MSCI (MSCI) 10-K/A 2 Mar 15 2014 FY Annual report (amended) Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2014	Feb. 20, 2015	Jun. 30, 2014
Document And Entity Information [Abstract]
Document Type	10-K/A
Amendment Flag	TRUE
Amendment Description	The Registrant is filing this Amendment No. 1 to Form 10-K for the fiscal year ended December 31, 2014 (“Amendment No. 1”) to correct an error on the cover page of the original Form 10-K as filed with the Securities and Exchange Commission on February 27, 2015 (the “Original Form 10-K”). The cover page of the Original Form 10-K mistakenly indicated that as of February 20, 2015, 127,233,209 shares of the Registrant’s $0.01 par value Common Stock were outstanding. The correct number of shares of the Registrant’s $0.01 par value Common Stock outstanding as of such date was 112,375,127, as indicated on the cover page of this Amendment No. 1. No changes are hereby made to the Registrant’s financial statements. Other than the change discussed above and the filing of the currently dated 302 certifications and updated XBRL data under Item 15 of Part IV of this Amendment No. 1, no changes have been made to the Original Form 10-K or the exhibits filed therewith. As such, this Amendment No.1 should be read in conjunction with the Original Form 10-K. The information contained in this Amendment No. 1 does not reflect events occurring subsequent to the filing of the Original Form 10-K.
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Trading Symbol	MSCI
Entity Registrant Name	MSCI INC.
Entity Central Index Key	1408198
Current Fiscal Year End Date	-19
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		112,375,127
Entity Public Float			$5,241,587,917

Consolidated_Statements_of_Fin

Consolidated Statements of Financial Condition (USD $)	Dec. 31, 2014	Dec. 31, 2013
ASSETS
Cash and cash equivalents	$508,799,000	$358,434,000
Accounts receivable (net of allowances of $857 and $1,280 as of December 31, 2014 and 2013, respectively)	178,717,000	169,490,000
Deferred taxes	22,209,000	52,888,000
Prepaid income taxes	29,180,000	14,568,000
Prepaid and other assets	31,727,000	28,890,000
Total current assets	770,632,000	624,270,000
Property, equipment and leasehold improvements (net of accumulated depreciation of $92,808 and $75,371 at December 31, 2014 and 2013, respectively)	94,074,000	85,588,000
Goodwill	1,564,904,000	1,813,164,000
Intangible assets (net of accumulated amortization of $372,209 and $374,377 at December 31, 2014 and 2013, respectively)	433,628,000	595,707,000
Other non-current assets	30,937,000	17,386,000
Total assets	2,894,175,000	3,136,115,000
LIABILITIES AND SHAREHOLDERS' EQUITY
Accounts payable	2,835,000	1,198,000
Accrued compensation and related benefits	111,408,000	121,124,000
Other accrued liabilities	47,894,000	41,212,000
Current maturities of long term debt	0	19,772,000
Deferred revenue	310,775,000	319,735,000
Total current liabilities	472,912,000	503,041,000
Long term debt, net of current maturities	800,000,000	788,010,000
Deferred taxes	137,838,000	234,649,000
Other non-current liabilities	50,592,000	46,068,000
Total liabilities	1,461,342,000	1,571,768,000
Commitments and Contingencies (see Note 6)
Shareholders' equity:
Preferred stock (par value $0.01; 100,000,000 shares authorized; no shares issued)
Common stock (par value $0.01; 750,000,000 common shares authorized at December 31, 2014 and 2013; 126,637,390 and 125,555,268 common shares issued at December 31, 2014 and 2013, respectively; and 112,072,469 and 118,083,111 common shares outstanding at December 31, 2014 and 2013, respectively)	1,266,000	1,256,000
Treasury shares, at cost (14,564,921 and 7,472,157 shares at December 31, 2014 and 2013, respectively)	-588,378,000	-268,391,000
Additional paid in capital	1,022,221,000	1,073,157,000
Retained earnings	1,022,695,000	758,975,000
Accumulated other comprehensive loss	-24,971,000	-650,000
Total shareholders' equity	1,432,833,000	1,564,347,000
Total liabilities and shareholders' equity	$2,894,175,000	$3,136,115,000

Consolidated_Statements_of_Fin1

Consolidated Statements of Financial Condition (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]
Accounts receivable, allowances	$857	$1,280
Property, equipment and leasehold improvements, accumulated depreciation	92,808	75,371
Intangible assets, accumulated amortization	$372,209	$374,377
Preferred stock, par value	$0.01	$0.01
Preferred stock, shares authorized	100,000,000	100,000,000
Preferred stock, shares issued	0	0
Common stock, par value	$0.01	$0.01
Common stock, shares authorized	750,000,000	750,000,000
Common stock, shares issued	126,637,390	125,555,268
Common stock, shares outstanding	112,072,469	118,083,111
Treasury shares	14,564,921	7,472,157

Consolidated_Statements_of_Inc

Consolidated Statements of Income (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Statement [Abstract]
Operating revenues	$996,680	$913,364	$826,990
Operating expenses:
Cost of services	308,574	275,403	230,282
Selling, general and administrative	279,352	232,448	211,905
Restructuring			-33
Amortization of intangible assets	45,877	44,798	50,017
Depreciation and amortization of property, equipment and leasehold improvements	25,711	20,384	16,584
Total operating expenses	659,514	573,033	508,755
Operating income	337,166	340,331	318,235
Interest income	-851	-889	-699
Interest expense	31,820	26,256	56,401
Other expense (income)	-2,141	2,136	1,732
Other expense (income), net	28,828	27,503	57,434
Income from continuing operations before provision for income taxes	308,338	312,828	260,801
Provision for income taxes	109,396	112,918	96,010
Income from continuing operations	198,942	199,910	164,791
Income (loss) from discontinued operations, net of income taxes	85,171	22,647	19,447
Net income	$284,113	$222,557	$184,238
Earnings per basic common share:
Earnings per basic common share from continuing operations	$1.72	$1.66	$1.34
Earnings per basic common share from discontinued operations	$0.73	$0.19	$0.16
Earnings per basic common share	$2.45	$1.85	$1.50
Earnings per diluted common share:
Earnings per diluted common share from continuing operations	$1.70	$1.64	$1.32
Earnings per diluted common share from discontinued operations	$0.73	$0.19	$0.16
Earnings per diluted common share	$2.43	$1.83	$1.48
Weighted average shares outstanding used in computing earnings per share:
Basic	115,737	120,100	122,023
Diluted	116,706	121,074	123,204
Dividend declared per common share	$0.18

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Net income	$284,113	$222,557	$184,238
Other comprehensive income (loss):
Foreign currency translation adjustments	-18,053	1,295	3,867
Income tax effect	-132	-500	-1,520
Foreign currency translation adjustments, net	-18,185	795	2,347
Unrealized gains (losses) on cash flow hedges		1,364	1,742
Income tax effect		-524	-691
Unrealized gains (losses) on cash flow hedges, net		840	1,051
Unrealized gains (losses) on available-for-sale securities		-5
Income tax effect		2
Unrealized gains (losses) on available-for-sale securities, net		-3
Pension and other post-retirement adjustments	-8,299	624	-1,434
Income tax effect	2,163	-110	334
Pension and other post-retirement adjustments, net	-6,136	514	-1,100
Other comprehensive income (loss), net of tax	-24,321	2,146	2,298
Comprehensive income	$259,792	$224,703	$186,536

Consolidated_Statements_of_Sha

Consolidated Statements of Shareholders' Equity (USD $)	Total	Common Stock [Member]	Treasury Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
In Thousands
Balance at Dec. 31, 2011	$1,294,151	$1,227	($49,827)	$995,665	$352,180	($5,094)
Net income	184,238				184,238
Other comprehensive income (loss), net of tax	2,298					2,298
Common stock issued	4	4
Compensation payable in common stock and options	24,997			24,997
Common stock repurchased and held in treasury	-105,989		-70,989	-35,000
Common stock issued to directors and held in treasury	-110		-110
Exercise of stock options	13,313	9		13,304
Excess tax benefits from employee stock incentive plans	1,048			1,048
Balance at Dec. 31, 2012	1,413,950	1,240	-120,926	1,000,014	536,418	-2,796
Net income	222,557				222,557
Other comprehensive income (loss), net of tax	2,146					2,146
Common stock issued	8	8
Compensation payable in common stock and options	24,552			24,552
Common stock repurchased and held in treasury	-112,183		-147,183	35,000
Common stock issued to directors and held in treasury	-282		-282
Exercise of stock options	11,702	8		11,694
Excess tax benefits from employee stock incentive plans	1,897			1,897
Balance at Dec. 31, 2013	1,564,347	1,256	-268,391	1,073,157	758,975	-650
Net income	284,113				284,113
Dividends	-20,397		-4		-20,393
Other comprehensive income (loss), net of tax	-24,321					-24,321
Common stock issued	5	5
Compensation payable in common stock and options	26,553			26,553
Common stock repurchased and held in treasury	-409,651		-319,651	-90,000
Common stock issued to directors and held in treasury	-332		-332
Exercise of stock options	9,681	5		9,676
Excess tax benefits from employee stock incentive plans	2,835			2,835
Balance at Dec. 31, 2014	$1,432,833	$1,266	($588,378)	$1,022,221	$1,022,695	($24,971)

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash flows from operating activities
Net income	$284,113	$222,557	$184,238
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of intangible assets	48,617	58,203	63,298
Stock-based compensation expense	26,585	25,004	25,323
Depreciation of property, equipment and leasehold improvements	25,930	22,302	18,700
Amortization of debt origination fees	7,748	3,348	18,065
Deferred taxes	-4,960	-15,066	-30,195
Amortization of discount on long-term debt	2,218	1,066	5,305
Excess tax benefits from share-based compensation	-2,835	-1,897	-1,048
Gross gain on disposition of subsidiary	-84,620
Other non-cash adjustments	1,847	-371	-49
Changes in assets and liabilities, net of assets acquired and liabilities assumed:
Accounts receivable	-26,821	-16,412	35,473
Prepaid income taxes	-14,998	7,927	7,278
Prepaid and other assets	-9,857	-4,459	-1,395
Accounts payable	2,128	-2,145	1,979
Deferred revenue	42,263	11,399	18,345
Accrued compensation and related benefits	88	7,057	-834
Other accrued liabilities	8,428	-260	-8,233
Other	-201	2,930	10,825
Net cash provided by operating activities	305,673	321,183	347,075
Cash flows from investing activities
Acquisitions, net of cash acquired	-14,921	-23,268	-119,554
Proceeds from redemption of short-term investments		70,900	207,032
Dispositions, net of cash provided	362,811
Purchase of investments			-137,306
Capitalized software development costs	-8,216	-3,285
Capital expenditures	-42,659	-40,255	-44,884
Proceeds from the sale of property, equipment and leasehold improvements	22	29	351
Net cash provided by (used in) investing activities	297,037	4,121	-94,361
Cash flows from financing activities:
Proceeds from borrowing, net of discount	800,000		876,087
Repayment of long-term debt	-810,000	-48,000	-1,103,563
Payment of issuance costs in connection with long term debt	-14,800		-3,870
Repurchase of treasury shares	-409,651	-112,183	-105,989
Dividends paid	-20,393
Proceeds from the exercise of stock options	9,681	11,702	13,311
Excess tax benefits from stock-based compensation	2,835	1,897	1,048
Net cash (used in) provided by financing activities	-442,328	-146,584	-322,976
Effect of exchange rates changes	-10,017	-3,595	1,360
Net increase (decrease) in cash and cash equivalents	150,365	175,125	-68,902
Cash and cash equivalents, beginning of period	358,434	183,309	252,211
Cash and cash equivalents, end of period	508,799	358,434	183,309
Supplemental disclosure of cash flow information:
Cash paid for interest	17,233	20,429	36,744
Cash paid for income taxes	120,419	128,167	134,439
Supplemental disclosure of non-cash investing activities:
Property, equipment and leasehold improvements in other accrued liabilities	$6,731	$3,396	$3,575

