9)
Total long-term debt	4,736.5	5,226.1
5.50% 2010 Senior Notes, due 2020
Debt, Long-term and Short-term, Combined Amount [Abstract]
Principal Amount	500	500
Fair Value of Interest Rate Swap	2.3	(3.7)
Unamortized (Discount) Premium	(0.4)	(0.6)
Unamortized Debt Issuance Costs	(0.4)	(0.7)
Carrying Value	$ 501.5	$ 495
Notes payable, interest rate	5.50%	5.50%
4.50% 2012 Senior Notes, due 2022
Debt, Long-term and Short-term, Combined Amount [Abstract]
Principal Amount	$ 500	$ 500
Fair Value of Interest Rate Swap	11	1.9
Unamortized (Discount) Premium	(1.3)	(1.6)
Unamortized Debt Issuance Costs	(1.1)	(1.4)
Carrying Value	$ 508.6	$ 498.9
Notes payable, interest rate	4.50%	4.50%
4.875% 2013 Senior Notes, due 2024
Debt, Long-term and Short-term, Combined Amount [Abstract]
Principal Amount	$ 500	$ 500
Unamortized (Discount) Premium	(1.4)	(1.5)
Unamortized Debt Issuance Costs	(1.7)	(2)
Carrying Value	$ 496.9	$ 496.5
Notes payable, interest rate	4.875%	4.875%
2.75% 2014 Senior Notes (5-Year), due 2019
Debt, Long-term and Short-term, Combined Amount [Abstract]
Unamortized (Discount) Premium		$ (0.1)
Unamortized Debt Issuance Costs		0
Carrying Value		$ 449.9
Notes payable, interest rate		2.75%
5.25% 2014 Senior Notes (30-Year), due 2044
Debt, Long-term and Short-term, Combined Amount [Abstract]
Principal Amount	$ 600	$ 600
Unamortized (Discount) Premium	3.2	3.2
Unamortized Debt Issuance Costs	(5.3)	(5.5)
Carrying Value	$ 597.9	$ 597.7
Notes payable, interest rate	5.25%	5.25%
1.75% 2015 Senior Notes, due 2027
Debt, Long-term and Short-term, Combined Amount [Abstract]
Principal Amount	$ 545.1	$ 571.6
Unamortized (Discount) Premium	0	0
Unamortized Debt Issuance Costs	(2.7)	(3.1)
Carrying Value	$ 542.4	$ 568.5
Notes payable, interest rate	1.75%	1.75%
2.75% 2017 Senior Notes, due 2021
Debt, Long-term and Short-term, Combined Amount [Abstract]
Principal Amount	$ 500	$ 500
Fair Value of Interest Rate Swap	13.5	4
Unamortized (Discount) Premium	(0.7)	(1)
Unamortized Debt Issuance Costs	(1.8)	(2.4)
Carrying Value	$ 511	$ 500.6
Notes payable, interest rate	2.75%	2.75%
2.625% 2017 Senior Notes, due 2023
Debt, Long-term and Short-term, Combined Amount [Abstract]
Principal Amount	$ 500	$ 500
Fair Value of Interest Rate Swap	8.3
Unamortized (Discount) Premium	(0.7)	(0.9)
Unamortized Debt Issuance Costs	(2.4)	(2.8)
Carrying Value	$ 505.2	$ 496.3
Notes payable, interest rate	2.625%	2.625%
3.25% 2017 Senior Notes, due 2028
Debt, Long-term and Short-term, Combined Amount [Abstract]
Principal Amount	$ 500	$ 500
Unamortized (Discount) Premium	(4.4)	(4.7)
Unamortized Debt Issuance Costs	(3.4)	(3.7)
Carrying Value	$ 492.2	$ 491.6
Notes payable, interest rate	3.25%	3.25%
3.25% 2018 Senior Notes, due 2021
Debt, Long-term and Short-term, Combined Amount [Abstract]
Principal Amount	$ 300	$ 300
Unamortized (Discount) Premium	(0.3)	(0.4)
Unamortized Debt Issuance Costs	(1)	(1.5)
Carrying Value	$ 298.7	$ 298.1
Notes payable, interest rate	3.25%	3.25%
4.25% 2018 Senior Notes, due 2029
Debt, Long-term and Short-term, Combined Amount [Abstract]
Principal Amount	$ 400	$ 400
Unamortized (Discount) Premium	(2.8)	(3)
Unamortized Debt Issuance Costs	(3)	(3.3)
Carrying Value	$ 394.2	$ 393.7
Notes payable, interest rate	4.25%	4.25%
4.875% 2018 Senior Notes, due 2048
Debt, Long-term and Short-term, Combined Amount [Abstract]
Principal Amount	$ 400	$ 400
Unamortized (Discount) Premium	(6.6)	(6.7)
Unamortized Debt Issuance Costs	(4)	(4.1)
Carrying Value	$ 389.4	$ 389.2
Notes payable, interest rate	4.875%	4.875%

