Moody's (MCO) 10-Q 1 May 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information shares in Millions	3 Months Ended
	Mar. 31, 2018shares
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Trading Symbol	MCO
Entity Registrant Name	MOODYS CORP /DE/
Entity Central Index Key	1,059,556
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding	191.9

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Statement [Abstract]
Revenues	$ 1,126.7	$ 975.2
Expenses
Operating	314.9	275.3
Selling, general and administrative	271.1	220.7
Depreciation and amortization	49.1	32.5
Acquisition-Related Expenses	0.8
Total expenses	635.9	528.5
Operating Income	490.8	446.7
Non-operating (expense) income, net
Interest income (expense), net	(50.7)	(47.4)
Other non-operating income (expense), net	1	(7.7)
CCXI gains		59.7
Total non-operating (expense) income, net	(49.7)	4.6
Income before provisions for income taxes	441.1	451.3
Provision for income taxes	64.3	105.4
Net income	376.8	345.9
Less: Net income attributable to noncontrolling interests	3.9	0.3
Net income attributable to Moody's	$ 372.9	$ 345.6
Earnings per share attributable to Moody's common shareholders
Basic	$ 1.95	$ 1.81
Diluted	$ 1.92	$ 1.78
Weighted average number of shares outstanding
Basic	191.4	191.1
Diluted	194.5	194.3
Dividends declared per share attributable to Moody's common shareholders	$ 0.44	$ 0

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 376.8	$ 345.9
Foreign currency translation:
Foreign currency translation adjustments - Pre Tax	121.6	14.4
Foreign currency translation adjustment - Tax	3.6	(2.3)
Foreign currency translation adjustments - Net of Tax	125.2	12.1
Cash flow hedges:
Net realized and unrealized gain (loss) on cash flow hedges - Pre Tax	1.9	(0.3)
Net realized and unrealized gain (loss) on cash flow hedges - Tax Amount	(0.4)	0.1
Net realized and unrealized gain (loss) on cash flow hedges - Net of Tax	1.5	(0.2)
Reclassification of losses included in net income - Pre Tax	(0.1)	(1.4)
Reclassification of losses included in net income - Tax Amount		0.5
Reclassification of losses included in net income- Net of Tax	(0.1)	(0.9)
Available for sale securities:
Net unrealized gains on available for sale securities - Pre Tax		0.5
Net unrealized gains on available for sale securities - Net of Tax		0.5
Pension and Other Retirement Benefits:
Amortization of actuarial losses and prior service costs included in net income - Pre Tax	1.4	2.4
Amortization of actuarial losses and prior service costs included in net income - Tax	(0.4)	(0.9)
Amortization of actuarial losses and prior service costs included in net income - Net of Tax	1	1.5
Total other comprehensive income (loss) - Pre Tax	124.8	15.6
Total other comprehensive income (loss) - Tax	2.8	(2.6)
Total other comprehensive income (loss) - Net of Tax	127.6	13
Comprehensive income	504.4	358.9
Less: Comprehensive income attributable to noncontrolling interests and redeemable noncontrolling interest	8.9	5.7
Comprehensive income attributable to Moody's	$ 495.5	$ 353.2

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 1,277.3	$ 1,071.5
Short-term investments	100.5	111.8
Accounts receivable, net of allowances of $36.0 in 2018 and $36.6 in 2017	1,207.4	1,147.2
Other current assets	233.6	250.1
Total current assets	2,818.8	2,580.6
Property and equipment, net of accumulated depreciation of $731.8 in 2018 and $706.0 in 2017	321.6	325.1
Goodwill	3,831.5	3,753.2
Intangible assets, net	1,641.6	1,631.6
Deferred tax assets, net	142.5	143.8
Other assets	258	159.9
Total assets	9,014	8,594.2
Current liabilities:
Accounts payable and accrued liabilities	532.6	750.3
Commercial paper	89.9	129.9
Current portion of long-term debt	299.7	299.5
Deferred revenue	998.7	883.6
Total current liabilities	1,920.9	2,063.3
Non-current portion of deferred revenue	127.8	140
Long-term debt	5,118	5,111.1
Deferred tax liabilities, net	382.2	341.6
Unrecognized tax benefits	490.9	389.1
Other liabilities	554.2	664
Total liabilities	8,594	8,709.1
Contingencies (Note 14)
Shareholders' (deficit) equity
Preferred stock, par value $.01 per share; 10,000,000 shares authorized; no shares issued and outstanding
Common stock	3.4	3.4
Capital surplus	506.6	528.6
Retained earnings	7,913	7,465.4
Treasury stock, at cost; 151,594,546 and 152,208,231 shares of common stock at March 31, 2017 and December 31, 2016, respectively	(8,171.4)	(8,152.9)
Accumulated other comprehensive loss	(51.9)	(172.2)
Total Moody's shareholders' deficit	199.7	(327.7)
Noncontrolling interests	220.3	212.8
Total shareholders' deficit	420	(114.9)
Total liabilities and shareholders' (deficit) equity	9,014	8,594.2
Series common stock
Shareholders' (deficit) equity
Common stock

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Accounts receivable, allowances	$ 36	$ 36.6
Property and equipment, accumulated depreciation	$ 731.8	$ 706
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	10,000,000	10,000,000
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	1,000,000,000	1,000,000,000
Common stock, shares issued	342,902,272	342,902,272
Treasury stock, shares	150,981,594	151,932,157
Series common stock
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	10,000,000	10,000,000

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities
Net income	$ 376.8	$ 345.9
Reconciliation of net income to net cash provided by operating activities:
Depreciation and amortization	49.1	32.5
Stock-based compensation expense	35.1	28.4
CCXI gains		(59.7)
Deferred income taxes	(4.2)	185
Changes in assets and liabilities:
Accounts receivable	(29.9)	(61.9)
Other current assets	47.8	(128.3)
Other assets	(14.5)	(3.2)
Accounts payable and accrued liabilities	(224.2)	(988.6)
Deferred revenue	167.7	125.9
Unrecognized tax benefits and other non-current tax liabilities	(17.9)	0.9
Other liabilities	5.7	10.7
Net cash provided by (used in) operating activities	391.5	(512.4)
Cash flows from investing activities
Capital additions	(15)	(18.7)
Purchases of investments	(50.3)	(34.5)
Sales and maturities of short-term investments	41.1	76.8
Cash paid for acquisitions, net of cash acquired and equity investments		(5)
Cash received upon diposal of a subsidiary, net of cash transferred to purchaser	5.7
Net cash used in investing activities	(18.5)	18.6
Cash flows from financing activities
Issuance of notes		798.5
Repayments of notes		(300)
Issuance of commercial paper	219.6	653.7
Repayments of commercial paper	(259.6)	(440.4)
Proceeds from stock-based compensation plans	28.5	22.1
Repurchase of shares related to stock-based compensation	(42)	(47.5)
Cost of treasury shares repurchased	(43.4)	(55)
Dividends	(84.1)	(72.6)
Dividends to noncontrolling interests	(1.1)	(0.2)
Debt issuance costs and related fees	(0.2)	(4.9)
Net cash provided (used in) by financing activities	(182.3)	553.7
Effect of exchange rate changes on cash and cash equivalents	15.1	18.2
Net increase (decrease) in cash and cash equivalents	205.8	78.1
Cash and cash equivalents, beginning of the period	1,071.5	2,051.5
Cash and cash equivalents, end of the period	$ 1,277.3	$ 2,129.6

GLOSSARY OF TERMS AND ABBREVIAT

GLOSSARY OF TERMS AND ABBREVIATIONS	3 Months Ended
	Mar. 31, 2018
Text Block [Abstract]
GLOSSARY OF TERMS AND ABBREVIATIONS	GLOSSARY OF TERMS AND ABBREVIATIONS The following terms, abbreviations and acronyms are used to identify frequently used terms in this report: TERM DEFINITION Acquisition-Related Amortization Amortization of definite-lived intangible assets acquired by the Company from all business combination transactions Acquisition-Related Expenses Consists of expenses incurred to complete and integrate the acquisition of Bureau van Dijk for which the integration will be a multi-year effort Adjusted Diluted EPS Diluted EPS excluding the impact of certain items as detailed in the section entitled “Non-GAAP Financial Measures” Adjusted Net Income Net Income excluding the impact of certain items as detailed in the section entitled “Non-GAAP Financial Measures” Adjusted Operating Income Operating income excluding depreciation and amortization Adjusted Operating Margin Adjusted Operating Income divided by revenue Americas Represents countries within North and South America, excluding the U.S. AOCI Accumulated other comprehensive income (loss); a separate component of shareholders’ (deficit) equity ASC The FASB Accounting Standards Codification; the sole source of authoritative GAAP as of July 1, 2009 except for rules and interpretive releases of the SEC, which are also sources of authoritative GAAP for SEC registrants ASC 605 The U.S. GAAP authoritative guidance for revenue accounting prior to the adoption of ASU No. 2014-09, “Revenue from Contracts with Customers (ASC Topic 606). Asia-Pacific Represents countries in Asia including but not limited to: Australia, China, India, Indonesia, Japan, Korea, Malaysia, Singapore, Sri Lanka and Thailand ASU The FASB Accounting Standards Update to the ASC. It also provides background information for accounting guidance and the bases for conclusions on the changes in the ASC. ASUs are not considered authoritative until codified into the ASC Board The board of directors of the Company BPS Basis points Bureau van Dijk Bureau van Dijk Electronic Publishing, B.V., a global provider of business intelligence and company information; acquired by the Company on August 10, 2017 via the acquisition of Yellow Maple I B.V., an indirect parent of Bureau van Dijk. CCXI China Cheng Xin International Credit Rating Co. Ltd.; China’s first and largest domestic credit rating agency approved by the People's Bank of China; the Company acquired a 49% interest in 2006; currently Moody’s owns 30% of CCXI. CCXI Gain In the first quarter of 2017 CCXI, as part of a strategic business realignment, issued additional capital to its majority shareholder in exchange for a ratings business wholly-owned by the majority shareholder and which has the right to rate a different class of debt instrument in the Chinese market. The capital issuance by CCXI in exchange for this ratings business diluted Moody’s ownership interest in CCXI to 30% of a larger business and resulted in a $59.7 million non-cash, non-taxable gain. CFG Corporate finance group; an LOB of MIS CLO Collateralized loan obligation CMBS Commercial mortgage-backed securities; part of the CREF asset class within SFG Commission European Commission Common Stock The Company’s common stock Company Moody’s Corporation and its subsidiaries; MCO; Moody’s Council Council of the European Union CP Commercial Paper CP Notes Unsecured commercial paper issued under the CP Program CP Program A program entered into on August 3, 2016 allowing the Company to privately place CP up to a maximum of $1 billion for which the maturity may not exceed 397 from the date of issue and which is backstopped by the 2015 facility. CRAs Credit rating agencies CRA3 Regulation (EU) No 462/2013 of the European Parliament and of the Council, which updated the regulatory regimes imposing additional procedural requirements on CRAs CREF Commercial real estate finance which includes REITs, commercial real estate CDOs and mortgage-backed securities; part of SFG D&A Depreciation and amortization DBPPs Defined benefit pension plans Debt/EBITDA Ratio of Total Debt to EBITDA EBITDA Earnings before interest, taxes, depreciation and amortization EMEA Represents countries within Europe, the Middle East and Africa EPS Earnings per share ERS The Enterprise Risk Solutions LOB within MA, which offers risk management software solutions as well as related risk management advisory engagements services ESA Economics and Structured Analytics; part of the RD&A line of business within MA ESMA European Securities and Markets Authority ETR Effective tax rate EU European Union EUR Euros Excess Tax Benefits The difference between the tax benefit realized at exercise of an option or delivery of a restricted share and the tax benefit recorded at the time the option or restricted share is expensed under GAAP Exchange Act The Securities Exchange Act of 1934, as amended FASB Financial Accounting Standards Board FIG Financial institutions group; an LOB of MIS Financial Reform Act Dodd-Frank Wall Street Reform and Consumer Protection Act Free Cash Flow Net cash provided by operating activities less cash paid for capital additions FSTC Financial Services Training and Certifications; part of the PS LOB and a reporting unit within the MA reportable segment; consists of on-line and classroom-based training services and CSI Global Education, Inc. FX Foreign exchange GAAP U.S. Generally Accepted Accounting Principles GBP British pounds ICRA ICRA Limited; a leading provider of credit ratings and research in India. The Company previously held 28.5% equity ownership and in June 2014, increased that ownership stake to just over 50% through the acquisition of additional shares IRS Internal Revenue Service IT Information technology KIS Korea Investors Service, Inc; a leading Korean rating agency and consolidated subsidiary of the Company KIS Pricing Korea Investors Service Pricing, Inc; a leading Korean provider of fixed income securities pricing and consolidated subsidiary of the Company LIBOR London Interbank Offered Rate LOB Line of business M&A Mergers and acquisitions MA Moody’s Analytics a reportable segment of MCO which provides a wide range of products and services that support financial analysis and risk management activities of institutional participants in global financial markets; consists of three LOBs – RD&A, ERS and PS Make Whole Amount The prepayment penalty amount relating to the Series 2007-1, Notes 2010 Senior Notes, 2012 Senior Notes, 2013 Senior Notes, 2014 Senior Notes (5-year), 2014 Senior Notes (30-year), 2015 Senior Notes and 2017 Senior Notes which is a premium based on the excess, if any, of the discounted value of the remaining scheduled payments over the prepaid principal MAKS Moody’s Analytics Knowledge Services; formerly known as Copal Amba; provides offshore research and analytic services to the global financial and corporate sectors; part of the PS LOB and a reporting unit within the MA reportable segment MCO Moody’s Corporation and its subsidiaries; the Company; Moody’s MD&A Management’s Discussion and Analysis of Financial Condition and Results of Operations MIS Moody’s Investors Service – a reportable segment of MCO; consists of five LOBs – SFG, CFG, FIG, PPIF and MIS Other MIS Other Consists of non-ratings revenue from ICRA, KIS Pricing and KIS Research. These businesses are components of MIS; MIS Other is an LOB of MIS Moody’s Moody’s Corporation and its subsidiaries; MCO; the Company Net Income Net income attributable to Moody’s Corporation, which excludes net income from consolidated noncontrolling interests belonging to the minority interest holder New Revenue Accounting Standard Updates to the ASC pursuant to ASU No. 2014-09, “Revenue from Contracts with Customers (ASC Topic 606)”. This new accounting guidance significantly changes the accounting framework under U.S. GAAP relating to revenue recognition and to the accounting for the deferral of incremental costs of obtaining or fulfilling a contract with a customer NM Percentage change is not meaningful Non-GAAP A financial measure not in accordance with GAAP; these measures, when read in conjunction with the Company’s reported results, can provide useful supplemental information for investors analyzing period-to-period comparisons of the Company’s performance, facilitate comparisons to competitors’ operating results and to provide greater transparency to investors of supplemental information used by management in its financial and operational decision making NRSRO Nationally Recognized Statistical Rating Organization OCI Other comprehensive income (loss); includes gains and losses on cash flow and net investment hedges, unrealized gains and losses on available for sale securities (in periods prior to January 1, 2018), certain gains and losses relating to pension and other retirement benefit obligations and foreign currency translation adjustments Other Retirement Plan The U.S. retirement healthcare and U.S. retirement life insurance plans PCS Post-Contract Customer Support PPIF Public, project and infrastructure finance; an LOB of MIS Profit Participation Plan Defined contribution profit participation plan that covers substantially all U.S. employees of the Company PS Professional Services, an LOB within MA consisting of MAKS and FSTC that provides research and analytical services as well as financial training and certification programs RD&A Research, Data and Analytics; an LOB within MA that distributes research and data developed by MIS as part of the ratings process, including in-depth research on major debt issuers, industry studies and commentary on topical credit-related events. Also, produces economic research and data and analytical tools such as quantitative credit risk scores as well as business intelligence and company information products. Reform Act Credit Rating Agency Reform Act of 2006 REIT Real Estate Investment Trust Relationship Revenue For MIS represents 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. For MIS Other represents subscription-based revenue. For MA, represents subscription-based revenue and software maintenance revenue Retirement Plans Moody’s funded and unfunded pension plans, the healthcare plans and life insurance plans SCDM SCDM Financial, a leading provider of analytical tools for participants in securitization markets. Moody’s acquired SCDM’s structured finance data and analytics business in February 2017 SEC U.S. Securities and Exchange Commission Securities Act Securities Act of 1933, as amended Series 2007-1 Notes Principal amount of $300 million, 6.06% senior unsecured notes Due in September 2017 pursuant to the 2007 Agreement; prepaid in March 2017 Settlement Charge Charge of $863.8 million recorded in the fourth quarter of 2016 related to an agreement entered into on January 13, 2017 with the U.S. Department of Justice and the attorneys general of 21 U.S. states and the District of Columbia to resolve pending and potential civil claims related to credit ratings that MIS assigned to certain structured finance instruments in the financial crisis era SFG Structured finance group; an LOB of MIS SG&A Selling, general and administrative expenses SSP Standalone selling price T&M Time-and-Material Tax Act The “Tax Cuts and Jobs Act” enacted into U.S. law on December 22, 2017 which significantly amends the tax code in the U.S. Total Debt All indebtedness of the Company as reflected on the consolidated balance sheets Transaction Revenue For MIS, represents the initial rating of a new debt issuance as well as other one-time fees. For MIS Other, represents revenue from professional services as well as data services, research and analytical engagements. For MA, represents perpetual software license fees and revenue from risk management advisory projects, training and certification services, and research and analytical engagements U.K. United Kingdom U.S. United States USD U.S. dollar UTBs Unrecognized tax benefits UTPs Uncertain tax positions VSOE Vendor specific objective evidence; as defined in the ASC, evidence of selling price limited to either of the following: the price charged for a deliverable when it is sold separately, or for a deliverable not yet being sold separately, the price established by management having the relevant authority 2007 Agreement Note purchase agreement dated September 7, 2007, relating to the Series 2007-1 Notes 2010 Indenture Supplemental indenture and related agreements dated August 19, 2010, relating to the 2010 Senior Notes 2010 Senior Notes Principal amount of $500 million, 5.50% senior unsecured notes Due in September 2020 pursuant to the 2010 Indenture 2012 Indenture Supplemental indenture and related agreements dated August 18, 2012, relating to the 2012 Senior Notes 2012 Senior Notes Principal amount of $500 million, 4.50% senior unsecured notes Due in September 2022 pursuant to the 2012 Indenture 2013 Indenture Supplemental indenture and related agreements dated August 12, 2013, relating to the 2013 Senior Notes 2013 Senior Notes Principal amount of the $500 million, 4.875% senior unsecured notes Due in February 2024 pursuant to the 2013 Indenture 2014 Indenture Supplemental indenture and related agreements dated July 16, 2014, relating to the 2014 Senior Notes 2014 Senior Notes (5-Year) Principal amount of $450 million, 2.75% senior unsecured notes Due in July 2019 2014 Senior Notes (30-Year) Principal amount of $600 million, 5.25% senior unsecured notes Due in July 2044 2015 Facility Five-year unsecured revolving credit facility, with capacity to borrow up to $1 billion; backstops CP issued under the CP Program 2015 Indenture Supplemental indenture and related agreements dated March 9, 2015, relating to the 2015 Senior Notes 2015 Senior Notes Principal amount €500 million, 1.75% senior unsecured notes issued March 9, 2015 and Due in March 2027 2017 Floating Rate Senior Notes Principal amount of $300 million, floating rate senior unsecured notes Due in September 2018 2017 Indenture Collectively the Supplemental indenture and related agreements dated March 2, 2017, relating to the 2017 Floating Rate Senior Notes and 2017 Notes Due 2023 and 2028, and the supplemental indenture and related agreements dated June 12, 2017, relating to the 2017 Notes Due 2023 and 2028 2017 Notes Due 2023 Principal amount of $500 million, 2.625% senior unsecured notes Due January 15, 2023 2017 Notes Due 2028 Principal amount $500 million, 3.250% senior unsecured notes Due January 15, 2028 2017 Senior Notes Principal amount of $500 million, 2.75% senior unsecured notes Due in December 2021 2017 Term Loan $500 million, three-year term loan facility entered into on June6, 2017 for which the Company drew down $500 million on August 8, 2017 to fund the acquisition of Bureau van Dijk

DESCRIPTION OF BUSINESS AND BAS

DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION	3 Months Ended
	Mar. 31, 2018
Text Block [Abstract]
DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION	NOTE 1 . 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) financial services training 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 on a wid e 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. Add itionally, 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. The MA segment develops a wide range of products and services that support financial analysis and risk management activities of institutional participants in global fina ncial markets. Within its RD&A business, MA distributes research and data developed by MIS as part of its ratings process, including in-depth research on major debt issuers, industry studies and commentary on topical credit-related events. The RD&A busines s also produces economic research and data and analytical tools such as quantitative credit risk scores as well as business intelligence and company information products. Within its ERS business, MA provides software solutions as well as related risk manag ement services. The PS business provides offshore analytical and research services along with financial training and certification programs. 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 2017 annual report on Form 10-K filed with the SEC on February 27, 2018 . 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 a nd 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 A merica. Certain reclassifications have been made to prior period amounts to conform to the current presentation. Adoption of New Accounting Standard s On January 1, 2018, the Company adopted ASU No. 2014-09, “Revenue from Contracts with Customers (ASC Topic 606)” using the modified retrospective approach which Moody’s has elected to apply only to those contracts which were not completed as of January 1, 2018. Additionally, the Company has not retrospectively restated contract positions for contract modifications made prior to the adoption. ASU No. 2014-09 also includes updates related to the accounting for the deferral of incremental costs of obtaining or fulfi lling a contract with a customer (“ASC Subtopic 340-40”). Hereunder, discussion of the provisions of ASC Topic 606 and ASC Subtopic 340-40 are both individually and collectively referred to as the “New Revenue Accounting Standard.” Results for reporting pe riods beginning on January 1, 2018 are presented under the guidance set forth in the New Revenue Accounting Standard, while prior period amounts have not been adjusted and continue to be reported in accordance with the previous accounting guidance. The mo st significant impacts to the Company’s financial statements from adopting the New Revenue Accounting Standard are primarily related to: i) the accounting for certain installed software subscription revenue in MA whereby the license rights within the arran gement are recognized at the inception of the contract based on SSP with the remainder recognized over the subscription period (compared to ASC Topic 605 whereby all installed software subscription revenue was previously recognized over the subscription pe riod); ii) the accounting for certain ERS and ESA revenue arrangements where VSOE was not available under ASC Topic 605 now results in the acceleration of revenue recognition (compared to ASC Topic 605 whereby revenue was deferred due to lack of VSOE until all elements without VSOE had been delivered); iii) sales commissions incurred in the MA segment will be capitaliz ed and amortized over an extended period which is generally based upon the average economic life of products/services sold and incorporates a nticipated subscription renewals ( compared to previous accounting guidance whereby capitalized sales commissions were amortized over the committed subscription period only ); iv) the immediate expensing of software implementation project costs to fulfill a contract for its ERS and ESA businesses which under previous accounting guidance were capitalized and expensed when related project revenue was recognized; v) the capitalization of work-in-process costs for in-progress MIS ratings at the end of each report ing period which under ASC Topic 605 were expensed as incurred ; vi ) the timing of when revenue for certain MIS ratings products is recognized; and vii) the estimation of variable consideration at contract inception whereas under ASC Topic 605 companies were not required to consider the amount of consideration for which it expect ed to be entitled . The Company does not anticipate that applying the provisions of the N ew Revenue Accounting S tandard will have a material impact to its 2018 consolidated Net Inc ome. However, there could be quarterly fluctuations in the financial results of both MIS and MA, or there could be increases or decreases in revenues and expenses which would largely offset and not be material to total consolidated Net Income for the full year. The table below provide s detail relating to the adjustment to the Company’s retained earnings balance upon adoption of the New Revenue Accounting Standard: Transition adjustment Benefit to / (reduction of) January 1, 2018 Retained Earnings Corresponding Balance Sheet Line Item Recognition of MA deferred revenue / increase in MA unbilled receivables (1) $108 million Deferred revenue, Non-current portion of deferred revenue, Accounts receivable, Other assets Increase to capitalized MA sales commissions (2) $78 million Other current assets, Other assets, Accounts payable and accrued liabilities Capitalization of work-in-process for in-progress ratings $9 million Other current assets Net impact of all other adjustments $4 million Various Net increase in tax liability on the above ($43 million) Deferred tax liabilities, net Total post-tax adjustment $156 million (1) Represents deferred revenue as of December 31, 2017 as well as amounts then unbilled that would have been recognized as revenue in 2017 or earlier if the New Revenue Standard was then in effect. These amounts will not be recognized as revenue in future statements of operations. Conversely, revenue will be recorded to the Company's statement of operations in 2018 under the New Revenue Accounting Standard, which otherwise would have been recognized in periods subsequent to 2018 if accounted for under ASC Topic 605. (2) Represents sales commissions that would have been capitalized as of December 31, 2017 if the New Revenue Accounting Standard was then in effect, but had previously been expensed by the Company under the previous accounting guidance. These sales commissions, as well as sales commissions incurred in 2018 related to new sales and renewals, will be amortized to expense in the statements of operations beginning in 2018 over an extended period generally based upon the average economic life of the products sold or over the period in which implementation and advisory services will be provided. The table below presents the cumulative effect of the changes made to the Company’s consolidated balance sheet at January 1, 2018 for the adoption of the New Revenue Accounting Standard : As reported December 31, 2017 Adjustment Due to New Revenue Accounting Standard Balance at January 1, 2018 ASSETS Current assets: Cash and cash equivalents $ 1,071.5 $ - $ 1,071.5 Short-term investments 111.8 - 111.8 Accounts receivable, net of allowances 1,147.2 16.8 1,164.0 Other current assets 250.1 32.9 283.0 Total current assets 2,580.6 49.7 2,630.3 Property and equipment, net 325.1 - 325.1 Goodwill 3,753.2 - 3,753.2 Intangible assets, net 1,631.6 - 1,631.6 Deferred tax assets, net 143.8 - 143.8 Other assets 159.9 71.3 231.2 Total assets 8,594.2 121.0 8,715.2 LIABILITIES, NONCONTROLLING INTERESTS AND SHAREHOLDERS' (DEFICIT)/EQUITY Current liabilities: Accounts payable and accrued liabilities 750.3 (0.8) 749.5 Commercial paper 129.9 - 129.9 Current portion of long-term debt 299.5 - 299.5 Deferred revenue 883.6 (69.3) 814.3 Total current liabilities 2,063.3 (70.1) 1,993.2 Non-current portion of deferred revenue 140.0 (8.0) 132.0 Long-term debt 5,111.1 - 5,111.1 Deferred tax liabilities, net 341.6 42.7 384.3 Unrecognized tax benefits 389.1 - 389.1 Other liabilities 664.0 0.3 664.3 Total liabilities 8,709.1 (35.1) 8,674.0 Shareholders' (deficit) equity: Common stock 3.4 - 3.4 Capital surplus 528.6 - 528.6 Retained earnings 7,465.4 156.1 7,621.5 Treasury stock (8,152.9) - (8,152.9) Accumulated other comprehensive loss (172.2) - (172.2) Total Moody's shareholders' (deficit) equity (327.7) 156.1 (171.6) Noncontrolling interests 212.8 - 212.8 Total shareholders' (deficit) equity (114.9) 156.1 41.2 Total liabilities, noncontrolling interests and shareholders' (deficit) equity $ 8,594.2 $ 121.0 $ 8,715.2 The below table presents the impacts on the Company’s statement of operations for the current reporting period from applying the provisions of the New Revenue Accounting Standard compared to the accounting standard in effect before the change: For the Three Months Ended March 31, 2018 As Reported Under previous accounting guidance Effect of Change Higher/(Lower) Revenue $ 1,126.7 $ 1,126.4 $ 0.3 Expenses Operating 314.9 315.5 (0.6) Selling, general and administrative 271.1 271.5 (0.4) Depreciation and amortization 49.1 49.1 - Acquisition-related expenses 0.8 0.8 - Total expenses 635.9 636.9 (1.0) Operating income 490.8 489.5 1.3 Non-operating (expense) income, net Interest expense, net (50.7) (50.7) - Other non-operating income (expense), net 1.0 1.0 - Total non-operating (expense) income, net (49.7) (49.7) - Income before provision for income taxes 441.1 439.8 1.3 Provision for income taxes 64.3 63.5 0.8 Net income 376.8 376.3 0.5 Less: Net income attributable to noncontrolling interests 3.9 3.9 - Net income attributable to Moody's $ 372.9 $ 372.4 $ 0.5 Earnings per share Basic $ 1.95 $ 1.95 $ - Diluted $ 1.92 $ 1.91 $ 0.01 Weighted average shares outstanding Basic 191.4 191.4 Diluted 194.5 194.5 The below table presents the impacts on the Company’s consolidated balance sheet at the end of the current reporting period from applying the provisions of the New Revenue Accounting Standard compared to the accounting standard in effect before the change: As Reported March 31, 2018 Under previous accounting guidance March 31, 2018 Effect of Change Higher/(Lower) ASSETS Current assets: Cash and cash equivalents $ 1,277.3 $ 1,277.3 $ - Short-term investments 100.5 100.5 - Accounts receivable, net of allowances 1,207.4 1,183.0 24.4 Other current assets 233.6 212.4 21.2 Total current assets: 2,818.8 2,773.2 45.6 Property and equipment, net 321.6 321.6 - Goodwill 3,831.5 3,831.5 - Intangible assets, net 1,641.6 1,641.6 - Deferred tax assets, net 142.5 142.6 (0.1) Other assets 258.0 182.8 75.2 Total assets $ 9,014.0 $ 8,893.3 $ 120.7 LIABILITIES, NONCONTROLLING INTERESTS AND SHAREHOLDERS' EQUITY Accounts payable and accrued liabilities $ 532.6 $ 532.5 $ 0.1 Commercial paper 89.9 89.9 - Current portion of long-term debt 299.7 299.7 - Deferred revenue 998.7 1,065.6 (66.9) Total current liabilities 1,920.9 1,987.7 (66.8) Non-current portion of deferred revenue 127.8 135.0 (7.2) Long-term debt 5,118.0 5,118.0 - Deferred tax liabilities, net 382.2 348.7 33.5 Unrecognized tax benefits 490.9 490.9 - Other liabilities 554.2 553.9 0.3 Total liabilities 8,594.0 8,634.2 (40.2) Shareholders' equity: Common stock 3.4 3.4 - Capital surplus 506.6 506.6 - Retained earnings 7,913.0 7,752.1 160.9 Treasury stock (8,171.4) (8,171.4) - Accumulated other comprehensive loss (51.9) (51.9) - Total Moody's shareholders' equity 199.7 38.8 160.9 Noncontrolling interests 220.3 220.3 - Total shareholders' equity 420.0 259.1 160.9 Total liabilities, noncontrolling interests and shareholders' equity $ 9,014.0 $ 8,893.3 $ 120.7 The below table presents the impacts on various line items within the operating cash flow within the Company’s statement of cash flows for the current reporting period from applying the provisions of the New Revenue Accounting Standard compared to the accounting standard in effect before the change. For the Three Months Ended March 31, 2018 As Reported Under previous accounting guidance Effect of Change Cash flows from operating activities Net income $ 376.8 $ 376.3 $ 0.5 Reconciliation of net income to net cash provided by operating activities: Depreciation and amortization 49.1 49.1 - Stock-based compensation 35.1 35.1 - Deferred income taxes (4.2) 4.0 (8.2) Changes in assets and liabilities: Accounts receivable (29.9) (22.3) (7.6) Other current assets 47.8 36.1 11.7 Other assets (14.5) (10.6) (3.9) Accounts payable and accrued liabilities (224.2) (229.4) 5.2 Deferred revenue 167.7 164.5 3.2 Unrecognized tax benefits and other non-current tax liabilities (17.9) (17.9) - Other liabilities 5.7 6.6 (0.9) Net cash provided by operating activities $ 391.5 $ 391.5 $ - The New Revenue Accounting Standard did not have any impact on individual line items within investing or financing cash flow s in the Company’s consolidated statement of cash flow s . In 2018, the adoption of the New Revenue Accounting Standard will likely result in higher cash taxes as the cumulative catch-up adjustment to retained earnings is taxable and there is expected to be acceleration of revenue recognition under the New Revenue Accounting Standard. On January 1 , 2018, the Company adopted ASU No. 2 017-07, “Compensation—Retirement Benefits (Topic 715), Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost”. As required by this ASU , the components of net periodic pension costs were disaggregated in the s tatement of operations on a retrospective basis. The Company has continued to reflect the service cost component in either Operating or SG&A expenses in M oody’s statement of operations . The other components of net benefit cost are presented within non-oper ating (expense) income, net, within the statement of operations. The adoption of this ASU has no impact on Net Income in the Company’s statements of operations. The impact to the Company’s statements of operations for the three months ended March 31, 2018 and March 31, 2017 related to the adoption of this ASU are set forth in the table below: For the Three Months Ended March 31, 2018 For the Three Months Ended March 31, 2017 As Reported Under previous accounting guidance Effect of Change Higher/(Lower) As Adjusted Under previous accounting guidance Effect of Change Higher/(Lower) Operating expenses $ 314.9 $ 316.3 $ (1.4) $ 275.3 $ 277.4 $ (2.1) Selling, general and administrative expenses 271.1 272.0 (0.9) 220.7 221.9 (1.2) Operating income 490.8 488.5 2.3 446.7 443.4 3.3 Interest expense, net (50.7) (46.0) 4.7 (47.4) (42.4) 5.0 Other non-operating income (expense), net 1.0 (1.4) 2.4 (7.7) (9.4) (1.7) On January 1, 2018, the Company adopted ASU No. 2016-01 “Financial Instruments—Overall (Subtopic 825-10), Recognition and Measurement of Financial Assets and Financial Liabilities” (“ASU 2016-01”). The amendments in this ASU update various aspects of recognition, measurement, presentation and disclosures relating to financial instruments. Upon adoption, the Company recorded a $2.3 million cumulative adjustment to reclassify net unrealized gains on investments in equity securities previously classified as available-for-sale under the previous guidance from AOCI to retained earnings. Beginning in the first quarter of 2018, the Company will measure equity investments with readily determinable fair values (except those accounted for under the equity method , those that result in consolidation of the investee and certain other investments) at fair value and recognize any changes in fair value in net income . The adoption of this ASU did not have material impact on the Company’s financial statements for the thr ee months ended March 31, 2018.