Introduction_and_Basis_of_Pres

Introduction and Basis of Presentation	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Introduction and Basis of Presentation	1. INTRODUCTION AND BASIS OF PRESENTATION
	Organization
	MSCI Inc., together with its wholly-owned subsidiaries (the “Company” or “MSCI”), is a global provider of investment decision support tools, including indexes, portfolio risk and performance analytics and multi-asset class market risk analytics products and services. The Company’s flagship products are its global equity indexes and environmental, social and governance (“ESG”) products marketed under the MSCI and MSCI ESG Research brands, its private real estate benchmarks marketed under the IPD brand, its portfolio risk and performance analytics covering global equity markets marketed under the Barra brand, its multi-asset class, market and credit risk analytics marketed under the RiskMetrics and Barra brands and its performance reporting products and services offered to the investment consultant community marketed under the InvestorForce brand.
	On March 17, 2014, MSCI Inc. entered into a definitive agreement to sell Institutional Shareholder Services Inc. (“ISS”). As a result, the Company reported the operating results of ISS in “Income from discontinued operations, net of income taxes” in the Consolidated Statements of Income for the years ended December 31, 2014, 2013 and 2012. As a result of this change, the Company now operates as one segment. Unless otherwise indicated, the disclosures accompanying these consolidated financial statements reflect the Company’s continuing operations.
	The Company completed the sale of ISS on April 30, 2014. See Note 3, “Dispositions and Discontinued Operations,” for further details.
	Basis of Presentation
	The consolidated financial statements include the accounts of MSCI Inc. and its wholly-owned subsidiaries. The Company’s policy is to consolidate all entities in which it owns more than 50% of the outstanding voting stock unless it does not control the entity. It is also the Company’s policy to consolidate any variable interest entity for which the Company is the primary beneficiary, of which the Company has none, as required by the Financial Accounting Standards Board’s (“FASB”) Accounting Standards Codification (“ASC”) Subtopic 810-10, “Consolidations.” For investments in any entities in which the Company owns 20% or less of the outstanding voting stock and significant influence does not exist, such investments are carried at cost.
	Revision
	In connection with the preparation of the Company’s unaudited condensed consolidated financial statements for the three months ended June 30, 2014, the Company determined that it had understated its net tax liabilities in certain years prior to December 31, 2012. As a result of these errors, the Company has recorded the following corrections to its Consolidated Statement of Financial Condition as of December 31, 2013: (i) an $11.3 million decrease to beginning retained earnings, (ii) a $0.7 million decrease to additional paid in capital, (iii) a $12.8 million decrease to prepaid taxes, (iv) a $13.6 million increase to long-term deferred tax liabilities and (v) a $14.3 million increase to goodwill. In accordance with the accounting guidance found in ASC Subtopic 250-10, “Accounting Changes and Error Corrections,” the Company has revised its Consolidated Statement of Financial Condition as of December 31, 2013 and the Consolidated Statement of Cash Flows for the year ended December 31, 2013 to reflect these corrections.
	In accordance with SEC Staff Accounting Bulletin No. 99, “Materiality,” the Company assessed the materiality of the adjustments and concluded that these corrections were not material to any of its previously issued financial statements. The Company also concluded that its compliance with debt covenants would not have been affected by these adjustments.
	Accordingly, the Company has revised the Consolidated Statement of Financial Condition as of December 31, 2013 from amounts previously reported as follows:
			As Previously			Adjustment			As Revised
			Reported
			(in thousands)
	Prepaid taxes		$	27,333		$	(12,765	)	$	14,568
	Total current assets		$	637,035		$	(12,765	)	$	624,270
	Goodwill		$	1,798,821		$	14,343		$	1,813,164
	Total assets		$	3,134,537		$	1,578		$	3,136,115
	Deferred taxes		$	221,054		$	13,595		$	234,649
	Total liabilities		$	1,558,173		$	13,595		$	1,571,768
	Additional paid in capital		$	1,073,893		$	(736	)	$	1,073,157
	Retained earnings		$	770,256		$	(11,281	)	$	758,975
	Total shareholders’ equity		$	1,576,364		$	(12,017	)	$	1,564,347
	Total liabilities and shareholders’ equity		$	3,134,537		$	1,578		$	3,136,115
	The Company has revised the Consolidated Statement of Cash Flows for the year ended December 31, 2013 from amounts previously reported as follows:
			As Previously			Adjustment			As Revised
			Reported
			(in thousands)
	Excess tax benefits from share-based compensation		$	(2,633	)	$	736		$	(1,897	)
	Net cash provided by operating activities		$	320,447		$	736		$	321,183
	Excess tax benefits from share-based compensation		$	2,633		$	(736	)	$	1,897
	Net cash (used in) provided by financing activities		$	(145,848	)	$	(736	)	$	(146,584	)
	The Company has revised the Consolidated Statements of Shareholders’ Equity for the years ended December 31, 2013, 2012 and 2011 from amounts previously reported as follows:
			As Previously			Adjustment			As Revised
			Reported
			(in thousands)
	As of December 31, 2011
	Retained earnings		$	363,461		$	(11,281	)	$	352,180
	Total shareholders’ equity		$	1,305,432		$	(11,281	)	$	1,294,151
	For the year ended December 31, 2013
	Excess tax benefits from share-based compensation		$	2,633		$	(736	)	$	1,897
	As of December 31, 2013
	Additional paid in capital		$	1,073,893		$	(736	)	$	1,073,157
	Total shareholders’ equity		$	1,576,364		$	(12,017	)	$	1,564,347
	Significant Accounting Policies
	Basis of Financial Statements and Use of Estimates
	The Company’s consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). These accounting principles require the Company to make certain estimates and judgments that can affect the reported amounts of assets and liabilities as of the date of the consolidated financial statements, as well as the reported amounts of revenue and expenses during the periods presented. Significant estimates and assumptions made by management include the deferral and recognition of revenue, research and development and software capitalization, the allowance for doubtful accounts, impairment of long-lived assets, accrued compensation, income taxes and other matters that affect the consolidated financial statements and related disclosures. The Company believes that estimates used in the preparation of these consolidated financial statements are reasonable; however, actual results could differ materially from these estimates.
	Inter-company balances and transactions are eliminated in consolidation.
	Revenue Recognition
	In general, the Company applies SEC Staff Accounting Bulletin No. 104 (“SAB 104”), “Revenue Recognition,” in determining revenue recognition. Accordingly, the Company recognizes revenue when all the following criteria are met:
		•		The Company has persuasive evidence of a legally binding arrangement,
		•		Delivery has occurred,
		•		Client fee is deemed fixed or determinable, and
		•		Collection is probable.
	When a sales arrangement requires the delivery of more than one product and service, revenue is recognized pursuant to the requirements of ASC Subtopic 605-25, “Revenue Arrangements with Multiple Deliverables.” Under the provisions of ASC Subtopic 605-25, elements within a multi-deliverable arrangement should be considered separate units of accounting if all of the following criteria are met:
		•		The delivered items have value to the client on a standalone basis. The items have value on a standalone basis if they can be sold separately by any vendor or the client could resell the delivered items on a standalone basis; and
		•		If the arrangement includes a general right of return relative to the delivered items, delivery or performance of the undelivered items is considered probable and substantially in the control of the vendor.
	The Company provides products and services to its clients under various software and non-software related arrangements. The Company has signed contracts with substantially all clients that set forth the fees to be paid for its products and services. Further, the Company regularly assesses the receivable balances for each client for collectability. The Company’s application service license arrangements generally do not include acceptance provisions, which generally allow a client to test the solution for a defined period of time before committing to the license. If a license agreement includes an acceptance provision, the Company does not recognize subscription revenues until the earlier of the receipt of a written client acceptance or, if not notified by the client that it is cancelling the license agreement, the expiration of the acceptance period.
	The Company’s subscription agreements for non-software-related application services include provisions that, among other things, allow clients, for no additional fee, to receive updates and modifications that may be made from time to time when and if available, for the term of the agreement, which is typically one year. These arrangements do not provide the client with the right to take possession of the application at any time. For sales arrangements with multiple deliverables, which may include application service subscription and professional services associated with implementation and other services, the Company evaluates each deliverable in these multiple-element arrangements to determine whether it represents a separate unit of accounting and allocates revenue accordingly.
	In most cases, the Company recognizes revenues from subscription arrangements ratably over the term of the license agreement pursuant to contract terms. The contracts state the terms under which these fees are to be calculated. The fees are recognized as the Company supplies the product and service to the client over the license period and are generally billed in advance, prior to the license start date. When implementation services are included, the Company recognizes revenues allocated to the subscription ratably from the date the application is put into production to the end of the license period. Revenues associated with the implementation services are recognized ratably over the useful life of those services. For products and services whose fees are based on estimated assets under management linked to the Company’s indexes, or contract values related to futures and options, the Company recognizes revenues based on estimates from independent third-party sources or the most recently reported information from the client. Revenues from subscription agreements for the receipt of periodic benchmark reports, digests, and other publications, which are most often associated with the Company’s real estate benchmark business, are recognized upon delivery of such reports or data updates.
	The Company’s software-related arrangements do not require significant modification or customization of any underlying software applications being licensed. Accordingly, the Company recognizes software revenues pursuant to the requirements of ASC Subtopic 985-605, “Software-Revenue Recognition.” The Company’s subscription agreements for software products include provisions that, among other things, would allow clients to receive unspecified, when and if available, software upgrades for no additional fee as well as the right to use the software products with maintenance and technical support for the term of the agreement, which is typically one year. Software agreements may include other consulting and professional services. In accordance with ASC Subtopic 985-605, “Software Revenue Recognition,” the Company does not have vendor specific objective evidence (“VSOE”) for these elements and therefore begins to recognize software related revenue ratably over the term of the license agreement once delivered.
	Adjustment to Revenues
	During the year ended December 31, 2012, as a result of a one-time adjustment, the Company recorded a $5.2 million cumulative revenue reduction to correct an error related to revenues previously reported through December 31, 2011. The effect of recording this adjustment in the first quarter of 2012 resulted in a one-time decrease to the energy and commodity analytics products revenues in the Company’s Consolidated Statement of Income and an increase in deferred revenues in the Company’s Consolidated Statement of Financial Condition. It was determined that under ASC Subtopic 985-605, the Company incorrectly established VSOE for certain energy and commodity analytics products and as a result should not have been recognizing a substantial portion of the revenue immediately upon delivery or renewal of a time based subscription license, the terms of which are generally one year. Rather, the entire license fee should have been recognized ratably over the term of the license. As such, the Company made the cumulative adjustment effective January 1, 2012 and started recognizing revenue related to all contracts still in effect as of this date ratably over the remainder of the term. The Company began recognizing revenue ratably over the contract term for any new contracts entered into on or after January 1, 2012. Based upon an evaluation of all relevant factors, management believes the correcting adjustment did not have a material impact on the Company’s previously reported results and, accordingly, has determined that restatement of previously issued financial statements is not necessary.
	Share-Based Compensation
Certain of the Company’s employees have received share-based compensation under certain compensation programs. The Company’s compensation expense reflects the fair value method of accounting for share-based payments under ASC Subtopic 718-10, “Compensation-Stock Compensation.” ASC Subtopic 718-10 requires measurement of compensation cost for equity-based awards at fair value and recognition of compensation cost over the service period, net of estimated forfeitures.
The fair value of MSCI restricted stock units (“RSUs”) is measured as the closing price of MSCI’s common stock on the date prior to grant. Restricted stock units subject to performance conditions (“PSUs”) are based on performance measures that impact the amount of shares that each recipient will receive upon vesting. PSUs are granted at fair market value, which is measured as the closing price of MSCI’s common stock on the date prior to grant.
The fair value of MSCI standard stock options is determined using the Black-Scholes valuation model and the single grant life method. Under the single grant life method, option awards with graded vesting are valued using a single weighted-average expected option life. The fair value of MSCI stock options that contain stock price contingencies is determined using a Monte Carlo simulation model, which creates a normal distribution of future stock prices, which is then used to value the awards based on their individual terms.
Based on interpretive guidance related to share-based compensation, the Company’s policy is to accrue the estimated cost of share-based awards that are granted to retirement-eligible employees over the course of the prior year in which they were earned rather than expensing the awards on the date of grant. A portion of the awards granted to employees consist of PSUs. The Company bases initial accruals of compensation cost on the estimated number of units for which the requisite service is expected to be rendered. If the estimated number of units changes from previous estimates, the cumulative effect on current and prior periods of a change is recognized in compensation cost in the period of the change.
Research and Development
The Company accounts for research and development costs in accordance with several accounting pronouncements, including ASC Subtopic 730-10, “Research and Development.” ASC Subtopic 730-10 requires that research and development costs generally be expensed as incurred. The majority of the Company’s research and development costs are incurred in developing, reviewing and enhancing the methodologies and data models offered within its product portfolio.
The Company applies the provisions of ASC Subtopic 350-40, “Internal Use Software,” and accounts for the cost of computer software developed for internal use by capitalizing qualifying costs, which are substantially incurred during the application development stage. The amounts capitalized include external direct costs of services used in developing internal-use software and for payroll and payroll-related costs of employees directly associated with the development activities. Additionally, costs incurred relating to upgrades and enhancements to the software are capitalized if it is determined that these upgrades or enhancements provide additional functionality to the software. The Company capitalized $8.3 million and $3.3 million of costs related to software developed for internal use in the Consolidated Statement of Financial Condition for the years ended December 31, 2014 and 2013, respectively.
Capitalized software development costs are amortized on a straight-line basis over the estimated useful life of the related product, which is typically three to five years, beginning with the date the software is placed into service.
Costs incurred in the preliminary and post-implementation stages of our products are expensed as incurred.
Income Taxes
Income tax expense is provided for using the asset and liability method, under which deferred tax assets and deferred tax liabilities are determined based on the temporary differences between the financial statement and income tax bases of assets and liabilities using currently enacted tax rates.
The Company regularly assesses the likelihood of additional assessments in each of the taxing jurisdictions in which it is required to file income tax returns. The Company recorded additional tax expense related to open tax years, which the Company’s management believes is adequate in relation to the potential for assessments. These amounts have been recorded in “Other non-current liabilities” on the Consolidated Statement of Financial Condition. The Company’s management believes the resolution of tax matters will not have a material effect on the Company’s consolidated financial condition. However, to the extent the Company is required to pay amounts in excess of its reserves, a resolution could have a material impact on its Consolidated Statement of Income for a particular future period. In addition, an unfavorable tax settlement could require use of cash and result in an increase in the effective tax rate in the period in which such resolution occurs.
Deferred Revenue
Deferred revenues represent amounts billed to customers for products and services in advance of delivery. The Company’s clients generally pay subscription fees annually or quarterly in advance. Deferred revenue is generally amortized ratably over the service period as revenue recognition criteria are met. Where the service period has not begun and the client has not paid or the contract has not been renewed, deferred revenues and accounts receivable are not recognized.
Goodwill
Goodwill is recorded as part of the Company’s acquisitions of businesses when the purchase price exceeds the fair value of the net tangible and separately identifiable intangible assets acquired. The Company’s goodwill relates to the acquisitions of Barra, Inc. (“Barra”), RiskMetrics Group, Inc. (“RiskMetrics”), Measurisk, LLC (“Measurisk”), IPD Group Limited (“IPD”), Investor Force Holdings, Inc. (“InvestorForce”) and Governance Holdings Co. (“GMI Ratings”). The Company’s goodwill is not amortized, but rather is subject to an impairment test each year, or more often if conditions indicate impairment may have occurred, pursuant to ASC Topic 350, “Intangibles—Goodwill and Other.”
The Company tests goodwill for impairment on an annual basis on July 1 and on an interim basis when certain events and circumstances exist. The testing for impairment is performed at the reporting unit level, which is deemed to be at the level of the MSCI business segments. Goodwill impairment is determined by comparing the estimated fair value of a reporting unit with its respective book value. If the estimated fair value exceeds the book value, goodwill at the reporting unit level is not deemed to be impaired. If the estimated fair value is below book value, however, further analysis is required to determine the amount of impairment. Additionally, if the book value of a reporting unit is zero or a negative value and it is determined that it is more likely than not that the goodwill is impaired, further analysis is required. As the estimated fair value of its reporting units exceeded their respective book value on the testing dates, no impairment of goodwill was recorded during the years ended December 31, 2014, 2013 and 2012.
Intangible Assets
Intangible assets consist of those definite-lived intangibles from the acquisitions of Barra in June 2004, RiskMetrics in June 2010, Measurisk in July 2010, IPD in November 2012, InvestorForce in January 2013 and GMI Ratings in August 2014. The Company amortizes definite-lived intangible assets over their estimated useful lives. Definite-lived intangible assets are tested for impairment when impairment indicators are present, and, if impaired, written down to fair value based on either discounted cash flows or appraised values. No impairment of intangible assets has been identified during any of the periods presented. The Company has no indefinite-lived intangibles. The intangible assets have remaining useful lives ranging from one to 20 years.
Foreign Currency Translation
Assets and liabilities of operations having non-U.S. dollar functional currencies are translated at year-end exchange rates, and income statement accounts are translated at weighted average exchange rates for the year. Gains or losses resulting from translating foreign currency financial statements, net of related tax effects, are reflected in accumulated other comprehensive loss, a separate component of shareholders’ equity. Gains or losses resulting from foreign currency transactions incurred in currencies other than the local functional currency are included in non-operating “Other expense (income), net” on the Consolidated Statement of Income.
Derivative Instruments
The Company applies ASC Subtopic 815-10, “Derivatives and Hedging,” which establishes accounting and reporting standards for derivative instruments and hedging activities. The Company may use interest rate swaps and forward contracts on foreign currency to manage risks generally associated with interest rate and foreign exchange rate fluctuations, respectively. The Company’s derivative financial instruments are used as risk management tools and not for speculative or trading purposes.
For derivative instruments that are designated and qualify as hedging instruments for accounting purposes, the Company documents and links the relationships between the hedging instruments and hedged items. The Company also assesses and documents at the hedge’s inception whether the derivatives used in hedging transactions were effective in offsetting changes in fair values associated with the hedged items. ASC Subtopic 815-10 provides that, for derivative instruments that qualify for hedge accounting being used to hedge cash flows, changes in the fair value are recognized in accumulated other comprehensive income (loss), a separate component of shareholders’ equity, until the hedged item is recognized in earnings. In addition, the ineffective portion of a derivative’s change in fair value is immediately recognized in earnings.
The Company manages foreign currency exchange rate risk through the use of derivative financial instruments comprised principally of forward contracts on foreign currency which are not designated as hedging instruments for accounting purposes. The objective of the derivative instruments is to minimize the income statement impact associated with assets and liabilities that are denominated in certain foreign currencies. Derivative instruments that do not qualify for hedge accounting are carried at fair value on the Consolidated Statement of Financial Condition with gains and losses recorded in the Consolidated Statement of Income.
Property, Equipment and Leasehold Improvements
Property, equipment and leasehold improvements are stated at cost less accumulated depreciation and amortization. Depreciation of furniture and fixtures and computer and communications equipment are amortized using the straight-line method over the estimated useful life of the asset. Estimates of useful lives are as follows: furniture & fixtures – seven years; computer and related equipment – three to five years. Leasehold improvements are amortized on a straight-line basis over one to 21 years, which represents the lesser of the estimated useful life of the asset or, where applicable, the remaining term of the lease.
Treasury Stock
The Company holds repurchased shares of common stock as treasury stock. The Company accounts for treasury stock under the cost method and includes treasury stock as a component of shareholders’ equity.
In accordance with ASC Subtopic 505-10, “Equity,” the Company accounts for the capped accelerated share repurchase (“ASR”) agreements into which it enters as two separate transactions: (a) as shares of common stock acquired in a treasury stock transaction recorded on the acquisition date of the shares and (b) as a forward contract indexed to the Company’s own common stock. As such, the Company accounts for the shares that it receives under capped ASR agreements during the period as a repurchase of its common stock for the purpose of calculating earnings per common share. The Company has determined that the forward contracts indexed to the Company’s common stock meet all the applicable criteria for equity classification in accordance with ASC Subtopic 815-10 and, therefore, the capped ASR agreements are not accounted for as derivative instruments.
Allowance for Doubtful Accounts
The Company licenses its products and services to investment managers mainly in the United States, Europe and Asia (primarily Hong Kong and Japan). The Company evaluates the credit of its customers and does not require collateral. The Company maintains an allowance on customer accounts where estimated losses may result from the inability of its customers to make required payments.
An allowance for doubtful accounts is recorded when it is probable and estimable that a receivable will not be collected. Changes in the allowance for doubtful accounts from December 31, 2011 to December 31, 2014 were as follows:
		Amount
		(in thousands)
Balance as of December 31, 2011		$	857
Addition to provision			403
Amounts written off, net of recoveries			(296	)
Balance as of December 31, 2012		$	964
Addition to provision			876
Amounts written off, net of recoveries			(560	)
Balance as of December 31, 2013		$	1,280
Addition to provision			452
Amounts written off, net of recoveries			(875	)
Balance as of December 31, 2014		$	857
Accrued Compensation
The Company makes significant estimates in determining its accrued non-stock based compensation and benefits expenses. A significant portion of the Company’s employee incentive compensation programs are discretionary. Each year end the Company determines the amount of discretionary cash bonus expense. The Company also reviews compensation and benefits expenses throughout the year to determine how overall performance compares to management’s expectations. These and other factors, including historical performance, are taken into account in accruing discretionary cash compensation estimates quarterly.
Concentrations
For the year ended December 31, 2014, BlackRock, Inc. accounted for 10.6% of the Company’s operating revenues. For the years ended December 31, 2013 and 2012, no single customer accounted for 10.0% or more of the Company’s operating revenues.