Indebtedness - Additional Infor

Indebtedness - Additional Information (Detail) $ in Millions	Jan. 03, 2019USD ($)
2.75% 2014 Senior Notes (5-Year), due 2019
Debt Instrument [Line Items]
Repayments of debt	$ 450

Indebtedness - Principal Paymen

Indebtedness - Principal Payments Due on Long-Term Borrowings (Detail) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Long-term Debt, Fiscal Year Maturity [Abstract]
2019 (After September 30)	$ 0
2020	500
2021	800
2022	500
2023	500
Thereafter	2,945.1
Total principal payment	5,245.1	$ 5,721.6
5.50% 2010 Senior Notes, due 2020
Long-term Debt, Fiscal Year Maturity [Abstract]
2020	500
Total principal payment	500	500
4.50% 2012 Senior Notes, due 2022
Long-term Debt, Fiscal Year Maturity [Abstract]
2022	500
Total principal payment	500	500
4.875% 2013 Senior Notes, due 2024
Long-term Debt, Fiscal Year Maturity [Abstract]
Thereafter	500
Total principal payment	500	500
5.25% 2014 Senior Notes (30-Year), due 2044
Long-term Debt, Fiscal Year Maturity [Abstract]
Thereafter	600
Total principal payment	600	600
1.75% 2015 Senior Notes, due 2027
Long-term Debt, Fiscal Year Maturity [Abstract]
Thereafter	545.1
Total principal payment	545.1	571.6
2.75% 2017 Senior Notes, due 2021
Long-term Debt, Fiscal Year Maturity [Abstract]
2021	500
Total principal payment	500	500
2.625% 2017 Senior Notes, due 2023
Long-term Debt, Fiscal Year Maturity [Abstract]
2023	500
Total principal payment	500	500
3.25% 2017 Senior Notes, due 2028
Long-term Debt, Fiscal Year Maturity [Abstract]
Thereafter	500
Total principal payment	500	500
3.25% 2018 Senior Notes, due 2021
Long-term Debt, Fiscal Year Maturity [Abstract]
2021	300
Total principal payment	300	300
4.25% 2018 Senior Notes, due 2029
Long-term Debt, Fiscal Year Maturity [Abstract]
Thereafter	400
Total principal payment	400	400
4.875% 2018 Senior Notes, due 2048
Long-term Debt, Fiscal Year Maturity [Abstract]
Thereafter	400
Total principal payment	$ 400	$ 400

Indebtedness - Summary of Compo

Indebtedness - Summary of Components of Interest as Presented in Consolidated Statements of Operations (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Debt Disclosure [Abstract]
Income	$ 3.6	$ 4.1	$ 12.5	$ 10.7
Expense on borrowings	(37.4)	(46.4)	(125.7)	(147.1)
UTPs and other tax related liabilities	(7)	(9.6)	(20.2)	(10.6)
Net periodic pension costs - interest component	(5.6)	(4.9)	(16.8)	(14.5)
Capitalized	0.5	0.4	1.2	1
Total	$ (45.9)	$ (56.4)	$ (149)	$ (160.5)

Indebtedness - Interest Paid (D

Indebtedness - Interest Paid (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Interest Paid, Including Capitalized Interest, Operating and Investing Activities [Abstract]
Interest paid	$ 148.6	$ 169.7