DESCRIPTION OF BUSINESS AND BA9

DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION (Tables)	3 Months Ended
	Mar. 31, 2018
Schedule of Cumulative Adjustment to Retained earnings due to prospective adoption of new revenue guidance	Transition adjustment Benefit to / (reduction of) January 1, 2018 Retained Earnings Corresponding Balance Sheet Line Item Recognition of MA deferred revenue / increase in MA unbilled receivables (1) $108 million Deferred revenue, Non-current portion of deferred revenue, Accounts receivable, Other assets Increase to capitalized MA sales commissions (2) $78 million Other current assets, Other assets, Accounts payable and accrued liabilities Capitalization of work-in-process for in-progress ratings $9 million Other current assets Net impact of all other adjustments $4 million Various Net increase in tax liability on the above ($43 million) Deferred tax liabilities, net Total post-tax adjustment $156 million (1) Represents deferred revenue as of December 31, 2017 as well as amounts then unbilled that would have been recognized as revenue in 2017 or earlier if the New Revenue Standard was then in effect. These amounts will not be recognized as revenue in future statements of operations. Conversely, revenue will be recorded to the Company's statement of operations in 2018 under the New Revenue Accounting Standard, which otherwise would have been recognized in periods subsequent to 2018 if accounted for under ASC Topic 605. (2) Represents sales commissions that would have been capitalized as of December 31, 2017 if the New Revenue Accounting Standard was then in effect, but had previously been expensed by the Company under the previous accounting guidance. These sales commissions, as well as sales commissions incurred in 2018 related to new sales and renewals, will be amortized to expense in the statements of operations beginning in 2018 over an extended period generally based upon the average economic life of the products sold or over the period in which implementation and advisory services will be provided.
New Revenue Accounting Standard [Member] | Balance Sheets [Member]
Schedule of New Accounting Pronouncements and Changes in Accounting Principles	As Reported March 31, 2018 Under previous accounting guidance March 31, 2018 Effect of Change Higher/(Lower) ASSETS Current assets: Cash and cash equivalents $ 1,277.3 $ 1,277.3 $ - Short-term investments 100.5 100.5 - Accounts receivable, net of allowances 1,207.4 1,183.0 24.4 Other current assets 233.6 212.4 21.2 Total current assets: 2,818.8 2,773.2 45.6 Property and equipment, net 321.6 321.6 - Goodwill 3,831.5 3,831.5 - Intangible assets, net 1,641.6 1,641.6 - Deferred tax assets, net 142.5 142.6 (0.1) Other assets 258.0 182.8 75.2 Total assets $ 9,014.0 $ 8,893.3 $ 120.7 LIABILITIES, NONCONTROLLING INTERESTS AND SHAREHOLDERS' EQUITY Accounts payable and accrued liabilities $ 532.6 $ 532.5 $ 0.1 Commercial paper 89.9 89.9 - Current portion of long-term debt 299.7 299.7 - Deferred revenue 998.7 1,065.6 (66.9) Total current liabilities 1,920.9 1,987.7 (66.8) Non-current portion of deferred revenue 127.8 135.0 (7.2) Long-term debt 5,118.0 5,118.0 - Deferred tax liabilities, net 382.2 348.7 33.5 Unrecognized tax benefits 490.9 490.9 - Other liabilities 554.2 553.9 0.3 Total liabilities 8,594.0 8,634.2 (40.2) Shareholders' equity: Common stock 3.4 3.4 - Capital surplus 506.6 506.6 - Retained earnings 7,913.0 7,752.1 160.9 Treasury stock (8,171.4) (8,171.4) - Accumulated other comprehensive loss (51.9) (51.9) - Total Moody's shareholders' equity 199.7 38.8 160.9 Noncontrolling interests 220.3 220.3 - Total shareholders' equity 420.0 259.1 160.9 Total liabilities, noncontrolling interests and shareholders' equity $ 9,014.0 $ 8,893.3 $ 120.7
New Revenue Accounting Standard [Member] | Income Statement [Member]
Schedule of New Accounting Pronouncements and Changes in Accounting Principles	For the Three Months Ended March 31, 2018 As Reported Under previous accounting guidance Effect of Change Higher/(Lower) Revenue $ 1,126.7 $ 1,126.4 $ 0.3 Expenses Operating 314.9 315.5 (0.6) Selling, general and administrative 271.1 271.5 (0.4) Depreciation and amortization 49.1 49.1 - Acquisition-related expenses 0.8 0.8 - Total expenses 635.9 636.9 (1.0) Operating income 490.8 489.5 1.3 Non-operating (expense) income, net Interest expense, net (50.7) (50.7) - Other non-operating income (expense), net 1.0 1.0 - Total non-operating (expense) income, net (49.7) (49.7) - Income before provision for income taxes 441.1 439.8 1.3 Provision for income taxes 64.3 63.5 0.8 Net income 376.8 376.3 0.5 Less: Net income attributable to noncontrolling interests 3.9 3.9 - Net income attributable to Moody's $ 372.9 $ 372.4 $ 0.5 Earnings per share Basic $ 1.95 $ 1.95 $ - Diluted $ 1.92 $ 1.91 $ 0.01 Weighted average shares outstanding Basic 191.4 191.4 Diluted 194.5 194.5
New Revenue Accounting Standard [Member] | Cash Flow [Member]
Schedule of New Accounting Pronouncements and Changes in Accounting Principles	For the Three Months Ended March 31, 2018 As Reported Under previous accounting guidance Effect of Change Cash flows from operating activities Net income $ 376.8 $ 376.3 $ 0.5 Reconciliation of net income to net cash provided by operating activities: Depreciation and amortization 49.1 49.1 - Stock-based compensation 35.1 35.1 - Deferred income taxes (4.2) 4.0 (8.2) Changes in assets and liabilities: Accounts receivable (29.9) (22.3) (7.6) Other current assets 47.8 36.1 11.7 Other assets (14.5) (10.6) (3.9) Accounts payable and accrued liabilities (224.2) (229.4) 5.2 Deferred revenue 167.7 164.5 3.2 Unrecognized tax benefits and other non-current tax liabilities (17.9) (17.9) - Other liabilities 5.7 6.6 (0.9) Net cash provided by operating activities $ 391.5 $ 391.5 $ -
Compensation-Retirement Benefits Accounting Standard [Member] | Income Statement [Member]
Schedule of New Accounting Pronouncements and Changes in Accounting Principles	For the Three Months Ended March 31, 2018 For the Three Months Ended March 31, 2017 As Reported Under previous accounting guidance Effect of Change Higher/(Lower) As Adjusted Under previous accounting guidance Effect of Change Higher/(Lower) Operating expenses $ 314.9 $ 316.3 $ (1.4) $ 275.3 $ 277.4 $ (2.1) Selling, general and administrative expenses 271.1 272.0 (0.9) 220.7 221.9 (1.2) Operating income 490.8 488.5 2.3 446.7 443.4 3.3 Interest expense, net (50.7) (46.0) 4.7 (47.4) (42.4) 5.0 Other non-operating income (expense), net 1.0 (1.4) 2.4 (7.7) (9.4) (1.7)
Cumulative Effect on Start Period [Member] | New Revenue Accounting Standard [Member] | Balance Sheets [Member]
Schedule of New Accounting Pronouncements and Changes in Accounting Principles	As reported December 31, 2017 Adjustment Due to New Revenue Accounting Standard Balance at January 1, 2018 ASSETS Current assets: Cash and cash equivalents $ 1,071.5 $ - $ 1,071.5 Short-term investments 111.8 - 111.8 Accounts receivable, net of allowances 1,147.2 16.8 1,164.0 Other current assets 250.1 32.9 283.0 Total current assets 2,580.6 49.7 2,630.3 Property and equipment, net 325.1 - 325.1 Goodwill 3,753.2 - 3,753.2 Intangible assets, net 1,631.6 - 1,631.6 Deferred tax assets, net 143.8 - 143.8 Other assets 159.9 71.3 231.2 Total assets 8,594.2 121.0 8,715.2 LIABILITIES, NONCONTROLLING INTERESTS AND SHAREHOLDERS' (DEFICIT)/EQUITY Current liabilities: Accounts payable and accrued liabilities 750.3 (0.8) 749.5 Commercial paper 129.9 - 129.9 Current portion of long-term debt 299.5 - 299.5 Deferred revenue 883.6 (69.3) 814.3 Total current liabilities 2,063.3 (70.1) 1,993.2 Non-current portion of deferred revenue 140.0 (8.0) 132.0 Long-term debt 5,111.1 - 5,111.1 Deferred tax liabilities, net 341.6 42.7 384.3 Unrecognized tax benefits 389.1 - 389.1 Other liabilities 664.0 0.3 664.3 Total liabilities 8,709.1 (35.1) 8,674.0 Shareholders' (deficit) equity: Common stock 3.4 - 3.4 Capital surplus 528.6 - 528.6 Retained earnings 7,465.4 156.1 7,621.5 Treasury stock (8,152.9) - (8,152.9) Accumulated other comprehensive loss (172.2) - (172.2) Total Moody's shareholders' (deficit) equity (327.7) 156.1 (171.6) Noncontrolling interests 212.8 - 212.8 Total shareholders' (deficit) equity (114.9) 156.1 41.2 Total liabilities, noncontrolling interests and shareholders' (deficit) equity $ 8,594.2 $ 121.0 $ 8,715.2

Adjustment to Retained Earnings

Adjustment to Retained Earnings (Detail) - Retained Earnings [Member] - New Revenue Accounting Standard [Member] $ in Millions	Mar. 31, 2018USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Item]
Effect of adoption adjustment Reduction to retained earnings	$ 156
Capitalization of Work-In-Process for In-Progress Ratings [Member] | Other Current Assets [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Item]
Effect of adoption adjustment Reduction to retained earnings	9
Other Adjustments [Member] | Various Assets [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Item]
Effect of adoption adjustment Reduction to retained earnings	4
Increase in Tax Liability [Member] | Deferred Tax Liabilities [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Item]
Effect of adoption adjustment Reduction to retained earnings	(43)
MA [Member] | Recognition of Deferred Revenue / Increase in Unbilled Receivables [Member] | Deferred Revenue Accounts Receivable and Other Assets [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Item]
Effect of adoption adjustment Reduction to retained earnings	108
MA [Member] | Increase to Capitalized Sales Commissions [Member] | Other current assets, Other assets, Accounts Payable and Accrued Liabilities [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Item]
Effect of adoption adjustment Reduction to retained earnings	$ 78

Cumulative Effect of the Change

Cumulative Effect of the Change in Beginning Financial Position for the adoption of Revenue Accounting Standard (Detail) - USD ($) $ in Millions	Mar. 31, 2018	Jan. 01, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 1,277.3		$ 1,071.5	$ 2,129.6	$ 2,051.5
Short-term investments	100.5		111.8
Accounts receivable, net of allowances	1,207.4		1,147.2
Other current assets	233.6		250.1
Assets Current	2,818.8		2,580.6
Property and equipment, net	321.6		325.1
Goodwill	3,831.5		3,753.2		1,023.6
Intangible assets, net	1,641.6		1,631.6
Deferred tax assets, net	142.5		143.8
Other assets	258		159.9
Total Assets	9,014		8,594.2
Current liabilities:
Accounts payable and accrued liabilities	532.6		750.3
Commercial paper	89.9		129.9
Current portion of long-term debt	299.7		299.5
Deferred revenue	998.7		883.6
Total current liabilities	1,920.9		2,063.3
Non-current portion of deferred revenue	127.8		140
Long-term debt	5,118		5,111.1
Deferred tax liabilities, net	382.2		341.6
Unrecognized tax benefits	490.9		389.1
Other liabilities	554.2		664
Total liabilities	8,594		8,709.1
Shareholders' (deficit) equity
Common stock	3.4		3.4
Capital surplus	506.6		528.6
Retained earnings	7,913		7,465.4
Treasury stock, value	(8,171.4)		(8,152.9)
Accumulated other comprehensive loss	(51.9)		(172.2)	$ (357.3)	$ (364.9)
Total Moody's shareholders' deficit	199.7		(327.7)
Noncontrolling interests	220.3		212.8
Total shareholders' deficit	420		(114.9)
Total liabilities and shareholders' (deficit) equity	9,014		$ 8,594.2
New Revenue Accounting Standard [Member]
Current assets:
Cash and cash equivalents		$ 1,071.5
Short-term investments		111.8
Accounts receivable, net of allowances		1,164
Other current assets		283
Assets Current		2,630.3
Property and equipment, net		325.1
Goodwill		3,753.2
Intangible assets, net		1,631.6
Deferred tax assets, net		143.8
Other assets		231.2
Total Assets		8,715.2
Current liabilities:
Accounts payable and accrued liabilities		749.5
Commercial paper		129.9
Current portion of long-term debt		299.5
Deferred revenue		814.3
Total current liabilities		1,993.2
Non-current portion of deferred revenue		132
Long-term debt		5,111.1
Deferred tax liabilities, net		384.3
Unrecognized tax benefits		389.1
Other liabilities		664.3
Total liabilities		8,674
Shareholders' (deficit) equity
Common stock		3.4
Capital surplus		528.6
Retained earnings		7,621.5
Treasury stock, value		(8,152.9)
Accumulated other comprehensive loss		(172.2)
Total Moody's shareholders' deficit		(171.6)
Noncontrolling interests		212.8
Total shareholders' deficit		41.2
Total liabilities and shareholders' (deficit) equity		8,715.2
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | New Revenue Accounting Standard [Member]
Current assets:
Accounts receivable, net of allowances	24.4	16.8
Other current assets	21.2	32.9
Assets Current	45.6	49.7
Deferred tax assets, net	(0.1)
Other assets	75.2	71.3
Total Assets	120.7	121
Current liabilities:
Accounts payable and accrued liabilities	0.1	(0.8)
Deferred revenue	(66.9)	(69.3)
Total current liabilities	(66.8)	(70.1)
Non-current portion of deferred revenue	(7.2)	(8)
Deferred tax liabilities, net	33.5	42.7
Other liabilities	0.3	0.3
Total liabilities	(40.2)	(35.1)
Shareholders' (deficit) equity
Retained earnings	160.9	156.1
Total Moody's shareholders' deficit	160.9	156.1
Total shareholders' deficit	160.9	156.1
Total liabilities and shareholders' (deficit) equity	$ 120.7	$ 121

Effect of Change in Income Stat

Effect of Change in Income Statement due to adoption of Revenue Accounting Standard (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenues	$ 1,126.7	$ 975.2
Expenses
Operating	314.9	275.3
Selling, general and administrative	271.1	220.7
Depreciation and amortization	49.1	32.5
Acquisition-Related Expenses	0.8
Total expenses	635.9	528.5
Operating income	490.8	446.7
Non-operating (expense) income, net
Interest income (expense), net	(50.7)	(47.4)
Other non-operating income (expense), net	1	(7.7)
Total non-operating (expense) income, net	(49.7)	4.6
Income before provisions for income taxes	441.1	451.3
Provision for income taxes	64.3	105.4
Net income	376.8	345.9
Less: Net income attributable to noncontrolling interests	3.9	0.3
Net income attributable to Moody's	$ 372.9	$ 345.6
Earnings per share attributable to Moody's common shareholders
Basic	$ 1.95	$ 1.81
Diluted	$ 1.92	$ 1.78
Weighted average number of shares outstanding
Basic	191.4	191.1
Diluted	194.5	194.3
Under Previous Accounting Guidance [Member] | New Revenue Accounting Standard [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenues	$ 1,126.4
Expenses
Operating	315.5
Selling, general and administrative	271.5
Depreciation and amortization	49.1
Acquisition-Related Expenses	0.8
Total expenses	636.9
Operating income	489.5
Non-operating (expense) income, net
Interest income (expense), net	(50.7)
Other non-operating income (expense), net	1
Total non-operating (expense) income, net	(49.7)
Income before provisions for income taxes	439.8
Provision for income taxes	63.5
Net income	376.3
Less: Net income attributable to noncontrolling interests	3.9
Net income attributable to Moody's	$ 372.4
Earnings per share attributable to Moody's common shareholders
Basic	$ 1.95
Diluted	$ 1.91
Weighted average number of shares outstanding
Basic	191.4
Diluted	194.5
Effect of Change [Member] | New Revenue Accounting Standard [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenues	$ 0.3
Expenses
Operating	(0.6)
Selling, general and administrative	(0.4)
Total expenses	(1)
Operating income	1.3
Non-operating (expense) income, net
Income before provisions for income taxes	1.3
Provision for income taxes	0.8
Net income	0.5
Net income attributable to Moody's	$ 0.5
Earnings per share attributable to Moody's common shareholders
Diluted	$ 0.01

Effect of Change in Balance She

Effect of Change in Balance Sheets from applying the Provision of the Revenue Accounting Standard (Detail) - USD ($) $ in Millions	Mar. 31, 2018	Jan. 01, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 1,277.3		$ 1,071.5	$ 2,129.6	$ 2,051.5
Short-term investments	100.5		111.8
Accounts receivable, net of allowances	1,207.4		1,147.2
Other current assets	233.6		250.1
Total current assets	2,818.8		2,580.6
Property and equipment, net	321.6		325.1
Goodwill	3,831.5		3,753.2		1,023.6
Intangible assets, net	1,641.6		1,631.6
Deferred tax assets, net	142.5		143.8
Other assets	258		159.9
Total Assets	9,014		8,594.2
Current liabilities:
Accounts payable and accrued liabilities	532.6		750.3
Commercial Paper	89.9		129.9
Current portion of long-term debt	299.7		299.5
Deferred revenue	998.7		883.6
Liabilities Current	1,920.9		2,063.3
Non-current portion of deferred revenue	127.8		140
Long-term debt	5,118		5,111.1
Deferred tax liabilities, net	382.2		341.6
Unrecognized tax benefits	490.9		389.1
Other liabilities	554.2		664
Total liabilities	8,594		8,709.1
Shareholders' (deficit) equity
Common stock	3.4		3.4
Capital surplus	506.6		528.6
Retained earnings	7,913		7,465.4
Treasury stock, value	(8,171.4)		(8,152.9)
Accumulated other comprehensive loss	(51.9)		(172.2)	$ (357.3)	$ (364.9)
Total Moody's shareholders' deficit	199.7		(327.7)
Noncontrolling interests	220.3		212.8
Total shareholders' deficit	420		(114.9)
Total liabilities and shareholders' (deficit) equity	9,014		$ 8,594.2
New Revenue Accounting Standard [Member]
Current assets:
Cash and cash equivalents		$ 1,071.5
Short-term investments		111.8
Accounts receivable, net of allowances		1,164
Other current assets		283
Total current assets		2,630.3
Property and equipment, net		325.1
Goodwill		3,753.2
Intangible assets, net		1,631.6
Deferred tax assets, net		143.8
Other assets		231.2
Total Assets		8,715.2
Current liabilities:
Accounts payable and accrued liabilities		749.5
Commercial Paper		129.9
Current portion of long-term debt		299.5
Deferred revenue		814.3
Liabilities Current		1,993.2
Non-current portion of deferred revenue		132
Long-term debt		5,111.1
Deferred tax liabilities, net		384.3
Unrecognized tax benefits		389.1
Other liabilities		664.3
Total liabilities		8,674
Shareholders' (deficit) equity
Common stock		3.4
Capital surplus		528.6
Retained earnings		7,621.5
Treasury stock, value		(8,152.9)
Accumulated other comprehensive loss		(172.2)
Total Moody's shareholders' deficit		(171.6)
Noncontrolling interests		212.8
Total shareholders' deficit		41.2
Total liabilities and shareholders' (deficit) equity		8,715.2
Under Previous Accounting Guidance [Member] | New Revenue Accounting Standard [Member]
Current assets:
Cash and cash equivalents	1,277.3
Short-term investments	100.5
Accounts receivable, net of allowances	1,183
Other current assets	212.4
Total current assets	2,773.2
Property and equipment, net	321.6
Goodwill	3,831.5
Intangible assets, net	1,641.6
Deferred tax assets, net	142.6
Other assets	182.8
Total Assets	8,893.3
Current liabilities:
Accounts payable and accrued liabilities	532.5
Commercial Paper	89.9
Current portion of long-term debt	299.7
Deferred revenue	1,065.6
Liabilities Current	1,987.7
Non-current portion of deferred revenue	135
Long-term debt	5,118
Deferred tax liabilities, net	348.7
Unrecognized tax benefits	490.9
Other liabilities	553.9
Total liabilities	8,634.2
Shareholders' (deficit) equity
Common stock	3.4
Capital surplus	506.6
Retained earnings	7,752.1
Treasury stock, value	8,171.4
Accumulated other comprehensive loss	(51.9)
Total Moody's shareholders' deficit	38.8
Noncontrolling interests	220.3
Total shareholders' deficit	259.1
Total liabilities and shareholders' (deficit) equity	8,893.3
Effect of Change [Member] | New Revenue Accounting Standard [Member]
Current assets:
Accounts receivable, net of allowances	24.4	16.8
Other current assets	21.2	32.9
Total current assets	45.6	49.7
Deferred tax assets, net	(0.1)
Other assets	75.2	71.3
Total Assets	120.7	121
Current liabilities:
Accounts payable and accrued liabilities	0.1	(0.8)
Deferred revenue	(66.9)	(69.3)
Liabilities Current	(66.8)	(70.1)
Non-current portion of deferred revenue	(7.2)	(8)
Deferred tax liabilities, net	33.5	42.7
Other liabilities	0.3	0.3
Total liabilities	(40.2)	(35.1)
Shareholders' (deficit) equity
Retained earnings	160.9	156.1
Total Moody's shareholders' deficit	160.9	156.1
Total shareholders' deficit	160.9	156.1
Total liabilities and shareholders' (deficit) equity	$ 120.7	$ 121

Effect of Change within Cash Fl

Effect of Change within Cash Flow from applying the Provision of the Revenue Accounting Standard (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities
Net income	$ 376.8	$ 345.9
Reconciliation of net income to net cash provided by operating activities:
Depreciation and amortization	49.1	32.5
Stock-based compensation expense	35.1	28.4
Deferred income taxes	(4.2)	185
Changes in assets and liabilities:
Accounts receivable	(29.9)	(61.9)
Other current assets	47.8	(128.3)
Other assets	(14.5)	(3.2)
Accounts payable and accrued liabilities	(224.2)	(988.6)
Deferred revenue	167.7	125.9
Unrecognized tax benefits and other non-current tax liabilities	(17.9)	0.9
Other liabilities	5.7	10.7
Net cash provided by (used in) operating activities	391.5	$ (512.4)
Under Previous Accounting Guidance [Member] | New Revenue Accounting Standard [Member]
Cash flows from operating activities
Net income	376.3
Reconciliation of net income to net cash provided by operating activities:
Depreciation and amortization	49.1
Stock-based compensation expense	35.1
Deferred income taxes	4
Changes in assets and liabilities:
Accounts receivable	(22.3)
Other current assets	36.1
Other assets	(10.6)
Accounts payable and accrued liabilities	(229.4)
Deferred revenue	164.5
Unrecognized tax benefits and other non-current tax liabilities	(17.9)
Other liabilities	6.6
Net cash provided by (used in) operating activities	391.5
Effect of Change [Member] | New Revenue Accounting Standard [Member]
Cash flows from operating activities
Net income	0.5
Reconciliation of net income to net cash provided by operating activities:
Deferred income taxes	(8.2)
Changes in assets and liabilities:
Accounts receivable	(7.6)
Other current assets	11.7
Other assets	(3.9)
Accounts payable and accrued liabilities	5.2
Deferred revenue	3.2
Other liabilities	$ (0.9)