Recent_Accounting_Standards_Up

Recent Accounting Standards Updates	12 Months Ended
	Dec. 31, 2014
Accounting Changes and Error Corrections [Abstract]
Recent Accounting Standards Updates	2. RECENT ACCOUNTING STANDARDS UPDATES
	In July 2013, the FASB issued Accounting Standards Update No. 2013-11, “Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists,” or ASU 2013-11. The amendments in this update require that an unrecognized tax benefit, or a portion of an unrecognized tax benefit, be presented in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward, except under a few limited circumstances. The amendments in this update do not require new recurring disclosures. This new guidance has been applied prospectively for interim and annual periods beginning after December 15, 2013. The adoption of ASU 2013-11 did not have a material impact on the Company’s consolidated financial statements.
	In April 2014, the FASB issued Accounting Standards Update No. 2014-08, “Presentation of Financial Statements (Topic 205) and Property, Plant, and Equipment (Topic 360): Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity,” or ASU 2014-08. The amendments in this update change the requirements for reporting discontinued operations under ASC Subtopic 205-20, “Presentation of Financial Statements—Discontinued Operations,” such as limiting discontinued operations reporting to disposals of components of an entity that represent strategic shifts that have (or will have) a major effect on an entity’s operations and financial results. The amendments in this update also require expanded disclosures in order to provide users of financial statements with more information about the assets, liabilities, revenues and expenses of discontinued operations. Further, the amendments require an entity to disclose the pretax profit or loss of an individually significant component of an entity that does not qualify for discontinued operations reporting. This new guidance is to be applied prospectively for annual periods beginning on or after December 15, 2014, and interim periods within those years, with early adoption permitted. The Company has elected not to early adopt ASU 2014-08 but does not expect the adoption of ASU 2014-08 to have a material effect on its consolidated financial statements.
	In May 2014, the FASB issued Accounting Standards Update No. 2014-09, “Revenue from Contracts with Customers,” or ASU 2014-09. The objective of ASU 2014-09 is to establish a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and will supersede most of the existing revenue recognition guidance, including industry-specific guidance. The core principle of ASU 2014-09 is that an entity recognizes revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. In applying the new guidance, an entity will (1) identify the contract(s) with a customer; (2) identify the performance obligations in the contract; (3) determine the transaction price; (4) allocate the transaction price to the contract’s performance obligations; and (5) recognize revenue when, or as, the entity satisfies a performance obligation. The new guidance is effective for annual reporting periods (including interim periods within those periods) beginning after December 15, 2016 for public companies. Early adoption is not permitted. Entities have the option of using either a full retrospective or modified approach to adopt ASU 2014-09. The Company is evaluating the potential impact that the update will have on its consolidated financial statements.
	In November 2014, the FASB issued Accounting Standards Update 2014-17, “Business Combinations (Topic 805): Pushdown Accounting,” or ASU 2014-17. ASU 2014-17 provides a company with the option to apply pushdown accounting in its separate financial statements upon occurrence of an event in which an acquirer obtains control of the acquired entity. The election to apply pushdown accounting can be made either in the period in which the change of control occurred, or in a subsequent period. ASU 2014-17 became effective as of November 18, 2014. The Company will evaluate this standard in the event of a future business combination.
	In January 2015, the FASB issued Accounting Standards Update 2015-01, “Income Statement—Extraordinary and Unusual Items (Subtopic 225-20): Simplifying Income Statement Presentation by Eliminating the Concept of Extraordinary Items,” or ASU 2015-01. ASU 2015-01 eliminates the concept of an extraordinary item from GAAP. As a result, a company will no longer be required to segregate extraordinary items from the results of ordinary operations, to separately present an extraordinary item on its income statement, net of tax, after income from continuing operations or to disclose income taxes and earnings-per-share data applicable to an extraordinary item. A reporting entity may apply the amendments prospectively or retrospectively to all prior periods presented in the financial statements. However, ASU 2015-01 will still retain the presentation and disclosure guidance for items that are unusual in nature and occur infrequently. The new guidance is effective for annual reporting periods (including interim periods within those periods) beginning after December 15, 2015, with early adoption permitted provided that the guidance is applied from the beginning of the fiscal year of adoption. The adoption of ASU 2015-01 is not expected to have a material effect on the Company’s consolidated financial statements.

Dispositions_and_Discontinued_

Dispositions and Discontinued Operations	12 Months Ended
	Dec. 31, 2014
Discontinued Operations and Disposal Groups [Abstract]
Dispositions and Discontinued Operations	3. DISPOSITIONS AND DISCONTINUED OPERATIONS
	Disposition of CFRA
	On March 31, 2013, MSCI completed the sale of its CFRA product line. The value of the disposed assets and liabilities and the resulting gain on disposal were not material to the Company.
	Disposition of ISS
	On March 17, 2014, MSCI entered into a definitive agreement to sell ISS. The results of operations from ISS and the CFRA product line are reflected in “Income from discontinued operations, net of income taxes” in the Consolidated Statements of Income.
	The sale of ISS was completed on April 30, 2014 for $367.4 million. The value of the assets and liabilities of ISS that were disposed, directly attributable transaction costs and the resulting gain on disposal that has been reported in “Income from discontinued operations, net of income taxes” for the year ended December 31, 2014 are as follows:
	(in thousands)
	Cash proceeds	$	367,355
	Less: working capital adjustments		(311	)
	Total proceeds		367,044
	Less assets sold and liabilities relieved resulting from disposal:
	Cash and cash equivalents		(4,544	)
	Accounts receivable		(15,765	)
	Deferred taxes (current)		(3,174	)
	Prepaid income taxes		(617	)
	Prepaid and other assets		(4,500	)
	Property, equipment and leasehold improvements (net of accumulated depreciation and amortization of $4,213)		(8,544	)
	Goodwill		(254,233	)
	Intangible assets (net of accumulated amortization of $50,283)		(121,269	)
	Other non-current assets		(1,645	)
	Accounts payable		574
	Accrued compensation and related benefits		6,783
	Other accrued liabilities		4,034
	Deferred revenue		51,767
	Deferred taxes (non-current)		59,129
	Other non-current liabilities		5,576
	Other comprehensive income including currency translation adjustments and pension and other post-retirement adjustments		4,004
	Net assets sold		(282,424	)
	Less: Transaction costs		(5,946	)
	Gain on sale of ISS	$	78,674
	Income (loss) from discontinued operations. Amounts associated with discontinued operations reflected in the Consolidated Statements of Income for the years ended December 31, 2014, 2013 and 2012 are as follows:
		Years Ended December 31,
		2014			2013		2012
		(in thousands)
	Revenue from discontinued operations	$	43,122		$	122,303	$	123,151
	Income from discontinued operations before provision for income taxes	$	86,230		$	32,793	$	28,608
	Provision for income taxes		1,059			10,146		9,161
	Income from discontinued operations, net of income taxes	$	85,171		$	22,647	$	19,447

Reclassifications_out_of_Accum

Reclassifications out of Accumulated Other Comprehensive Income (Loss)	12 Months Ended
	Dec. 31, 2014
Statement of Comprehensive Income [Abstract]
Reclassifications out of Accumulated Other Comprehensive Income (Loss)	4. RECLASSIFICATIONS OUT OF ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)
	As required by ASC Subtopic 220-10, “Comprehensive Income—Overall,” the following table presents the amounts reclassified from accumulated other comprehensive income (loss) by the respective line item in the Consolidated Statement of Income:
	Reclassifications Out of Accumulated Other Comprehensive Income (Loss)(1)
	(in thousands)
	Details about Accumulated Other		Amount Reclassified from Accumulated						Affected Line Item in the
	Comprehensive Income (Loss) Components		Other Comprehensive Income (Loss)						Unaudited Condensed
									Consolidated Statements of Income
			Year Ended			Year Ended
			December 31,			December 31,
			2014			2013
	Unrealized losses on cash flow hedges
	Interest rate contracts		$	—		$	(1,364	)	Interest expense
				—			524		Tax benefit
			$	—		$	(840	)	Net of tax
	Unrealized gains on available-for-sale securities
	Short-term investments		$	—		$	5		Interest income
				—			(2	)	Tax expense
			$	—		$	3		Net of tax
	Defined benefit pension plans
	Amount recognized as a component of net periodic benefit expense for curtailments and settlements		$	(104	)	$	(32	)(2)
				(15	)		6		Tax expense (3)
			$	(119	)	$	(26	)	Net of tax (4)
	Foreign currency translation adjustment		$	4,184		$	—	(5)
	Total reclassifications for the period, net of tax		$	4,065		$	(863	)
	(1)	Amounts in parentheses indicate expenses or losses moved to the Consolidated Statements of Income.
	(2)	Includes $(186,000) for the year ended December 31, 2014 that was reclassified to “Income from discontinued operations, net of taxes” as part of the gain on the disposition of ISS.
	(3)	Includes $6,000 for the year ended December 31, 2014 that was reclassified to “Income from discontinued operations, net of taxes” as part of the gain on the disposition of ISS.
	(4)	Includes $(180,000) for the year ended December 31, 2014 that was reclassified to “Income from discontinued operations, net of taxes” as part of the gain on the disposition of ISS.
	(5)	This accumulated other comprehensive income component for the year ended December 31, 2014 was reclassified to “Income from discontinued operations, net of taxes” as part of the gain on the disposition of ISS.

Earnings_Per_Common_Share

Earnings Per Common Share	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Earnings Per Common Share	5. EARNINGS PER COMMON SHARE
	Basic earnings per share (“EPS”) is computed by dividing income available to MSCI common shareholders by the weighted average number of common shares outstanding during the period. Common shares outstanding include common stock and vested restricted stock unit awards where recipients have satisfied either the explicit vesting terms or retirement-eligible requirements. Diluted EPS reflects the assumed conversion of all dilutive securities. There were 78,260, 26,407 and 6,714, stock options and restricted stock units excluded from the calculation of diluted EPS for the years ended December 31, 2014, 2013 and 2012, respectively, because of their anti-dilutive effect.
	The Company computes EPS using the two-class method and determines whether instruments granted in share-based payment transactions are participating securities. The following table presents the computation of basic and diluted EPS:
			For the Years Ended
			December 31,			December 31,			December 31,
	(in thousands, except per share data)		2014			2013			2012
	Income from continuing operations, net of income taxes		$	198,942		$	199,910		$	164,791
	Income (loss) from discontinued operations, net of income taxes			85,171			22,647			19,447
	Net income		$	284,113		$	222,557		$	184,238
	Less: Allocations of earnings to unvested restricted stock units (1)			(368	)		(633	)		(1,547	)
	Earnings available to MSCI common shareholders		$	283,745		$	221,924		$	182,691
	Basic weighted average common shares outstanding			115,737			120,100			122,023
	Effect of dilutive securities:
	Stock options and restricted stock units			969			974			1,181
	Diluted weighted average common shares outstanding			116,706			121,074			123,204
	Earnings per basic common share from continuing operations		$	1.72		$	1.66		$	1.34
	Earnings per basic common share from discontinued operations			0.73			0.19			0.16
	Earnings per basic common share		$	2.45		$	1.85		$	1.5
	Earnings per diluted common share from continuing operations		$	1.7		$	1.64		$	1.32
	Earnings per diluted common share from discontinued operations			0.73			0.19			0.16
	Earnings per diluted common share		$	2.43		$	1.83		$	1.48
	(1)	Restricted stock units granted to employees prior to 2013 and all restricted stock units granted to independent directors of the Company have a right to participate in all of the earnings of the Company in the computation of basic EPS and, therefore, these restricted stock units are not included as incremental shares in the diluted EPS computation.

Commitments_and_Contingencies

Commitments and Contingencies

12 Months Ended

Dec. 31, 2014

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

6. COMMITMENTS AND CONTINGENCIES

Legal matters. From time to time, the Company is party to various litigation matters incidental to the conduct of its business. The Company is not presently party to any legal proceedings the resolution of which the Company believes would have a material effect on its business, operating results, financial condition or cash flows.

Leases. The Company leases facilities under non-cancelable operating lease agreements. The terms of certain lease agreements provide for rental payments on a graduated basis. The Company recognizes rent expense on the straight-line basis over the lease period and has accrued for rent expense incurred but not paid. Rent expense for the years ended December 31, 2014, 2013 and 2012 was $27.0 million, $24.2 million and $22.1 million, respectively.

Future minimum commitments for the Company’s operating leases in place as of December 31, 2014 are as follows:

Years Ending December 31,

Amount

(in thousands)

2015

$

30,511

2016

29,890

2017

26,633

2018

25,142

2019

20,662

Thereafter

155,036

Total

$

287,874

Return of capital. On December 13, 2012, the Board of Directors approved a stock repurchase program authorizing the purchase of up to $300.0 million worth of shares of MSCI’s common stock beginning immediately and continuing through December 31, 2014 (the “2012 Repurchase Program”).

On December 13, 2012, as part of the 2012 Repurchase Program, the Company entered into an accelerated share repurchase (“ASR”) agreement with a financial institution to initiate share repurchases aggregating $100.0 million (the “December 2012 ASR Agreement”). As a result of the December 2012 ASR Agreement, the Company received 2.2 million shares on December 14, 2012 and 0.8 million shares on July 31, 2013 for a combined average purchase price of $33.47 per share.

On August 1, 2013, MSCI entered into a second ASR agreement to initiate share repurchases aggregating $100.0 million (the “August 2013 ASR Agreement”). As a result of the August 2013 ASR Agreement, the Company received 1.9 million shares on August 2, 2013 and 0.5 million shares on December 30, 2013 for a combined average purchase price of $41.06 per share.