Indebtedness - Fair Value and C

Indebtedness - Fair Value and Carrying Value of Long-Term Debt (Detail) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Long term debt	$ 5,238	$ 5,676
Estimated Fair Value	5,755.7	5,782.5
5.50% 2010 Senior Notes, due 2020
Debt Instrument [Line Items]
Long term debt	501.5	495
Estimated Fair Value	$ 515	$ 517.7
Notes payable, interest rate	5.50%	5.50%
4.50% 2012 Senior Notes, due 2022
Debt Instrument [Line Items]
Long term debt	$ 508.6	$ 498.9
Estimated Fair Value	$ 531.7	$ 513.7
Notes payable, interest rate	4.50%	4.50%
4.875% 2013 Senior Notes, due 2024
Debt Instrument [Line Items]
Long term debt	$ 496.9	$ 496.5
Estimated Fair Value	$ 551.8	$ 522.4
Notes payable, interest rate	4.875%	4.875%
2.75% 2014 Senior Notes (5-Year), due 2019
Debt Instrument [Line Items]
Long term debt		$ 449.9
Estimated Fair Value		$ 449.9
Notes payable, interest rate		2.75%
5.25% 2014 Senior Notes (30-Year), due 2044
Debt Instrument [Line Items]
Long term debt	$ 597.9	$ 597.7
Estimated Fair Value	$ 768.7	$ 638.1
Notes payable, interest rate	5.25%	5.25%
1.75% 2015 Senior Notes, due 2027
Debt Instrument [Line Items]
Long term debt	$ 542.4	$ 568.5
Estimated Fair Value	$ 596.7	$ 585.3
Notes payable, interest rate	1.75%	1.75%
2.75% 2017 Senior Notes, due 2021
Debt Instrument [Line Items]
Long term debt	$ 511	$ 500.6
Estimated Fair Value	$ 506.3	$ 489.7
Notes payable, interest rate	2.75%	2.75%
2.625% 2017 Senior Notes, due 2023
Debt Instrument [Line Items]
Long term debt	$ 505.2	$ 496.3
Estimated Fair Value	$ 506.5	$ 476.9
Notes payable, interest rate	2.625%	2.625%
3.25% 2017 Senior Notes, due 2028
Debt Instrument [Line Items]
Long term debt	$ 492.2	$ 491.6
Estimated Fair Value	$ 526	$ 472.8
Notes payable, interest rate	3.25%	3.25%
3.25% 2018 Senior Notes, due 2021
Debt Instrument [Line Items]
Long term debt	$ 298.7	$ 298.1
Estimated Fair Value	$ 305.1	$ 298.6
Notes payable, interest rate	3.25%	3.25%
4.25% 2018 Senior Notes, due 2029
Debt Instrument [Line Items]
Long term debt	$ 394.2	$ 393.7
Estimated Fair Value	$ 451	$ 407.6
Notes payable, interest rate	4.25%	4.25%
4.875% 2018 Senior Notes, due 2048
Debt Instrument [Line Items]
Long term debt	$ 389.4	$ 389.2
Estimated Fair Value	$ 496.9	$ 409.8
Notes payable, interest rate	4.875%	4.875%

Leases - Additional Information

Leases - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2019	Sep. 30, 2019
Operating Leased Assets [Line Items]
Impairment of right-of-use	$ 24.8
Minimum
Operating Leased Assets [Line Items]
Lessee, operating lease, renewal term (years)		1 year
Maximum
Operating Leased Assets [Line Items]
Lessee, operating lease, renewal term (years)		20 years

Leases - Components of Lease Co

Leases - Components of Lease Cost (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Lease, Cost [Abstract]
Operating lease cost	$ 24.2	$ 73.3
Short-term lease cost	0	0.4
Variable lease cost	5	12.7
Total lease cost	$ 29.2	$ 86.4

Leases - Operating Leases Infor

Leases - Operating Leases Information (Detail) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019USD ($)	Sep. 30, 2019USD ($)
Leases [Abstract]
Cash paid for amounts included in the measurement of operating lease liabilities	$ 26.6	$ 79.8
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 12	$ 27.9
Weighted-average remaining lease term (years)	6 years 10 months 24 days	6 years 10 months 24 days
Weighted-average discount rate applied to operating leases (percent)	3.60%	3.60%

Leases - Operating Leases, Futu

Leases - Operating Leases, Future Minimum Payment (Detail) $ in Millions	Sep. 30, 2019USD ($)
Leases [Abstract]
2019 (After September 30)	$ 27.2
2020	107.7
2021	102.1
2022	88.7
2023	83.2
Thereafter	251
Total minimum lease payments	659.9
Less: Interest	75.4
Present value of lease liabilities:	584.5
Lease liabilities - current	89.5
Lease liabilities - noncurrent	$ 495

Leases - Operating Lease, Minim

Leases - Operating Lease, Minimum Rent for Payment (Detail) $ in Millions	Dec. 31, 2018USD ($)
Leases [Abstract]
2019	$ 105.9
2020	102.3
2021	95.6
2022	84.4
2023	81
After 2023	246.5
Total	$ 715.7

Contingencies - Additional Info

Contingencies - Additional Information (Detail) - USD ($) $ in Millions	1 Months Ended		3 Months Ended		9 Months Ended
	Oct. 31, 2019	Aug. 31, 2013	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Loss Contingencies [Line Items]
Unsupported allegations of minimum underpaid taxes		$ 120
Litigation settlement, amount awarded to other party			$ 15.5	$ 0	$ 15.5	$ 0
Subsequent Event
Loss Contingencies [Line Items]
Litigation settlement, amount awarded to other party	$ 15.5