Effect of Change within Income

Effect of Change within Income Statement related to the Adoption of New Compensation - Retirement Benefit Policy (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Item]
Operating expenses	$ 314.9	$ 275.3
Selling, general and administrative	271.1	220.7
Operating income	490.8	446.7
Interest expense, net	(50.7)	(47.4)
Other non-operating income (expense), net	1	(7.7)
Compensation-Retirement Benefits Accounting Standard [Member] | Previous Accounting Guidance [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Item]
Operating expenses	316.3	277.4
Selling, general and administrative	272	221.9
Operating income	488.5	443.4
Interest expense, net	(46)	(42.4)
Other non-operating income (expense), net	(1.4)	(9.4)
Compensation-Retirement Benefits Accounting Standard [Member] | Effect of Change [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Item]
Operating expenses	(1.4)	(2.1)
Selling, general and administrative	(0.9)	(1.2)
Operating income	2.3	3.3
Interest expense, net	4.7	5
Other non-operating income (expense), net	$ 2.4	$ (1.7)

Description of Business and B16

Description of Business and Basis of Presentation - Additional Information (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Item]
Number of reportable segments	2
Accounting Standards Update 2016-01 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Item]
Amount reclassified from AOCI, Available fo Sale Securities - Net of Tax	$ (2.3)

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	3 Months Ended
	Mar. 31, 2018
Text Block [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	NOTE 2 . SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES The Company adopted the New Revenue Accounting Standard on January 1, 2018 using the modified retrospective transition method. Below are the Company’s revised accounting policies reflecting the provisions of the New Revenue Accounting Standard and ASU 2016-01 (as codified under ASC Topic 321) further discussed in Note 1. All other significant accounting policies described in the Form 10-K for the year ended December 31, 2017 remain unchanged. Als o refer to Note 3 of the condensed consolidated financial statements for certain quantitative disclosures relating to the Company’s revenue from contracts with customers. Revenue Recognition and Costs to Obtain or Fulfill a Contract with a Customer Reven ue recognition: Revenue is recognized when control of promised goods or services is transferred to the customer, in an amount that reflects the consideration the Company expects to be entitled to in exchange for those goods or services. When contracts with customers contain multiple performance obligations, the Company accounts for individual performance obligations separately if they are distinct. The transaction price is allocated to each distinct performance obligation on a relative SSP basis. The Compan y determines the SSP by using the price charged for a deliverable when sold separately or uses management’s best estimate of SSP for goods or services not sold separately based on the maximum number of observable data points, including: internal factors re levant to its pricing practices such as costs and margin objectives; standalone sales prices of similar products; percentage of the fee charged for a primary product or service relative to a related product or service; and customer segment and geography. A dditional consideration is also given to market conditions such as competitor pricing strategies and market trends. Sales, usage-based, value added and other taxes are excluded from revenues. MIS Revenue In the MIS segment, revenue arrangements are general ly comprised of two distinct performance obligations, an initial rating and the related monitoring service. Revenue attributed to initial ratings of issued securities is generally recognized when the rating is delivered to the issuer. Revenue attributed to monitoring of issuers or issued securities is recognized ratably over the period in which the monitoring is performed, generally one year. In the case of certain structured finance products, primarily CMBS, issuers can elect to pay all of the annual monit oring fees upfront. These fees are deferred and recognized over the future monitoring periods based on the expected lives of the rated securities. MIS arrangements generally have standard contractual terms for which the stated payments are due at conclusio n of the ratings process for initial ratings and either upfront or in arrears for monitoring services; and are signed by customers either on a per issue basis or at the beginning of the relationship with the customer. However, customer fee arrangements may be adjusted for which the Company accounts for as variable consideration at inception, which is constrained based on the Company’s assessment of the realization of the adjustment amount. The Company allocates the transaction price within arrangements that include both the initial rating and the related monitoring service based upon the relative SSP of each service. The Company generally uses management’s best estimate based on observable pricing points in determining SSP for its initial ratings as the Comp any rarely provides initial ratings separately without providing related monitoring services. The SSP for monitoring fees in these arrangements are generally based upon directly observable selling prices where the monitoring service is sold separately. MA Revenue In the MA segment, products and services offered by the Company include hosted research and data subscriptions, installed software subscriptions, perpetual installed software licenses and related maintenance, or PCS, and professional services. Subs cription and PCS contracts are generally invoiced in advance of the contractual coverage period, which is principally one year, but can range from 3-5 years; while perpetual software licenses are generally invoiced upon delivery and professional services a re invoiced as those services are provided. Payment terms and conditions vary by contract type, but primarily include a requirement of payment within 30 to 60 days. Revenue from research, data and other hosted subscriptions is recognized ratably over the r elated subscription period. A large portion of these services are invoiced in the months of November, December and January. Revenue from the sale of a software license, when considered distinct from the related software implementation services, is generall y recognized at the time the product master or first copy is delivered or transferred to the customer. However, in instances where the software license (perpetual or subscription) and related implementation services are considered to be one combined perfor mance obligation, revenue is recognized on a percentage-of-completion basis (input method) as implementation services are performed over time, which is consistent with the pattern of recognition for the software implementation services if considered to be a separate distinct performance obligation. The Company exercises judgment in determining the level of integration and interdependency between the promise to grant the software license and the promise to deliver the related implementation services. This de termination influences whether the software license is considered distinct and accounted for separately, or not distinct and accounted for together with the implementation services and recognized over time. PCS is generally recognized ratably over the cont ractual period commencing when the software license is fully delivered. Revenue from installed software subscriptions, which includes PCS, is bifurcated into a software license performance obligation and a PCS performance obligation, which follow the patte rns of recognition described above. For implementation services and other service projects within the ERS and ESA LOBs for which fees are fixed, the Company determined progress towards completion is most accurately measured on a percentage-of-completion ba sis (input method) as this approach utilizes the most directly observable data points and is therefore used to recognize the related revenue. For implementation services where price varies based on time expended, a time-based measure of progress towards co mpletion of the performance obligation is utilized. Revenue from professional services rendered within the PS LOB is generally recognized as the services are performed. Products and services offered within the MA segment are sold either stand-alone or toge ther in various combinations. In instances where an arrangement contains multiple performance obligations, the Company accounts for the individual performance obligations separately if they are considered distinct. Revenue is generally allocated to all per formance obligations based upon the relative SSP at contract inception. Judgment is often required to determine the SSP for each distinct performance obligation. Revenue is recognized for each performance obligation based upon the conditions for revenue re cognition noted above. In the MA segment, customers usually pay a fixed fee for the products and services based on signed contracts. However, accounting for variable consideration is applied mainly for: i) estimates for cancellation rights and price conces sions and ii) T&M based services. The Company estimates the variable consideration associated with cancellation rights and price concessions based on the expected amount to be provided to customers and reduces the amount of revenue to be recognized. T&M based contracts represent about half of MA’s service projects within the ERS and ESA LOBs. The Company provides agreed upon services at a contracted daily or hourly rate. The commitment represents a series of goods and services that are substantially the s ame and have the same pattern of transfer to the customer. As such, if T&M services are sold with other MA products, the Company allocates the variable consideration entirely to the T&M performance obligation if the services are sold at standard pricing or at a similar discount level compared to other performance obligations in the same revenue contract. If these criteria are not met, the Company estimates variable consideration for each performance obligation upfront. Each form of variable consideration is included in the transaction price only to the extent that it is probable that a significant reversal of any incremental revenue will not occur. Costs to Obtain or Fulfill a Contract with a Customer: Costs incurred to obtain customer contracts, such as sa les commissions, are deferred and recorded within other current assets and other assets when such costs are determined to be incremental to obtaining a contract, would not have been incurred otherwise and the Company expects to recover those costs. These c osts are amortized to expense consistent with the recognition pattern of the related revenue. Depending on the line of business to which the contract relates, this may be based upon the average economic life of the products sold or average period for which services are provided, inclusive of anticipated contract renewals. Determining the estimated economic life of the products sold requires judgment with respect to anticipated future technological changes. The Company had a balance of $ 95.5 million in such deferred costs as of March 31, 2018 and recognized $ 8.6 million of related amortization during the three-month period ended March 31, 2018, which is included within SG&A expenses in the consolidated statement of operations. Costs incurred to obtain custome r contracts are only in the MA segment. The Company also capitalizes work-in-process costs for in-progress MIS ratings, which is amortized consistent with the rendering of the related services to the customers. The Company had a balance of $ 10.2 million in such deferred costs as of March 31, 2018 and recognized $ 9.4 million of amortization of the costs deferred as of January 1, 2018 during the three-month period ended March 31, 2018, which is included within operating expenses in the consolidated statement of operations. In addition, within the MA segment, the Company capitalizes royalty costs related to third-party information data providers associated with hosted company information and business intelligence products. The Company had a balance of $ 32.4 mil lion in such deferred costs as of March 31, 2018 and recognized $ 14.2 million of related amortization during the three-month period ended March 31, 2018, which is included within operating expenses in the consolidated statement of operations. Fair Value of Financial Instruments The Company’s financial instruments include cash, cash equivalents, trade receivables and payables, all of which are short-term in nature and, accordingly, approximate fair value. Additionally, the Company invests in certain short-te rm investments consisting primarily of certificates of deposit that are carried at cost, which approximates fair value due to their short-term maturities. The Company also has certain investments in closed-ended and open-ended mutual funds in India which a re accounted for as equity securities with readily determinable fair values under ASC Topic 321. Beginning in the first quarter of 2018, the Company will measure these investments at fair value with both realized gains and losses and unrealized holding gai ns and losses for these investments included in net income. Prior to January 1, 2018, the investments in closed-ended and open-ended mutual funds in India were designated as ‘available for sale’ under Topic 320 of the ASC. Accordingly, unrealized gains and losses on these investments were recorded to other comprehensive income and were reclassified out of accumulated other comprehensive income to the statement of operations when the investment matured or was sold using a specific identification method. Also , the Company uses derivative instruments to manage certain financial exposures that occur in the normal course of business. These derivative instruments are carried at fair value on the Company’s consolidated balance sheets. Fair value is defined by the A SC as the price that would be received from selling an asset or paid to transfer a liability (i.e., an exit price) in an orderly transaction between market participants at the measurement date. The determination of this fair value is based on the principal or most advantageous market in which the Company could commence transactions and considers assumptions that market participants would use when pricing the asset or liability, such as inherent risk, transfer restrictions and risk of nonperformance. Also, d etermination of fair value assumes that market participants will consider the highest and best use of the asset. The ASC establishes a fair value hierarchy whereby the inputs contained in valuation techniques used to measure fair value are categorized into three broad levels as follows: Level 1: quoted market prices in active markets that the reporting entity has the ability to access at the date of the fair value measurement; Level 2: inputs other than quoted market prices described in Level 1 that are obs ervable for the asset or liability, either directly or indirectly, such as quoted prices in active markets for similar assets or liabilities, quoted prices for identical or similar assets or liabilities in markets that are not active or other inputs that a re observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities; Level 3: unobservable inputs that are supported by little or no market activity and that are significant to the fair value measurement of the assets or liabilities.

SUMMARY OF SIGNIFICANT ACCOUN18

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	3 Months Ended
	Mar. 31, 2018
Text Block [Abstract]
Revenue Recognition and Costs to Obtain or Fulfill a Contract with a Customer	Revenue Recognition and Costs to Obtain or Fulfill a Contract with a Customer Reven ue recognition: Revenue is recognized when control of promised goods or services is transferred to the customer, in an amount that reflects the consideration the Company expects to be entitled to in exchange for those goods or services. When contracts with customers contain multiple performance obligations, the Company accounts for individual performance obligations separately if they are distinct. The transaction price is allocated to each distinct performance obligation on a relative SSP basis. The Compan y determines the SSP by using the price charged for a deliverable when sold separately or uses management’s best estimate of SSP for goods or services not sold separately based on the maximum number of observable data points, including: internal factors re levant to its pricing practices such as costs and margin objectives; standalone sales prices of similar products; percentage of the fee charged for a primary product or service relative to a related product or service; and customer segment and geography. A dditional consideration is also given to market conditions such as competitor pricing strategies and market trends. Sales, usage-based, value added and other taxes are excluded from revenues. MIS Revenue In the MIS segment, revenue arrangements are general ly comprised of two distinct performance obligations, an initial rating and the related monitoring service. Revenue attributed to initial ratings of issued securities is generally recognized when the rating is delivered to the issuer. Revenue attributed to monitoring of issuers or issued securities is recognized ratably over the period in which the monitoring is performed, generally one year. In the case of certain structured finance products, primarily CMBS, issuers can elect to pay all of the annual monit oring fees upfront. These fees are deferred and recognized over the future monitoring periods based on the expected lives of the rated securities. MIS arrangements generally have standard contractual terms for which the stated payments are due at conclusio n of the ratings process for initial ratings and either upfront or in arrears for monitoring services; and are signed by customers either on a per issue basis or at the beginning of the relationship with the customer. However, customer fee arrangements may be adjusted for which the Company accounts for as variable consideration at inception, which is constrained based on the Company’s assessment of the realization of the adjustment amount. The Company allocates the transaction price within arrangements that include both the initial rating and the related monitoring service based upon the relative SSP of each service. The Company generally uses management’s best estimate based on observable pricing points in determining SSP for its initial ratings as the Comp any rarely provides initial ratings separately without providing related monitoring services. The SSP for monitoring fees in these arrangements are generally based upon directly observable selling prices where the monitoring service is sold separately. MA Revenue In the MA segment, products and services offered by the Company include hosted research and data subscriptions, installed software subscriptions, perpetual installed software licenses and related maintenance, or PCS, and professional services. Subs cription and PCS contracts are generally invoiced in advance of the contractual coverage period, which is principally one year, but can range from 3-5 years; while perpetual software licenses are generally invoiced upon delivery and professional services a re invoiced as those services are provided. Payment terms and conditions vary by contract type, but primarily include a requirement of payment within 30 to 60 days. Revenue from research, data and other hosted subscriptions is recognized ratably over the r elated subscription period. A large portion of these services are invoiced in the months of November, December and January. Revenue from the sale of a software license, when considered distinct from the related software implementation services, is generall y recognized at the time the product master or first copy is delivered or transferred to the customer. However, in instances where the software license (perpetual or subscription) and related implementation services are considered to be one combined perfor mance obligation, revenue is recognized on a percentage-of-completion basis (input method) as implementation services are performed over time, which is consistent with the pattern of recognition for the software implementation services if considered to be a separate distinct performance obligation. The Company exercises judgment in determining the level of integration and interdependency between the promise to grant the software license and the promise to deliver the related implementation services. This de termination influences whether the software license is considered distinct and accounted for separately, or not distinct and accounted for together with the implementation services and recognized over time. PCS is generally recognized ratably over the cont ractual period commencing when the software license is fully delivered. Revenue from installed software subscriptions, which includes PCS, is bifurcated into a software license performance obligation and a PCS performance obligation, which follow the patte rns of recognition described above. For implementation services and other service projects within the ERS and ESA LOBs for which fees are fixed, the Company determined progress towards completion is most accurately measured on a percentage-of-completion ba sis (input method) as this approach utilizes the most directly observable data points and is therefore used to recognize the related revenue. For implementation services where price varies based on time expended, a time-based measure of progress towards co mpletion of the performance obligation is utilized. Revenue from professional services rendered within the PS LOB is generally recognized as the services are performed. Products and services offered within the MA segment are sold either stand-alone or toge ther in various combinations. In instances where an arrangement contains multiple performance obligations, the Company accounts for the individual performance obligations separately if they are considered distinct. Revenue is generally allocated to all per formance obligations based upon the relative SSP at contract inception. Judgment is often required to determine the SSP for each distinct performance obligation. Revenue is recognized for each performance obligation based upon the conditions for revenue re cognition noted above. In the MA segment, customers usually pay a fixed fee for the products and services based on signed contracts. However, accounting for variable consideration is applied mainly for: i) estimates for cancellation rights and price conces sions and ii) T&M based services. The Company estimates the variable consideration associated with cancellation rights and price concessions based on the expected amount to be provided to customers and reduces the amount of revenue to be recognized. T&M based contracts represent about half of MA’s service projects within the ERS and ESA LOBs. The Company provides agreed upon services at a contracted daily or hourly rate. The commitment represents a series of goods and services that are substantially the s ame and have the same pattern of transfer to the customer. As such, if T&M services are sold with other MA products, the Company allocates the variable consideration entirely to the T&M performance obligation if the services are sold at standard pricing or at a similar discount level compared to other performance obligations in the same revenue contract. If these criteria are not met, the Company estimates variable consideration for each performance obligation upfront. Each form of variable consideration is included in the transaction price only to the extent that it is probable that a significant reversal of any incremental revenue will not occur. Costs to Obtain or Fulfill a Contract with a Customer: Costs incurred to obtain customer contracts, such as sa les commissions, are deferred and recorded within other current assets and other assets when such costs are determined to be incremental to obtaining a contract, would not have been incurred otherwise and the Company expects to recover those costs. These c osts are amortized to expense consistent with the recognition pattern of the related revenue. Depending on the line of business to which the contract relates, this may be based upon the average economic life of the products sold or average period for which services are provided, inclusive of anticipated contract renewals. Determining the estimated economic life of the products sold requires judgment with respect to anticipated future technological changes. The Company had a balance of $ 95.5 million in such deferred costs as of March 31, 2018 and recognized $ 8.6 million of related amortization during the three-month period ended March 31, 2018, which is included within SG&A expenses in the consolidated statement of operations. Costs incurred to obtain custome r contracts are only in the MA segment. The Company also capitalizes work-in-process costs for in-progress MIS ratings, which is amortized consistent with the rendering of the related services to the customers. The Company had a balance of $ 10.2 million in such deferred costs as of March 31, 2018 and recognized $ 9.4 million of amortization of the costs deferred as of January 1, 2018 during the three-month period ended March 31, 2018, which is included within operating expenses in the consolidated statement of operations. In addition, within the MA segment, the Company capitalizes royalty costs related to third-party information data providers associated with hosted company information and business intelligence products. The Company had a balance of $ 32.4 mil lion in such deferred costs as of March 31, 2018 and recognized $ 14.2 million of related amortization during the three-month period ended March 31, 2018, which is included within operating expenses in the consolidated statement of operations.
Fair Value Measurement Policy [Policy Text Block]	Fair Value of Financial Instruments The Company’s financial instruments include cash, cash equivalents, trade receivables and payables, all of which are short-term in nature and, accordingly, approximate fair value. Additionally, the Company invests in certain short-te rm investments consisting primarily of certificates of deposit that are carried at cost, which approximates fair value due to their short-term maturities. The Company also has certain investments in closed-ended and open-ended mutual funds in India which a re accounted for as equity securities with readily determinable fair values under ASC Topic 321. Beginning in the first quarter of 2018, the Company will measure these investments at fair value with both realized gains and losses and unrealized holding gai ns and losses for these investments included in net income. Prior to January 1, 2018, the investments in closed-ended and open-ended mutual funds in India were designated as ‘available for sale’ under Topic 320 of the ASC. Accordingly, unrealized gains and losses on these investments were recorded to other comprehensive income and were reclassified out of accumulated other comprehensive income to the statement of operations when the investment matured or was sold using a specific identification method. Also , the Company uses derivative instruments to manage certain financial exposures that occur in the normal course of business. These derivative instruments are carried at fair value on the Company’s consolidated balance sheets. Fair value is defined by the A SC as the price that would be received from selling an asset or paid to transfer a liability (i.e., an exit price) in an orderly transaction between market participants at the measurement date. The determination of this fair value is based on the principal or most advantageous market in which the Company could commence transactions and considers assumptions that market participants would use when pricing the asset or liability, such as inherent risk, transfer restrictions and risk of nonperformance. Also, d etermination of fair value assumes that market participants will consider the highest and best use of the asset. The ASC establishes a fair value hierarchy whereby the inputs contained in valuation techniques used to measure fair value are categorized into three broad levels as follows: Level 1: quoted market prices in active markets that the reporting entity has the ability to access at the date of the fair value measurement; Level 2: inputs other than quoted market prices described in Level 1 that are obs ervable for the asset or liability, either directly or indirectly, such as quoted prices in active markets for similar assets or liabilities, quoted prices for identical or similar assets or liabilities in markets that are not active or other inputs that a re observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities; Level 3: unobservable inputs that are supported by little or no market activity and that are significant to the fair value measurement of the assets or liabilities.

Summary Of Significant Accoun19

Summary Of Significant Accounting Policies - Additional Information (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)
MA [Member] | Subscription and Maintenance Contracts [Member] | Advance Payment [Member]
Capitalized Contract Cost [Line Items]
Contractual Coverage Period	1 year
MA [Member] | Minimum [Member]
Capitalized Contract Cost [Line Items]
Payment Terms	30 days
MA [Member] | Minimum [Member] | Subscription and Maintenance Contracts [Member]
Capitalized Contract Cost [Line Items]
Contractual Coverage Period	3 years
MA [Member] | Maximum [Member]
Capitalized Contract Cost [Line Items]
Payment Terms	60 days
MA [Member] | Maximum [Member] | Subscription and Maintenance Contracts [Member]
Capitalized Contract Cost [Line Items]
Contractual Coverage Period	5 years
MA [Member] | SG&A Expense [Member]
Capitalized Contract Cost [Line Items]
Deferred Cost Balance	$ 95.5
Contract Cost Amortization	8.6
MA [Member] | Royalty Cost [Member] | Operating Expense [Member]
Capitalized Contract Cost [Line Items]
Deferred Cost Balance	32.4
Contract Cost Amortization	$ 14.2
MIS [Member] | Monitoring of Issuers or Issued Securities [Member]
Capitalized Contract Cost [Line Items]
Contractual Coverage Period	1 year
MIS [Member] | Capitalization of Work-In-Process for In-Progress Ratings [Member] | Operating Expense [Member]
Capitalized Contract Cost [Line Items]
Deferred Cost Balance	$ 10.2
Contract Cost Amortization	$ 9.4

REVENUES

REVENUES	3 Months Ended
	Mar. 31, 2018
Text Block [Abstract]
REVENUES	NOTE 3 . REVENUES Revenue by Category The following table presents the Company’s revenues disaggregated by LOB: Three Months Ended March 31, 2018 2017 (1) MIS: Corporate finance (CFG) Investment-grade $ 81.1 $ 72.1 High-yield 57.9 64.2 Bank loans 108.1 101.4 Other accounts (2) 130.6 115.1 Total CFG 377.7 352.8 Structured finance (SFG) Asset-backed securities 28.2 22.7 Residential mortgage backed securities 24.3 20.4 Commercial real estate finance 33.2 29.3 Structured credit 43.4 27.4 Other accounts 0.6 0.4 Total SFG 129.7 100.2 Financial institutions (FIG) Banking 77.0 79.1 Insurance 28.3 25.1 Managed investments 5.7 5.1 Other accounts 3.3 3.0 Total FIG 114.3 112.3 Public, project and infrastructure finance (PPIF) Public finance / sovereign 46.9 53.0 Project and infrastructure 46.3 45.1 Total PPIF 93.2 98.1 Total ratings revenue 714.9 663.4 MIS Other 5.0 4.8 Total external revenue 719.9 668.2 Intersegment royalty 29.8 26.0 Total MIS 749.7 694.2 MA: Research, data and analytics (RD&A) 269.2 175.4 Enterprise risk solutions (ERS) 100.1 95.9 Professional services (PS) 37.5 35.7 Total external revenue 406.8 307.0 Intersegment revenue 5.0 3.7 Total MA 411.8 310.7 Eliminations (34.8) (29.7) Total MCO $ 1,126.7 $ 975.2 (1) Prior period amounts have not been adjusted under the modified retrospective method of adoption for the New Revenue Accounting Standard. (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. The following table presents the Company’s revenues disaggregated by LOB and geographic area: Three Months Ended March 31, 2018 United States International Total MIS: Corporate finance (CFG) $ 246.7 $ 131.0 $ 377.7 Structured finance (SFG) 84.6 45.1 129.7 Financial institutions (FIG) 48.5 65.8 114.3 Public, project and infrastructure finance (PPIF) 53.4 39.8 93.2 Total ratings revenue 433.2 281.7 714.9 MIS Other 0.2 4.8 5.0 Total 433.4 286.5 719.9 MA: Research, data and analytics (RD&A) 112.6 156.6 269.2 Enterprise risk solutions (ERS) 38.5 61.6 100.1 Professional services (PS) 13.2 24.3 37.5 Total 164.3 242.5 406.8 Total MCO $ 597.7 $ 529.0 $ 1,126.7 Three Months Ended March 31, 2017 (1) United States International Total MIS: Corporate finance (CFG) $ 243.8 $ 109.0 $ 352.8 Structured finance (SFG) 65.0 35.2 100.2 Financial institutions (FIG) 50.6 61.7 112.3 Public, project and infrastructure finance (PPIF) 63.0 35.1 98.1 Total ratings revenue 422.4 241.0 663.4 MIS Other 0.1 4.7 4.8 Total 422.5 245.7 668.2 MA: Research, data and analytics (RD&A) 101.4 74.0 175.4 Enterprise risk solutions (ERS) 40.2 55.7 95.9 Professional services (PS) 13.7 22.0 35.7 Total 155.3 151.7 307.0 Total MCO $ 577.8 $ 397.4 $ 975.2 (1) Prior period amounts have not been adjusted under the modified retrospective method of adoption for the New Revenue Accounting Standard. The tables below summarize the split between transaction and relationship revenue. In the MIS segment, excluding MIS Other, transaction revenue represents the initial rating of a new debt issuance as well as other one-time fees while relationship revenue represents the recurring monitoring fees of a rated debt obligation and/or entities that issue such obligations, as well as revenue from programs such as commercial paper, medium-term notes and shelf registrations. In MIS Other, transaction revenue represe nts 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 March 31, 2018 2017 (2) Transaction Relationship Total Transaction Relationship Total Corporate Finance $ 274.9 $ 102.8 $ 377.7 $ 260.6 $ 92.2 $ 352.8 73% 27% 100% 74% 26% 100% Structured Finance $ 83.1 $ 46.6 $ 129.7 $ 57.5 $ 42.7 $ 100.2 64% 36% 100% 57% 43% 100% Financial Institutions $ 50.0 $ 64.3 $ 114.3 $ 53.4 $ 58.9 $ 112.3 44% 56% 100% 48% 52% 100% Public, Project and Infrastructure Finance $ 54.4 $ 38.8 $ 93.2 $ 59.2 $ 38.9 $ 98.1 58% 42% 100% 60% 40% 100% MIS Other $ 0.6 $ 4.4 $ 5.0 $ 0.3 $ 4.5 $ 4.8 12% 88% 100% 6% 94% 100% Total MIS $ 463.0 $ 256.9 $ 719.9 $ 431.0 $ 237.2 $ 668.2 64% 36% 100% 65% 35% 100% Moody's Analytics $ 60.8 (1) $ 346.0 $ 406.8 $ 64.6 $ 242.4 $ 307.0 15% 85% 100% 21% 79% 100% Total Moody's Corporation $ 523.8 $ 602.9 $ 1,126.7 $ 495.6 $ 479.6 $ 975.2 46% 54% 100% 51% 49% 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 table below). (2) Prior period amounts have not been adjusted under the modified retrospective method of adoption for the New Revenue Accounting Standard. The following table presents the timing of revenue recognition: Three Months Ended March 31, 2018 MIS MA Total Revenue recognized at a point in time $ 463.0 $ 15.5 $ 478.5 Revenue recognized over time 256.9 391.3 648.2 Total $ 719.9 $ 406.8 $ 1,126.7 Contract balances, Unbilled receivables and Remaining performance obligations Unbilled receivables At March 31, 2018, accounts receivable included approximately $ 344.0 million 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 . Additionally, there are other instances in which the timing of wh en the Company has the unconditional right to considerati on and recognizes revenue prior to invoicing the customer, for which an unbilled receivable is recorded. In addition, for certain MA arrangements, the timing of when the Company has the uncondition al right to consideration and recognizes revenue occurs prior to invoicing the customer. Consequently, at March 31, 2018, accounts receivable included approximately $ 40.1 million of unbilled receivables related to the MA segment. Historically, the Company has not had material differences between the estimated revenue and the actual billings. 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 t hat contract is recognized. This deferred revenue is relieved when the Company satisfies the related performance obligation and revenue is recognized. Significant changes in the deferred revenue balances during the three months ended March 31, 2018 are as follows: Three Months Ended March 31, 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 (93.4) (173.9) (267.3) Increases due to amounts billable excluding amounts recognized as revenue during the period 154.9 279.8 434.7 Effect of exchange rate changes 1.3 11.5 12.8 Total Changes in deferred revenue 62.8 117.4 180.2 Balance at March 31, 2018 $ 397.5 $ 729.0 $ 1,126.5 Deferred revenue - current $ 273.4 $ 725.3 $ 998.7 Deferred revenue - noncurrent $ 124.1 $ 3.7 $ 127.8 Deferred revenue increased during the three months ended March 31, 2018 primarily due to the significant portion of contract renewals that occur during the first quarter within both segments. Remaining performance obligations The following tables include the expected recognition period for the remaining performance obligations for each reportab le segment as of March 31, 2018 : MIS Total Less than 1 year 1 - 5 years 6 - 10 Years 11 - 15 years 16-20 years Over 20 Years $ 150.5 $ 21.9 $ 65.2 $ 43.6 $ 8.7 $ 4.5 $ 6.6 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, t he 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 a n original expected length of one year or less. MA Total Less than 1 Year 1 - 2 Years Over 2 Years $ 1,418.6 $ 1,089.0 $ 217.6 $ 112.0 The balances in the MA table above include both amounts recorded as deferred revenue on the balance sheet as of March 31, 2018 as well as amounts not yet invoiced to customers as of March 31, 2018 largely reflecting future revenue related to signed multi-year arrangements for hosted and installed subscription based products.