On February 6, 2014, MSCI utilized the remaining repurchase authorization provided by the 2012 Repurchase Program by entering into a third ASR agreement to initiate share repurchases aggregating $100.0 million (the “February 2014 ASR Agreement”). As a result of the February 2014 ASR Agreement, the Company received 1.7 million shares on February 7, 2014 and 0.6 million shares on May 5, 2014 for a combined average purchase price of $43.10 per share.

On February 4, 2014, the Board of Directors approved a stock repurchase program authorizing the purchase of up to $300.0 million worth of shares of MSCI’s common stock (the “2014 Repurchase Program”). On September 17, 2014, the Board of Directors increased the approval under the 2014 Repurchase Program from $300.0 million to $850.0 million. Share repurchases made pursuant to 2014 Repurchase Program may take place through December 31, 2016 in the open market or in privately negotiated transactions from time to time based on market and other conditions. This authorization may be modified, suspended, terminated or extended by the Board of Directors at any time without prior notice.

On September 18, 2014, as part of the 2014 Repurchase Program, the Company entered into a fourth ASR agreement to initiate share repurchases aggregating $300.0 million (the “September 2014 ASR Agreement”). On September 19, 2014, the Company paid $300.0 million in cash and received approximately 4.5 million shares of MSCI’s common stock under the September 2014 ASR Agreement. The total number of shares to be repurchased will be based primarily on an arithmetic average of the volume-weighted average prices of MSCI’s common stock on each trading day during the repurchase period. This average price will be capped such that only under limited circumstances will MSCI be required to deliver shares or pay cash at settlement. The Company may also receive additional shares at or prior to maturity of the September 2014 ASR Agreement in May 2015.

The $300.0 million payment for the September 2014 ASR Agreement was initially split and recorded as a $210.0 million increase to “Treasury stock” and a $90.0 million decrease to “Additional paid in capital” on the Company’s Consolidated Statement of Financial Condition to reflect the initial estimate of the value of shares received.

On September 17, 2014, the Board of Directors approved a plan to initiate a regular quarterly cash dividend. Accordingly, the Board of Directors declared a quarterly dividend of $0.18 per share of common stock that was paid on October 31, 2014 to shareholders of record as of the close of trading on October 15, 2014. The Company expects the initial annual dividend rate to be $0.72 per share. The aggregate cash dividend paid on October 31, 2014 amounted to $20.4 million.

Long-term debt. On June 1, 2010, the Company entered into a senior secured credit facility (the “2010 Credit Facility”). On March 14, 2011, the Company completed the repricing of the 2010 Credit Facility pursuant to Amendment No. 2 to the 2010 Credit Facility. On May 4, 2012, the Company amended and restated its 2010 Credit Facility (the credit agreement as so amended and restated, the “Amended and Restated Credit Facility”). The Amended and Restated Credit Facility provided for the incurrence of a new senior secured five-year Term Loan A Facility in an aggregate amount of $880.0 million (the “2012 Term Loan”) and a $100.0 million senior secured revolving facility (the “2012 Revolving Credit Facility”). The Amended and Restated Credit Facility also amended certain negative covenants, including financial covenants.

In March 2013, the Company made a $15.0 million prepayment on the 2012 Term Loan.

On December 12, 2013, the Company entered into an agreement that extended the maturity of the Amended and Restated Credit Facility from May 2017 to December 2018 (the “2013 Amended and Restated Credit Facility”). The Company also amended the amortization schedule of required debt payments under the 2012 Term Loan. Pursuant to the 2013 Amended and Restated Credit Facility, the Company was required to repay $5.1 million in quarterly payments over the first two years and $10.1 million in quarterly payments over the following three years, with the exception of the final payment in December 2018, which was to be $658.1 million.

On November 20, 2014, the Company completed its private offering of $800.0 million in aggregate principal amount of 5.25% senior unsecured notes due 2024 (the “Senior Notes”) and also entered into a new $200.0 million senior unsecured revolving credit agreement (the “2014 Revolving Credit Agreement”) by and among the Company, as borrower, certain of its subsidiaries, as guarantors (the “subsidiary guarantors”), the lenders party thereto, and JPMorgan Chase Bank, N.A., as administrative agent. The Company used the net proceeds from the offering of the Senior Notes, together with cash on hand, to prepay in full its $794.8 million of outstanding indebtedness under the 2013 Amended and Restated Credit Facility.

The Senior Notes are scheduled to mature and be paid in full on November 20, 2024. At any time prior to November 15, 2019, the Company may redeem all or part of the Senior Notes upon not less than 30 nor more than 60 days’ prior notice at a redemption price equal to the sum of (i) 100% of the principal amount thereof, plus (ii) a make-whole premium as of the date of redemption, plus (iii) accrued and unpaid interest and additional interest, if any, thereon, to the date of redemption. In addition, the Company may redeem all or part of the Senior Notes, together with accrued and unpaid interest, on or after November 15, 2019, at redemption prices set forth in the Indenture dated as of November 20, 2014, among the Company, the subsidiary guarantors, and Wells Fargo Bank, National Association, as trustee. At any time prior to November 15, 2017, the Company may use the proceeds of certain equity offerings to redeem up to 35% of the aggregate principal amount of the Senior Notes, including any permitted additional notes, at a redemption price equal to 105.25% of the principal amount.

The 2014 Revolving Credit Agreement replaced the 2012 Revolving Credit Facility. The 2014 Revolving Credit Agreement has an initial term of five years that may be extended, at the Company’s request, for two additional one year terms.

Interest on the Senior Notes accrues at a fixed rate of 5.25% per annum and is payable semiannually in arrears on May 15 and November 15 of each year, commencing May 15, 2015; the Company will make interest payments to holders of record of the Senior Notes on the immediately preceding May 1 and November 1.

On the Company’s Consolidated Statement of Financial Condition at December 31, 2014, there was no “Current maturities of long-term debt” and “Long-term debt, net of current maturities” of $800.0 million.

On the Company’s Consolidated Statement of Financial Condition at December 31, 2013, there was “Current maturities of long-term debt” of $19.8 million, net of a $0.5 million discount and “Long-term debt, net of current maturities” of $788.0 million, net of a $1.7 million discount.

In connection with entering into the Senior Notes and the 2014 Revolving Credit Agreement, the Company paid certain fees which, together with the existing fees related to prior credit facilities, are being amortized over the life of the Senior Notes and 2014 Revolving Credit Agreement. At December 31, 2014, $14.7 million of the deferred financing fees remain unamortized, $1.8 million of which is included in “Prepaid and other assets” and $12.9 million of which is included in “Other non-current assets” on the Company’s Consolidated Statement of Financial Condition.

The Company amortized $7.7 million and $3.3 million of deferred financing fees in interest expense during the years ended December 31, 2014 and 2013, respectively. Approximately $2.2 million and $1.1 million of debt discount was amortized in interest expense during the years ended December 31, 2014 and 2013, respectively.

At December 31, 2014 and 2013, the fair market value of the Company’s debt obligations were $831.0 million and $812.0 million, respectively. The fair market value is determined in accordance with accounting standards related to the determination of fair value and represents Level 2 valuations, which are based on one or more quoted prices in markets that are not considered to be active or for which all significant inputs are observable, either directly or indirectly. The Company utilizes the market approach and obtains security pricing from a vendor who uses broker quotes and third-party pricing services to determine fair values.

Derivatives and Hedging Activities. The Company is exposed to certain risks arising from both its business operations and economic conditions. The Company principally manages its exposures to a wide variety of business and operational risks through management of its core business activities. The Company manages economic risks, including interest rate, liquidity, and credit risk primarily by managing the amount, sources, and duration of its debt funding and the use of derivative financial instruments. Specifically, the Company had previously entered into derivative financial instruments to manage exposures that arose from business activities that result in the receipt or payment of future known and uncertain cash amounts, the value of which are determined by interest rates, and may do so again in the future. The Company’s derivative financial instruments were used to manage differences in the amount, timing and duration of the Company’s known or expected cash payments principally related to the Company’s borrowings.

Certain of the Company’s foreign operations expose the Company to fluctuations of foreign exchange rates. These fluctuations may impact the value of the Company’s cash receipts and payments in terms of the Company’s functional currency, the U.S. dollar. The Company enters into derivative financial instruments to protect the value or fix the amount of certain obligations in terms of its functional currency.

Cash Flow Hedges of Interest Rate Risk. As a result of the repayment of the Company’s then-outstanding term loans on May 4, 2012 and March 14, 2011, the Company discontinued prospective hedge accounting on its then-existing interest rate swaps as they no longer met hedge accounting requirements. The Company has not entered into new interest rate swaps to hedge its debt. The Company continued to report the net loss related to the discontinued cash flow hedges in accumulated other comprehensive income (loss) and reclassified this amount into earnings through the contractual term of the swap agreements which ended in August 2013.

Non-designated Hedges of Foreign Exchange Risk. Derivatives not designated as hedges are not speculative and are used to manage the Company’s economic exposure to foreign exchange rate movements but do not meet the strict hedge accounting requirements. Changes in the fair value of derivatives not designated in hedging relationships are recorded directly in earnings. As of December 31, 2014, the Company had outstanding foreign currency forwards with a notional amount of $11.6 million that were not designated as hedges in qualifying hedging relationships.

The following table presents the fair values of the Company’s derivative instruments and the location in which they are presented on the Company’s Consolidated Statements of Financial Condition:

(in thousands)

Consolidated Statements of

As of

As of

Financial Condition Location

December 31, 2014

December 31, 2013

Derivatives designated as hedging instruments:

Liability derivatives:

Foreign exchange contracts

Other accrued liabilities

$

(243

)

$

(156

)

The following tables present the effect of the Company’s financial derivatives and the location in which they are presented on the Company’s Consolidated Statements of Financial Condition and Consolidated Statements of Income:

Derivatives in

Amount of Gain or (Loss)

Location of  Gain

Amount of Gain  or

Location of  Gain

Amount of Gain

Cash Flow

Recognized in Accumulated

or (Loss)

(Loss) Reclassified

or (Loss)

or  (Loss) Recognized

Hedging

Other Comprehensive

Reclassified

from Accumulated Other

Recognized

in Income on Derivatives

Relationships

Income (Loss) on Derivatives

from Accumulated

Comprehensive Income (Loss)

in Income on

(Ineffective Portion

(Effective Portion) for the

Other

into Income (Effective

Derivatives

and Amount

Years Ended

Comprehensive

Portion) for the

(Ineffective

Excluded from

December 31,

Income into

Years Ended

Portion and

Effectiveness

Income

December 31,

Amount Excluded

Testing) for the

(Effective Portion)

from

Years Ended

Effectiveness

December 31,

(in thousands)

2014

2013

2012

2014

2013

2012

Testing)

2014

2013

2012

Interest rate swaps

$

—

$

—

$

(695

)

Interest expense

$

—

$

(1,364

)

$

2,437

Interest expense

$

—

$

—

$

—

Derivatives Not Designated as Hedging Instruments

Location of

Amount of Gain or (Loss)

Gain or  (Loss)

Recognized in Income on

Recognized in

Derivatives for the Years

Income on

Ended December 31,

(in thousands)

Derivatives

2014

2013

2012

Foreign exchange contracts

Other expense

$

(834

)

$

(139

)

$

(200

)

(income)

Property_Equipment_and_Leaseho

Property, Equipment and Leasehold Improvements	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Property, Equipment and Leasehold Improvements	7. PROPERTY, EQUIPMENT AND LEASEHOLD IMPROVEMENTS
	Property, equipment and leasehold improvements at December 31, 2014 and 2013 consisted of the following:
				As of
	Type		Estimated	December  31,			December 31,
			Useful Lives	2014(1)			2013
				(in thousands)
	Computer & related equipment		3 to 5 years	$	118,537		$	86,384
	Furniture & fixtures		7 years		9,569			9,108
	Leasehold improvements		1 to 21 years		49,756			52,776
	Work-in-process		—		9,020			12,691
	Subtotal				186,882			160,959
	Accumulated depreciation and amortization				(92,808	)		(75,371	)
	Property, equipment and leasehold improvements, net			$	94,074		$	85,588
	(1)	Property, equipment and leasehold improvements as of December 31, 2014 reflects the disposition and addition of property, equipment and leasehold improvements associated with the sale of ISS and acquisition of Governance Holdings Co. (“GMI Ratings”), respectively. See Note 3, “Dispositions and Discontinued Operations,” and Note 11, “Acquisitions,” for additional information.
	Depreciation and amortization expense of property, equipment and leasehold improvements was $25.7 million, $20.4 million and $16.6 million for the years ended December 31, 2014, 2013 and 2012, respectively.

Goodwill_and_Intangible_Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	8. GOODWILL AND INTANGIBLE ASSETS
	Goodwill.
	The Company carries goodwill as reflected in the table below:
			Goodwill
	(in thousands)
	Goodwill at December 31, 2012		$	1,797,753
	Changes to goodwill (1)			13,902
	Foreign exchange translation adjustment			1,509
	Goodwill at December 31, 2013		$	1,813,164
	Changes to goodwill (2)			(244,299	)
	Foreign exchange translation adjustment			(3,961	)
	Goodwill at December 31, 2014		$	1,564,904
	-1	Changes to goodwill reflect the acquisition of InvestorForce, which contributed $11.6 million, adjustments to the valuation of acquired IPD assets and liabilities, which contributed $2.7 million and the disposition of the CFRA product line, which removed $0.5 million. See Note 3, “Dispositions and Discontinued Operations,” and Note 12, “Acquisitions,” for additional information.
	-2	Changes to goodwill reflect the disposition and addition of goodwill associated with the sale of ISS, which removed $254.2 million, and the acquisition of GMI Ratings, which contributed $9.9 million. See Note 3, “Dispositions and Discontinued Operations,” and Note 12, “Acquisitions,” for additional information.
	Intangible Assets.
	Amortization expense related to intangible assets for the years ended December 31, 2014, 2013 and 2012, was $45.9 million, $44.8 million and $50.0 million, respectively.
	The gross carrying amounts, accumulated amortization and net intangible asset totals related to the Company’s identifiable intangible assets are as follows:
			As of
	(in thousands)		December 31,			December 31,
			2014 (1)			2013
	Gross intangible assets:
	Customer relationships		$	360,835		$	478,735
	Trademarks/trade names			223,382			257,282
	Technology/software			193,681			199,778
	Proprietary process			—			3,800
	Proprietary data			28,627			28,527
	Covenant not to compete			900			—
	Subtotal			807,425			968,122
	Foreign exchange translation adjustment			(1,588	)		1,962
	Total gross intangible assets		$	805,837		$	970,084
	Accumulated amortization:
	Customer relationships		$	(119,058	)	$	(125,359	)
	Trademarks/trade names			(81,545	)		(75,696	)
	Technology/software			(167,083	)		(168,481	)
	Proprietary process			—			(2,269	)
	Proprietary data			(4,589	)		(2,326	)
	Covenant not to compete			(187	)		—
	Subtotal			(372,462	)		(374,131	)
	Foreign exchange translation adjustment			253			(246	)
	Total accumulated amortization		$	(372,209	)	$	(374,377	)
	Net intangible assets:
	Customer relationships		$	241,777		$	353,376
	Trademarks/trade names			141,837			181,586
	Technology/software			26,598			31,297
	Proprietary process			—			1,531
	Proprietary data			24,038			26,201
	Covenant not to compete			713			—
	Subtotal			434,963			593,991
	Foreign exchange translation adjustment			(1,335	)		1,716
	Total net intangible assets		$	433,628		$	595,707
	-1	Intangible assets and the associated accumulated amortization as of December 31, 2014 reflect the disposition and addition of intangible assets associated with the sale of ISS and acquisition of GMI Ratings, respectively. See Note 3, “Dispositions and Discontinued Operations,” and Note 12, “Acquisitions,” for additional information.
	Estimated amortization expense for succeeding years is presented below:
	For the Years Ending December 31,		Amortization
			Expense
			(in thousands)
	2015		$	47,111
	2016			46,684
	2017			41,457
	2018			38,721
	2019			37,420
	Thereafter			222,235
	Total		$	433,628