Segment Information - Additiona

Segment Information - Additional Information (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2019USD ($)segment
Segment Reporting Information [Line Items]
Number of operating segments (segment) | segment	2
2018 Restructuring Program | MIS
Segment Reporting Information [Line Items]
Cumulative expense incurred to date	$ 61.3
2018 Restructuring Program | MA
Segment Reporting Information [Line Items]
Cumulative expense incurred to date	$ 45.7

Segment Information - Financial

Segment Information - Financial Information by Segment (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information, Operating Income (Loss) [Abstract]
Revenue	$ 1,240.5	$ 1,080.8	$ 3,596.2	$ 3,382.6
Total Expense	691.7	614	2,102.2	1,891
Operating income	548.8	466.8	1,494	1,491.6
Restructuring	(1)	0	58.3	0
Depreciation and amortization	48.6	46.1	149.9	143.6
Acquisition-Related Expenses	0	1.3	3.4	4.1
Impairment pursuant to the planned divestiture of MAKS	2	0	10.7	0
Captive insurance company settlement	15.5	0	15.5	0
Adjusted Operating Income	613.9	514.2	1,731.8	1,639.3
Eliminations
Segment Reporting Information, Operating Income (Loss) [Abstract]
Revenue	(36.4)	(34.2)	(106.3)	(102)
Total Expense	(36.4)	(34.2)	(106.3)	(102)
Operating income	0	0	0	0
Restructuring	0	0	0	0
Depreciation and amortization	0	0	0	0
Acquisition-Related Expenses	0	0	0	0
Impairment pursuant to the planned divestiture of MAKS	0	0	0	0
Captive insurance company settlement	0	0	0	0
Adjusted Operating Income	0	0	0	0
MIS
Segment Reporting Information, Operating Income (Loss) [Abstract]
Revenue	746.6	644.8	2,155.1	2,117
MIS | Operating Segments
Segment Reporting Information, Operating Income (Loss) [Abstract]
Revenue	780.9	676.4	2,254.7	2,209
Total Expense	339.9	303.5	1,027.9	951
Operating income	441	372.9	1,226.8	1,258
Restructuring	(0.1)	0	29.1	0
Depreciation and amortization	18	15.8	53	49.3
Acquisition-Related Expenses	0	0	0	0
Impairment pursuant to the planned divestiture of MAKS	0	0	0	0
Captive insurance company settlement	9.4	0	9.4	0
Adjusted Operating Income	468.3	388.7	1,318.3	1,307.3
MA
Segment Reporting Information, Operating Income (Loss) [Abstract]
Revenue	493.9	436	1,441.1	1,265.6
MA | Operating Segments
Segment Reporting Information, Operating Income (Loss) [Abstract]
Revenue	496	438.6	1,447.8	1,275.6
Total Expense	388.2	344.7	1,180.6	1,042
Operating income	107.8	93.9	267.2	233.6
Restructuring	(0.9)	0	29.2	0
Depreciation and amortization	30.6	30.3	96.9	94.3
Acquisition-Related Expenses	0	1.3	3.4	4.1
Impairment pursuant to the planned divestiture of MAKS	2	0	10.7	0
Captive insurance company settlement	6.1	0	6.1	0
Adjusted Operating Income	$ 145.6	$ 125.5	$ 413.5	$ 332

Segment Information - Consolida

Segment Information - Consolidated Revenue Information by Geographic Area (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Revenue	$ 1,240.5	$ 1,080.8	$ 3,596.2	$ 3,382.6
United States
Segment Reporting Information [Line Items]
Revenue	659.6	559.6	1,909.6	1,782.7
Non-U.S.
Segment Reporting Information [Line Items]
Revenue	580.9	521.2	1,686.6	1,599.9
EMEA
Segment Reporting Information [Line Items]
Revenue	361.5	344.5	1,056.8	1,047.9
Asia-Pacific
Segment Reporting Information [Line Items]
Revenue	142.4	123	415.4	366.9
Americas
Segment Reporting Information [Line Items]
Revenue	$ 77	$ 53.7	$ 214.4	$ 185.1

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - Subsequent Event	Oct. 21, 2019$ / shares
Subsequent Event [Line Items]
Dividend declared, declaration date	Oct. 21, 2019
Dividend declared, per share	$ 0.50
Dividend declared, payable date	Dec. 12, 2019
Dividend declared, record date	Nov. 21, 2019

Uncategorized Items - mco-20190

Label	Element	Value
Accounting Standards Update 2018-02 [Member] | Parent [Member]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets	us-gaap_NewAccountingPronouncementOrChangeInAccountingPrincipleCumulativeEffectOfChangeOnEquityOrNetAssets1	$ 0