REVENUES (Tables)

REVENUES (Tables)	3 Months Ended
	Mar. 31, 2018
Disaggregation of Revenue [Line Items]
Revenue by Category	Three Months Ended March 31, 2018 2017 (1) MIS: Corporate finance (CFG) Investment-grade $ 81.1 $ 72.1 High-yield 57.9 64.2 Bank loans 108.1 101.4 Other accounts (2) 130.6 115.1 Total CFG 377.7 352.8 Structured finance (SFG) Asset-backed securities 28.2 22.7 Residential mortgage backed securities 24.3 20.4 Commercial real estate finance 33.2 29.3 Structured credit 43.4 27.4 Other accounts 0.6 0.4 Total SFG 129.7 100.2 Financial institutions (FIG) Banking 77.0 79.1 Insurance 28.3 25.1 Managed investments 5.7 5.1 Other accounts 3.3 3.0 Total FIG 114.3 112.3 Public, project and infrastructure finance (PPIF) Public finance / sovereign 46.9 53.0 Project and infrastructure 46.3 45.1 Total PPIF 93.2 98.1 Total ratings revenue 714.9 663.4 MIS Other 5.0 4.8 Total external revenue 719.9 668.2 Intersegment royalty 29.8 26.0 Total MIS 749.7 694.2 MA: Research, data and analytics (RD&A) 269.2 175.4 Enterprise risk solutions (ERS) 100.1 95.9 Professional services (PS) 37.5 35.7 Total external revenue 406.8 307.0 Intersegment revenue 5.0 3.7 Total MA 411.8 310.7 Eliminations (34.8) (29.7) Total MCO $ 1,126.7 $ 975.2 (1) Prior period amounts have not been adjusted under the modified retrospective method of adoption for the New Revenue Accounting Standard. (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.
Revenue by Line of Business within Each Geographical Segment	Three Months Ended March 31, 2018 United States International Total MIS: Corporate finance (CFG) $ 246.7 $ 131.0 $ 377.7 Structured finance (SFG) 84.6 45.1 129.7 Financial institutions (FIG) 48.5 65.8 114.3 Public, project and infrastructure finance (PPIF) 53.4 39.8 93.2 Total ratings revenue 433.2 281.7 714.9 MIS Other 0.2 4.8 5.0 Total 433.4 286.5 719.9 MA: Research, data and analytics (RD&A) 112.6 156.6 269.2 Enterprise risk solutions (ERS) 38.5 61.6 100.1 Professional services (PS) 13.2 24.3 37.5 Total 164.3 242.5 406.8 Total MCO $ 597.7 $ 529.0 $ 1,126.7 Three Months Ended March 31, 2017 (1) United States International Total MIS: Corporate finance (CFG) $ 243.8 $ 109.0 $ 352.8 Structured finance (SFG) 65.0 35.2 100.2 Financial institutions (FIG) 50.6 61.7 112.3 Public, project and infrastructure finance (PPIF) 63.0 35.1 98.1 Total ratings revenue 422.4 241.0 663.4 MIS Other 0.1 4.7 4.8 Total 422.5 245.7 668.2 MA: Research, data and analytics (RD&A) 101.4 74.0 175.4 Enterprise risk solutions (ERS) 40.2 55.7 95.9 Professional services (PS) 13.7 22.0 35.7 Total 155.3 151.7 307.0 Total MCO $ 577.8 $ 397.4 $ 975.2 (1) Prior period amounts have not been adjusted under the modified retrospective method of adoption for the New Revenue Accounting Standard.
Transaction and Relationship Revenue	Three Months Ended March 31, 2018 2017 (2) Transaction Relationship Total Transaction Relationship Total Corporate Finance $ 274.9 $ 102.8 $ 377.7 $ 260.6 $ 92.2 $ 352.8 73% 27% 100% 74% 26% 100% Structured Finance $ 83.1 $ 46.6 $ 129.7 $ 57.5 $ 42.7 $ 100.2 64% 36% 100% 57% 43% 100% Financial Institutions $ 50.0 $ 64.3 $ 114.3 $ 53.4 $ 58.9 $ 112.3 44% 56% 100% 48% 52% 100% Public, Project and Infrastructure Finance $ 54.4 $ 38.8 $ 93.2 $ 59.2 $ 38.9 $ 98.1 58% 42% 100% 60% 40% 100% MIS Other $ 0.6 $ 4.4 $ 5.0 $ 0.3 $ 4.5 $ 4.8 12% 88% 100% 6% 94% 100% Total MIS $ 463.0 $ 256.9 $ 719.9 $ 431.0 $ 237.2 $ 668.2 64% 36% 100% 65% 35% 100% Moody's Analytics $ 60.8 (1) $ 346.0 $ 406.8 $ 64.6 $ 242.4 $ 307.0 15% 85% 100% 21% 79% 100% Total Moody's Corporation $ 523.8 $ 602.9 $ 1,126.7 $ 495.6 $ 479.6 $ 975.2 46% 54% 100% 51% 49% 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 table below). (2) Prior period amounts have not been adjusted under the modified retrospective method of adoption for the New Revenue Accounting Standard.
Schedule of Revenue Recognition Timing	Three Months Ended March 31, 2018 MIS MA Total Revenue recognized at a point in time $ 463.0 $ 15.5 $ 478.5 Revenue recognized over time 256.9 391.3 648.2 Total $ 719.9 $ 406.8 $ 1,126.7
Schedule of Changes in the Deferred Revenue Balances	Three Months Ended March 31, 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 (93.4) (173.9) (267.3) Increases due to amounts billable excluding amounts recognized as revenue during the period 154.9 279.8 434.7 Effect of exchange rate changes 1.3 11.5 12.8 Total Changes in deferred revenue 62.8 117.4 180.2 Balance at March 31, 2018 $ 397.5 $ 729.0 $ 1,126.5 Deferred revenue - current $ 273.4 $ 725.3 $ 998.7 Deferred revenue - noncurrent $ 124.1 $ 3.7 $ 127.8
MIS [Member]
Disaggregation of Revenue [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block]	MIS Total Less than 1 year 1 - 5 years 6 - 10 Years 11 - 15 years 16-20 years Over 20 Years $ 150.5 $ 21.9 $ 65.2 $ 43.6 $ 8.7 $ 4.5 $ 6.6
MA [Member]
Disaggregation of Revenue [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block]	MA Total Less than 1 Year 1 - 2 Years Over 2 Years $ 1,418.6 $ 1,089.0 $ 217.6 $ 112.0

Revenue by Category (Detail)

Revenue by Category (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Disaggregation of Revenue [Line Items]
Revenues	$ 1,126.7	$ 975.2
MIS [Member]
Disaggregation of Revenue [Line Items]
Revenues	749.7	694.2
MIS [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	719.9	668.2
MIS [Member] | Intersegment Royality [Member]
Disaggregation of Revenue [Line Items]
Revenues	29.8	26
MIS [Member] | Corporate finance (CFG) [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	377.7	352.8
MIS [Member] | Corporate finance (CFG) [Member] | External Revenues [Member] | Investment-grade [Member]
Disaggregation of Revenue [Line Items]
Revenues	81.1	72.1
MIS [Member] | Corporate finance (CFG) [Member] | External Revenues [Member] | High-yield [Member]
Disaggregation of Revenue [Line Items]
Revenues	57.9	64.2
MIS [Member] | Corporate finance (CFG) [Member] | External Revenues [Member] | Bank loans [Member]
Disaggregation of Revenue [Line Items]
Revenues	108.1	101.4
MIS [Member] | Corporate finance (CFG) [Member] | External Revenues [Member] | Other product lines [Member]
Disaggregation of Revenue [Line Items]
Revenues	130.6	115.1
MIS [Member] | Structured Finance (SFG) [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	129.7	100.2
MIS [Member] | Structured Finance (SFG) [Member] | External Revenues [Member] | Assets Backed Securities [Member]
Disaggregation of Revenue [Line Items]
Revenues	28.2	22.7
MIS [Member] | Structured Finance (SFG) [Member] | External Revenues [Member] | Residential Mortgage Backed Securities Product [Member]
Disaggregation of Revenue [Line Items]
Revenues	24.3	20.4
MIS [Member] | Structured Finance (SFG) [Member] | External Revenues [Member] | Commercial real estate finance [Member]
Disaggregation of Revenue [Line Items]
Revenues	33.2	29.3
MIS [Member] | Structured Finance (SFG) [Member] | External Revenues [Member] | Structured credit [Member]
Disaggregation of Revenue [Line Items]
Revenues	43.4	27.4
MIS [Member] | Structured Finance (SFG) [Member] | External Revenues [Member] | Other product lines [Member]
Disaggregation of Revenue [Line Items]
Revenues	0.6	0.4
MIS [Member] | Financial institutions (FIG) [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	114.3	112.3
MIS [Member] | Financial institutions (FIG) [Member] | External Revenues [Member] | Banking [Member]
Disaggregation of Revenue [Line Items]
Revenues	77	79.1
MIS [Member] | Financial institutions (FIG) [Member] | External Revenues [Member] | Insurance [Member]
Disaggregation of Revenue [Line Items]
Revenues	28.3	25.1
MIS [Member] | Financial institutions (FIG) [Member] | External Revenues [Member] | Managed investments [Member]
Disaggregation of Revenue [Line Items]
Revenues	5.7	5.1
MIS [Member] | Financial institutions (FIG) [Member] | External Revenues [Member] | Other product lines [Member]
Disaggregation of Revenue [Line Items]
Revenues	3.3	3
MIS [Member] | Public, Project And Infrastructure Finance (PPIF) [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	93.2	98.1
MIS [Member] | Public, Project And Infrastructure Finance (PPIF) [Member] | External Revenues [Member] | Public finance / sovereign [Member]
Disaggregation of Revenue [Line Items]
Revenues	46.9	53
MIS [Member] | Public, Project And Infrastructure Finance (PPIF) [Member] | External Revenues [Member] | Project and infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenues	46.3	45.1
MIS [Member] | Rating Revenue [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	714.9	663.4
MIS [Member] | MIS Other [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	5	4.8
MA [Member]
Disaggregation of Revenue [Line Items]
Revenues	411.8	310.7
MA [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	406.8	307
MA [Member] | Intersegment Royality [Member]
Disaggregation of Revenue [Line Items]
Revenues	5	3.7
MA [Member] | Research, Data And Analytics (RD&A) [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	269.2	175.4
MA [Member] | Enterprise Risk Solutions (ERS) [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	100.1	95.9
MA [Member] | Professional Services (PS) [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	37.5	35.7
Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ (34.8)	$ (29.7)

Revenues disaggregated by Line

Revenues disaggregated by Line of Business and Geographical Area (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Disaggregation of Revenue [Line Items]
Revenues	$ 1,126.7	$ 975.2
U S
Disaggregation of Revenue [Line Items]
Revenues	597.7	577.8
International [Member]
Disaggregation of Revenue [Line Items]
Revenues	529	397.4
MIS [Member]
Disaggregation of Revenue [Line Items]
Revenues	749.7	694.2
MIS [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	719.9	668.2
MIS [Member] | U S | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	433.4	422.5
MIS [Member] | International [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	286.5	245.7
MIS [Member] | Corporate finance (CFG) [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	377.7	352.8
MIS [Member] | Corporate finance (CFG) [Member] | U S | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	246.7	243.8
MIS [Member] | Corporate finance (CFG) [Member] | International [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	131	109
MIS [Member] | Structured Finance (SFG) [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	129.7	100.2
MIS [Member] | Structured Finance (SFG) [Member] | U S | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	84.6	65
MIS [Member] | Structured Finance (SFG) [Member] | International [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	45.1	35.2
MIS [Member] | Financial institutions (FIG) [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	114.3	112.3
MIS [Member] | Financial institutions (FIG) [Member] | U S | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	48.5	50.6
MIS [Member] | Financial institutions (FIG) [Member] | International [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	65.8	61.7
MIS [Member] | Public, Project And Infrastructure Finance (PPIF) [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	93.2	98.1
MIS [Member] | Public, Project And Infrastructure Finance (PPIF) [Member] | U S | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	53.4	63
MIS [Member] | Public, Project And Infrastructure Finance (PPIF) [Member] | International [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	39.8	35.1
MIS [Member] | Rating Revenue [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	714.9	663.4
MIS [Member] | Rating Revenue [Member] | U S | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	433.2	422.4
MIS [Member] | Rating Revenue [Member] | International [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	281.7	241
MIS [Member] | MIS Other [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	5	4.8
MIS [Member] | MIS Other [Member] | U S | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	0.2	0.1
MIS [Member] | MIS Other [Member] | International [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	4.8	4.7
MA [Member]
Disaggregation of Revenue [Line Items]
Revenues	411.8	310.7
MA [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	406.8	307
MA [Member] | U S | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	164.3	155.3
MA [Member] | International [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	242.5	151.7
MA [Member] | Research Data And Analytics [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	269.2	175.4
MA [Member] | Research Data And Analytics [Member] | U S | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	112.6	101.4
MA [Member] | Research Data And Analytics [Member] | International [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	156.6	74
MA [Member] | Enterprise Risk Solutions [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	100.1	95.9
MA [Member] | Enterprise Risk Solutions [Member] | U S | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	38.5	40.2
MA [Member] | Enterprise Risk Solutions [Member] | International [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	61.6	55.7
MA [Member] | Professional Services [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	37.5	35.7
MA [Member] | Professional Services [Member] | U S | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	13.2	13.7
MA [Member] | Professional Services [Member] | International [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 24.3	$ 22

Transaction and Relationship Re

Transaction and Relationship Revenue (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Disaggregation of Revenue [Line Items]
Revenues	$ 1,126.7	$ 975.2
Percentage of Revenues	100.00%	100.00%
MIS [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 749.7	$ 694.2
MIS [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 719.9	$ 668.2
Percentage of Revenues	100.00%	100.00%
MA [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 411.8	$ 310.7
MA [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 406.8	$ 307
Percentage of Revenues	100.00%	100.00%
Corporate finance (CFG) [Member] | MIS [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 377.7	$ 352.8
Percentage of Revenues	100.00%	100.00%
Structured Finance (SFG) [Member] | MIS [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 129.7	$ 100.2
Percentage of Revenues	100.00%	100.00%
Financial institutions (FIG) [Member] | MIS [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 114.3	$ 112.3
Percentage of Revenues	100.00%	100.00%
Public, Project And Infrastructure Finance (PPIF) [Member] | MIS [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 93.2	$ 98.1
Percentage of Revenues	100.00%	100.00%
MIS Other [Member] | MIS [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 5	$ 4.8
Percentage of Revenues	100.00%	100.00%
Transaction Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 523.8	$ 495.6
Percentage of Revenues	46.00%	51.00%
Transaction Revenue [Member] | MIS [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 463	$ 431
Percentage of Revenues	64.00%	65.00%
Transaction Revenue [Member] | MA [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 60.8	$ 64.6
Percentage of Revenues	15.00%	21.00%
Transaction Revenue [Member] | Corporate finance (CFG) [Member] | MIS [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 274.9	$ 260.6
Percentage of Revenues	73.00%	74.00%
Transaction Revenue [Member] | Structured Finance (SFG) [Member] | MIS [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 83.1	$ 57.5
Percentage of Revenues	64.00%	57.00%
Transaction Revenue [Member] | Financial institutions (FIG) [Member] | MIS [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 50	$ 53.4
Percentage of Revenues	44.00%	48.00%
Transaction Revenue [Member] | Public, Project And Infrastructure Finance (PPIF) [Member] | MIS [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 54.4	$ 59.2
Percentage of Revenues	58.00%	60.00%
Transaction Revenue [Member] | MIS Other [Member] | MIS [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 0.6	$ 0.3
Percentage of Revenues	12.00%	6.00%
Relationship Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 602.9	$ 479.6
Percentage of Revenues	54.00%	49.00%
Relationship Revenue [Member] | MIS [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 256.9	$ 237.2
Percentage of Revenues	36.00%	35.00%
Relationship Revenue [Member] | MA [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 346	$ 242.4
Percentage of Revenues	85.00%	79.00%
Relationship Revenue [Member] | Corporate finance (CFG) [Member] | MIS [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 102.8	$ 92.2
Percentage of Revenues	27.00%	26.00%
Relationship Revenue [Member] | Structured Finance (SFG) [Member] | MIS [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 46.6	$ 42.7
Percentage of Revenues	36.00%	43.00%
Relationship Revenue [Member] | Financial institutions (FIG) [Member] | MIS [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 64.3	$ 58.9
Percentage of Revenues	56.00%	52.00%
Relationship Revenue [Member] | Public, Project And Infrastructure Finance (PPIF) [Member] | MIS [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 38.8	$ 38.9
Percentage of Revenues	42.00%	40.00%
Relationship Revenue [Member] | MIS Other [Member] | MIS [Member] | External Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 4.4	$ 4.5
Percentage of Revenues	88.00%	94.00%

Revenue Recognition Timing (Det

Revenue Recognition Timing (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)
Disaggregation of Revenue [Line Items]
Revenue Recognized	$ 1,126.7
At Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue Recognized	478.5
Over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue Recognized	648.2
Moodys Investors Service [Member]
Disaggregation of Revenue [Line Items]
Revenue Recognized	719.9
Moodys Investors Service [Member] | At Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue Recognized	463
Moodys Investors Service [Member] | Over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue Recognized	256.9
Moodys Analytics [Member]
Disaggregation of Revenue [Line Items]
Revenue Recognized	406.8
Moodys Analytics [Member] | At Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue Recognized	15.5
Moodys Analytics [Member] | Over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue Recognized	$ 391.3

Schedule of Changes in the Defe

Schedule of Changes in the Deferred Revenue Balances (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Deferred revenue - current	$ 998.7	$ 883.6
Deferred revenue - noncurrent	127.8	$ 140
Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
Disaggregation of Revenue [Line Items]
Balance at January 1, 2018	946.3
Revenue recognized that was included in the contract liability balance at the beginning of the period	(267.3)
Increases due to billings excluding amounts recognized as revenue during the period	434.7
Effect of exchange rate changes	12.8
Total Changes in deferred revenue	180.2
Balance at March 31, 2018	1,126.5
MIS [Member]
Disaggregation of Revenue [Line Items]
Deferred revenue - current	273.4
Deferred revenue - noncurrent	124.1
MIS [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
Disaggregation of Revenue [Line Items]
Balance at January 1, 2018	334.7
Revenue recognized that was included in the contract liability balance at the beginning of the period	(93.4)
Increases due to billings excluding amounts recognized as revenue during the period	154.9
Effect of exchange rate changes	1.3
Total Changes in deferred revenue	62.8
Balance at March 31, 2018	397.5
MA [Member]
Disaggregation of Revenue [Line Items]
Deferred revenue - current	725.3
Deferred revenue - noncurrent	3.7
MA [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
Disaggregation of Revenue [Line Items]
Balance at January 1, 2018	611.6
Revenue recognized that was included in the contract liability balance at the beginning of the period	(173.9)
Increases due to billings excluding amounts recognized as revenue during the period	279.8
Effect of exchange rate changes	11.5
Total Changes in deferred revenue	117.4
Balance at March 31, 2018	$ 729

Expected Recognition Period for

Expected Recognition Period for Remaining Performance Obligations (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)
MIS [Member]
Disaggregation of Revenue [Line Items]
Remaining Performance Obligation	$ 150.5
MIS [Member] | Less Than One Year [Member]
Disaggregation of Revenue [Line Items]
Remaining Performance Obligation	$ 21.9
Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
MIS [Member] | 1 - 5 years [Member]
Disaggregation of Revenue [Line Items]
Remaining Performance Obligation	$ 65.2
MIS [Member] | 1 - 5 years [Member] | Minimum [Member]
Disaggregation of Revenue [Line Items]
Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
MIS [Member] | 1 - 5 years [Member] | Maximum [Member]
Disaggregation of Revenue [Line Items]
Remaining Performance Obligation, Expected Timing of Satisfaction, Period	5 years
MIS [Member] | 6 - 10 Years [Member]
Disaggregation of Revenue [Line Items]
Remaining Performance Obligation	$ 43.6
MIS [Member] | 6 - 10 Years [Member] | Minimum [Member]
Disaggregation of Revenue [Line Items]
Remaining Performance Obligation, Expected Timing of Satisfaction, Period	6 years
MIS [Member] | 6 - 10 Years [Member] | Maximum [Member]
Disaggregation of Revenue [Line Items]
Remaining Performance Obligation, Expected Timing of Satisfaction, Period	10 years
MIS [Member] | 11 - 15 years [Member]
Disaggregation of Revenue [Line Items]
Remaining Performance Obligation	$ 8.7
MIS [Member] | 11 - 15 years [Member] | Minimum [Member]
Disaggregation of Revenue [Line Items]
Remaining Performance Obligation, Expected Timing of Satisfaction, Period	11 years
MIS [Member] | 11 - 15 years [Member] | Maximum [Member]
Disaggregation of Revenue [Line Items]
Remaining Performance Obligation, Expected Timing of Satisfaction, Period	15 years
MIS [Member] | 16-20 years [Member]
Disaggregation of Revenue [Line Items]
Remaining Performance Obligation	$ 4.5
MIS [Member] | 16-20 years [Member] | Minimum [Member]
Disaggregation of Revenue [Line Items]
Remaining Performance Obligation, Expected Timing of Satisfaction, Period	16 years
MIS [Member] | 16-20 years [Member] | Maximum [Member]
Disaggregation of Revenue [Line Items]
Remaining Performance Obligation, Expected Timing of Satisfaction, Period	20 years
MIS [Member] | Over 20 Years [Member]
Disaggregation of Revenue [Line Items]
Remaining Performance Obligation	$ 6.6
Remaining Performance Obligation, Expected Timing of Satisfaction, Period	20 years
MA [Member]
Disaggregation of Revenue [Line Items]
Remaining Performance Obligation	$ 1,418.6
MA [Member] | Less Than One Year [Member]
Disaggregation of Revenue [Line Items]
Remaining Performance Obligation	$ 1,089
Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
MA [Member] | 1 - 2 Years [Member]
Disaggregation of Revenue [Line Items]
Remaining Performance Obligation	$ 217.6
MA [Member] | 1 - 2 Years [Member] | Minimum [Member]
Disaggregation of Revenue [Line Items]
Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
MA [Member] | 1 - 2 Years [Member] | Maximum [Member]
Disaggregation of Revenue [Line Items]
Remaining Performance Obligation, Expected Timing of Satisfaction, Period	2 years
MA [Member] | Over 2 Years [Member]
Disaggregation of Revenue [Line Items]
Remaining Performance Obligation	$ 112
Remaining Performance Obligation, Expected Timing of Satisfaction, Period	2 years

Revenues - Additional Informati

Revenues - Additional Information (Detail) $ in Millions	Mar. 31, 2018USD ($)
MIS [Member]
Disaggregation of Revenue [Line Items]
Unbilled Receivables	$ 344
MA [Member]
Disaggregation of Revenue [Line Items]
Unbilled Receivables	$ 40.1

STOCK-BASED COMPENSATION

STOCK-BASED COMPENSATION	3 Months Ended
	Mar. 31, 2018
Text Block [Abstract]
STOCK-BASED COMPENSATION	NOTE 4 . 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 March 31, 2018 2017 Stock-based compensation expense $ 35.1 $ 28.4 Tax benefit $ 7.2 $ 9.1 During the first three months of 2018 , th e Company granted 0.2 million employee stock options, which had a weighted av erage grant date fair value of $45.87 per share based on the Black-Scholes option-pricing model. The Company also granted 0.7 million shares of restricted stock in the first three months of 2018 , which had a weighted av erage grant date fair value of $167.50 per share . Both the employee stock options and restricted stock generally vest ra tably over a four-year period. Ad ditionally, 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 a three-year period. The weighted average grant date fair value of these awards was $162.42 per share. The following weighted average assumptions were used in determining the fair value for options granted in 2018 : Expected dividend yield 1.05% Expected stock volatility 25.6% Risk-free interest rate 2.81% Expected holding period 6.2 years Grant date fair value $45.87 Unrecognized stock-based compensation expense at March 31, 2018 was $11.7 million and $220.1 million for stock options and unvested restricted stock, respectively, which is expected to be recognized over a weighted average period of 1.4 years and 1.8 years, respectively. Additionally, there was $43.1 million of unrecognized stock-based compensation expense relating to the aforementioned non-market based performance-based awards, which is expected to be recognized o ver a weighted average period of 1.1 years. The following tables summarize information relating to stock option exercises and restricted stock vesting: Three Months Ended March 31, Exercise of stock options: 2018 2017 Proceeds from stock option exercises $ 26.6 $ 20.6 Aggregate intrinsic value $ 61.9 $ 21.6 Tax benefit realized upon exercise $ 15.0 $ 7.9 Number of shares exercised 0.5 0.4 Three Months Ended March 31, Vesting of restricted stock: 2018 2017 Fair value of shares vested $ 146.7 $ 106.8 Tax benefit realized upon vesting $ 33.9 $ 33.7 Number of shares vested 0.9 0.9 Three Months Ended March 31, Vesting of performance-based restricted stock: 2018 2017 Fair value of shares vested $ 23.0 $ 19.5 Tax benefit realized upon vesting $ 5.5 $ 6.9 Number of shares vested 0.1 0.2

STOCK-BASED COMPENSATION (Table

STOCK-BASED COMPENSATION (Tables)	3 Months Ended
	Mar. 31, 2018
Text Block [Abstract]
Stock-Based Compensation Cost and Associated Tax Benefit	Three Months Ended March 31, 2018 2017 Stock-based compensation expense $ 35.1 $ 28.4 Tax benefit $ 7.2 $ 9.1
Weighted Average Assumptions used in Determining Fair Value for Options Granted	Expected dividend yield 1.05% Expected stock volatility 25.6% Risk-free interest rate 2.81% Expected holding period 6.2 years Grant date fair value $45.87
Stock Option Exercises and Restricted Stock Vesting	Three Months Ended March 31, Exercise of stock options: 2018 2017 Proceeds from stock option exercises $ 26.6 $ 20.6 Aggregate intrinsic value $ 61.9 $ 21.6 Tax benefit realized upon exercise $ 15.0 $ 7.9 Number of shares exercised 0.5 0.4 Three Months Ended March 31, Vesting of restricted stock: 2018 2017 Fair value of shares vested $ 146.7 $ 106.8 Tax benefit realized upon vesting $ 33.9 $ 33.7 Number of shares vested 0.9 0.9 Three Months Ended March 31, Vesting of performance-based restricted stock: 2018 2017 Fair value of shares vested $ 23.0 $ 19.5 Tax benefit realized upon vesting $ 5.5 $ 6.9 Number of shares vested 0.1 0.2