Employee_Benefits

Employee Benefits	12 Months Ended
	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Employee Benefits	9. EMPLOYEE BENEFITS
	The Company sponsors a 401(k) plan for eligible U.S. employees and defined contribution and defined benefit pension plans that cover substantially all of its non-U.S. employees. For the years ended December 31, 2014, 2013 and 2012, costs relating to 401(k), pension and post-retirement benefit expenses were $22.2 million, $18.2 million and $16.2 million, respectively. Amounts included in cost of services were $13.1 million, $10.9 million and $9.6 million for the years ended December 31, 2014, 2013 and 2012, respectively. Amounts included in selling, general and administrative expense for the years ended December 31, 2014, 2013 and 2012 were $9.1 million, $7.3 million and $6.6 million, respectively.
	401(k) and Other Defined Contribution Plans. Eligible employees may participate in the MSCI 401(k) plan (or any other regional defined contribution plan sponsored by MSCI) immediately upon hire. Eligible employees receive 401(k) and other defined contribution plan matching contributions and, in the case of the MSCI 401(k) plan, an additional Company contribution of 3% of the employees’ cash compensation, which is subject to vesting and certain other limitations. The Company’s expenses associated with the 401(k) plan and other defined contribution plans for the years ended December 31, 2014, 2013 and 2012 were $19.3 million, $15.7 million and $13.1 million, respectively.
	Net Periodic Benefit Expense. Net periodic benefit expense incurred by the Company related to defined benefit pension plans was $2.8 million, $2.5 million and $3.1 million for the years ended December 31, 2014, 2013 and 2012, respectively.
	The Company uses a measurement date of December 31 to calculate obligations under its pension and postretirement plans. As of December 31, 2014, the Company carried a $16.7 million net liability in other non-current liabilities on its Consolidated Statement of Financial Condition related to its future pension obligations. As of December 31, 2013, the Company carried a $7.7 million net liability in other non-current liabilities on its Consolidated Statement of Financial Condition related to its future pension obligations. The increase was primarily driven by changes in the discount rates used to determine the value of the Company’s future pension obligations. The fair value of the defined benefit plan assets were $14.3 million and $15.7 million at December 31, 2014 and 2013, respectively.

ShareBased_Compensation

Share-Based Compensation	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Compensation	10. SHARE-BASED COMPENSATION
	The following footnote reflects the share-based compensation activity recognized by the Company, including the amounts recognized in both continuing operations and discontinued operations for all periods referenced.
	On November 6, 2007, the Company’s Board of Directors approved the award of founders grants to its employees in the form of RSUs and/or options (“Founders Grant Award”). The RSUs and options vested over a four-year period beginning from the November 14, 2007 grant date through November 14, 2011.
	On June 1, 2010, the Company awarded certain of its employees with a grant in the form of PSUs (“Performance Award”). The Performance Award performance-vested based upon the Company achieving specific performance targets over a measurement period ended on December 31, 2012. The Performance Award vested and converted to shares in February 2013.
	On December 10, 2010, the Compensation Committee of the Board of Directors of the Company approved the grant of a special one-time price and time vested stock option award to the Company’s Chief Executive Officer (“2010 CEO Award”). The award was valued at $3.6 million using a Monte Carlo simulation based on the closing price of the Company’s common stock at the close of business on December 13, 2010. The 2010 CEO Award time-vests over a five-year period, with approximately 25% of the award vesting on each of the second, third, fourth and fifth anniversaries of the grant and is subject to certain market performance.
	On December 14, 2010, the Company, as a component of the 2010 annual bonus, awarded a portion of its employees with a grant in the form of restricted stock units (“2010 Bonus Award”). The aggregate value of the grants was $18.9 million. Approximately $6.2 million was awarded to retirement-eligible employees under the award terms. A portion of the 2010 Bonus Award consisted of RSUs vesting over a three-year period, with one-third vesting on each anniversary of the grant in 2011, 2012 and 2013, respectively. A smaller portion of the 2010 Bonus Award consisted of PSUs subject to achieving both specific performance targets over a measurement period ending on December 31, 2012 and a time-vesting period, with one-half time vesting on December 31, 2012 and 2013, respectively.
	On February 2, 2012, the Company, as a component of the 2011 annual bonus, awarded a portion of its employees with a grant in the form of restricted stock units (“2011 Bonus Award”). The aggregate value of the grants was $21.2 million. Approximately $6.7 million of the aggregate value of the grants was awarded to retirement-eligible employees under the award terms which had been expensed in the year ended December 31, 2011. A portion of the 2011 Bonus Award consisted of RSUs vesting over a three-year period, with one-third vesting on each anniversary of the grant in 2013, 2014 and 2015, respectively. A smaller portion of the 2011 Bonus Award consisted of PSUs subject to achieving both specific performance targets over a measurement period ending on December 31, 2013 and a time-vesting period, with one-half time vesting on December 31, 2013 and 2014, respectively.
	In January 2013, the Company, as a component of the 2012 annual bonus, awarded a portion of its employees with a grant in the form of restricted stock units (“2012 Bonus Award”). The aggregate value of the grants was $21.7 million. Approximately $6.2 million was awarded to retirement eligible employees under the award terms which had been expensed in the year ended December 31, 2012. A portion of the 2012 Bonus Award consisted of RSUs vesting over a three-year period, with one-third vesting on each anniversary of the grant in 2014, 2015 and 2016. A smaller portion of the 2012 Bonus Award consisted of PSUs subject to achieving both specific performance targets over a measurement period ending on December 31, 2014 and a time-vesting period, with one-half time vesting on December 31, 2014 and 2015, respectively.
	In January 2014, the Company, as a component of the 2013 annual bonus, awarded a portion of its employees with a grant in the form of restricted stock units (“2013 Bonus Award”). The aggregate value of the grants was $24.3 million. Approximately $6.8 million was awarded to retirement eligible employees under the award terms which had been expensed in the year ended December 31, 2013. A portion of the 2013 Bonus Award consisted of RSUs vesting over a three-year period, with one-third vesting on each anniversary of the grant in 2015, 2016 and 2017. A smaller portion of the 2013 Bonus Award consisted of PSUs subject to achieving both specific performance targets over a measurement period ending on December 31, 2015 and a time-vesting period, with one-half time vesting on December 31, 2015 and 2016, respectively.
	In January 2015, the Company, as a component of the 2014 annual bonus, awarded a portion of its employees with a grant in the form of RSUs and PSUs (“2014 Bonus Award”). The total number of units granted was 485,170. The aggregate value of the grants was $26.5 million. Approximately $7.2 million was awarded to retirement eligible employees under the award terms which had been expensed in the year ended December 31, 2014.
	On January 27, 2015, the Compensation Committee of the Board of Directors of the Company approved the grant of a special one-time PSU award to certain of the Company’s employees (“2015 Special Incentive Award”), with an aggregate value of $5.0 million. The initial total number of units granted was 91,657, based on the closing price of the Company’s common stock on January 26, 2015. The 2015 Special Incentive Award vests over a five-year period, with one-third of the award both time and performance vesting on each of the third, fourth and fifth anniversaries of the grant.
	During the year ended December 31, 2014, the Company granted 5,371 shares in MSCI common stock and awarded 27,447 RSUs to directors who were not employees of the Company during the period. During the year ended December 31, 2013, the Company granted 4,688 shares in MSCI common stock and awarded 20,514 RSUs to directors who were not employees of the Company during the period.
	For the CEO Award and the 2015 Special Incentive Award, all or a portion of the award may be cancelled in certain limited situations, including termination for cause, if employment is terminated before the end of the relevant restriction period. For the remainder of the awards granted by the Company, all or a portion of the award may be cancelled if employment is terminated for certain reasons before the end of the relevant restriction period for non-retirement-eligible employees.
	In connection with awards under its equity-based compensation and benefit plans, the Company is authorized to use newly issued shares or certain shares of common stock held in treasury.
	The components of share-based compensation expense related to the awards to Company employees and directors who are not employees of the Company of restricted stock units and restricted stock awards (representing shares of common stock) and options to purchase shares of common stock, as applicable, are presented below:
			For the Years Ended
	(in thousands)		December 31,			December 31,		December 31,
			2014			2013		2012
	Deferred stock		$	25,830		$	23,910	$	23,198
	Stock options			1,201			1,643		2,398
	Total share-based compensation expense		$	27,031		$	25,553	$	25,596
	The amount of this expense included in cost of services for the years ended December 31, 2014, 2013 and 2012 was $10.8 million, $9.8 million and $8.8 million, respectively. The amount of this expense included in selling, general and administrative expense for the years ended December 31, 2014, 2013 and 2012 was $14.8 million, $12.9 million and $14.1 million, respectively. The amount of this expense included in income from discontinued operations, net of income taxes for the years ended December 31, 2014, 2013 and 2012 was $1.4 million, $2.8 million and $2.7 million, respectively.
	The tax benefits for share-based compensation expense related to deferred stock and stock options granted to Company employees and to directors who are not employees of the Company were $2.8 million, $2.6 million and $1.0 million for the years ended December 31, 2014, 2013 and 2012, respectively.
	As of December 31, 2014, $11.6 million of compensation cost related to MSCI unvested share-based awards granted to the Company’s employees and to directors who are not employees of the Company had not yet been recognized. The unrecognized compensation cost relating to unvested stock-based awards expected to vest will be recognized primarily over the next one to three years.
	In connection with awards under its equity-based compensation and benefit plans, the Company is authorized to issue shares of common stock. As of December 31, 2014, 6.3 million shares of common stock were available for future grants under these plans.
	Deferred Stock Awards. Certain Company employees have been granted deferred stock awards pursuant to a share-based compensation plan. The plan provides for the deferral of a portion of certain employees’ discretionary compensation with awards made in the form of RSUs, PSUs and restricted stock awards (together, the “Deferred Stock Awards”). Recipients of RSUs, restricted stock awards and PSUs granted prior to January 2014 generally have rights to receive dividend equivalents that are not subject to vesting. Recipients of RSUs and PSUs granted in January 2014, and RSUs granted thereafter, generally have rights to receive dividend equivalents that are subject to vesting. Recipients of PSUs granted in January 2015 do not have rights to receive dividend equivalents until actual achievement of performance measures has been confirmed. The Company reports the target number of PSUs granted unless it has determined, based on the actual achievement of performance measures, that an employee will receive a different amount of shares underlying the PSUs, in which case the Company reports the amount of shares employees are likely to receive.
	The following table sets forth activity concerning the Company’s vested and unvested deferred stock awards applicable to its employees (share data in thousands):
	For the Year Ended December 31, 2014		Number of			Weighted
			Shares			Average
						Grant
						Date  Fair
						Value
	Vested and unvested deferred stock awards at December 31, 2013 (1)			1,237		$	33.84
	Granted			639		$	42.32
	Conversion to common stock			(567	)	$	34.54
	Canceled			(96	)	$	35.82
	Vested and unvested deferred stock awards at December 31, 2014			1,213		$	37.82
	-1	As of December 31, 2014, 1,195 restricted stock units and restricted stock awards, with a weighted average price of $37.80, were vested or expected to vest.
	The total fair value of Deferred Stock Awards held by the Company’s employees converted to MSCI common stock during the years ended December 31, 2014, 2013 and 2012 was $24.5 million, $28.2 million and $15.3 million, respectively.
	The following table sets forth activity concerning the Company’s unvested deferred stock awards related to its employees (share data in thousands):
	For the Year Ended December 31, 2014		Number of			Weighted
			Shares			Average
						Grant
						Date  Fair
						Value
	Unvested deferred stock awards at December 31, 2013			894		$	33.85
	Granted			479		$	42.35
	Vested			(412	)	$	34.39
	Canceled			(78	)	$	36.35
	Unvested deferred stock awards at December 31, 2014			883		$	37.99
	Unvested deferred stock awards expected to vest			866		$	37.96
	Stock Option Awards. No MSCI stock options were issued during the years ended December 31, 2014 and 2012. During the year ended December 31, 2013, the Company awarded stock options. The award was valued using a Black-Scholes valuation model. The weighted average fair value of MSCI stock options issued by the Company in the year ended December 31, 2013 was $19.18 utilizing the following assumptions:
			Assumptions
	Risk free interest rate			1.87	%
	Expected option life in years			6.5
	Expected stock price volatility			46.07	%
	Expected dividend yield			—
	The expected stock price volatility assumption was determined using the historical volatility of the Company.
	The following table sets forth activity concerning MSCI stock options granted to the Company’s employees for the years ended December 31, 2014 (option data and dollar values in thousands, except exercise price):
	For the Year Ended December 31, 2014		Number of			Weighted		Weighted		Aggregated
			Options			Average		Average		Intrinsic
						Exercise		Remaining		Value
						Price		Life
								(Years)
Options outstanding at December 31, 2013			1,986		$	21.85		4.55		N/A
Granted or assumed			—		$	—		N/A		N/A
Forfeited			(1	)	$	24.49		N/A		N/A
Conversion to common stock			(498	)	$	19.32		N/A		N/A
Options outstanding at December 31, 2014			1,487		$	22.69		3.76	$	36,802
Options exercisable at December 31, 2014			1,303		$	20.49		3.28	$	35,120
Options vested or expected to vest			1,487		$	22.69		3.76	$	36,802
The following table presents information relating to the Company’s outstanding stock options as of December 31, 2014 (number of options outstanding and aggregate intrinsic value data in thousands):
At December 31, 2014		Options Outstanding
Range of Exercise Prices		Number			Weighted		Average		Aggregate
		Outstanding			Average		Remaining		Intrinsic
					Exercise		Life (Years)		Value
					Price
$2.76 to $16.48			130		$	12.69		2.42	$	4,512
$18.00			763		$	18		2.87	$	22,469
$20.45 to $25.64			282		$	23.16		3.34	$	6,833
$36.70 to $40.23			312		$	37.88		6.88	$	2,988
Total			1,487						$	36,802
The following table presents information relating to the Company’s exercisable stock options as of December 31, 2014 (number of options outstanding and aggregate intrinsic value data in thousands):
At December 31, 2014		Options Exercisable
Range of Exercise Prices		Number			Weighted		Average		Aggregate
		Outstanding			Average		Remaining		Intrinsic
					Exercise		Life (Years)		Value
					Price
$2.76 to $16.48			130		$	12.69		2.42	$	4,512
$18.00			763		$	18		2.87	$	22,469
$20.45 to $25.64			282		$	23.16		3.34	$	6,833
$36.70 to $40.23			128		$	37.27		6.4	$	1,306
Total			1,303						$	35,120
The intrinsic value of the stock options exercised by the Company’s employees during the years ended December 31, 2014, 2013 and 2012 was $12.8 million, $13.9 million and $14.5 million, respectively.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income Taxes	11. INCOME TAXES
	The provision for income taxes (benefits) consisted of (in thousands):
			For the Years Ended
			December 31,			December 31,			December 31,
			2014			2013			2012
	Current
	U.S. federal		$	84,959		$	97,739		$	72,786
	U.S. state and local			13,929			16,820			25,049
	Non U.S.			18,505			18,270			19,996
				117,393			132,829			117,831
	Deferred
	U.S. federal			(2,606	)		(14,362	)		(18,234	)
	U.S. state and local			(3,356	)		(3,802	)		(3,821	)
	Non U.S.			(2,035	)		(1,747	)		234
				(7,997	)		(19,911	)		(21,821	)
	Provision for income taxes from continuing operations		$	109,396		$	112,918		$	96,010
	Provision for income taxes from discontinued operations		$	1,059		$	10,146		$	9,161
	The following table reconciles the provision to the U.S. federal statutory income tax rate:
			For the Years Ended
			December 31,			December 31,			December 31,
			2014			2013			2012
	U.S. federal statutory income tax rate			35	%		35	%		35.00	%
	U.S. state and local income taxes, net of U.S. federal income tax benefits			2.72	%		3.05	%		2.14	%
	Change in tax rates applicable to non-U.S. earnings			(1.88	%)		(0.93	%)		(1.57	%)
	Domestic tax credits			(0.86	%)		(0.95	%)		—	%
	Other			0.5	%		(0.07	%)		1.24	%
	Effective income tax rate			35.48	%		36.1	%		36.81	%
	Deferred income taxes reflect the net tax effects of temporary differences between the financial reporting and tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when such differences are expected to reverse. Significant components of the Company’s deferred tax assets and liabilities as of December 31, 2014 and 2013, were as follows (in thousands):
			As of
			December 31,			December 31,
			2014			2013
	Deferred tax assets:
	Employee compensation and benefit plans		$	24,765		$	26,165
	Deferred rent			7,229			9,526
	Property, equipment and leasehold improvements, net			—			1,520
	State taxes			2,322			2,323
	Pension			2,494			395
	Unearned revenue			1,117			1,238
	NOL carryforward – current			1,667			3,813
	NOL carryforward – non-current			34,249			7,506
	Other			1,979			112
	Subtotal			75,822			52,598
	Less: valuation allowance (1)			(21,232	)		(7	)
	Total deferred tax assets		$	54,590		$	52,591
	Deferred tax liabilities:
	Intangible assets		$	(154,965	)	$	(233,980	)
	Foreign currency translation			(629	)		(372	)
	Property, equipment and leasehold improvements, net			(10,435	)		—
	Other			(246	)		—
	Total deferred tax liabilities		$	(166,275	)	$	(234,352	)
	Net deferred tax liabilities		$	(111,685	)	$	(181,761	)
	(1)	The Company’s valuation allowance was not significant on December 31, 2013 or in prior periods but increased in the year ended December 31, 2014 as a result of a capital loss carryforward recognized on the sale of ISS that is not currently expected to be utilized.
	In the year ended December 31, 2013, the Company reported a non-current net operating loss (“NOL”) carryforward of $34.7 million with a valuation allowance against it of $23.4 million. The Company subsequently determined that the maximum NOL available for use was $11.3 million, of which $3.8 million was current and $7.3 million was non-current. The Company has changed its disclosure for the year ended December 31, 2013 to show an NOL carryforward of $11.3 million and a valuation allowance of less than $0.1 million. The United States portion of the NOL’s are subject to an annual limitation on utilization and will begin to expire in 2026. In addition, the December 31, 2013 deferred tax liability was understated by $13.6 million. The amounts in the table above reflect the revised balances. See Note 1, “Introduction And Basis Of Presentation—Revision,” for further details.
	The following table presents the components of income before provision for income taxes generated by domestic or foreign operations for the periods indicated (in thousands):
			For the Years Ended
			December 31,			December 31,			December 31,
			2014			2013			2012
	Domestic		$	269,944		$	276,549		$	220,072
	Foreign (1)			38,394			36,279			40,729
	Total income before provision for income taxes		$	308,338		$	312,828		$	260,801
	(1)	Foreign income before provision for income taxes is defined as income generated from operations located outside the U.S.
	Cumulative earnings attributable to foreign subsidiaries were $149.1 million, $188.6 million and $164.9 million for the years ended December 31, 2014, 2013, and 2012, respectively. No provisions for income tax that could occur upon repatriation have been recorded on these earnings which are permanently invested abroad. It is not practicable to determine the amount of income taxes payable in the event all such foreign earnings are repatriated.
	The Company intends to permanently reinvest the undistributed earnings of all foreign operations indefinitely except for any entities that are branches of U.S. companies or check-the-box entities that have elected to be treated as disregarded entities for U.S. tax purposes and are held directly by a U.S. company or MSCI Ltd. As a result, the Company does not accrue for the U.S. taxes that would be recognized upon repatriation of these earnings.
	The Company regularly assesses the likelihood of additional assessments in each of the taxing jurisdictions in which it files income tax returns. The Company has established unrecognized tax benefits that the Company believes are adequate in relation to the potential for additional assessments. Once established, the Company adjusts unrecognized tax benefits only when more information is available or when an event occurs necessitating a change. As part of the Company’s periodic review of unrecognized tax benefits and based on new information regarding the status of federal and state examinations, the Company’s unrecognized tax benefits were remeasured. It is reasonably possible that significant changes in the balance of unrecognized tax benefits may occur within the next 12 months. At this time, however, it is not possible to reasonably estimate the expected change to the total amount of unrecognized tax benefits and the impact on the effective tax rate over the next 12 months.
The Company believes the resolution of tax matters will not have a material effect on the Consolidated Statement of Financial Condition of the Company, although a resolution could have a material impact on the Company’s Consolidated Statement of Income for a particular future period and on the Company’s effective tax rate for any period in which such resolution occurs.
The following table presents a reconciliation of the beginning and ending amount of the gross unrecognized tax benefits, excluding interest and penalties, for the years ended December 31, 2014, 2013 and 2012:
Gross unrecognized tax benefits		Year Ended			Year Ended			Year Ended
		December 31,			December 31,			December 31,
		2014			2013			2012
(amounts in thousands)
Beginning balance		$	7,089		$	6,827		$	13,168
Increases based on tax positions related to the current period			292			194			—
Increases based on tax positions related to prior periods			1,969			2,690			349
Decreases based on tax positions related to prior periods			(346	)		(2,474	)		(427	)
Increases/ (Decreases) related to settlements with taxing authorities			(1,652	)		—			(6,263	)
Increases/(Decreases) related to a lapse of applicable statute of limitations			(827	)		(148	)		—
Ending balance		$	6,525		$	7,089		$	6,827
The total amount of unrecognized tax benefits was $5.5 million, net of federal benefit of state issues, competent authority and foreign tax credit offsets, as of December 31, 2014, which, if recognized, would favorably affect the effective tax rate in future periods. The Company recognizes the accrual of interest and penalties related to unrecognized tax benefits in the Provision for Income Taxes in the Consolidated Statement of Income. For the year ended December 31, 2014, the Company recognized less than $0.1 million of interest in the Consolidated Statement of Income. No significant penalties were recognized in the Consolidated Statement of Income for the year ended December 31, 2014.
The Company is under examination by the Internal Revenue Service and other tax authorities in certain jurisdictions, including foreign jurisdictions, such as the United Kingdom, and states in which the Company has significant business operations, such as New York. The tax years currently under examination vary by jurisdiction but include years ranging from 2005 through 2013. As a result of having previously been a member of the Morgan Stanley consolidated group, the Company may have future settlements with Morgan Stanley related to the ultimate disposition of their New York State and New York City examination relating to the tax years 2007 through 2008 and their IRS examination relating to the tax years 2006 through 2008. The Company does not believe it has any material exposure to the New York State and New York City examination. Additionally, the Company believes it has adequate reserves for any tax issues that may arise out of the IRS examination relating to the tax years 2006 through 2008 and therefore does not believe any related settlement with Morgan Stanley will have a material impact.