Stock-Based Compensation Cost a

Stock-Based Compensation Cost and Associated Tax Benefit (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Employee Service Share-based Compensation, Aggregate Disclosures [Abstract]
Stock-based compensation expense	$ 35.1	$ 28.4
Tax benefit	$ 7.2	$ 9.1

Weighted Average Assumptions us

Weighted Average Assumptions used in Determining Fair Value for Options Granted (Detail)	3 Months Ended
	Mar. 31, 2018$ / shares
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected dividend yield	1.05%
Expected stock volatility	25.61%
Risk-free interest rate	2.81%
Expected holding period	6 years 2 months 12 days
Grant date fair value	$ 45.87

Stock Option Exercises and Rest

Stock Option Exercises and Restricted Stock Vesting (Detail) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Employee Stock Options [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Proceeds from stock option exercises	$ 26.6	$ 20.6
Aggregate intrinsic value	61.9	21.6
Tax benefit realized upon exercise	$ 15	$ 7.9
Number of shares exercised	0.5	0.4
Restricted Stock [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Fair value of shares vested	$ 146.7	$ 106.8
Tax benefit realized upon vesting	$ 33.9	$ 33.7
Number of shares vested	0.9	0.9
Vesting of Performance Based Restricted Stock [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Fair value of shares vested	$ 23	$ 19.5
Tax benefit realized upon vesting	$ 5.5	$ 6.9
Number of shares vested	0.1	0.2

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Employee stock options, granted | shares	0.2
Employee stock options, weighted average grant date fair value | $ / shares	$ 45.87
Employee Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Other than options, award vesting period (in years)	1 year 4 months 26 days
Unrecognized compensation expense | $	$ 11.7
Weighted average period to recognize expense	4 years
Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Other than options, Shares granted | shares	0.7
Other than options, weighted average grant date fair value | $ / shares	$ 167.5
Other than options, award vesting period (in years)	1 year 9 months 24 days
Unrecognized compensation expense | $	$ 220.1
Weighted average period to recognize expense	4 years
Performance Based Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Other than options, Shares granted | shares	0.1
Other than options, weighted average grant date fair value | $ / shares	$ 162.42
Other than options, award vesting period (in years)	1 year 1 month
Unrecognized compensation expense | $	$ 43.1
Weighted average period to recognize expense	3 years

INCOME TAXES

INCOME TAXES	3 Months Ended
	Mar. 31, 2018
Text Block [Abstract]
INCOME TAXES	NOTE 5 . INCOME TAXES Moody’s effective tax rate for the first quarter of 2018 was 14.6% , down from 23.4% for the prior-year period. The decline in the tax rate primarily reflects the impact of an enacted lower corporate tax rate in the U.S. pursuant to the Tax Act. Additionally, the ETR in 2018 includes an approximate $31 million benefit relating to Excess Tax Benefits on stock-based compensation as well as a net uncertain tax position benefit s pu rsuant to statute of limitation lapses. The ETR in the first quarter of 2017 reflected the non-taxable CCXI basis as well as approximately $19 million in Excess Tax Benefits on stock-based compensation. On December 22, 2017, the Tax Cut and Jobs Act was signed into law which resulted in signific ant changes to U.S. corporate tax laws. The Tax Act includes a mandatory one-time deemed repatriation tax (“transition tax”) on previously untaxed accumulated earnings of foreign subsidiaries and beginning in 2018 reduces the statutory federal corporate in come tax rate from 35% to 21%. Due to the complexities of the Tax Act, the SEC issued guidance requiring that companies provide a reasonable estimate of the impact of the Tax Act to the extent such reasonable estimate has been determined. Accordingly, as of December 31, 2017 the Company recorded a provisional estimate for the transition tax of $247.3 million, a portion of which will be payable over eight years, starting in 2018, and will not accrue interest. The above provisional estimate may be impacted b y a number of additional considerations, including but not limited to the issuance of regulations and our ongoing analysis of the new law. As a result of the Tax Act, all previously net undistributed foreign earnings have now been subject to U.S. tax. Howe ver, the Company intends to co ntinue to indefinitely reinvest earnings outside the U.S. and accordingly the Company has not provided non-U.S. deferred income taxes on these indefinitely reinvested earnings. It is not practicable to determine the amount of non-U.S. deferred taxes that might be required to be provided if such earnings were distributed in the future, due to complexities in the tax laws and in the hypothetical calculations that would have to be made. The Company classifies interest related to U TBs 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 UTBs of $101.8 million ($109.6 million net of federal ta x) du ring the first quarter of 2018. Moody’s Corporation and subsidiaries are subject to U.S. federal income tax as well as income tax in various state, local and foreign jurisdictions. The Company’s U.S. federal income tax returns for the years 2011 and 2 012 are under examination and its returns for 2013 through 2016 remain 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 unde r examination. The Company’s U.K. tax return for 2012 is currently under examination and its returns for 2013 through 2016 remain open to examination. For ongoing audits, it is possible the balance of UTBs could decrease in the next twelve months as a resu lt 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 n ecessitate increases to the balance of UTBs. 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 UTBs 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 UTBs. The following table shows the amount the Company paid for income taxes: Three Months Ended March 31, 2018 2017 Income taxes paid $ 44.2 $ 23.4

INCOME TAXES (Tables)

INCOME TAXES (Tables)	3 Months Ended
	Mar. 31, 2018
Text Block [Abstract]
Income Taxes Paid	Three Months Ended March 31, 2018 2017 Income taxes paid $ 44.2 $ 23.4

Income Taxes Paid (Detail)

Income Taxes Paid (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Taxes Paid, Net [Abstract]
Income Taxes Paid	$ 44.2	$ 23.4

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	Dec. 22, 2017
Income Tax Contingency [Line Items]
Effective tax rate	14.60%	23.40%
Overall increase (decrease) in unrecognized tax benefits (UTPs)	$ 101.8
Excess Tax Benefit from Share Based Compensation	31	$ 19
Estimated Repatriation Tax Liability Resulting from Tax Reform Legislation				$ 247.3
U.S. Statutory Tax Rate			35.00%
Net of federal tax benefit [Member]
Income Tax Contingency [Line Items]
Overall increase (decrease) in unrecognized tax benefits (UTPs)	$ 109.6
Tax Reform [Member]
Income Tax Contingency [Line Items]
U.S. Statutory Tax Rate			21.00%

WEIGHTED AVERAGE SHARES OUTSTAN

WEIGHTED AVERAGE SHARES OUTSTANDING	3 Months Ended
	Mar. 31, 2018
Text Block [Abstract]
WEIGHTED AVERAGE SHARES OUTSTANDING	NOTE 6 . WEIGHTED AVERAGE SHARES OUTSTANDING Below is a reconciliation of basic to diluted shares outstanding: Three Months Ended March 31, 2018 2017 Basic 191.4 191.1 Dilutive effect of shares issuable under stock-based compensation plans 3.1 3.2 Diluted 194.5 194.3 Anti-dilutive options to purchase common shares and restricted stock as well as contingently issuable restricted stock excluded from the table above 0.7 1.0 The calculation of diluted EPS requires certain assumptions regarding the use of both cash proceeds and assumed proceeds that would be received upon the exercise of stock options and vesting of restricted stock outstanding as of March 31, 2018 and 2017 .

WEIGHTED AVERAGE SHARES OUTST40

WEIGHTED AVERAGE SHARES OUTSTANDING (Tables)	3 Months Ended
	Mar. 31, 2018
Text Block [Abstract]
Reconciliation of Basic to Diluted Shares Outstanding	Three Months Ended March 31, 2018 2017 Basic 191.4 191.1 Dilutive effect of shares issuable under stock-based compensation plans 3.1 3.2 Diluted 194.5 194.3 Anti-dilutive options to purchase common shares and restricted stock as well as contingently issuable restricted stock excluded from the table above 0.7 1.0

Reconciliation of Basic to Dilu

Reconciliation of Basic to Diluted Shares Outstanding (Detail) - shares shares in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Basic	191.4	191.1
Dilutive effect of shares issuable under stock-based compensation plans	3.1	3.2
Diluted	194.5	194.3
Anti-dilutive options to purchase common shares and restricted stock as well as contingently issuable restricted stock which are excluded from the table above	0.7	1

CASH EQUIVALENT AND INVESTMENTS

CASH EQUIVALENT AND INVESTMENTS	3 Months Ended
	Mar. 31, 2018
Text Block [Abstract]
CASH EQUIVALENT AND INVESTMENT	NOTE 7 . CASH EQUIVALENTS AND INVESTMENTS The table below provides additional information on the Company’s cash equivalents and investments: As of March 31, 2018 Balance sheet location Cost Gross Unrealized Gains Fair Value Cash and cash equivalents Short-term investments Other assets Money market mutual funds $ 24.8 $ - $ 24.8 $ 24.8 $ - $ - Certificates of deposit and money market deposit accounts (1) $ 281.7 $ - $ 281.7 $ 176.6 $ 100.5 $ 4.6 Fixed maturity and open ended mutual funds (2) $ 35.0 $ 4.7 $ 39.7 $ - $ - $ 39.7 As of December 31, 2017 Balance sheet location Cost Gross Unrealized Gains Fair Value Cash and cash equivalents Short-term investments Other assets Money market mutual funds $ 42.2 $ - $ 42.2 $ 42.2 $ - $ - Certificates of deposit and money market deposit accounts (1) $ 351.4 $ - $ 351.4 $ 238.6 $ 111.8 $ 1.0 Fixed maturity and open ended mutual funds (2) $ 16.8 $ 4.3 $ 21.1 $ - $ - $ 21.1 (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 to 12 month at both March 31, 2018 and December 31, 2017. The remaining contractual maturities for the certificates of deposits classified in other assets are 14 to 45 months at March 31, 2018 and 15 to 48 months at December 31, 2017. Time deposits with a maturity of less than 90 days at time of purchase are classified as cash and cash equivalents. (2) Consists of investments in fixed maturity mutual funds and open-ended mutual funds. The remaining contractual maturities for the fixed maturity instruments range from three to four months and six months to seven months at March 31, 2018 and December 31, 2017 respectively. As a result of the adoption of ASU 2016-01, as further discussed in Note 1 and Note 2, the money market mutual funds and the fixed maturity and open- ended mutual funds in the table above are deemed to be equity securities with readily determinable fair value s with changes in the fair value recognized through net income under ASC Topic 32 1. The fair value of these instruments is determined using Level 1 inputs as defined in the ASC .

CASH EQUIVALENT AND INVESTMEN43

CASH EQUIVALENT AND INVESTMENTS (Tables)	3 Months Ended
	Mar. 31, 2018
Text Block [Abstract]
Schedule of Cash and Cash Equivalents	As of March 31, 2018 Balance sheet location Cost Gross Unrealized Gains Fair Value Cash and cash equivalents Short-term investments Other assets Money market mutual funds $ 24.8 $ - $ 24.8 $ 24.8 $ - $ - Certificates of deposit and money market deposit accounts (1) $ 281.7 $ - $ 281.7 $ 176.6 $ 100.5 $ 4.6 Fixed maturity and open ended mutual funds (2) $ 35.0 $ 4.7 $ 39.7 $ - $ - $ 39.7 As of December 31, 2017 Balance sheet location Cost Gross Unrealized Gains Fair Value Cash and cash equivalents Short-term investments Other assets Money market mutual funds $ 42.2 $ - $ 42.2 $ 42.2 $ - $ - Certificates of deposit and money market deposit accounts (1) $ 351.4 $ - $ 351.4 $ 238.6 $ 111.8 $ 1.0 Fixed maturity and open ended mutual funds (2) $ 16.8 $ 4.3 $ 21.1 $ - $ - $ 21.1 (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 to 12 month at both March 31, 2018 and December 31, 2017. The remaining contractual maturities for the certificates of deposits classified in other assets are 14 to 45 months at March 31, 2018 and 15 to 48 months at December 31, 2017. Time deposits with a maturity of less than 90 days at time of purchase are classified as cash and cash equivalents. (2) Consists of investments in fixed maturity mutual funds and open-ended mutual funds. The remaining contractual maturities for the fixed maturity instruments range from three to four months and six months to seven months at March 31, 2018 and December 31, 2017 respectively.

Cash Equivalent and Investmen44

Cash Equivalent and Investments (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Cash and Cash Equivalents [Line Items]
Fair value	$ 39.7	$ 21.1
Cash and cash equivalents	1,277.3	1,071.5	$ 2,129.6	$ 2,051.5
Short-term investments	100.5	111.8
Money Market [Member]
Cash and Cash Equivalents [Line Items]
Cost	24.8	42.2
Fair value	24.8	42.2
Cash and cash equivalents	24.8	42.2
Certificates Of Deposit [Member]
Cash and Cash Equivalents [Line Items]
Cost	281.7	351.4
Fair value	281.7	351.4
Cash and cash equivalents	176.6	238.6
Short-term investments	100.5	111.8
Other assets	4.6	1
Fixed Maturity and Mutual Funds [Member]
Cash and Cash Equivalents [Line Items]
Cost	35	16.8
Gross unrealized gain	4.7	4.3
Fair value	39.7	21.1
Other assets	$ 39.7	$ 21.1

Cash Equivalent and Investmen45

Cash Equivalent and Investments (Parenthetical) (Detail)	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Minimum [Member] | Certificates Of Deposit [Member] | Short Term Investments [Member]
Schedule Of Investments [Line Items]
Securities Maturity period	1 month	1 month
Minimum [Member] | Certificates Of Deposit [Member] | Other Assets [Member]
Schedule Of Investments [Line Items]
Securities Maturity period	14 months	15 months
Minimum [Member] | Fixed Maturity and Mutual Funds [Member]
Schedule Of Investments [Line Items]
Securities Maturity period	3 months	6 months
Maximum [Member] | Certificates Of Deposit [Member] | Short Term Investments [Member]
Schedule Of Investments [Line Items]
Securities Maturity period	12 months	12 months
Maximum [Member] | Certificates Of Deposit [Member] | Cash And Cash Equivalents [Member]
Schedule Of Investments [Line Items]
Securities Maturity period	90 days
Maximum [Member] | Certificates Of Deposit [Member] | Other Assets [Member]
Schedule Of Investments [Line Items]
Securities Maturity period	45 months	48 months
Maximum [Member] | Fixed Maturity and Mutual Funds [Member]
Schedule Of Investments [Line Items]
Securities Maturity period	4 months	7 months

ACQUISITIONS

ACQUISITIONS	3 Months Ended
	Mar. 31, 2018
Text Block [Abstract]
ACQUISITIONS	NOTE 8 . ACQUISITIONS The business combinations described below are accounted for using the acquisition method of accounting whereby assets acquired and liabilities assumed were recognized at fair value on the date of the transaction. Any excess of the purchase price over the fair value of the assets acquired and liabilities assumed was recorded to goodwill. Bureau van Dijk On August 10, 2017, a subsidiary of the Company acquired 100% of Yellow Maple I B.V., an indirect parent company of Bureau van Dijk Electronic Publishing B.V., a global provider of business intelligence and company informatio n products. The cash payment of $3,542.0 million was funded with a combination of cash on hand, primarily offshore, and new debt financing. The acquisition extends Moody’s position as a leader in risk data and analytical insight. Shown below is the purchase price allocation, which summarizes the fair value of the assets and liabilities assumed, at the date of acquisition: (Amounts in millions) Current assets $ 158.4 Property and equipment, net 4.2 Intangible assets: Customer relationships (23 year weighted average life) $ 998.7 Product technology (12 year weighted average life) 258.5 Trade name (18 year weighted average life) 82.3 Database (10 year weighted average life) 12.9 Total intangible assets (21 year weighted average life) 1,352.4 Goodwill 2,619.0 Other assets 5.9 Liabilities Deferred revenue $ (101.1) Accounts payable and accrued liabilities (48.6) Deferred tax liabilities, net (329.8) Other liabilities (118.4) Total liabilities (597.9) Net assets acquired $ 3,542.0 The Company has performed a preliminary valuation analysis of the fair market value of assets and liabilities of the Bureau van Dijk business. The final purchase price allocation will be determined when the Company has completed and fully reviewed the detailed valuations. The final allocation could differ materially from the preliminary allocation. The final allocation may include changes in allocations to acquired intangible assets as well as goodwill and other changes to assets and liabilities includi ng reserves for uncertain tax positions and deferred tax liabilities. The estimated useful lives of acquired intangibles assets are also preliminary. Additionally, at March 31, 2018 the Company has not finalized its allocation of certain of the goodwill ac quired to other MA reporting units that are anticipated to benefit from synergies from the acquisition. Current assets in the table ab ove include acquired cash of $36.0 million. Additionally, current assets include accounts receivable of approxima tely $88.0 million (net of an allowance fo r uncollectible accounts of 3.7 million). The acquired deferred revenue balance of approximately $154 million was reduced by $53 million as part of acquisition accounting to establish th e fair value of deferred revenue. This will reduce reported revenue by $53 million over the remaining contractual period of in - progress customer arrangements assumed as of the acquisition date. This resulted in approximately $ 10 million less in reported re venue for the three months ended March 31, 2018 with the remaining $7 million to reduce revenue in subsequent quarterly periods during 2018. Amortization of acquired intangible assets was approximately $ 19 million for the three months ended March 31, 2018 . Goodwill Under the acquisition method of accounting for business combinations, the excess of the purchase price over the fair value of the net assets acquired is allocated to goodwill. Goodwill typically results through expected synergies from combining o perations of an acquiree and an acquirer, anticipated new customer acquisition and products, as well as from intangible assets that do not qualify for separate recognition. The goodwill recognized as a result of this acquisition includes, among other thing s, the value of combining the complementary product portfolios of the Company and Bureau van Dijk, which is expected to extend the Company’s reach to new and evolving market segments as well as cost savings synergies, expected new customer acquisitions and products. Goodwill, which has been assigned to the MA segment, is not deductible for tax purposes. Bureau van Dijk is a separate reporting unit for purposes of the Company’s annual goodwill impairment assessment. Other Liabilities Assumed In connection with the acquisition, the Company assumed liabilities relating to UTBs as well as deferred tax liabilities which relate to acquired intangible assets. These items are included in other liabilities in the table above. Supplementary Unaudited Pro Forma Info rmation Supplemental information on an unaudited pro forma basis is presented below for the three months ended March 31 , 2017 as if the acquisition of Bureau van Dijk occurred on January 1, 2016. The pro forma financial information is presented for compara tive purposes only, based on certain estimates and assumptions, which the Company believes to be reasonable but not necessarily indicative of future results of operations or the results that would have been reported if the acquisition had been completed at January 1, 2016. The unaudited pro forma information includes amortization of acquired intangible assets , based on the preliminary purchase price allocation and an estimate of useful lives reflected above, and incremental financing costs resulting from th e acquisition, net of income tax, which was estimated using the weighted average statutory tax rates in effect in the jurisdiction for which the pro forma adjustment relates. (Amounts in millions) For three months ended March 31, 2017 Pro forma Revenue $ 1,041.6 Pro forma Net Income attributable to Moody's $ 339.6 The unaudited pro forma results do not include any anticipated cost savings or other effects of the planned integration of Bureau van Dijk . Accordingly, the pro forma results above are not necessarily indicative of the results that would have been reported if the acquisition had occurred on the dates indicated, nor are the pro forma results indicative of results which may occur in the future. The Bureau van Dijk results included in the table above have been converted to U.S. GAAP from IFRS as issue d by the IASB and have been translated to USD at rates in eff ect for the periods presented. SCDM Financial On February 13, 2017, a subsidiary of the Company acquired the structured finance data and analytics business of SCDM Financial. The aggregate purchase price was not material and the near term impact to the Company’s operations and cash flow is not expected to be material. This business unit operates in the MA reportable segment and goodwill related to this acquisition has been allocated to the RD&A reporting unit.

ACQUISITIONS (Tables)

ACQUISITIONS (Tables) - Bureau van Dijk (BvD) [Member]	3 Months Ended
	Mar. 31, 2018
Summary of Fair Values of Assets Acquired and Liabilities Assumed	(Amounts in millions) Current assets $ 158.4 Property and equipment, net 4.2 Intangible assets: Customer relationships (23 year weighted average life) $ 998.7 Product technology (12 year weighted average life) 258.5 Trade name (18 year weighted average life) 82.3 Database (10 year weighted average life) 12.9 Total intangible assets (21 year weighted average life) 1,352.4 Goodwill 2,619.0 Other assets 5.9 Liabilities Deferred revenue $ (101.1) Accounts payable and accrued liabilities (48.6) Deferred tax liabilities, net (329.8) Other liabilities (118.4) Total liabilities (597.9) Net assets acquired $ 3,542.0
BvD Pro Forma Information	(Amounts in millions) For three months ended March 31, 2017 Pro forma Revenue $ 1,041.6 Pro forma Net Income attributable to Moody's $ 339.6

Purchase Price Allocation (Deta

Purchase Price Allocation (Detail) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017	Aug. 10, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Indemnification asset	$ 16.8	$ 17
Goodwill	$ 3,831.5	$ 3,753.2		$ 1,023.6
Bureau van Dijk (BvD) [Member]
Business Acquisition [Line Items]
Current assets			$ 158.4
Property and equipment, net			4.2
Total intangible assets			1,352.4
Goodwill			2,619
Other assets			5.9
Deferred revenue			(101.1)
Accounts payable and accrued liabilities			(48.6)
Deferred tax liabilities, net			(329.8)
Other liabilities			(118.4)
Liabilities assumed			(597.9)
Net assets acquired			3,542
Bureau van Dijk (BvD) [Member] | Trade Names [Member]
Business Acquisition [Line Items]
Total intangible assets			82.3
Bureau van Dijk (BvD) [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Total intangible assets			998.7
Bureau van Dijk (BvD) [Member] | Databases [Member]
Business Acquisition [Line Items]
Total intangible assets			12.9
Bureau van Dijk (BvD) [Member] | Product Technology [Member]
Business Acquisition [Line Items]
Total intangible assets			$ 258.5

Purchase Price Allocation (Pare

Purchase Price Allocation (Parenthetical) (Detail) - Bureau van Dijk (BvD) [Member]	Aug. 10, 2017
Business Acquisition [Line Items]
Weighted average life of intangible assets acquired (in years)	21 years
Trade Names [Member]
Business Acquisition [Line Items]
Weighted average life of intangible assets acquired (in years)	18 years
Customer Relationships [Member]
Business Acquisition [Line Items]
Weighted average life of intangible assets acquired (in years)	23 years
Databases [Member]
Business Acquisition [Line Items]
Weighted average life of intangible assets acquired (in years)	10 years
Product Technology [Member]
Business Acquisition [Line Items]
Weighted average life of intangible assets acquired (in years)	12 years

BvD Pro Forma Information (Deta

BvD Pro Forma Information (Detail) - Bureau van Dijk (BvD) [Member] $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)
Business Acquisition [Line Items]
Proforma revenue	$ 1,041.6
Proforma net income from continuing operations	$ 339.6

Acquisitions - Additional Infor

Acquisitions - Additional Information (Detail) - USD ($) $ in Millions	Aug. 10, 2017	Mar. 31, 2018	Mar. 31, 2017
Business Acquisition [Line Items]
Acquisition-Related Expenses		$ 0.8
Amortization expense		25.7	$ 8.5
Bureau van Dijk (BvD) [Member]
Business Acquisition [Line Items]
Business acquisition interests acquired	100.00%
Acquired cash included in current assets	$ 36
Account receivables gross included in current assets	88
Cash paid for acquisitions, net of cash required	3,542
Reduction in Deferred Revenue to establish the fair value	53	10
Allowance for Uncollectible Accounts	3.7
Amortization expense		19
Remaining Reduction in Deferred Revenue to establish the fair value		$ 7
Acquired Deferred Revenue	$ 154

DERIVATIVE INSTRUMENTS AND HEDG

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES	3 Months Ended
	Mar. 31, 2018
Text Block [Abstract]
DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES	NOTE 9 . DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES The Company is exposed to global market risks, including risks from changes in FX rates and changes in interest rates. Accordingly, the Company uses derivatives in certain instances to manage the aforementioned financial exposures that occur in the normal course of business. The Company does not hold or issue derivatives for speculative purposes. Derivatives and non-derivative instruments designated as accounting hedges: Interest Rate Swaps The Com pany 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 va lue 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 s waps designated as fair value hedges: Hedged Item Nature of Swap Notional Amount Floating Interest Rate As of March 31, 2018 As of December 31, 2017 2010 Senior Notes due 2020 Pay Floating/Receive Fixed $ 500.0 $ 500.0 3-month LIBOR 2014 Senior Notes due 2019 Pay Floating/Receive Fixed $ 450.0 $ 450.0 3-month LIBOR 2012 Senior Notes due 2022 Pay Floating/Receive Fixed $ 80.0 $ 80.0 3-month LIBOR The following table summarizes the impact to the statement of operations of the Company’s interest rate swaps designated as fair value hedges : Amount of Income Recognized in the Consolidated Statements of Operations Three Months Ended March 31, Derivatives Designated as Fair Value Accounting Hedges Location on Consolidated Statement of Operations 2018 2017 Interest rate swaps Interest expense, net $ (0.1) $ 2.4 Cross-currency swaps and net investment hedges In conjunction with the issuance of the 2015 Senior Notes, the Company entered into a cr oss-currency swap to exchange € 100 million for U.S. dollars on the date of the settlement of the notes. The purpose of this cross-currency swap was to mitigate FX risk on the remaining principal balance on the 2015 Senior Notes that initially was not designated as a net investment hedge. Under the terms of the swap, the Company paid the counterparty interest on the $110.5 million received at 3.945% per annum and the counterparty pai d the Company interest on the € 100 million paid at 1.75% per annum. These interest payments were settled in March of each year, beginning in 2016, until either the maturity of the cross-currency swap in 2027 or upon early termination at the discretion of the Company. The principal payments on this cross currency swap were to be settled in 2027, concurrent with the repayment of the 2015 Senior Notes at maturity or upon early termination at the disc retion of the Company. In March 2016, the Company designated these cross-currency swaps as cash flow hedges. Accordingly, changes in fair value subsequent to the date the swaps were designated as cash flow hedges were recognized in OCI. Gains and losses on the swaps initially recognized in OCI were reclassified to the statement of operations in the period in which changes in the underlying hedged item affects net income. On December 18, 2017, the Company terminated the cross-currency swap and designated the full € 500 million principal of the 2015 Senior Notes as a net investment hedge as discussed below. The Company has designated € 500 million of the 2015 Senior Notes Due 2027 as a net investment hedge. This hedge is intended to mitigate FX exposure related to euro net investments in certain foreign subsidiaries against changes in euro/USD exchange rates. This net investment hedge is designated as accounting hedges under the applicable sections of Topic 815 of the ASC and will end upon the repayment of the no tes in 2027 unless terminated earlier at the discretion of the Company. Hedge effectiveness is assessed based on the overall changes in the fair value of the hedge. For hedges that meet the effectiveness requirements, any change in the fair value is record ed in OCI in the foreign currency translation account. Any change in the fair value of the Company’s outstanding net hedges that is the result of ineffectiveness would be recognized immediately in other non-operating (expense) income, net in the Company’s consolidated statement of o perations. The following table provides information on the gains/(losses) on the Company’s net investment and cash flow hedges: Amount of Gain/(Loss) Recognized in AOCI on Derivative (Effective Portion), net of Tax Amount of Gain/(Loss) Reclassified from AOCI into Income (Effective Portion), net of Tax Amount of Gain/(Loss) Recognized Directly into Income (Ineffective Portion), net of tax Non-Derivative Instruments in Net Investment Hedging Relationships Three Months Ended Three Months Ended Three Months Ended March 31, March 31, March 31, 2018 2017 2018 2017 2018 2017 Long-term debt $ (10.9) $ (3.6) $ - $ - $ - $ - Total net investment hedges $ (10.9) $ (3.6) $ - $ - $ - $ - Derivatives in Cash Flow Hedging Relationships Cross currency swap $ 1.5 $ (0.2) $ 0.1 * $ 1.0 * $ (0.5) ** $ - Interest rate contracts - - - (0.1) - - Total cash flow hedges $ 1.5 $ (0.2) $ 0.1 $ 0.9 $ (0.5) $ - Total $ (9.4) $ (3.8) $ 0.1 $ 0.9 $ (0.5) $ - * For the three months ended March, 31, 2018, reflects $0.1 million in gains recorded in other non-operating income (expense), net. For the three months ended March 31, 2017, reflects reflects $1.5 million in gains recorded in other non-operating income (expense), net and $0.5 million relating to the tax effect of the aforementioned item. ** For the three months ended March, 31, 2018, reflects $0.7 million in losses recorded in other non-operating income (expense), net and $0.2 million relating to the tax effect of the aforementioned item. The cumulative amount of realized and unrecognized net investment hedge and cash flow hedge gains (losses) recorded in AOCI is as follows: Cumulative Gains/(Losses), net of tax March 31, December 31, Net investment hedges 2018 2017 FX forwards $ 23.5 $ 23.5 Long-term debt (35.6) (24.7) Total net investment hedges $ (12.1) $ (1.2) Cash flow hedges Interest rate contracts $ (0.4) $ (0.4) Cross currency swap 2.7 1.3 Total cash flow hedges 2.3 0.9 Total net losses in AOCI $ (9.8) $ (0.3) 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 a t various times through July 2018. The following table summarizes the notional amounts of the Company’s outstanding foreign exchange forwards: March 31, December 31, 2018 2017 Notional amount of currency pair: Sell Buy Sell Buy Contracts sell USD for GBP $ 708.7 £ 512.9 $ 484.7 £ 362.3 Contracts to sell USD for Japanese Yen $ 24.9 ¥ 2,700.0 $ 24.3 ¥ 2,700.0 Contracts to sell USD for Canadian dollars $ 51.7 C$ 64.0 $ 51.7 C$ 64.0 Contracts to sell USD for Singapore dollars $ - S$ - $ 39.2 S$ 53.0 Contracts to sell USD for Euros $ 74.8 € 60.0 $ 465.2 € 390.0 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) gains on the Company’s derivatives which are not designated as hedging instruments: Three Months Ended March 31, Derivatives Not Designated as Accounting Hedges Location on Statement of Operations 2018 2017 Foreign exchange forwards Other non-operating income, net $ 27.6 $ (2.3) The table below shows the classification between assets and liabilities on the Company’s consolidated balance sheets for the fair value of the derivative instrument as well as the carrying value of its non-derivative debt instruments designated and qualifying as net investment hedges : Derivative and Non-Derivative Instruments Balance Sheet Location March 31, 2018 December 31, 2017 Assets: Derivatives designated as accounting hedges: Interest rate swaps Other assets $ - $ 0.5 Total derivatives designated as accounting hedges - 0.5 Derivatives not designated as accounting hedges: FX forwards on certain assets and liabilities Other current assets 14.5 12.5 Total assets $ 14.5 $ 13.0 Liabilities: Derivatives designated as accounting hedges: Interest rate swaps Other non-current liabilities $ 12.2 $ 3.5 Total derivatives designated as accounting hedges 12.2 3.5 Non-derivative instrument designated as accounting hedge Long-term debt designated as net investment hedge Long-term debt 614.9 600.4 Derivatives not designated as accounting hedges: FX forwards on certain assets and liabilities Accounts payable and accrued liabilities 4.1 2.0 Total liabilities $ 631.2 $ 605.9