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2014
Business Combinations [Abstract]
Acquisitions	12. ACQUISITIONS
	The acquisition method of accounting is based on ASC Subtopic 805-10, “Business Combinations,” and uses the fair value concepts defined in ASC Subtopic 820-10, “Fair Value Measurements and Disclosures,” which the Company has adopted as required. The total purchase price is allocated to the net tangible and intangible assets based upon their fair values as of the acquisition dates. The excess of the purchase price over the fair values of the net tangible assets and intangible assets was recorded as goodwill. The allocation of the purchase price was based upon a valuation and is subject to change within the one-year measurement period following the acquisition. MSCI expects to continue to obtain information to assist it in determining the fair value of the net assets acquired at the acquisition date during the measurement period.
	Acquisition of GMI Ratings
	On August 11, 2014, the Company completed the acquisition of GMI Ratings for $15.5 million in cash through its subsidiary MSCI ESG Research Inc. GMI Ratings is a provider of corporate governance research and ratings on companies worldwide. Clients of GMI Ratings include institutional investors, banks, insurers, auditors, regulators and corporations seeking to incorporate ESG factors into risk assessment and decision-making.
	As of December 31, 2014, the preliminary purchase price allocations for the GMI Ratings acquisition were $9.9 million for goodwill, $3.6 million for identifiable intangible assets, $6.7 million for assets other than identifiable intangible assets and $4.7 million for other liabilities.
	Acquisition of InvestorForce
	On January 29, 2013, MSCI completed the acquisition of InvestorForce by paying $23.6 million in cash. The acquisition of InvestorForce enhances MSCI’s position as a leader in performance analysis and risk transparency and furthers its goal of providing investment decision support tools to institutional investors across all client segments and asset classes. InvestorForce is a provider of performance reporting solutions to the institutional investment community in the United States, providing investment consultants with an integrated solution for daily monitoring, analysis of and reporting on institutional assets.
	The purchase price allocations for the InvestorForce acquisition were $11.6 million for goodwill, $9.1 million for identifiable intangible assets, $6.4 million for assets other than identifiable intangible assets and $3.5 million for other liabilities.
	Acquisition of IPD
	On November 30, 2012, MSCI Limited, an indirect wholly-owned subsidiary of the Company, paid cash of $124.8 million to acquire real estate performance measurement group IPD. The acquisition of IPD expands the Company’s multi-asset class offering by facilitating the integration of private real estate assets into its models, as well as adding a family of real estate indexes to the Company’s family of equity indexes. IPD is dedicated to the objective measurement of the commercial real estate market. IPD is a provider of real estate performance analysis for funds, investors, managers, lenders and occupiers and offers a wide range of services that include research, reporting, benchmarking and indexes.
	The purchase price allocations for the IPD acquisition were $76.5 million for goodwill, $58.7 million for identifiable intangible assets, $18.6 million for assets other than identifiable intangible assets and $29.0 million for other liabilities.

Segment_Information

Segment Information	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Segment Information	13. SEGMENT INFORMATION
	ASC Subtopic 280-10, “Segment Reporting,” establishes standards for reporting information about operating segments. Operating segments are defined as components of an enterprise about which separate financial information is available that is evaluated regularly by the chief operating decision maker, or CODM, in deciding how to allocate resources and in assessing performance. MSCI’s Chief Executive Officer, who is considered to be its CODM, reviews financial information presented on an operating segment basis for purposes of making operating decisions and assessing financial performance.
	MSCI operated as two segments in the year ended December 31, 2013: the Performance and Risk business and the Governance business. These designations were made as the discrete operating results of these segments were reviewed by the Company’s CODM for purposes of making operating decisions and assessing financial performance.
	On March 17, 2014, MSCI Inc. entered into a definitive agreement to sell ISS, which, together with the CFRA product line disposed of on March 31, 2013, made up the Company’s Governance segment, the results for which are now reflected in “Income from discontinued operations, net of income taxes” in the Consolidated Statements of Income. The Company completed the sale of ISS on April 30, 2014. As a result, the Company now operates and reports as a single business segment (see Note 3, “Dispositions and Discontinued Operations,” for further details).
	Revenue by geography is based on the shipping address of the customer. The following table sets forth revenue for the periods indicated by geographic area.
		For the Years Ended
	(in thousands)	December 31,		December 31,		December 31,
		2014		2013		2012
	Revenues
	Americas:
	United States	$	471,145	$	416,999	$	394,401
	Other		37,189		34,547		27,783
	Total Americas		508,334		451,546		422,184
	Europe, the Middle East and Africa (“EMEA”):
	United Kingdom		154,308		141,938		107,189
	Other		209,893		202,664		179,535
	Total EMEA		364,201		344,602		286,724
	Asia & Australia:
	Japan		46,642		46,752		53,649
	Other		77,503		70,464		64,433
	Total Asia & Australia		124,145		117,216		118,082
	Total	$	996,680	$	913,364	$	826,990
	Long-lived assets consist of property, equipment, leasehold improvements, goodwill and intangible assets, net of accumulated depreciation and amortization. The following table sets forth long-lived assets on the dates indicated by geographic area:
		As of
	(in thousands)	December 31,		December 31,
		2014		2013
	Long-lived assets
	Americas:
	United States	$	1,944,433	$	2,338,124
	Other		3,293		4,082
	Total Americas		1,947,726		2,342,206
	EMEA:
	United Kingdom		120,781		133,411
	Other		13,345		11,871
	Total EMEA		134,126		145,282
	Asia & Australia:
	Japan		837		1,543
	Other		9,917		5,428
	Total Asia & Australia		10,754		6,971
	Total	$	2,092,606	$	2,494,459

Quarterly_Results_of_Operation

Quarterly Results of Operations	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Quarterly Results of Operations	14. QUARTERLY RESULTS OF OPERATIONS (unaudited):
			2014												2013
			First			Second			Third			Fourth			First			Second			Third			Fourth
			Quarter			Quarter			Quarter			Quarter			Quarter			Quarter			Quarter			Quarter
			(in thousands, except per share data)
	Operating revenues		$	239,688		$	254,226		$	251,661		$	251,105		$	219,469		$	228,423		$	228,608		$	236,864
	Cost of services			75,427			76,816			78,876			77,455			65,300			69,696			68,151			72,256
	Selling, general and administrative			67,658			71,516			70,833			69,345			55,515			52,842			59,917			64,174
	Amortization of intangible assets			11,270			11,442			11,574			11,591			11,166			11,222			11,193			11,217
	Depreciation and amortization of property, equipment and leasehold improvements			5,828			5,921			6,342			7,620			4,597			4,774			5,443			5,570
	Total operating expenses			160,183			165,695			167,625			166,011			136,578			138,534			144,704			153,217
	Operating income			79,505			88,531			84,036			85,094			82,891			89,889			83,904			83,647
	Interest income			(156	)		(192	)		(277	)		(226	)		(237	)		(186	)		(227	)		(239	)
	Interest expense (1)			5,059			5,366			5,604			15,791			7,016			6,499			5,828			6,913
	Other expense (income)			1,071			(726	)		(1,287	)		(1,199	)		1,922			(328	)		563			(21	)
	Other expense (income), net			5,974			4,448			4,040			14,366			8,701			5,985			6,164			6,653
	Income from continuing operations before provision for income taxes			73,531			84,083			79,996			70,728			74,190			83,904			77,740			76,994
	Provision for income taxes			26,385			27,280			28,272			27,459			21,232			27,763			27,804			36,119
	Income from continuing operations			47,146			56,803			51,724			43,269			52,958			56,141			49,936			40,875
	Income (loss) from discontinued operations, net of income taxes			33,253			50,857			(10	)		1,071			5,979			4,912			5,374			6,382
	Net income		$	80,399		$	107,660		$	51,714		$	44,340		$	58,937		$	61,053		$	55,310		$	47,257
	Earnings per basic common share
	From continuing operations		$	0.4		$	0.48		$	0.44		$	0.38		$	0.44		$	0.46		$	0.42		$	0.34
	From discontinued operations			0.28			0.44			—			0.01			0.05			0.04			0.04			0.06
	Earnings per basic common share		$	0.68		$	0.92		$	0.44		$	0.39		$	0.49		$	0.5		$	0.46		$	0.4
	Earnings per diluted common share
	From continuing operations		$	0.4		$	0.48		$	0.44		$	0.38		$	0.43		$	0.46		$	0.42		$	0.34
	From discontinued operations			0.28			0.43			—			0.01			0.05			0.04			0.04			0.05
	Earnings per diluted common share		$	0.68		$	0.91		$	0.44		$	0.39		$	0.48		$	0.5		$	0.46		$	0.39
	Weighted average shares outstanding used in computing per share data
	Basic			117,582			116,702			116,251			112,299			120,746			121,149			119,607			118,828
	Diluted			118,597			117,664			117,163			113,289			121,702			122,069			120,578			119,877
	-1	Increased interest expense during the fourth quarter of 2014 was primarily the result of the debt discount and deferred financing fees written off in association with the offering of the Senior Notes and the 2014 Revolving Facility.

Subsequent_Events

Subsequent Events	12 Months Ended
	Dec. 31, 2014
Subsequent Events [Abstract]
Subsequent Events	15. SUBSEQUENT EVENTS
	On February 3, 2015, the Board of Directors of the Company declared a quarterly dividend of $0.18 per share of common stock to be paid on March 13, 2015 to shareholders of record as of the close of trading on February 20, 2015.

Introduction_and_Basis_of_Pres1

Introduction and Basis of Presentation (Policies)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation
	The consolidated financial statements include the accounts of MSCI Inc. and its wholly-owned subsidiaries. The Company’s policy is to consolidate all entities in which it owns more than 50% of the outstanding voting stock unless it does not control the entity. It is also the Company’s policy to consolidate any variable interest entity for which the Company is the primary beneficiary, of which the Company has none, as required by the Financial Accounting Standards Board’s (“FASB”) Accounting Standards Codification (“ASC”) Subtopic 810-10, “Consolidations.” For investments in any entities in which the Company owns 20% or less of the outstanding voting stock and significant influence does not exist, such investments are carried at cost.
Revision	Revision
	In connection with the preparation of the Company’s unaudited condensed consolidated financial statements for the three months ended June 30, 2014, the Company determined that it had understated its net tax liabilities in certain years prior to December 31, 2012. As a result of these errors, the Company has recorded the following corrections to its Consolidated Statement of Financial Condition as of December 31, 2013: (i) an $11.3 million decrease to beginning retained earnings, (ii) a $0.7 million decrease to additional paid in capital, (iii) a $12.8 million decrease to prepaid taxes, (iv) a $13.6 million increase to long-term deferred tax liabilities and (v) a $14.3 million increase to goodwill. In accordance with the accounting guidance found in ASC Subtopic 250-10, “Accounting Changes and Error Corrections,” the Company has revised its Consolidated Statement of Financial Condition as of December 31, 2013 and the Consolidated Statement of Cash Flows for the year ended December 31, 2013 to reflect these corrections.
	In accordance with SEC Staff Accounting Bulletin No. 99, “Materiality,” the Company assessed the materiality of the adjustments and concluded that these corrections were not material to any of its previously issued financial statements. The Company also concluded that its compliance with debt covenants would not have been affected by these adjustments.
	Accordingly, the Company has revised the Consolidated Statement of Financial Condition as of December 31, 2013 from amounts previously reported as follows:
			As Previously			Adjustment			As Revised
			Reported
			(in thousands)
	Prepaid taxes		$	27,333		$	(12,765	)	$	14,568
	Total current assets		$	637,035		$	(12,765	)	$	624,270
	Goodwill		$	1,798,821		$	14,343		$	1,813,164
	Total assets		$	3,134,537		$	1,578		$	3,136,115
	Deferred taxes		$	221,054		$	13,595		$	234,649
	Total liabilities		$	1,558,173		$	13,595		$	1,571,768
	Additional paid in capital		$	1,073,893		$	(736	)	$	1,073,157
	Retained earnings		$	770,256		$	(11,281	)	$	758,975
	Total shareholders’ equity		$	1,576,364		$	(12,017	)	$	1,564,347
	Total liabilities and shareholders’ equity		$	3,134,537		$	1,578		$	3,136,115
	The Company has revised the Consolidated Statement of Cash Flows for the year ended December 31, 2013 from amounts previously reported as follows:
			As Previously			Adjustment			As Revised
			Reported
			(in thousands)
	Excess tax benefits from share-based compensation		$	(2,633	)	$	736		$	(1,897	)
	Net cash provided by operating activities		$	320,447		$	736		$	321,183
	Excess tax benefits from share-based compensation		$	2,633		$	(736	)	$	1,897
	Net cash (used in) provided by financing activities		$	(145,848	)	$	(736	)	$	(146,584	)
	The Company has revised the Consolidated Statements of Shareholders’ Equity for the years ended December 31, 2013, 2012 and 2011 from amounts previously reported as follows:
			As Previously			Adjustment			As Revised
			Reported
			(in thousands)
	As of December 31, 2011
	Retained earnings		$	363,461		$	(11,281	)	$	352,180
	Total shareholders’ equity		$	1,305,432		$	(11,281	)	$	1,294,151
	For the year ended December 31, 2013
	Excess tax benefits from share-based compensation		$	2,633		$	(736	)	$	1,897
	As of December 31, 2013
	Additional paid in capital		$	1,073,893		$	(736	)	$	1,073,157
	Total shareholders’ equity		$	1,576,364		$	(12,017	)	$	1,564,347
Basis of Financial Statements and Use of Estimates	Basis of Financial Statements and Use of Estimates
	The Company’s consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). These accounting principles require the Company to make certain estimates and judgments that can affect the reported amounts of assets and liabilities as of the date of the consolidated financial statements, as well as the reported amounts of revenue and expenses during the periods presented. Significant estimates and assumptions made by management include the deferral and recognition of revenue, research and development and software capitalization, the allowance for doubtful accounts, impairment of long-lived assets, accrued compensation, income taxes and other matters that affect the consolidated financial statements and related disclosures. The Company believes that estimates used in the preparation of these consolidated financial statements are reasonable; however, actual results could differ materially from these estimates.
	Inter-company balances and transactions are eliminated in consolidation.
Revenue Recognition	Revenue Recognition
	In general, the Company applies SEC Staff Accounting Bulletin No. 104 (“SAB 104”), “Revenue Recognition,” in determining revenue recognition. Accordingly, the Company recognizes revenue when all the following criteria are met:
		•		The Company has persuasive evidence of a legally binding arrangement,
		•		Delivery has occurred,
		•		Client fee is deemed fixed or determinable, and
		•		Collection is probable.
	When a sales arrangement requires the delivery of more than one product and service, revenue is recognized pursuant to the requirements of ASC Subtopic 605-25, “Revenue Arrangements with Multiple Deliverables.” Under the provisions of ASC Subtopic 605-25, elements within a multi-deliverable arrangement should be considered separate units of accounting if all of the following criteria are met:
		•		The delivered items have value to the client on a standalone basis. The items have value on a standalone basis if they can be sold separately by any vendor or the client could resell the delivered items on a standalone basis; and
		•		If the arrangement includes a general right of return relative to the delivered items, delivery or performance of the undelivered items is considered probable and substantially in the control of the vendor.
	The Company provides products and services to its clients under various software and non-software related arrangements. The Company has signed contracts with substantially all clients that set forth the fees to be paid for its products and services. Further, the Company regularly assesses the receivable balances for each client for collectability. The Company’s application service license arrangements generally do not include acceptance provisions, which generally allow a client to test the solution for a defined period of time before committing to the license. If a license agreement includes an acceptance provision, the Company does not recognize subscription revenues until the earlier of the receipt of a written client acceptance or, if not notified by the client that it is cancelling the license agreement, the expiration of the acceptance period.
	The Company’s subscription agreements for non-software-related application services include provisions that, among other things, allow clients, for no additional fee, to receive updates and modifications that may be made from time to time when and if available, for the term of the agreement, which is typically one year. These arrangements do not provide the client with the right to take possession of the application at any time. For sales arrangements with multiple deliverables, which may include application service subscription and professional services associated with implementation and other services, the Company evaluates each deliverable in these multiple-element arrangements to determine whether it represents a separate unit of accounting and allocates revenue accordingly.
	In most cases, the Company recognizes revenues from subscription arrangements ratably over the term of the license agreement pursuant to contract terms. The contracts state the terms under which these fees are to be calculated. The fees are recognized as the Company supplies the product and service to the client over the license period and are generally billed in advance, prior to the license start date. When implementation services are included, the Company recognizes revenues allocated to the subscription ratably from the date the application is put into production to the end of the license period. Revenues associated with the implementation services are recognized ratably over the useful life of those services. For products and services whose fees are based on estimated assets under management linked to the Company’s indexes, or contract values related to futures and options, the Company recognizes revenues based on estimates from independent third-party sources or the most recently reported information from the client. Revenues from subscription agreements for the receipt of periodic benchmark reports, digests, and other publications, which are most often associated with the Company’s real estate benchmark business, are recognized upon delivery of such reports or data updates.
	The Company’s software-related arrangements do not require significant modification or customization of any underlying software applications being licensed. Accordingly, the Company recognizes software revenues pursuant to the requirements of ASC Subtopic 985-605, “Software-Revenue Recognition.” The Company’s subscription agreements for software products include provisions that, among other things, would allow clients to receive unspecified, when and if available, software upgrades for no additional fee as well as the right to use the software products with maintenance and technical support for the term of the agreement, which is typically one year. Software agreements may include other consulting and professional services. In accordance with ASC Subtopic 985-605, “Software Revenue Recognition,” the Company does not have vendor specific objective evidence (“VSOE”) for these elements and therefore begins to recognize software related revenue ratably over the term of the license agreement once delivered.
	Adjustment to Revenues
	During the year ended December 31, 2012, as a result of a one-time adjustment, the Company recorded a $5.2 million cumulative revenue reduction to correct an error related to revenues previously reported through December 31, 2011. The effect of recording this adjustment in the first quarter of 2012 resulted in a one-time decrease to the energy and commodity analytics products revenues in the Company’s Consolidated Statement of Income and an increase in deferred revenues in the Company’s Consolidated Statement of Financial Condition. It was determined that under ASC Subtopic 985-605, the Company incorrectly established VSOE for certain energy and commodity analytics products and as a result should not have been recognizing a substantial portion of the revenue immediately upon delivery or renewal of a time based subscription license, the terms of which are generally one year. Rather, the entire license fee should have been recognized ratably over the term of the license. As such, the Company made the cumulative adjustment effective January 1, 2012 and started recognizing revenue related to all contracts still in effect as of this date ratably over the remainder of the term. The Company began recognizing revenue ratably over the contract term for any new contracts entered into on or after January 1, 2012. Based upon an evaluation of all relevant factors, management believes the correcting adjustment did not have a material impact on the Company’s previously reported results and, accordingly, has determined that restatement of previously issued financial statements is not necessary.
Share-Based Compensation	Share-Based Compensation
	Certain of the Company’s employees have received share-based compensation under certain compensation programs. The Company’s compensation expense reflects the fair value method of accounting for share-based payments under ASC Subtopic 718-10, “Compensation-Stock Compensation.” ASC Subtopic 718-10 requires measurement of compensation cost for equity-based awards at fair value and recognition of compensation cost over the service period, net of estimated forfeitures.
	The fair value of MSCI restricted stock units (“RSUs”) is measured as the closing price of MSCI’s common stock on the date prior to grant. Restricted stock units subject to performance conditions (“PSUs”) are based on performance measures that impact the amount of shares that each recipient will receive upon vesting. PSUs are granted at fair market value, which is measured as the closing price of MSCI’s common stock on the date prior to grant.
	The fair value of MSCI standard stock options is determined using the Black-Scholes valuation model and the single grant life method. Under the single grant life method, option awards with graded vesting are valued using a single weighted-average expected option life. The fair value of MSCI stock options that contain stock price contingencies is determined using a Monte Carlo simulation model, which creates a normal distribution of future stock prices, which is then used to value the awards based on their individual terms.
	Based on interpretive guidance related to share-based compensation, the Company’s policy is to accrue the estimated cost of share-based awards that are granted to retirement-eligible employees over the course of the prior year in which they were earned rather than expensing the awards on the date of grant. A portion of the awards granted to employees consist of PSUs. The Company bases initial accruals of compensation cost on the estimated number of units for which the requisite service is expected to be rendered. If the estimated number of units changes from previous estimates, the cumulative effect on current and prior periods of a change is recognized in compensation cost in the period of the change.
Research and Development	Research and Development
	The Company accounts for research and development costs in accordance with several accounting pronouncements, including ASC Subtopic 730-10, “Research and Development.” ASC Subtopic 730-10 requires that research and development costs generally be expensed as incurred. The majority of the Company’s research and development costs are incurred in developing, reviewing and enhancing the methodologies and data models offered within its product portfolio.
	The Company applies the provisions of ASC Subtopic 350-40, “Internal Use Software,” and accounts for the cost of computer software developed for internal use by capitalizing qualifying costs, which are substantially incurred during the application development stage. The amounts capitalized include external direct costs of services used in developing internal-use software and for payroll and payroll-related costs of employees directly associated with the development activities. Additionally, costs incurred relating to upgrades and enhancements to the software are capitalized if it is determined that these upgrades or enhancements provide additional functionality to the software. The Company capitalized $8.3 million and $3.3 million of costs related to software developed for internal use in the Consolidated Statement of Financial Condition for the years ended December 31, 2014 and 2013, respectively.
	Capitalized software development costs are amortized on a straight-line basis over the estimated useful life of the related product, which is typically three to five years, beginning with the date the software is placed into service.
	Costs incurred in the preliminary and post-implementation stages of our products are expensed as incurred.
Income Taxes	Income Taxes
	Income tax expense is provided for using the asset and liability method, under which deferred tax assets and deferred tax liabilities are determined based on the temporary differences between the financial statement and income tax bases of assets and liabilities using currently enacted tax rates.
	The Company regularly assesses the likelihood of additional assessments in each of the taxing jurisdictions in which it is required to file income tax returns. The Company recorded additional tax expense related to open tax years, which the Company’s management believes is adequate in relation to the potential for assessments. These amounts have been recorded in “Other non-current liabilities” on the Consolidated Statement of Financial Condition. The Company’s management believes the resolution of tax matters will not have a material effect on the Company’s consolidated financial condition. However, to the extent the Company is required to pay amounts in excess of its reserves, a resolution could have a material impact on its Consolidated Statement of Income for a particular future period. In addition, an unfavorable tax settlement could require use of cash and result in an increase in the effective tax rate in the period in which such resolution occurs.
Deferred Revenue	Deferred Revenue
	Deferred revenues represent amounts billed to customers for products and services in advance of delivery. The Company’s clients generally pay subscription fees annually or quarterly in advance. Deferred revenue is generally amortized ratably over the service period as revenue recognition criteria are met. Where the service period has not begun and the client has not paid or the contract has not been renewed, deferred revenues and accounts receivable are not recognized.
Goodwill	Goodwill
	Goodwill is recorded as part of the Company’s acquisitions of businesses when the purchase price exceeds the fair value of the net tangible and separately identifiable intangible assets acquired. The Company’s goodwill relates to the acquisitions of Barra, Inc. (“Barra”), RiskMetrics Group, Inc. (“RiskMetrics”), Measurisk, LLC (“Measurisk”), IPD Group Limited (“IPD”), Investor Force Holdings, Inc. (“InvestorForce”) and Governance Holdings Co. (“GMI Ratings”). The Company’s goodwill is not amortized, but rather is subject to an impairment test each year, or more often if conditions indicate impairment may have occurred, pursuant to ASC Topic 350, “Intangibles—Goodwill and Other.”
	The Company tests goodwill for impairment on an annual basis on July 1 and on an interim basis when certain events and circumstances exist. The testing for impairment is performed at the reporting unit level, which is deemed to be at the level of the MSCI business segments. Goodwill impairment is determined by comparing the estimated fair value of a reporting unit with its respective book value. If the estimated fair value exceeds the book value, goodwill at the reporting unit level is not deemed to be impaired. If the estimated fair value is below book value, however, further analysis is required to determine the amount of impairment. Additionally, if the book value of a reporting unit is zero or a negative value and it is determined that it is more likely than not that the goodwill is impaired, further analysis is required. As the estimated fair value of its reporting units exceeded their respective book value on the testing dates, no impairment of goodwill was recorded during the years ended December 31, 2014, 2013 and 2012.
Intangible Assets	Intangible Assets
	Intangible assets consist of those definite-lived intangibles from the acquisitions of Barra in June 2004, RiskMetrics in June 2010, Measurisk in July 2010, IPD in November 2012, InvestorForce in January 2013 and GMI Ratings in August 2014. The Company amortizes definite-lived intangible assets over their estimated useful lives. Definite-lived intangible assets are tested for impairment when impairment indicators are present, and, if impaired, written down to fair value based on either discounted cash flows or appraised values. No impairment of intangible assets has been identified during any of the periods presented. The Company has no indefinite-lived intangibles. The intangible assets have remaining useful lives ranging from one to 20 years.
Foreign Currency Translation	Foreign Currency Translation
	Assets and liabilities of operations having non-U.S. dollar functional currencies are translated at year-end exchange rates, and income statement accounts are translated at weighted average exchange rates for the year. Gains or losses resulting from translating foreign currency financial statements, net of related tax effects, are reflected in accumulated other comprehensive loss, a separate component of shareholders’ equity. Gains or losses resulting from foreign currency transactions incurred in currencies other than the local functional currency are included in non-operating “Other expense (income), net” on the Consolidated Statement of Income.
Derivative Instruments	Derivative Instruments
	The Company applies ASC Subtopic 815-10, “Derivatives and Hedging,” which establishes accounting and reporting standards for derivative instruments and hedging activities. The Company may use interest rate swaps and forward contracts on foreign currency to manage risks generally associated with interest rate and foreign exchange rate fluctuations, respectively. The Company’s derivative financial instruments are used as risk management tools and not for speculative or trading purposes.
	For derivative instruments that are designated and qualify as hedging instruments for accounting purposes, the Company documents and links the relationships between the hedging instruments and hedged items. The Company also assesses and documents at the hedge’s inception whether the derivatives used in hedging transactions were effective in offsetting changes in fair values associated with the hedged items. ASC Subtopic 815-10 provides that, for derivative instruments that qualify for hedge accounting being used to hedge cash flows, changes in the fair value are recognized in accumulated other comprehensive income (loss), a separate component of shareholders’ equity, until the hedged item is recognized in earnings. In addition, the ineffective portion of a derivative’s change in fair value is immediately recognized in earnings.
	The Company manages foreign currency exchange rate risk through the use of derivative financial instruments comprised principally of forward contracts on foreign currency which are not designated as hedging instruments for accounting purposes. The objective of the derivative instruments is to minimize the income statement impact associated with assets and liabilities that are denominated in certain foreign currencies. Derivative instruments that do not qualify for hedge accounting are carried at fair value on the Consolidated Statement of Financial Condition with gains and losses recorded in the Consolidated Statement of Income.
Property, Equipment and Leasehold Improvements	Property, Equipment and Leasehold Improvements
	Property, equipment and leasehold improvements are stated at cost less accumulated depreciation and amortization. Depreciation of furniture and fixtures and computer and communications equipment are amortized using the straight-line method over the estimated useful life of the asset. Estimates of useful lives are as follows: furniture & fixtures – seven years; computer and related equipment – three to five years. Leasehold improvements are amortized on a straight-line basis over one to 21 years, which represents the lesser of the estimated useful life of the asset or, where applicable, the remaining term of the lease.
Treasury Stock	Treasury Stock
	The Company holds repurchased shares of common stock as treasury stock. The Company accounts for treasury stock under the cost method and includes treasury stock as a component of shareholders’ equity.
	In accordance with ASC Subtopic 505-10, “Equity,” the Company accounts for the capped accelerated share repurchase (“ASR”) agreements into which it enters as two separate transactions: (a) as shares of common stock acquired in a treasury stock transaction recorded on the acquisition date of the shares and (b) as a forward contract indexed to the Company’s own common stock. As such, the Company accounts for the shares that it receives under capped ASR agreements during the period as a repurchase of its common stock for the purpose of calculating earnings per common share. The Company has determined that the forward contracts indexed to the Company’s common stock meet all the applicable criteria for equity classification in accordance with ASC Subtopic 815-10 and, therefore, the capped ASR agreements are not accounted for as derivative instruments.
Allowance for Doubtful Accounts	Allowance for Doubtful Accounts
	The Company licenses its products and services to investment managers mainly in the United States, Europe and Asia (primarily Hong Kong and Japan). The Company evaluates the credit of its customers and does not require collateral. The Company maintains an allowance on customer accounts where estimated losses may result from the inability of its customers to make required payments.
	An allowance for doubtful accounts is recorded when it is probable and estimable that a receivable will not be collected. Changes in the allowance for doubtful accounts from December 31, 2011 to December 31, 2014 were as follows:
			Amount
			(in thousands)
	Balance as of December 31, 2011		$	857
	Addition to provision			403
	Amounts written off, net of recoveries			(296	)
	Balance as of December 31, 2012		$	964
	Addition to provision			876
	Amounts written off, net of recoveries			(560	)
	Balance as of December 31, 2013		$	1,280
	Addition to provision			452
	Amounts written off, net of recoveries			(875	)
	Balance as of December 31, 2014		$	857
Accrued Compensation	Accrued Compensation
	The Company makes significant estimates in determining its accrued non-stock based compensation and benefits expenses. A significant portion of the Company’s employee incentive compensation programs are discretionary. Each year end the Company determines the amount of discretionary cash bonus expense. The Company also reviews compensation and benefits expenses throughout the year to determine how overall performance compares to management’s expectations. These and other factors, including historical performance, are taken into account in accruing discretionary cash compensation estimates quarterly.
Concentrations	Concentrations
	For the year ended December 31, 2014, BlackRock, Inc. accounted for 10.6% of the Company’s operating revenues. For the years ended December 31, 2013 and 2012, no single customer accounted for 10.0% or more of the Company’s operating revenues.