DERIVATIVE INSTRUMENTS AND HE53

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES (Tables)	3 Months Ended
	Mar. 31, 2018
Schedule of Interest Rate Swap	Hedged Item Nature of Swap Notional Amount Floating Interest Rate As of March 31, 2018 As of December 31, 2017 2010 Senior Notes due 2020 Pay Floating/Receive Fixed $ 500.0 $ 500.0 3-month LIBOR 2014 Senior Notes due 2019 Pay Floating/Receive Fixed $ 450.0 $ 450.0 3-month LIBOR 2012 Senior Notes due 2022 Pay Floating/Receive Fixed $ 80.0 $ 80.0 3-month LIBOR
Gains and Losses on Derivatives Designated as Hedging Instruments	Amount of Income Recognized in the Consolidated Statements of Operations Three Months Ended March 31, Derivatives Designated as Fair Value Accounting Hedges Location on Consolidated Statement of Operations 2018 2017 Interest rate swaps Interest expense, net $ (0.1) $ 2.4
Summary of Notional Amounts of Outstanding Foreign Exchange Forwards	March 31, December 31, 2018 2017 Notional amount of currency pair: Sell Buy Sell Buy Contracts sell USD for GBP $ 708.7 £ 512.9 $ 484.7 £ 362.3 Contracts to sell USD for Japanese Yen $ 24.9 ¥ 2,700.0 $ 24.3 ¥ 2,700.0 Contracts to sell USD for Canadian dollars $ 51.7 C$ 64.0 $ 51.7 C$ 64.0 Contracts to sell USD for Singapore dollars $ - S$ - $ 39.2 S$ 53.0 Contracts to sell USD for Euros $ 74.8 € 60.0 $ 465.2 € 390.0 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)	Amount of Gain/(Loss) Recognized in AOCI on Derivative (Effective Portion), net of Tax Amount of Gain/(Loss) Reclassified from AOCI into Income (Effective Portion), net of Tax Amount of Gain/(Loss) Recognized Directly into Income (Ineffective Portion), net of tax Non-Derivative Instruments in Net Investment Hedging Relationships Three Months Ended Three Months Ended Three Months Ended March 31, March 31, March 31, 2018 2017 2018 2017 2018 2017 Long-term debt $ (10.9) $ (3.6) $ - $ - $ - $ - Total net investment hedges $ (10.9) $ (3.6) $ - $ - $ - $ - Derivatives in Cash Flow Hedging Relationships Cross currency swap $ 1.5 $ (0.2) $ 0.1 * $ 1.0 * $ (0.5) ** $ - Interest rate contracts - - - (0.1) - - Total cash flow hedges $ 1.5 $ (0.2) $ 0.1 $ 0.9 $ (0.5) $ - Total $ (9.4) $ (3.8) $ 0.1 $ 0.9 $ (0.5) $ - * For the three months ended March, 31, 2018, reflects $0.1 million in gains recorded in other non-operating income (expense), net. For the three months ended March 31, 2017, reflects reflects $1.5 million in gains recorded in other non-operating income (expense), net and $0.5 million relating to the tax effect of the aforementioned item. ** For the three months ended March, 31, 2018, reflects $0.7 million in losses recorded in other non-operating income (expense), net and $0.2 million relating to the tax effect of the aforementioned item.
Cumulative Amount of Unrecognized Hedge Losses Recorded in Accumulated Other Comprehensive Income	Cumulative Gains/(Losses), net of tax March 31, December 31, Net investment hedges 2018 2017 FX forwards $ 23.5 $ 23.5 Long-term debt (35.6) (24.7) Total net investment hedges $ (12.1) $ (1.2) Cash flow hedges Interest rate contracts $ (0.4) $ (0.4) Cross currency swap 2.7 1.3 Total cash flow hedges 2.3 0.9 Total net losses in AOCI $ (9.8) $ (0.3)
Gains and Losses Recognized in Consolidated Statement of Operations on Derivatives Not Designated as Hedging instruments	Three Months Ended March 31, Derivatives Not Designated as Accounting Hedges Location on Statement of Operations 2018 2017 Foreign exchange forwards Other non-operating income, net $ 27.6 $ (2.3)
Fair Value of Derivative Instruments	Derivative and Non-Derivative Instruments Balance Sheet Location March 31, 2018 December 31, 2017 Assets: Derivatives designated as accounting hedges: Interest rate swaps Other assets $ - $ 0.5 Total derivatives designated as accounting hedges - 0.5 Derivatives not designated as accounting hedges: FX forwards on certain assets and liabilities Other current assets 14.5 12.5 Total assets $ 14.5 $ 13.0 Liabilities: Derivatives designated as accounting hedges: Interest rate swaps Other non-current liabilities $ 12.2 $ 3.5 Total derivatives designated as accounting hedges 12.2 3.5 Non-derivative instrument designated as accounting hedge Long-term debt designated as net investment hedge Long-term debt 614.9 600.4 Derivatives not designated as accounting hedges: FX forwards on certain assets and liabilities Accounts payable and accrued liabilities 4.1 2.0 Total liabilities $ 631.2 $ 605.9

Schedule of Interest Rate Swap

Schedule of Interest Rate Swap (Details) - Interest Rate Swap (3-month LIBOR) [Member] - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
2010 Senior Notes [Member]
Derivative [Line Items]
Hedged Item	2010 Senior Notes due 2020
Nature of Swap	Pay Floating/Receive Fixed
Notional amount	$ 500	$ 500
Floating Interest Rate	3-month LIBOR
2012 Senior Notes [Member]
Derivative [Line Items]
Hedged Item	2012 Senior Notes due 2022
Nature of Swap	Pay Floating/Receive Fixed
Notional amount	$ 80	80
Floating Interest Rate	3-month LIBOR
2014 Senior Notes (5-Year) [Member]
Derivative [Line Items]
Hedged Item	2014 Senior Notes due 2019
Nature of Swap	Pay Floating/Receive Fixed
Notional amount	$ 450	$ 450
Floating Interest Rate	3-month LIBOR

Summary of Net Gain (Loss) on F

Summary of Net Gain (Loss) on Foreign Exchange Forwards Not Designated as Hedging Instruments and on Interest Rate Swaps Designated as Fair Value Hedges (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Derivatives Designated as Accounting Hedges [Member] | Interest Rate Swap [Member] | Interest Expense [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of gain (loss) recognized in income	$ (0.1)	$ 2.4
Derivatives Not Designated as Accounting Hedges [Member] | Foreign Exchange Forward [Member] | Other Nonoperating (Expense) Income [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of gain (loss) recognized in income	$ 27.6	$ (2.3)

Gains (Losses) Recognized in AO

Gains (Losses) Recognized in AOCI and Reclassified from AOCI on Derivatives (Effective Portion) (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Derivative Instruments Gain Loss [Line Items]
Amount of Gain/(Loss) Recognized in AOCI on Derivative (Effective Portion)	$ (9.4)	$ (3.8)
Amount of Gain Reclassified from AOCI into Income (Effective Portion)	0.1	0.9
Gain/(Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness Testing)	(0.5)
Net Investment Hedging [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain/(Loss) Recognized in AOCI on Derivative (Effective Portion)	(10.9)	(3.6)
Net Investment Hedging [Member] | Long Term Debt [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain/(Loss) Recognized in AOCI on Derivative (Effective Portion)	(10.9)	(3.6)
Cash Flow Hedging [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain/(Loss) Recognized in AOCI on Derivative (Effective Portion)	1.5	(0.2)
Amount of Gain Reclassified from AOCI into Income (Effective Portion)	0.1	0.9
Gain/(Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness Testing)	(0.5)
Cash Flow Hedging [Member] | Cross-Currency Swap [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain/(Loss) Recognized in AOCI on Derivative (Effective Portion)	1.5	(0.2)
Amount of Gain Reclassified from AOCI into Income (Effective Portion)	0.1	1
Gain/(Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness Testing)	$ (0.5)
Cash Flow Hedging [Member] | Interest Rate Contract [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain Reclassified from AOCI into Income (Effective Portion)		$ (0.1)

Gains (Losses) Recognized in 57

Gains (Losses) Recognized in AOCI and Reclassified from AOCI on Derivatives (Effective Portion) (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Derivative Instruments Gain Loss [Line Items]
Amount of Gain Reclassified from AOCI into Income (Effective Portion)	$ 0.1	$ 0.9
Gain/(Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness Testing)	(0.5)
Cash Flow Hedging [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain Reclassified from AOCI into Income (Effective Portion)	0.1	0.9
Gain/(Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness Testing)	(0.5)
Cash Flow Hedging [Member] | Currency Swap [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain Reclassified from AOCI into Income (Effective Portion)	0.1	1
Gain/(Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness Testing)	(0.5)
Cash Flow Hedging [Member] | Currency Swap [Member] | Other Nonoperating Income (Expense) [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain Reclassified from AOCI into Income (Effective Portion)	0.1	1.5
Gain/(Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness Testing)	(0.7)
Cash Flow Hedging [Member] | Currency Swap [Member] | Tax Effect [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain Reclassified from AOCI into Income (Effective Portion)		$ 0.5
Gain/(Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness Testing)	$ 0.2

Cumulative Amount of Unrecogniz

Cumulative Amount of Unrecognized Hedge Losses Recorded in Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Derivative [Line Items]
Cumulative amount of unrecognized hedge losses recorded in AOCI	$ (9.8)	$ (0.3)
Net Investment Hedging [Member]
Derivative [Line Items]
Cumulative amount of unrecognized hedge losses recorded in AOCI	(12.1)	(1.2)
Net Investment Hedging [Member] | Foreign Exchange Forward [Member]
Derivative [Line Items]
Cumulative amount of unrecognized hedge losses recorded in AOCI	23.5	23.5
Net Investment Hedging [Member] | Long-Term Debt [Member]
Derivative [Line Items]
Cumulative amount of unrecognized hedge losses recorded in AOCI	(35.6)	(24.7)
Cash Flow Hedging [Member]
Derivative [Line Items]
Cumulative amount of unrecognized hedge losses recorded in AOCI	2.3	0.9
Cash Flow Hedging [Member] | Interest Rate Contract [Member]
Derivative [Line Items]
Cumulative amount of unrecognized hedge losses recorded in AOCI	(0.4)	(0.4)
Cash Flow Hedging [Member] | Cross-Currency Swap [Member]
Derivative [Line Items]
Cumulative amount of unrecognized hedge losses recorded in AOCI	$ 2.7	$ 1.3

Summary of Notional Amounts of

Summary of Notional Amounts of Outstanding Foreign Exchange Forwards, Cash Flow Hedging (Detail) € in Millions, ¥ in Millions, £ in Millions, $ in Millions, $ in Millions, $ in Millions	Mar. 31, 2018CAD ($)	Mar. 31, 2018EUR (€)	Mar. 31, 2018GBP (£)	Mar. 31, 2018JPY (¥)	Mar. 31, 2018USD ($)	Dec. 31, 2017CAD ($)	Dec. 31, 2017EUR (€)	Dec. 31, 2017GBP (£)	Dec. 31, 2017JPY (¥)	Dec. 31, 2017SGD ($)	Dec. 31, 2017USD ($)
Contracts to Sell US Dollars for GBP [Member] | Sell [Member]
Derivative [Line Items]
Derivative Notional Amount					$ 708.7						$ 484.7
Contracts to Sell US Dollars for GBP [Member] | Buy [Member]
Derivative [Line Items]
Derivative Notional Amount | £			£ 512.9					£ 362.3
Contracts to Sell USD for JPY [Member] | Sell [Member]
Derivative [Line Items]
Derivative Notional Amount					24.9						24.3
Contracts to Sell USD for JPY [Member] | Buy [Member]
Derivative [Line Items]
Derivative Notional Amount | ¥				¥ 2,700					¥ 2,700
Contracts to Sell USD for CAD [Member] | Sell [Member]
Derivative [Line Items]
Derivative Notional Amount					51.7						51.7
Contracts to Sell USD for CAD [Member] | Buy [Member]
Derivative [Line Items]
Derivative Notional Amount	$ 64					$ 64
Contracts to Sell US Dollars for Singapore dollars [Member] | Sell [Member]
Derivative [Line Items]
Derivative Notional Amount											39.2
Contracts to Sell US Dollars for Singapore dollars [Member] | Buy [Member]
Derivative [Line Items]
Derivative Notional Amount										$ 53
Contracts to Sell USD for Euros [Member] | Sell [Member]
Derivative [Line Items]
Derivative Notional Amount					$ 74.8						$ 465.2
Contracts to Sell USD for Euros [Member] | Buy [Member]
Derivative [Line Items]
Derivative Notional Amount | €		€ 60					€ 390

Fair Value of Derivative Instru

Fair Value of Derivative Instruments (Detail) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Derivatives Fair Value [Line Items]
Derivatives assets	$ 14.5	$ 13
Derivatives liabilities	631.2	605.9
Interest Rate Swap [Member] | Long Term Debt [Member] | Non Derivative Designated As Hedging Instrument [Member] | Net Investment Hedging [Member]
Derivatives Fair Value [Line Items]
Derivatives assets	614.9	600.4
Derivatives Designated as Accounting Hedges [Member]
Derivatives Fair Value [Line Items]
Derivatives assets		0.5
Derivatives liabilities	12.2	3.5
Derivatives Designated as Accounting Hedges [Member] | Interest Rate Swap [Member] | Other Assets [Member]
Derivatives Fair Value [Line Items]
Derivatives assets		0.5
Derivatives Designated as Accounting Hedges [Member] | Interest Rate Swap [Member] | Other Noncurrent Liabilities [Member]
Derivatives Fair Value [Line Items]
Derivatives liabilities	12.2	3.5
Derivatives Not Designated as Accounting Hedges [Member] | Foreign Exchange Forward [Member] | Other Current Assets [Member]
Derivatives Fair Value [Line Items]
Derivatives assets	14.5	12.5
Derivatives Not Designated as Accounting Hedges [Member] | Foreign Exchange Forward [Member] | Accounts Payable And Accrued Liabilities [Member]
Derivatives Fair Value [Line Items]
Derivatives liabilities	$ 4.1	$ 2

Derivative Instruments And He61

Derivative Instruments And Hedging Activities - Additional Information (Detail) - Derivatives Designated as Accounting Hedges [Member] - 2015 Senior Notes [Member] € in Millions, $ in Millions	Mar. 31, 2018EUR (€)	Mar. 31, 2018USD ($)
Currency Swap [Member] | Cross-Currency Paid [Member]
Derivative [Line Items]
Notional amount | $		$ 110.5
Derivative, swaption interest rate	3.945%	3.945%
Currency Swap [Member] | Cross-Currency Received [Member]
Derivative [Line Items]
Notional amount	€ 100
Derivative, swaption interest rate	1.75%	1.75%
Net Investment Hedging [Member] | Cross-Currency Paid [Member]
Derivative [Line Items]
Notional amount	€ 500

GOODWILL AND OTHER ACQUIRED INT

GOODWILL AND OTHER ACQUIRED INTANGIBLE ASSETS	3 Months Ended
	Mar. 31, 2018
Text Block [Abstract]
GOODWILL AND OTHER ACQUIRED INTANGIBLE ASSETS	NOTE 10 . GOODWILL AND OTHER ACQUIRED INTANGIBLE ASSETS The following table summarizes the activity in goodwill for the periods indicated: Three Months Ended March 31, 2018 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 $ 285.2 $ - $ 285.2 $ 3,480.2 $ (12.2) $ 3,468.0 $ 3,765.4 $ (12.2) $ 3,753.2 Foreign currency translation adjustments 6.4 - 6.4 71.9 - 71.9 78.3 - 78.3 Ending balance $ 291.6 $ - $ 291.6 $ 3,552.1 $ (12.2) $ 3,539.9 $ 3,843.7 $ (12.2) $ 3,831.5 Year ended December 31, 2017 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 $ 277.0 $ - $ 277.0 $ 758.8 $ (12.2) $ 746.6 $ 1,035.8 $ (12.2) $ 1,023.6 Additions/adjustments - - - 2,622.6 - 2,622.6 2,622.6 - 2,622.6 Foreign currency translation adjustments 8.2 - 8.2 98.8 - 98.8 107.0 - 107.0 Ending balance $ 285.2 $ - $ 285.2 $ 3,480.2 $ (12.2) $ 3,468.0 $ 3,765.4 $ (12.2) $ 3,753.2 The 2017 additions/adjustments for the MA segment in the table above relate to the acquisition of Bureau van Dijk and structured finance data and analytics business of SCDM. Acquired intangible assets and related amortization consisted of: March 31, December 31, 2018 2017 Customer relationships $ 1,371.7 $ 1,345.1 Accumulated amortization (175.4) (159.9) Net customer relationships 1,196.3 1,185.2 Trade secrets 30.1 30.2 Accumulated amortization (28.1) (28.1) Net trade secrets 2.0 2.1 Software/product technology 366.1 358.6 Accumulated amortization (86.7) (78.0) Net Software/product technology 279.4 280.6 Trade names 164.6 161.6 Accumulated amortization (29.2) (26.7) Net trade names 135.4 134.9 Other (1) 58.2 57.4 Accumulated amortization (29.7) (28.6) Net other 28.5 28.8 Total acquired intangible assets, net $ 1,641.6 $ 1,631.6 (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 March 31, 2018 2017 Amortization expense $ 25.7 $ 8.5 Estimated future amortization expense for acquired intangible assets subject to amortization is as follows: Year Ending December 31, 2018 (after March 31) $ 77.0 2019 98.9 2020 96.5 2021 96.3 2022 95.8 Thereafter 1,177.1 Total estimated future amortization $ 1,641.6 Amortizable intangible assets are reviewed for recoverability whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. If the estimated undiscounted future cash flows are lower than the carrying amount of the related asset, a loss is recognized for the difference between the carrying amount and the estimated fair value of the asset. There were no impairments to intangible assets during the t hree months ended March 31, 2018 and 2017 .

GOODWILL AND OTHER ACQUIRED I63

GOODWILL AND OTHER ACQUIRED INTANGIBLE ASSETS (Tables)	3 Months Ended
	Mar. 31, 2018
Activity in Goodwill	Three Months Ended March 31, 2018 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 $ 285.2 $ - $ 285.2 $ 3,480.2 $ (12.2) $ 3,468.0 $ 3,765.4 $ (12.2) $ 3,753.2 Foreign currency translation adjustments 6.4 - 6.4 71.9 - 71.9 78.3 - 78.3 Ending balance $ 291.6 $ - $ 291.6 $ 3,552.1 $ (12.2) $ 3,539.9 $ 3,843.7 $ (12.2) $ 3,831.5 Year ended December 31, 2017 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 $ 277.0 $ - $ 277.0 $ 758.8 $ (12.2) $ 746.6 $ 1,035.8 $ (12.2) $ 1,023.6 Additions/adjustments - - - 2,622.6 - 2,622.6 2,622.6 - 2,622.6 Foreign currency translation adjustments 8.2 - 8.2 98.8 - 98.8 107.0 - 107.0 Ending balance $ 285.2 $ - $ 285.2 $ 3,480.2 $ (12.2) $ 3,468.0 $ 3,765.4 $ (12.2) $ 3,753.2
Acquired Intangible Assets and Related Amortization	March 31, December 31, 2018 2017 Customer relationships $ 1,371.7 $ 1,345.1 Accumulated amortization (175.4) (159.9) Net customer relationships 1,196.3 1,185.2 Trade secrets 30.1 30.2 Accumulated amortization (28.1) (28.1) Net trade secrets 2.0 2.1 Software/product technology 366.1 358.6 Accumulated amortization (86.7) (78.0) Net Software/product technology 279.4 280.6 Trade names 164.6 161.6 Accumulated amortization (29.2) (26.7) Net trade names 135.4 134.9 Other (1) 58.2 57.4 Accumulated amortization (29.7) (28.6) Net other 28.5 28.8 Total acquired intangible assets, net $ 1,641.6 $ 1,631.6 (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	Three Months Ended March 31, 2018 2017 Amortization expense $ 25.7 $ 8.5
Estimated Future Amortization Expense for Acquired Intangible Assets Subject to Amortization	Year Ending December 31, 2018 (after March 31) $ 77.0 2019 98.9 2020 96.5 2021 96.3 2022 95.8 Thereafter 1,177.1 Total estimated future amortization $ 1,641.6

Activity in Goodwill (Detail)

Activity in Goodwill (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Goodwill [Line Items]
Beginning balance, Goodwill gross	$ 3,765.4	$ 1,035.8
Additions/adjustments, gross		2,622.6
Foreign currency translation adjustments, gross	78.3	107
Ending balance, Goodwill gross	3,843.7	3,765.4
Beginning balance, Accumulated impairment charge	(12.2)	(12.2)
Ending balance, Accumulated impairment charge	(12.2)	(12.2)
Beginning balance, goodwill net	3,753.2	1,023.6
Additions/adjustments		2,622.6
Foreign currency translation adjustments	78.3	107
Ending balance, goodwill net	3,831.5	3,753.2
MIS [Member]
Goodwill [Line Items]
Beginning balance, Goodwill gross	285.2	277
Foreign currency translation adjustments, gross	6.4	8.2
Ending balance, Goodwill gross	291.6	285.2
Beginning balance, goodwill net	285.2	277
Foreign currency translation adjustments	6.4	8.2
Ending balance, goodwill net	291.6	285.2
MA [Member]
Goodwill [Line Items]
Beginning balance, Goodwill gross	3,480.2	758.8
Additions/adjustments, gross		2,622.6
Foreign currency translation adjustments, gross	71.9	98.8
Ending balance, Goodwill gross	3,552.1	3,480.2
Beginning balance, Accumulated impairment charge	(12.2)	(12.2)
Ending balance, Accumulated impairment charge	(12.2)	(12.2)
Beginning balance, goodwill net	3,468	746.6
Additions/adjustments		2,622.6
Foreign currency translation adjustments	71.9	98.8
Ending balance, goodwill net	$ 3,539.9	$ 3,468

Acquired Intangible Assets and

Acquired Intangible Assets and Related Amortization (Detail) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Finite Lived Intangible Assets [Line Items]
Acquired intangible assets, net	$ 1,641.6	$ 1,631.6
Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Acquired intangible assets, gross	1,371.7	1,345.1
Accumulated amortization	(175.4)	(159.9)
Acquired intangible assets, net	1,196.3	1,185.2
Trade Secrets [Member]
Finite Lived Intangible Assets [Line Items]
Acquired intangible assets, gross	30.1	30.2
Accumulated amortization	(28.1)	(28.1)
Acquired intangible assets, net	2	2.1
Computer Software Intangible Asset [Member]
Finite Lived Intangible Assets [Line Items]
Acquired intangible assets, gross	366.1	358.6
Accumulated amortization	(86.7)	(78)
Acquired intangible assets, net	279.4	280.6
Trade Names [Member]
Finite Lived Intangible Assets [Line Items]
Acquired intangible assets, gross	164.6	161.6
Accumulated amortization	(29.2)	(26.7)
Acquired intangible assets, net	135.4	134.9
Other Intangible Assets [Member]
Finite Lived Intangible Assets [Line Items]
Acquired intangible assets, gross	58.2	57.4
Accumulated amortization	(29.7)	(28.6)
Acquired intangible assets, net	$ 28.5	$ 28.8

Amortization Expense Relating t

Amortization Expense Relating to Acquired Intangible Assets (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Finite Lived Intangible Assets [Line Items]
Amortization expense	$ 25.7	$ 8.5

Estimated Future Amortization E

Estimated Future Amortization Expense for Acquired Intangible Assets Subject to Amortization (Detail) $ in Millions	Mar. 31, 2018USD ($)
Schedule Of Actual And Estimated Amortization Expense [Line Items]
2018 (after March 31)	$ 77
2,019	98.9
2,020	96.5
2,021	96.3
2,022	95.8
Thereafter	1,177.1
Total estimated future amortization	$ 1,641.6

Goodwill And Other Acquired I68

Goodwill And Other Acquired Intangible Assets - Additional Information (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)
Goodwill [Line Items]
Impairments to intangible assets	$ 0

FAIR VALUE

FAIR VALUE	3 Months Ended
	Mar. 31, 2018
FAIR VALUE	NOTE 11 . FAIR VALUE The table below presents information about items that are carried at fair value at March 31, 2018 and December 31, 2017 : Fair Value Measurement as of March 31, 2018 Description Balance Level 1 Level 2 Assets: Derivatives (a) $ 14.5 $ - $ 14.5 Money market mutual funds 24.8 24.8 - Fixed maturity and open ended mutual funds 39.7 39.7 - Total $ 79.0 $ 64.5 $ 14.5 Liabilities: Derivatives (a) $ 16.3 $ - $ 16.3 Total $ 16.3 $ - $ 16.3 Fair Value Measurement as of December 31, 2017 Description Balance Level 1 Level 2 Assets: Derivatives (a) $ 13.0 $ - $ 13.0 Money market mutual funds 42.2 42.2 - Fixed maturity and open ended mutual funds 21.1 21.1 - Total $ 76.3 $ 63.3 $ 13.0 Liabilities: Derivatives (a) $ 5.5 $ - $ 5.5 Total $ 5.5 $ - $ 5.5 (a) Represents FX forwards on certain assets and liabilities and on net investments in certain foreign subsidiaries as well as interest rate swaps and cross-currency swaps as more fully described in Note 9 to the condensed consolidated financial statements. The following are descriptions of the methodologies utilized by the Company to estimate the fair value of its derivative contracts, fixed maturity plans, 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, inte rest 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. Fixed maturity and open-ended mutual funds: As a result of the adoption of ASU 2016-01, as further discussed in Note 1 and Note 2, the fixed maturity and o pen- ended 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. Prior to the Company’s adoption of ASU No. 2016-01, any un realized gains and losses were recognized through OCI until the instruments mature d or were sold. The fair value of these instruments is determined using Level 1 inputs as defined in the ASC. Money market mutual funds: Similar to fixed maturity and open- e nded mutual funds , the money market 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 as required by ASU 2016-01. The money market mutual funds represent publicly traded funds with a stable $ 1 net asset value.

FAIR VALUE (Tables)

FAIR VALUE (Tables)	3 Months Ended
	Mar. 31, 2018
Text Block [Abstract]
Financial Instruments Carried at Fair Value on Recurring Basis	Fair Value Measurement as of March 31, 2018 Description Balance Level 1 Level 2 Assets: Derivatives (a) $ 14.5 $ - $ 14.5 Money market mutual funds 24.8 24.8 - Fixed maturity and open ended mutual funds 39.7 39.7 - Total $ 79.0 $ 64.5 $ 14.5 Liabilities: Derivatives (a) $ 16.3 $ - $ 16.3 Total $ 16.3 $ - $ 16.3 Fair Value Measurement as of December 31, 2017 Description Balance Level 1 Level 2 Assets: Derivatives (a) $ 13.0 $ - $ 13.0 Money market mutual funds 42.2 42.2 - Fixed maturity and open ended mutual funds 21.1 21.1 - Total $ 76.3 $ 63.3 $ 13.0 Liabilities: Derivatives (a) $ 5.5 $ - $ 5.5 Total $ 5.5 $ - $ 5.5 (a) Represents FX forwards on certain assets and liabilities and on net investments in certain foreign subsidiaries as well as interest rate swaps and cross-currency swaps as more fully described in Note 9 to the condensed consolidated financial statements.

Financial Instruments Carried a

Financial Instruments Carried at Fair Value on Recurring Basis (Detail) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative Contracts	$ 14.5	$ 13
Money market funds	24.8	42.2
Fixed maturity and open ended mutual funds	39.7	21.1
Total, Assets	79	76.3
Derivatives, Liabilities	16.3	5.5
Total, Liabilities	16.3	5.5
Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Money market funds	24.8	42.2
Fixed maturity and open ended mutual funds	39.7	21.1
Total, Assets	64.5	63.3
Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative Contracts	14.5	13
Total, Assets	14.5	13
Derivatives, Liabilities	16.3	5.5
Total, Liabilities	$ 16.3	$ 5.5

Fair Value - Additional Informa

Fair Value - Additional Information (Detail)	Mar. 31, 2018USD ($)
Fair Value Inputs [Abstract]
Net asset stable value for public traded funds	$ 1

OTHER BALANCE SHEET INFORMATION

OTHER BALANCE SHEET INFORMATION	3 Months Ended
	Mar. 31, 2018
Text Block [Abstract]
OTHER BALANCE SHEET AND STATEMENT OF OPERATIONS INFORMATION	NOTE 12 . OTHER BALANCE SHEET AND STATEMENT OF OPERATIONS INFORMATION The following tables contain additional detail related to certain balance sheet captions: March 31, December 31, 2018 2017 Other current assets: Prepaid taxes $ 55.5 $ 94.9 Prepaid expenses 95.7 91.7 Capitalized costs to obtain and fulfill sales contracts (1) 39.2 15.9 Other 43.2 47.6 Total other current assets $ 233.6 $ 250.1 March 31, December 31, 2018 2017 Other assets: Investments in joint ventures $ 100.4 $ 99.1 Deposits for real-estate leases 12.2 12.3 Indemnification assets related to acquisitions 16.8 17.0 Mutual funds and fixed deposits 44.3 22.1 Costs to obtain sales contracts (1) 69.3 - Other 15.0 9.4 Total other assets $ 258.0 $ 159.9 (1) The 2018 amount reflects capitalized costs to obtain sales contracts (sales commissions) pursuant to the adoption of the New Revenue Accounting Standard, which are amortized over an average 7 year period as well as costs incurred and capitalized for in process ratings (current assets only). March 31, December 31, 2018 2017 Accounts payable and accrued liabilities: Salaries and benefits $ 136.6 $ 129.6 Incentive compensation 51.0 246.7 Customer credits, advanced payments and advanced billings 27.4 22.2 Self-insurance reserves 9.9 8.1 Dividends 4.8 6.2 Professional service fees 49.9 47.1 Interest accrued on debt 30.2 73.9 Accounts payable 32.0 21.8 Income taxes 86.7 79.2 Pension and other retirement employee benefits (see Note 14) 5.9 5.9 Accrued royalties 19.6 26.4 Other 78.6 83.2 Total accounts payable and accrued liabilities $ 532.6 $ 750.3 March 31, December 31, 2018 2017 Other liabilities: Pension and other retirement employee benefits (see Note 14) $ 256.0 $ 244.5 Deferred rent - non-current portion 101.7 103.1 Interest accrued on UTPs 52.8 54.7 Other tax matters 1.3 1.3 Income tax liability - non-current (2) 108.0 232.2 Other 34.4 28.2 Total other liabilities $ 554.2 $ 664.0 (2) Primarily reflects the transition tax pursuant to the Tax Act, which was enacted into law in December 2017. Changes in the Company’s self-insurance reserves for claims insured by the Company’s wholly-owned insurance subsidiary, which primarily relate to legal defense costs for claims from prior years, are as follows: Three Months Ended Year Ended March 31, December 31, 2018 2017 Balance January 1, $ 8.1 $ 11.1 Accruals (reversals), net 2.4 9.6 Payments (0.6) (12.6) Balance $ 9.9 $ 8.1 Other Non-Operating Income (Expense): The following table summarizes the components of other non-operating income (expense): Three Months Ended March 31, 2018 2017 FX loss $ (5.9) $ (9.6) Net periodic pension costs - other component (1) 2.3 1.7 Joint venture income 1.3 1.0 Other 3.3 (0.8) Total $ 1.0 $ (7.7) (1) The Company adopted ASU No. 2017-07 in the first quarter of 2018, whereby all components of pension expense except for the service cost component are required to be presented in other non-operating income. The service cost component continues to be reported as an operating expense.

OTHER BALANCE SHEET INFORMATI74

OTHER BALANCE SHEET INFORMATION (Tables)	3 Months Ended
	Mar. 31, 2018
Text Block [Abstract]
Additional Details Related to Certain Balance Sheet Captions	March 31, December 31, 2018 2017 Other current assets: Prepaid taxes $ 55.5 $ 94.9 Prepaid expenses 95.7 91.7 Capitalized costs to obtain and fulfill sales contracts (1) 39.2 15.9 Other 43.2 47.6 Total other current assets $ 233.6 $ 250.1 March 31, December 31, 2018 2017 Other assets: Investments in joint ventures $ 100.4 $ 99.1 Deposits for real-estate leases 12.2 12.3 Indemnification assets related to acquisitions 16.8 17.0 Mutual funds and fixed deposits 44.3 22.1 Costs to obtain sales contracts (1) 69.3 - Other 15.0 9.4 Total other assets $ 258.0 $ 159.9 (1) The 2018 amount reflects capitalized costs to obtain sales contracts (sales commissions) pursuant to the adoption of the New Revenue Accounting Standard, which are amortized over an average 7 year period as well as costs incurred and capitalized for in process ratings (current assets only). March 31, December 31, 2018 2017 Accounts payable and accrued liabilities: Salaries and benefits $ 136.6 $ 129.6 Incentive compensation 51.0 246.7 Customer credits, advanced payments and advanced billings 27.4 22.2 Self-insurance reserves 9.9 8.1 Dividends 4.8 6.2 Professional service fees 49.9 47.1 Interest accrued on debt 30.2 73.9 Accounts payable 32.0 21.8 Income taxes 86.7 79.2 Pension and other retirement employee benefits (see Note 14) 5.9 5.9 Accrued royalties 19.6 26.4 Other 78.6 83.2 Total accounts payable and accrued liabilities $ 532.6 $ 750.3 March 31, December 31, 2018 2017 Other liabilities: Pension and other retirement employee benefits (see Note 14) $ 256.0 $ 244.5 Deferred rent - non-current portion 101.7 103.1 Interest accrued on UTPs 52.8 54.7 Other tax matters 1.3 1.3 Income tax liability - non-current (2) 108.0 232.2 Other 34.4 28.2 Total other liabilities $ 554.2 $ 664.0 (2) Primarily reflects the transition tax pursuant to the Tax Act, which was enacted into law in December 2017.
Self Insurance Reserves	Three Months Ended Year Ended March 31, December 31, 2018 2017 Balance January 1, $ 8.1 $ 11.1 Accruals (reversals), net 2.4 9.6 Payments (0.6) (12.6) Balance $ 9.9 $ 8.1
Other Non-Operating	Three Months Ended March 31, 2018 2017 FX loss $ (5.9) $ (9.6) Net periodic pension costs - other component (1) 2.3 1.7 Joint venture income 1.3 1.0 Other 3.3 (0.8) Total $ 1.0 $ (7.7) (1) The Company adopted ASU No. 2017-07 in the first quarter of 2018, whereby all components of pension expense except for the service cost component are required to be presented in other non-operating income. The service cost component continues to be reported as an operating expense.

Additional Details Related to C

Additional Details Related to Certain Balance Sheet Captions (Detail) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Other current assets:
Prepaid taxes	$ 55.5	$ 94.9
Prepaid expenses	95.7	91.7
Other	43.2	47.6
Total other current assets	233.6	250.1
Other assets
Investments in joint ventures	100.4	99.1
Deposits for real-estate leases	12.2	12.3
Indemnification assets related to acquisitions	16.8	17
Mutual funds and fixed deposits	44.3	22.1
Other	15	9.4
Total other assets	258	159.9
Accounts payable and accrued liabilities
Salaries and benefits	136.6	129.6
Incentive compensation	51	246.7
Customer credits, advanced payments and advanced billings	27.4	22.2
Self-insurance reserves	9.9	8.1
Dividends	4.8	6.2
Professional service fees	49.9	47.1
Interest accrued on debt	30.2	73.9
Accounts payable	32	21.8
Income taxes	86.7	79.2
Pension and other post retirement employee benefits	5.9	5.9
Accrued royalties	19.6	26.4
Other	78.6	83.2
Total accounts payable and accrued liabilities	532.6	750.3
Other liabilities
Pension and other post retirement employee benefits	256	244.5
Deferred rent-non-current portion	101.7	103.1
Interest accrued on UTPs	52.8	54.7
Other tax matters	1.3	1.3
Other	34.4	28.2
Income tax liability - non-current	108	232.2
Total other liabilities	554.2	664
Other Current Assets [Member]
Other current assets:
Capitalized costs to obtain and fulfill sales contracts	39.2	$ 15.9
Other Assets [Member]
Other current assets:
Capitalized costs to obtain and fulfill sales contracts	$ 69.3

Changes in Self Insurance Reser

Changes in Self Insurance Reserves (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Disclosure Changes in Self Insurance Reserves [Abstract]
Self-insurance reserves, beginning balance	$ 8.1	$ 11.1
Accruals (reversals), net	2.4	9.6
Payments	(0.6)	(12.6)
Self-insurance reserves, ending balance	$ 9.9	$ 8.1

Other Non-Operating Interest (D

Other Non-Operating Interest (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Other Nonoperating Income (Expense) [Abstract]
FX gain/(loss)	$ (5.9)	$ (9.6)
Pension Expense	2.3	1.7
Joint venture income	1.3	1
Other	3.3	(0.8)
Total	$ 1	$ (7.7)

Other Balance Sheet Informati78

Other Balance Sheet Information - Additional Detail (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2017USD ($)
Minority Interest [Line Items]
Gain on dilution of Stock in Subsidiary	$ 59.7

COMPREHENSIVE INCOME RECLASSIFI

COMPREHENSIVE INCOME RECLASSIFICATION	3 Months Ended
	Mar. 31, 2018
Text Block [Abstract]
COMPREHENSIVE INCOME AND ACCUMULATED OTHER COMPREHENSIVE INCOME	NOTE 13 . COMPREHENSIVE INCOME AND ACCUMULATED OTHER COMPREHENSIVE INCOME The following table provides details about the reclassifications out of AOCI: Three Months Ended Affected line in the consolidated statement of operations March 31, March 31, 2018 2017 Gain on cash flow hedges Cross-currency swap $ 0.1 $ 1.5 Other non-operating (expense) income, net Treasury rate lock - (0.1) Interest expense, net Total before income taxes 0.1 1.4 Income tax effect of items above - (0.5) Provision for income taxes Total gains on cash flow hedges 0.1 0.9 Pension and other retirement benefits Amortization of actuarial losses and prior service costs included in net income (0.9) (1.5) Operating expense Amortization of actuarial losses and prior service costs included in net income (0.5) (0.9) SG&A expense Total before income taxes (1.4) (2.4) Income tax effect of item above 0.4 0.9 Provision for income taxes Total pension and other retirement benefits (1.0) (1.5) Total losses included in Net Income attributable to reclassifications out of AOCI $ (0.9) $ (0.6) The following table shows changes in AOCI by component (net of tax): Three Months Ended March 31, 2018 Pension and Other Retirement Benefits Gains / (Losses) on Cash Flow Hedges Foreign Currency Translation Adjustments Gains on Available for Sale Securities Total Balance December 31, 2017 $ (61.5) $ 0.9 $ (113.9) $ 2.3 $ (172.2) Adoption of ASU 2016-01 (Refer to Note 1 and Note 2) - - - (2.3) (2.3) Other comprehensive income before reclassifications - 1.5 120.2 - 121.7 Amounts reclassified from AOCI 1.0 (0.1) - - 0.9 Other comprehensive income/(loss) 1.0 1.4 120.2 (2.3) 120.3 Balance March 31, 2018 $ (60.5) $ 2.3 $ 6.3 $ - $ (51.9) Three Months Ended March 31, 2017 Pension and Other Retirement Benefits Gains / (Losses) on Cash Flow Hedges Foreign Currency Translation Adjustments Gains on Available for Sale Securities Total Balance December 31, 2016 $ (79.5) $ 1.7 $ (290.2) $ 3.1 $ (364.9) Other comprehensive income before reclassifications - (0.2) 6.9 0.3 7.0 Amounts reclassified from AOCI 1.5 (0.9) - - 0.6 Other comprehensive income/(loss) 1.5 (1.1) 6.9 0.3 7.6 Balance March 31, 2017 $ (78.0) $ 0.6 $ (283.3) $ 3.4 $ (357.3)

COMPREHENSIVE INCOME RECLASSI80

COMPREHENSIVE INCOME RECLASSIFICATIONS (Tables)	3 Months Ended
	Mar. 31, 2018
Text Block [Abstract]
Reclassifications out of AOCI	Three Months Ended Affected line in the consolidated statement of operations March 31, March 31, 2018 2017 Gain on cash flow hedges Cross-currency swap $ 0.1 $ 1.5 Other non-operating (expense) income, net Treasury rate lock - (0.1) Interest expense, net Total before income taxes 0.1 1.4 Income tax effect of items above - (0.5) Provision for income taxes Total gains on cash flow hedges 0.1 0.9 Pension and other retirement benefits Amortization of actuarial losses and prior service costs included in net income (0.9) (1.5) Operating expense Amortization of actuarial losses and prior service costs included in net income (0.5) (0.9) SG&A expense Total before income taxes (1.4) (2.4) Income tax effect of item above 0.4 0.9 Provision for income taxes Total pension and other retirement benefits (1.0) (1.5) Total losses included in Net Income attributable to reclassifications out of AOCI $ (0.9) $ (0.6)
Components of Accumulated Other Comprehensive Income	Three Months Ended March 31, 2018 Pension and Other Retirement Benefits Gains / (Losses) on Cash Flow Hedges Foreign Currency Translation Adjustments Gains on Available for Sale Securities Total Balance December 31, 2017 $ (61.5) $ 0.9 $ (113.9) $ 2.3 $ (172.2) Adoption of ASU 2016-01 (Refer to Note 1 and Note 2) - - - (2.3) (2.3) Other comprehensive income before reclassifications - 1.5 120.2 - 121.7 Amounts reclassified from AOCI 1.0 (0.1) - - 0.9 Other comprehensive income/(loss) 1.0 1.4 120.2 (2.3) 120.3 Balance March 31, 2018 $ (60.5) $ 2.3 $ 6.3 $ - $ (51.9) Three Months Ended March 31, 2017 Pension and Other Retirement Benefits Gains / (Losses) on Cash Flow Hedges Foreign Currency Translation Adjustments Gains on Available for Sale Securities Total Balance December 31, 2016 $ (79.5) $ 1.7 $ (290.2) $ 3.1 $ (364.9) Other comprehensive income before reclassifications - (0.2) 6.9 0.3 7.0 Amounts reclassified from AOCI 1.5 (0.9) - - 0.6 Other comprehensive income/(loss) 1.5 (1.1) 6.9 0.3 7.6 Balance March 31, 2017 $ (78.0) $ 0.6 $ (283.3) $ 3.4 $ (357.3)

Reclassification out of AOCI (D

Reclassification out of AOCI (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash Flow Hedges, net of tax:
Gains on cash flow hedges - Pre Tax	$ 0.1	$ 1.4
Gains on cash flow hedges - Tax		(0.5)
Gains on cash flow hedges - Net of Tax	0.1	0.9
Pension and Other Post-Retirement Benefits, net of tax:
Amortization of actuarial losses and prior service costs included in net income - Pre Tax	(1.4)	(2.4)
Amortization of actuarial losses and prior service costs included in net income - Tax	0.4	0.9
Amortization of actuarial losses and prior service costs included in net income - Net of Tax	(1)	(1.5)
Income Loss Attributable to Reclassification Out Of AOCI Net Of Tax	(0.9)	(0.6)
Operating Expense [Member]
Pension and Other Post-Retirement Benefits, net of tax:
Amortization of actuarial losses and prior service costs included in net income - Pre Tax	(0.9)	(1.5)
SG&A Expense [Member]
Pension and Other Post-Retirement Benefits, net of tax:
Amortization of actuarial losses and prior service costs included in net income - Pre Tax	(0.5)	(0.9)
Currency Swap [Member] | Other Nonoperating Income (Expense) [Member]
Cash Flow Hedges, net of tax:
Gains on cash flow hedges - Pre Tax	$ 0.1	1.5
Interest Rate Contract [Member] | Interest Expense [Member]
Cash Flow Hedges, net of tax:
Gains on cash flow hedges - Pre Tax		$ (0.1)

Changes in Components of Accumu

Changes in Components of Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Beginning Balance	$ (172.2)	$ (364.9)
Reclassification adjustment from AOCI, Pension and Other Postretirement Benefit Plans - Net of Tax	1	1.5
Pension and other retirement benefit - Net of Tax	1	1.5
Net unrealized gain (losses) on cash flow - Net of Tax	1.5	(0.2)
Reclassification gain (losses) on cash flow - Net of Tax	(0.1)	(0.9)
Gains/(Losses) on cash flow hedges - Net of Tax	1.4	(1.1)
Foreign currency translation adjustments before reclassification - Net of Tax	125.2	12.1
Available for sale securities before reclassification - Net of Tax		0.5
Amounts reclassified from AOCI	0.9	0.6
Total other comprehensive income (loss) - Net of Tax	127.6	13
Ending Balance	(51.9)	(357.3)
Parent [Member]
Foreign currency translation adjustments before reclassification - Net of Tax	120.2	6.9
Foreign currency translation adjustments - Net of Tax	120.2	6.9
Available for sale securities before reclassification - Net of Tax		0.3
Gains on Available for sale securities - Net of Tax		0.3
Other comprehensive income/(loss) before reclassifications	121.7	7
Total other comprehensive income (loss) - Net of Tax	120.3	7.6
Financial Instruments - Overall (ASU 2016-01) [Member]
Amount reclassified from AOCI, Available fo Sale Securities - Net of Tax	(2.3)
Gains on Available for sale securities - Net of Tax	(2.3)
Gains Losses on Cash Flow Hedges [Member]
Beginning Balance	0.9	1.7
Ending Balance	2.3	0.6
Pension and Other Retirement Benefits [Member]
Beginning Balance	(61.5)	(79.5)
Ending Balance	(60.5)	(78)
Foreign Currency Translation Adjustments [Member]
Beginning Balance	(113.9)	(290.2)
Ending Balance	6.3	(283.3)
Gains on Available for Sale Securities [Member]
Beginning Balance	$ 2.3	3.1
Ending Balance		$ 3.4

PENSION AND OTHER POST-RETIREME

PENSION AND OTHER POST-RETIREMENT BENEFITS	3 Months Ended
	Mar. 31, 2018
Text Block [Abstract]
PENSION AND OTHER RETIREMENT BENEFITS	NOTE 14 . PENSION AND OTHER RETIREMENT BENEFITS M oody’s maintains funded and unfunded noncontributory Defined Benefit Pension Plans. 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 noncontribu tory. 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. retirem ent life insurance plans are collectively referred to herein a s the “Other Retirement Plans”. 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 rece ive 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 b ased on existing plan formulas. The components of net periodic benefit expense re lated to the Retirement Plans are as follows: Three Months Ended March 31, Pension Plans Other Retirement Plans 2018 2017 2018 2017 Components of net periodic expense Service cost $ 4.8 $ 4.9 $ 0.7 $ 0.6 Interest cost 4.4 4.7 0.3 0.3 Expected return on plan assets (3.8) (4.1) - - Amortization of net actuarial loss from earlier periods 1.6 2.4 - - Amortization of net prior service costs from earlier periods (0.1) - (0.1) (0.1) Net periodic expense $ 6.9 $ 7.9 $ 0.9 $ 0.8 The Company made payments of $ 0.9 million related to its unfunded U.S. DBPPs and $ 0.1 million to its U.S. other retirement plans during the three months ended March 31, 201 8 . The Company anticipates making payments of $ 4.0 million and $ 0.9 million to its unfunded U.S. DBPPs and U.S. other retirement plans, respectively, during the remainder of 2018 .

PENSION AND OTHER POST-RETIRE84

PENSION AND OTHER POST-RETIREMENT BENEFITS (Tables)	3 Months Ended
	Mar. 31, 2018
Text Block [Abstract]
Components of Net Periodic Benefit Expense Related to Post-Retirement Plans	Three Months Ended March 31, Pension Plans Other Retirement Plans 2018 2017 2018 2017 Components of net periodic expense Service cost $ 4.8 $ 4.9 $ 0.7 $ 0.6 Interest cost 4.4 4.7 0.3 0.3 Expected return on plan assets (3.8) (4.1) - - Amortization of net actuarial loss from earlier periods 1.6 2.4 - - Amortization of net prior service costs from earlier periods (0.1) - (0.1) (0.1) Net periodic expense $ 6.9 $ 7.9 $ 0.9 $ 0.8

Components of Net Periodic Bene

Components of Net Periodic Benefit Expense Related to Post-Retirement Plans (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 4.7	$ 5
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	4.8	4.9
Interest cost	4.4	4.7
Expected return on plan assets	(3.8)	(4.1)
Amortization of net actuarial loss from earlier periods	1.6	2.4
Amortization of net prior service costs from earlier periods	(0.1)
Net periodic expense	6.9	7.9
Other Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0.7	0.6
Interest cost	0.3	0.3
Amortization of net prior service costs from earlier periods	(0.1)	(0.1)
Net periodic expense	$ 0.9	$ 0.8

Pension and Other Post-Retire86

Pension and Other Post-Retirement Benefits - Additional Information (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)
Unfunded Pension Plans [Member]
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit payment amount	$ 0.9
Estimated additional payments in 2018	4
Other Postretirement Benefit Plans Defined Benefit [Member]
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit payment amount	0.1
Estimated additional payments in 2018	$ 0.9

INDEBTEDNESS

INDEBTEDNESS	3 Months Ended
	Mar. 31, 2018
Text Block [Abstract]
INDEBTEDNESS	NOTE 15 . INDEBTEDNESS The following table summarizes total indebtedness: March 31, 2018 Principal Amount Fair Value of Interest Rate Swaps (1) Unamortized (Discount) Premium Unamortized Debt Issuance Costs Carrying Value Notes Payable: 5.50% 2010 Senior Notes, due 2020 $ 500.0 $ (5.6) $ (0.9) $ (1.0) $ 492.5 4.50% 2012 Senior Notes, due 2022 500.0 (2.3) (1.9) (1.7) 494.1 4.875% 2013 Senior Notes, due 2024 500.0 - (1.8) (2.3) 495.9 2.75% 2014 Senior Notes (5-Year), due 2019 450.0 (4.3) (0.2) (0.9) 444.6 5.25% 2014 Senior Notes (30-Year), due 2044 600.0 - 3.3 (5.6) 597.7 1.75% 2015 Senior Notes, due 2027 614.9 - - (3.5) 611.4 2.75% 2017 Senior Notes, due 2021 500.0 - (1.2) (3.0) 495.8 2017 Floating Rate Senior Notes, due 2018 300.0 - - (0.3) 299.7 2.625% 2017 Notes, due 2023 500.0 - (1.0) (3.4) 495.6 3.25% 2017 Notes, due 2028 500.0 - (5.1) (3.9) 491.0 2017 Term Loan Facility, due 2020 500.0 - - (0.6) 499.4 Commercial Paper 90.0 - (0.1) - 89.9 Total debt $ 5,554.9 $ (12.2) $ (8.9) $ (26.2) $ 5,507.6 Current portion (389.6) Total long-term debt $ 5,118.0 December 31, 2017 Principal Amount Fair Value of Interest Rate Swaps (1) Unamortized (Discount) Premium Unamortized Debt Issuance Costs Carrying Value Notes Payable: 5.50% 2010 Senior Notes, due 2020 $ 500.0 $ - $ (1.0) $ (1.2) $ 497.8 4.50% 2012 Senior Notes, due 2022 500.0 (0.8) (2.0) (1.7) 495.5 4.875% 2013 Senior Notes, due 2024 500.0 - (1.8) (2.4) 495.8 2.75% 2014 Senior Notes (5-Year), due 2019 450.0 (2.2) (0.2) (1.1) 446.5 5.25% 2014 Senior Notes (30-Year), due 2044 600.0 - 3.3 (5.7) 597.6 1.75% 2015 Senior Notes, due 2027 600.4 - - (3.6) 596.8 2.75% 2017 Senior Notes, due 2021 500.0 - (1.3) (3.2) 495.5 2017 Floating Rate Senior Notes, due 2018 300.0 - - (0.5) 299.5 2.625% 2017 Notes, due 2023 500.0 - (1.1) (3.5) 495.4 3.25% 2017 Notes, due 2028 500.0 - (5.2) (3.9) 490.9 2017 Term Loan Facility, due 2020 500.0 - - (0.7) 499.3 Commercial Paper 130.0 - (0.1) - 129.9 Total debt $ 5,580.4 $ (3.0) $ (9.4) $ (27.5) $ 5,540.5 Current portion (429.4) Total long-term debt $ 5,111.1 (1) The Company has entered into interest rate swaps on the 2010 Senior Notes, the 2012 Senior Notes and the 2014 Senior Notes (5-Year) which are more fully discussed in Note 9 above. Commercial Paper As of March 31, 201 8 , the Company has CP borrowings outstanding of $ 90 million with a weighted average maturity da te at the time of issuance of 31 days. At March 31, 2018 , the weighted average remaining maturity and intere st rate on CP outstanding was 7 days and 2.11 % respectively. At March 31, 2018 , 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 a nd payable. As of March 31, 2018 , 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 (5-year) due 2019 2014 Senior Notes (30-year) due 2044 2015 Senior Notes due 2027 Term Loan Facility due 2020 2017 Floating Rate Senior Notes due 2018 2017 Senior Notes due 2021 2017 Notes due 2023 2017 Notes due 2028 Commercial Paper Total 2018 (after March 31,) $ - $ - $ - $ - $ - $ - $ - $ 300.0 $ - $ - $ - $ 90.0 $ 390.0 2019 - - - 450.0 - - - - - - - - 450.0 2020 500.0 - - - - - 500.0 - - - - - 1,000.0 2021 - - - - - - - - 500.0 - - - 500.0 2022 - 500.0 - - - - - - - - - - 500.0 Thereafter - - 500.0 - 600.0 614.9 - - - 500.0 500.0 - 2,714.9 Total $ 500.0 $ 500.0 $ 500.0 $ 450.0 $ 600.0 $ 614.9 $ 500.0 $ 300.0 $ 500.0 $ 500.0 $ 500.0 $ 90.0 $ 5,554.9 Interest expense, net The following table summarizes the components of interest as presented in the consolidated statements of operations: Three Months Ended March 31, 2018 2017 Income $ 3.2 $ 4.1 Expense on borrowings (51.3) (44.7) Expense on UTPs and other tax related liabilities 1.8 (2.1) Net periodic pension costs - interest component (1) (4.7) (5.0) Capitalized 0.3 0.3 Total Interest (expense) income, net $ (50.7) $ (47.4) (1) The Company adopted ASU No. 2017-07 in the first quarter of 2018, whereby all components of pension expense except for the service cost component are required to be presented in other non-operating income. The service cost component continues to be reported as an operating expense. The following table shows the cash paid for interest: Three Months Ended March 31, 2018 2017 Interest paid $ 80.5 $ 74.7 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 2014 Senior Notes (5-Year) and the 2012 Senior Notes 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 fair value and carrying value of the Company’s debt (excluding Commercial Paper) as of March 31, 2018 and December 31, 2017 are as follows : March 31, 2018 December 31, 2017 Carrying Amount Estimated Fair Value Carrying Amount Estimated Fair Value 2010 Senior Notes $ 492.5 $ 527.8 $ 497.8 $ 537.9 2012 Senior Notes 494.1 521.9 495.5 535.6 2013 Senior Notes 495.9 531.1 495.8 547.8 2014 Senior Notes (5-Year) 444.6 448.9 446.5 452.8 2014 Senior Notes (30-Year) 597.7 692.2 597.6 722.4 2015 Senior Notes 611.4 630.5 596.8 617.7 2017 Senior Notes (5-Year) 495.8 490.4 495.5 500.0 2017 Floating Rate Senior Notes 299.7 300.2 299.5 300.2 2.65% 2017 Notes, due 2023 495.6 481.9 495.4 494.8 3.25% 2017 Notes, due 2028 491.0 475.3 490.9 493.6 2017 Term Loan Facility, due 2020 499.4 499.4 499.3 499.3 Total $ 5,417.7 $ 5,599.6 $ 5,410.6 $ 5,702.1 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.

INDEBTEDNESS (Tables)

INDEBTEDNESS (Tables)	3 Months Ended
	Mar. 31, 2018
Text Block [Abstract]
Summary of Total Indebtedness	March 31, 2018 Principal Amount Fair Value of Interest Rate Swaps (1) Unamortized (Discount) Premium Unamortized Debt Issuance Costs Carrying Value Notes Payable: 5.50% 2010 Senior Notes, due 2020 $ 500.0 $ (5.6) $ (0.9) $ (1.0) $ 492.5 4.50% 2012 Senior Notes, due 2022 500.0 (2.3) (1.9) (1.7) 494.1 4.875% 2013 Senior Notes, due 2024 500.0 - (1.8) (2.3) 495.9 2.75% 2014 Senior Notes (5-Year), due 2019 450.0 (4.3) (0.2) (0.9) 444.6 5.25% 2014 Senior Notes (30-Year), due 2044 600.0 - 3.3 (5.6) 597.7 1.75% 2015 Senior Notes, due 2027 614.9 - - (3.5) 611.4 2.75% 2017 Senior Notes, due 2021 500.0 - (1.2) (3.0) 495.8 2017 Floating Rate Senior Notes, due 2018 300.0 - - (0.3) 299.7 2.625% 2017 Notes, due 2023 500.0 - (1.0) (3.4) 495.6 3.25% 2017 Notes, due 2028 500.0 - (5.1) (3.9) 491.0 2017 Term Loan Facility, due 2020 500.0 - - (0.6) 499.4 Commercial Paper 90.0 - (0.1) - 89.9 Total debt $ 5,554.9 $ (12.2) $ (8.9) $ (26.2) $ 5,507.6 Current portion (389.6) Total long-term debt $ 5,118.0 December 31, 2017 Principal Amount Fair Value of Interest Rate Swaps (1) Unamortized (Discount) Premium Unamortized Debt Issuance Costs Carrying Value Notes Payable: 5.50% 2010 Senior Notes, due 2020 $ 500.0 $ - $ (1.0) $ (1.2) $ 497.8 4.50% 2012 Senior Notes, due 2022 500.0 (0.8) (2.0) (1.7) 495.5 4.875% 2013 Senior Notes, due 2024 500.0 - (1.8) (2.4) 495.8 2.75% 2014 Senior Notes (5-Year), due 2019 450.0 (2.2) (0.2) (1.1) 446.5 5.25% 2014 Senior Notes (30-Year), due 2044 600.0 - 3.3 (5.7) 597.6 1.75% 2015 Senior Notes, due 2027 600.4 - - (3.6) 596.8 2.75% 2017 Senior Notes, due 2021 500.0 - (1.3) (3.2) 495.5 2017 Floating Rate Senior Notes, due 2018 300.0 - - (0.5) 299.5 2.625% 2017 Notes, due 2023 500.0 - (1.1) (3.5) 495.4 3.25% 2017 Notes, due 2028 500.0 - (5.2) (3.9) 490.9 2017 Term Loan Facility, due 2020 500.0 - - (0.7) 499.3 Commercial Paper 130.0 - (0.1) - 129.9 Total debt $ 5,580.4 $ (3.0) $ (9.4) $ (27.5) $ 5,540.5 Current portion (429.4) Total long-term debt $ 5,111.1 (1) The Company has entered into interest rate swaps on the 2010 Senior Notes, the 2012 Senior Notes and the 2014 Senior Notes (5-Year) which are more fully discussed in Note 9 above.
Principal Payments Due on Long-Term Borrowings	Year Ending December 31, 2010 Senior Notes due 2020 2012 Senior Notes due 2022 2013 Senior Notes due 2024 2014 Senior Notes (5-year) due 2019 2014 Senior Notes (30-year) due 2044 2015 Senior Notes due 2027 Term Loan Facility due 2020 2017 Floating Rate Senior Notes due 2018 2017 Senior Notes due 2021 2017 Notes due 2023 2017 Notes due 2028 Commercial Paper Total 2018 (after March 31,) $ - $ - $ - $ - $ - $ - $ - $ 300.0 $ - $ - $ - $ 90.0 $ 390.0 2019 - - - 450.0 - - - - - - - - 450.0 2020 500.0 - - - - - 500.0 - - - - - 1,000.0 2021 - - - - - - - - 500.0 - - - 500.0 2022 - 500.0 - - - - - - - - - - 500.0 Thereafter - - 500.0 - 600.0 614.9 - - - 500.0 500.0 - 2,714.9 Total $ 500.0 $ 500.0 $ 500.0 $ 450.0 $ 600.0 $ 614.9 $ 500.0 $ 300.0 $ 500.0 $ 500.0 $ 500.0 $ 90.0 $ 5,554.9
Summary of Components of Interest as Presented in Consolidated Statements of Operations	Three Months Ended March 31, 2018 2017 Income $ 3.2 $ 4.1 Expense on borrowings (51.3) (44.7) Expense on UTPs and other tax related liabilities 1.8 (2.1) Net periodic pension costs - interest component (1) (4.7) (5.0) Capitalized 0.3 0.3 Total Interest (expense) income, net $ (50.7) $ (47.4) (1) The Company adopted ASU No. 2017-07 in the first quarter of 2018, whereby all components of pension expense except for the service cost component are required to be presented in other non-operating income. The service cost component continues to be reported as an operating expense.
Interest Paid	Three Months Ended March 31, 2018 2017 Interest paid $ 80.5 $ 74.7
Fair Value and Carrying Value of Long-Term Debt	March 31, 2018 December 31, 2017 Carrying Amount Estimated Fair Value Carrying Amount Estimated Fair Value 2010 Senior Notes $ 492.5 $ 527.8 $ 497.8 $ 537.9 2012 Senior Notes 494.1 521.9 495.5 535.6 2013 Senior Notes 495.9 531.1 495.8 547.8 2014 Senior Notes (5-Year) 444.6 448.9 446.5 452.8 2014 Senior Notes (30-Year) 597.7 692.2 597.6 722.4 2015 Senior Notes 611.4 630.5 596.8 617.7 2017 Senior Notes (5-Year) 495.8 490.4 495.5 500.0 2017 Floating Rate Senior Notes 299.7 300.2 299.5 300.2 2.65% 2017 Notes, due 2023 495.6 481.9 495.4 494.8 3.25% 2017 Notes, due 2028 491.0 475.3 490.9 493.6 2017 Term Loan Facility, due 2020 499.4 499.4 499.3 499.3 Total $ 5,417.7 $ 5,599.6 $ 5,410.6 $ 5,702.1

Summary of Total Indebtedness (

Summary of Total Indebtedness (Detail) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Principal Amount	$ 5,554.9	$ 5,580.4
Fair Value of Interest Rate Swap	(12.2)	(3)
Unamortized (Discount) Premium	(8.9)	(9.4)
Unamortized Debt Issuance Costs	(26.2)	(27.5)
Total Debt	5,507.6	5,540.5
Current portion	(389.6)	(429.4)
Carrying Amount	5,417.7	5,410.6
Current portion of long-term debt	(299.7)	(299.5)
Total long-term debt, non-current	5,118	5,111.1
Commercial Paper [Member]
Debt Instrument [Line Items]
Principal Amount	90	130
Unamortized (Discount) Premium	(0.1)	(0.1)
Total Debt	89.9	129.9
2010 Senior Notes [Member]
Debt Instrument [Line Items]
Principal Amount	500	500
Fair Value of Interest Rate Swap	(5.6)
Unamortized (Discount) Premium	(0.9)	(1)
Unamortized Debt Issuance Costs	(1)	(1.2)
Carrying Amount	492.5	497.8
2012 Senior Notes [Member]
Debt Instrument [Line Items]
Principal Amount	500	500
Fair Value of Interest Rate Swap	(2.3)	(0.8)
Unamortized (Discount) Premium	(1.9)	(2)
Unamortized Debt Issuance Costs	(1.7)	(1.7)
Carrying Amount	494.1	495.5
2013 Senior Notes [Member]
Debt Instrument [Line Items]
Principal Amount	500	500
Unamortized (Discount) Premium	(1.8)	(1.8)
Unamortized Debt Issuance Costs	(2.3)	(2.4)
Carrying Amount	495.9	495.8
2014 Senior Notes (5-Year) [Member]
Debt Instrument [Line Items]
Principal Amount	450	450
Fair Value of Interest Rate Swap	(4.3)	(2.2)
Unamortized (Discount) Premium	(0.2)	(0.2)
Unamortized Debt Issuance Costs	(0.9)	(1.1)
Carrying Amount	444.6	446.5
2014 Senior Notes (30-Year) [Member]
Debt Instrument [Line Items]
Principal Amount	600	600
Unamortized (Discount) Premium	3.3	3.3
Unamortized Debt Issuance Costs	(5.6)	(5.7)
Carrying Amount	597.7	597.6
2015 Senior Notes [Member]
Debt Instrument [Line Items]
Principal Amount	614.9	600.4
Unamortized Debt Issuance Costs	(3.5)	(3.6)
Carrying Amount	611.4	596.8
2017 Senior Notes [Member]
Debt Instrument [Line Items]
Principal Amount	500	500
Unamortized (Discount) Premium	(1.2)	(1.3)
Unamortized Debt Issuance Costs	(3)	(3.2)
Carrying Amount	495.8	495.5
2017 Floating Rate Senior Notes [Member]
Debt Instrument [Line Items]
Principal Amount	300	300
Unamortized Debt Issuance Costs	(0.3)	(0.5)
Carrying Amount	299.7	299.5
2.625% 2017 Notes, due 2023 [Member]
Debt Instrument [Line Items]
Principal Amount	500	500
Unamortized (Discount) Premium	(1)	(1.1)
Unamortized Debt Issuance Costs	(3.4)	(3.5)
Carrying Amount	495.6	495.4
3.25% 2017 Notes, due 2028 [Member]
Debt Instrument [Line Items]
Principal Amount	500	500
Unamortized (Discount) Premium	(5.1)	(5.2)
Unamortized Debt Issuance Costs	(3.9)	(3.9)
Carrying Amount	491	490.9
2017 Term Loan Facility, due 2020 [Member]
Debt Instrument [Line Items]
Principal Amount	500	500
Unamortized Debt Issuance Costs	(0.6)	(0.7)
Carrying Amount	$ 499.4	$ 499.3

Summary of Total Indebtedness90

Summary of Total Indebtedness (Parenthetical) (Detail)	Mar. 31, 2018	Dec. 31, 2017
2010 Senior Notes [Member]
Debt Instrument [Line Items]
Notes Payable, interest rate	5.50%	5.50%
2012 Senior Notes [Member]
Debt Instrument [Line Items]
Notes Payable, interest rate	4.50%	4.50%
2013 Senior Notes [Member]
Debt Instrument [Line Items]
Notes Payable, interest rate	4.875%	4.875%
2014 Senior Notes (5-Year) [Member]
Debt Instrument [Line Items]
Notes Payable, interest rate	2.75%	2.75%
2014 Senior Notes (30-Year) [Member]
Debt Instrument [Line Items]
Notes Payable, interest rate	5.25%	5.25%
2015 Senior Notes [Member]
Debt Instrument [Line Items]
Notes Payable, interest rate	1.75%	1.75%
2017 Senior Notes [Member]
Debt Instrument [Line Items]
Notes Payable, interest rate	2.75%	2.75%
2.625% 2017 Notes, due 2023 [Member]
Debt Instrument [Line Items]
Notes Payable, interest rate	2.65%	2.65%
3.25% 2017 Notes, due 2028 [Member]
Debt Instrument [Line Items]
Notes Payable, interest rate	3.25%	3.25%

Principal Payments Due on Long-

Principal Payments Due on Long-Term Borrowings (Detail) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
2018 (after March 31,)	$ 390
2,019	450
2,020	1,000
2,021	500
2,022	500
Thereafter	2,714.9
Total principal payment	5,554.9	$ 5,580.4
Commercial Paper [Member]
Debt Instrument [Line Items]
2018 (after March 31,)	90
Total principal payment	90	130
2010 Senior Notes [Member]
Debt Instrument [Line Items]
2,020	500
Total principal payment	500	500
2012 Senior Notes [Member]
Debt Instrument [Line Items]
2,022	500
Total principal payment	500	500
2013 Senior Notes [Member]
Debt Instrument [Line Items]
Thereafter	500
Total principal payment	500	500
2014 Senior Notes (5-Year) [Member]
Debt Instrument [Line Items]
2,019	450
Total principal payment	450	450
2014 Senior Notes (30-Year) [Member]
Debt Instrument [Line Items]
Thereafter	600
Total principal payment	600	600
2015 Senior Notes [Member]
Debt Instrument [Line Items]
Thereafter	614.9
Total principal payment	614.9	600.4
2017 Floating Rate Senior Notes [Member]
Debt Instrument [Line Items]
2018 (after March 31,)	300
Total principal payment	300	300
2017 Senior Notes [Member]
Debt Instrument [Line Items]
2,021	500
Total principal payment	500	500
2.625% 2017 Notes, due 2023 [Member]
Debt Instrument [Line Items]
Thereafter	500
Total principal payment	500	500
3.25% 2017 Notes, due 2028 [Member]
Debt Instrument [Line Items]
Thereafter	500
Total principal payment	500	500
2017 Term Loan Facility, due 2020 [Member]
Debt Instrument [Line Items]
2,020	500
Total principal payment	$ 500	$ 500

Summary of Components of Intere

Summary of Components of Interest as Presented in Consolidated Statements of Operations (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Debt Instrument [Line Items]
Income	$ 3.2	$ 4.1
Expense on borrowings	(51.3)	(44.7)
Income (expense) on UTPs and other tax related liabilities	1.8	(2.1)
Capitalized	0.3	0.3
Net periodic pension costs - interest component	(4.7)	(5)
Total	$ (50.7)	$ (47.4)

Interest Paid (Detail)

Interest Paid (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Debt Instrument [Line Items]
Interest paid	$ 80.5	$ 74.7

Fair Value and Carrying Value o

Fair Value and Carrying Value of Long-Term Debt (Detail) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Long term debt	$ 5,417.7	$ 5,410.6
Estimated Fair Value	5,599.6	5,702.1
2010 Senior Notes [Member]
Debt Instrument [Line Items]
Long term debt	492.5	497.8
Estimated Fair Value	527.8	537.9
2012 Senior Notes [Member]
Debt Instrument [Line Items]
Long term debt	494.1	495.5
Estimated Fair Value	521.9	535.6
2013 Senior Notes [Member]
Debt Instrument [Line Items]
Long term debt	495.9	495.8
Estimated Fair Value	531.1	547.8
2014 Senior Notes (5-Year) [Member]
Debt Instrument [Line Items]
Long term debt	444.6	446.5
Estimated Fair Value	448.9	452.8
2014 Senior Notes (30-Year) [Member]
Debt Instrument [Line Items]
Long term debt	597.7	597.6
Estimated Fair Value	692.2	722.4
2015 Senior Notes [Member]
Debt Instrument [Line Items]
Long term debt	611.4	596.8
Estimated Fair Value	630.5	617.7
2017 Senior Notes [Member]
Debt Instrument [Line Items]
Long term debt	495.8	495.5
Estimated Fair Value	490.4	500
2017 Floating Rate Senior Notes [Member]
Debt Instrument [Line Items]
Long term debt	299.7	299.5
Estimated Fair Value	300.2	300.2
2.625% 2017 Notes, due 2023 [Member]
Debt Instrument [Line Items]
Long term debt	495.6	495.4
Estimated Fair Value	481.9	494.8
3.25% 2017 Notes, due 2028 [Member]
Debt Instrument [Line Items]
Long term debt	491	490.9
Estimated Fair Value	475.3	493.6
2017 Term Loan Facility, due 2020 [Member]
Debt Instrument [Line Items]
Long term debt	499.4	499.3
Estimated Fair Value	$ 499.4	$ 499.3

Indebtedness - Additional Infor

Indebtedness - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Debt, aggregate principal amount	$ 5,554.9	$ 5,580.4
Commercial Paper [Member]
Debt Instrument [Line Items]
Debt, aggregate principal amount	$ 90
Commercial paper, interest rate	2.11%
Maturity Date	7 days
Commercial Paper [Member] | Date of Issuance [Member]
Debt Instrument [Line Items]
Maturity Date	31 days

CONTINGENCIES

CONTINGENCIES	3 Months Ended
	Mar. 31, 2018
Text Block [Abstract]
CONTINGENCIES	NOTE 16 . 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 jurisdictio ns, and Moody’s is subject to ongoing tax audits as addressed in Note 5 to the financial statements, any of which may result in claims, legal proceedings, assessments, fines, penalties or restrictions on business activities . Management periodically assesse s 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 record s 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 accord ingly. 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 i ts 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 unfavorabl e developments or resolutions can occur, the ultimate outcome of such matters, including the amount of any loss, may differ from those estimates.

SEGMENT INFORMATION

SEGMENT INFORMATION	3 Months Ended
	Mar. 31, 2018
Text Block [Abstract]
SEGMENT INFORMATION	NOTE 17 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 pri cing 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 segmen t consists of three LOBs - RD&A, ERS and PS. In August 2017, a subsidiary of the Company acquired Yellow Maple I B.V., an indirect parent of Bureau van Dijk. Bureau van Dijk is part of the MA reportable segment and its revenue is included in the RD&A LOB . Refer to Note 8 for further discussion on the acquisition . 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 MI S 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 an d 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. Additionally, overhead costs and corporate expenses of the Company that exclusively benefit only one segment are fully charged to that segment. Overhead costs and corporate expenses of the Company that benefit both segments are allocated to each segment based on a revenue-split methodology. Accordingly, a reportable segment’s share of these costs will increase as its proportion of revenue relative to Moody’s total revenue increases. Overhead expenses include costs such as rent and occupancy, information technology and support staff such as finance, human resources and information technology. “Eliminati ons” in the table below 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 March 31, 2018 2017 MIS MA Eliminations Consolidated MIS MA Eliminations Consolidated* Revenue $ 749.7 $ 411.8 $ (34.8) $ 1,126.7 $ 694.2 $ 310.7 $ (29.7) $ 975.2 Operating, SG&A * 310.4 310.4 (34.8) 586.0 286.2 239.5 (29.7) 496.0 Adjusted Operating Income* 439.3 101.4 - 540.7 408.0 71.2 - 479.2 Less: Depreciation and amortization 16.8 32.3 - 49.1 18.9 13.6 - 32.5 Acquisition-Related Expenses - 0.8 - 0.8 - - - - Operating income* $ 422.5 $ 68.3 $ - $ 490.8 $ 389.1 $ 57.6 $ - $ 446.7 *Pursuant to the adoption of a new accounting standard relating to pension accounting as more fully discussed in Note 1, only the service cost component of net periodic pension expense will be classified within operating and SG&A expenses with the remaining components being classified as non-operating expenses. Prior period segment results have been restated to reflect this reclassification. Accordingly, operating and SG&A expenses for MIS and MA were reduced by $2.1 million and $1.2 million, respectively, for the three months ended March 31, 2017. CONSOLIDATED REVENUE INFORMATION BY GEOGRAPHIC AREA Three Months Ended March 31, 2018 2017 Revenue: U.S. $ 597.7 $ 577.8 International: EMEA 347.3 236.3 Asia-Pacific 120.2 99.4 Americas 61.5 61.7 Total International 529.0 397.4 Total $ 1,126.7 $ 975.2

SEGMENT INFORMATION (Tables)

SEGMENT INFORMATION (Tables)	3 Months Ended
	Mar. 31, 2018
Text Block [Abstract]
Financial Information by Segment	Three Months Ended March 31, 2018 2017 MIS MA Eliminations Consolidated MIS MA Eliminations Consolidated* Revenue $ 749.7 $ 411.8 $ (34.8) $ 1,126.7 $ 694.2 $ 310.7 $ (29.7) $ 975.2 Operating, SG&A * 310.4 310.4 (34.8) 586.0 286.2 239.5 (29.7) 496.0 Adjusted Operating Income* 439.3 101.4 - 540.7 408.0 71.2 - 479.2 Less: Depreciation and amortization 16.8 32.3 - 49.1 18.9 13.6 - 32.5 Acquisition-Related Expenses - 0.8 - 0.8 - - - - Operating income* $ 422.5 $ 68.3 $ - $ 490.8 $ 389.1 $ 57.6 $ - $ 446.7 *Pursuant to the adoption of a new accounting standard relating to pension accounting as more fully discussed in Note 1, only the service cost component of net periodic pension expense will be classified within operating and SG&A expenses with the remaining components being classified as non-operating expenses. Prior period segment results have been restated to reflect this reclassification. Accordingly, operating and SG&A expenses for MIS and MA were reduced by $2.1 million and $1.2 million, respectively, for the three months ended March 31, 2017.
Consolidated Revenue Information by Geographic Area	Three Months Ended March 31, 2018 2017 Revenue: U.S. $ 597.7 $ 577.8 International: EMEA 347.3 236.3 Asia-Pacific 120.2 99.4 Americas 61.5 61.7 Total International 529.0 397.4 Total $ 1,126.7 $ 975.2

Financial Information by Segmen

Financial Information by Segment (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Segment Reporting Information [Line Items]
Revenues	$ 1,126.7	$ 975.2
Operating, SG&A	586	496
Adjusted Operating Income	540.7	479.2
Depreciation and amortization	49.1	32.5
Acquisition-Related Expenses	0.8
Operating Income	490.8	446.7
MIS [Member]
Segment Reporting Information [Line Items]
Revenues	749.7	694.2
Operating, SG&A	310.4	286.2
Adjusted Operating Income	439.3	408
Depreciation and amortization	16.8	18.9
Operating Income	422.5	389.1
MA [Member]
Segment Reporting Information [Line Items]
Revenues	411.8	310.7
Operating, SG&A	310.4	239.5
Adjusted Operating Income	101.4	71.2
Depreciation and amortization	32.3	13.6
Acquisition-Related Expenses	0.8
Operating Income	68.3	57.6
Eliminations [Member]
Segment Reporting Information [Line Items]
Revenues	(34.8)	(29.7)
Operating, SG&A	$ (34.8)	$ (29.7)

Financial Information by Seg100

Financial Information by Segment (Parenthetical) (Detail) - Compensation-Retirement Benefits Accounting Standard [Member] $ in Millions	3 Months Ended
	Mar. 31, 2017USD ($)
Moodys Investors Service [Member]
Segment Reporting Information [Line Items]
Reduction in Operating, SG&A	$ 2.1
Moodys Analytics [Member]
Segment Reporting Information [Line Items]
Reduction in Operating, SG&A	$ 1.2

Consolidated Revenue Informatio

Consolidated Revenue Information by Geographic Area (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Segment Reporting Information [Line Items]
Revenues	$ 1,126.7	$ 975.2
U S
Segment Reporting Information [Line Items]
Revenues	597.7	577.8
International Regions [Member]
Segment Reporting Information [Line Items]
Revenues	529	397.4
International Regions [Member] | Europe Middle East And Africa [Member]
Segment Reporting Information [Line Items]
Revenues	347.3	236.3
International Regions [Member] | Asia Pacific [Member]
Segment Reporting Information [Line Items]
Revenues	120.2	99.4
International Regions [Member] | Americas [Member]
Segment Reporting Information [Line Items]
Revenues	$ 61.5	$ 61.7

RECENTLY ISSUED ACCOUNTING STAN

RECENTLY ISSUED ACCOUNTING STANDARDS	3 Months Ended
	Mar. 31, 2018
Text Block [Abstract]
RECENTLY ISSUED ACCOUNTING STANDARDS	NOTE 18 . RECENTLY ISSUED ACCOUNTING STANDARDS In February 2016, the FASB issued ASU No. 2016-02, “Leases (Topic 842)” requiring lessees to recognize a right-of-use asset and lease liability for all leases with terms of more than 12 months. Recognition, measurement and presentation of expenses and cash flows will depend on classification as either a finance or operating lease. This ASU is effective for fiscal years beginning after December 15, 2018, with early adoption permitted. This standard must be adopted using a modified retrospective approach whereby leases will be presented in accordance with the new standard as of the earliest period presented. The Company is currently evaluating the impact of this ASU on the Company’s financial statements. The Company believes that the most notable impact to its financial statements upon the adoption of this ASU will be the recognition of a material right-of-use asset and lease liability for its real estate leases. 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 amo rtized cost carrying value of the asset rather than a direct reduction to the carrying value, with changes in the allowance impacting earnings. This ASU is effective for annual and interim reporting periods beginning after December 15, 2019, with early ado ption 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 the adequacy of its allowance for doubtful a ccounts on accounts receivable. In July 2017, the FASB issued ASU No. 2017-12, “Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities”. This ASU enables entities to enhance transparency relating to risk management activities and simplifies the application of hedge accounting in certain circumstances. This ASU is effective for fiscal years beginning after December 15, 2018, including interim periods within those years with early adoption permitted. The Company is cur rently in the process of assessing the impact that this ASU will have on its financial statements. In February 2018, FASB issued ASU 2018-02, “Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income”. Under current GAAP, adjustm ents 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 ef fect”). The provisions of this ASU permit the reclassification of the stranded tax effect related to the Tax Act from AOCI to retained earnings. This ASU is effective for all entities for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years, with early adoption permitted. Adoption of this ASU is to be applied either in the period of adoption or retrospectively to each period in which the effect of the Tax Act were recognized. The Company is currently evaluating the i mpact of this ASU on its financial statements. In March 2018, the FASB issued ASU 2018-05, "Income Taxes (Topic 740) - Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 118". This ASU adds SEC paragraphs to the codification pursuan t to the SEC Staff Accounting Bulletin No. 118, which addresses the application of U.S. GAAP in situations when a registrant does not have the necessary information available, prepared, or analyzed (including computations) in reasonable detail to finalize the calculations for the 2017 income tax effects of the Tax Act. This ASU provides entities with a one year measurement period from the December 22, 2017 enactment date, in order to complete the accounting for the effects of the Tax Act. The Company is cur rently evaluating the impact of the adoption of this guidance on its financial statements.

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	3 Months Ended
	Mar. 31, 2018
Text Block [Abstract]
SUBSEQUENT EVENTS	NOTE 19 . SUBSEQUENT EVENT On April 24, 2018 , the Board approved the declaration of a quarterly dividend of $0.44 per share of Moody’s common stock, payable on June 11, 2018 to shareholders of record at the close of business on May 21, 2018 .

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - Subsequent Event [Member]	Apr. 24, 2018$ / shares
Dividends Payable [Line Items]
Dividend declared, per share	$ 0.44
Dividend declared, declaration date	Apr. 24, 2018
Dividend declared, payable date	Jun. 11, 2018
Dividend declared, record date	May 21, 2018