Introduction_and_Basis_of_Pres2

Introduction and Basis of Presentation (Tables)	12 Months Ended
	Dec. 31, 2014
Changes in Allowance for Doubtful Accounts	Changes in the allowance for doubtful accounts from December 31, 2011 to December 31, 2014 were as follows:
		Amount
		(in thousands)
	Balance as of December 31, 2011	$	857
	Addition to provision		403
	Amounts written off, net of recoveries		(296	)
	Balance as of December 31, 2012	$	964
	Addition to provision		876
	Amounts written off, net of recoveries		(560	)
	Balance as of December 31, 2013	$	1,280
	Addition to provision		452
	Amounts written off, net of recoveries		(875	)
	Balance as of December 31, 2014	$	857
Balance Sheet [Member]
Schedule of Revised Consolidated Financial Statements Amounts Previously Reported	Accordingly, the Company has revised the Consolidated Statement of Financial Condition as of December 31, 2013 from amounts previously reported as follows:
		As Previously			Adjustment			As Revised
		Reported
		(in thousands)
	Prepaid taxes	$	27,333		$	(12,765	)	$	14,568
	Total current assets	$	637,035		$	(12,765	)	$	624,270
	Goodwill	$	1,798,821		$	14,343		$	1,813,164
	Total assets	$	3,134,537		$	1,578		$	3,136,115
	Deferred taxes	$	221,054		$	13,595		$	234,649
	Total liabilities	$	1,558,173		$	13,595		$	1,571,768
	Additional paid in capital	$	1,073,893		$	(736	)	$	1,073,157
	Retained earnings	$	770,256		$	(11,281	)	$	758,975
	Total shareholders’ equity	$	1,576,364		$	(12,017	)	$	1,564,347
	Total liabilities and shareholders’ equity	$	3,134,537		$	1,578		$	3,136,115
Statements of Cash Flows [Member]
Schedule of Revised Consolidated Financial Statements Amounts Previously Reported	The Company has revised the Consolidated Statement of Cash Flows for the year ended December 31, 2013 from amounts previously reported as follows:
		As Previously			Adjustment			As Revised
		Reported
		(in thousands)
	Excess tax benefits from share-based compensation	$	(2,633	)	$	736		$	(1,897	)
	Net cash provided by operating activities	$	320,447		$	736		$	321,183
	Excess tax benefits from share-based compensation	$	2,633		$	(736	)	$	1,897
	Net cash (used in) provided by financing activities	$	(145,848	)	$	(736	)	$	(146,584	)
Statements of Stockholders' Equity [Member]
Schedule of Revised Consolidated Financial Statements Amounts Previously Reported	The Company has revised the Consolidated Statements of Shareholders’ Equity for the years ended December 31, 2013, 2012 and 2011 from amounts previously reported as follows:
		As Previously			Adjustment			As Revised
		Reported
		(in thousands)
	As of December 31, 2011
	Retained earnings	$	363,461		$	(11,281	)	$	352,180
	Total shareholders’ equity	$	1,305,432		$	(11,281	)	$	1,294,151
	For the year ended December 31, 2013
	Excess tax benefits from share-based compensation	$	2,633		$	(736	)	$	1,897
	As of December 31, 2013
	Additional paid in capital	$	1,073,893		$	(736	)	$	1,073,157
	Total shareholders’ equity	$	1,576,364		$	(12,017	)	$	1,564,347

Dispositions_and_Discontinued_1

Dispositions and Discontinued Operations (Tables)	12 Months Ended
	Dec. 31, 2014
Discontinued Operations and Disposal Groups [Abstract]
Schedule of Value of Assets and Liabilities Disposed	The sale of ISS was completed on April 30, 2014 for $367.4 million. The value of the assets and liabilities of ISS that were disposed, directly attributable transaction costs and the resulting gain on disposal that has been reported in “Income from discontinued operations, net of income taxes” for the year ended December 31, 2014 are as follows:
	(in thousands)
	Cash proceeds	$	367,355
	Less: working capital adjustments		(311	)
	Total proceeds		367,044
	Less assets sold and liabilities relieved resulting from disposal:
	Cash and cash equivalents		(4,544	)
	Accounts receivable		(15,765	)
	Deferred taxes (current)		(3,174	)
	Prepaid income taxes		(617	)
	Prepaid and other assets		(4,500	)
	Property, equipment and leasehold improvements (net of accumulated depreciation and amortization of $4,213)		(8,544	)
	Goodwill		(254,233	)
	Intangible assets (net of accumulated amortization of $50,283)		(121,269	)
	Other non-current assets		(1,645	)
	Accounts payable		574
	Accrued compensation and related benefits		6,783
	Other accrued liabilities		4,034
	Deferred revenue		51,767
	Deferred taxes (non-current)		59,129
	Other non-current liabilities		5,576
	Other comprehensive income including currency translation adjustments and pension and other post-retirement adjustments		4,004
	Net assets sold		(282,424	)
	Less: Transaction costs		(5,946	)
	Gain on sale of ISS	$	78,674
Schedule of Income (Loss) Amounts Associated with Discontinued Operations	Income (loss) from discontinued operations. Amounts associated with discontinued operations reflected in the Consolidated Statements of Income for the years ended December 31, 2014, 2013 and 2012 are as follows:
		Years Ended December 31,
		2014			2013		2012
		(in thousands)
	Revenue from discontinued operations	$	43,122		$	122,303	$	123,151
	Income from discontinued operations before provision for income taxes	$	86,230		$	32,793	$	28,608
	Provision for income taxes		1,059			10,146		9,161
	Income from discontinued operations, net of income taxes	$	85,171		$	22,647	$	19,447

Reclassifications_out_of_Accum1

Reclassifications out of Accumulated Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2014
Statement of Comprehensive Income [Abstract]
Schedule of Reclassifications out of Accumulated Other Comprehensive Income (Loss)	Reclassifications Out of Accumulated Other Comprehensive Income (Loss)(1)
	(in thousands)
	Details about Accumulated Other		Amount Reclassified from Accumulated						Affected Line Item in the
	Comprehensive Income (Loss) Components		Other Comprehensive Income (Loss)						Unaudited Condensed
									Consolidated Statements of Income
			Year Ended			Year Ended
			December 31,			December 31,
			2014			2013
	Unrealized losses on cash flow hedges
	Interest rate contracts		$	—		$	(1,364	)	Interest expense
				—			524		Tax benefit
			$	—		$	(840	)	Net of tax
	Unrealized gains on available-for-sale securities
	Short-term investments		$	—		$	5		Interest income
				—			(2	)	Tax expense
			$	—		$	3		Net of tax
	Defined benefit pension plans
	Amount recognized as a component of net periodic benefit expense for curtailments and settlements		$	(104	)	$	(32	)(2)
				(15	)		6		Tax expense (3)
			$	(119	)	$	(26	)	Net of tax (4)
	Foreign currency translation adjustment		$	4,184		$	—	(5)
	Total reclassifications for the period, net of tax		$	4,065		$	(863	)
	(1)	Amounts in parentheses indicate expenses or losses moved to the Consolidated Statements of Income.
	(2)	Includes $(186,000) for the year ended December 31, 2014 that was reclassified to “Income from discontinued operations, net of taxes” as part of the gain on the disposition of ISS.
	(3)	Includes $6,000 for the year ended December 31, 2014 that was reclassified to “Income from discontinued operations, net of taxes” as part of the gain on the disposition of ISS.
	(4)	Includes $(180,000) for the year ended December 31, 2014 that was reclassified to “Income from discontinued operations, net of taxes” as part of the gain on the disposition of ISS.
	(5)	This accumulated other comprehensive income component for the year ended December 31, 2014 was reclassified to “Income from discontinued operations, net of taxes” as part of the gain on the disposition of ISS.

Earnings_Per_Common_Share_Tabl

Earnings Per Common Share (Tables)	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Computation of Basic and Diluted EPS	The following table presents the computation of basic and diluted EPS:
			For the Years Ended
			December 31,			December 31,			December 31,
	(in thousands, except per share data)		2014			2013			2012
	Income from continuing operations, net of income taxes		$	198,942		$	199,910		$	164,791
	Income (loss) from discontinued operations, net of income taxes			85,171			22,647			19,447
	Net income		$	284,113		$	222,557		$	184,238
	Less: Allocations of earnings to unvested restricted stock units (1)			(368	)		(633	)		(1,547	)
	Earnings available to MSCI common shareholders		$	283,745		$	221,924		$	182,691
	Basic weighted average common shares outstanding			115,737			120,100			122,023
	Effect of dilutive securities:
	Stock options and restricted stock units			969			974			1,181
	Diluted weighted average common shares outstanding			116,706			121,074			123,204
	Earnings per basic common share from continuing operations		$	1.72		$	1.66		$	1.34
	Earnings per basic common share from discontinued operations			0.73			0.19			0.16
	Earnings per basic common share		$	2.45		$	1.85		$	1.5
	Earnings per diluted common share from continuing operations		$	1.7		$	1.64		$	1.32
	Earnings per diluted common share from discontinued operations			0.73			0.19			0.16
	Earnings per diluted common share		$	2.43		$	1.83		$	1.48
	(1)	Restricted stock units granted to employees prior to 2013 and all restricted stock units granted to independent directors of the Company have a right to participate in all of the earnings of the Company in the computation of basic EPS and, therefore, these restricted stock units are not included as incremental shares in the diluted EPS computation.

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2014

Commitments and Contingencies Disclosure [Abstract]

Summary of Future Minimum Commitments Under Operating Leases

Future minimum commitments for the Company’s operating leases in place as of December 31, 2014 are as follows:

Years Ending December 31,

Amount

(in thousands)

2015

$

30,511

2016

29,890

2017

26,633

2018

25,142

2019

20,662

Thereafter

155,036

Total

$

287,874

Summary of Fair Values of Derivative Instruments

The following table presents the fair values of the Company’s derivative instruments and the location in which they are presented on the Company’s Consolidated Statements of Financial Condition:

(in thousands)

Consolidated Statements of

As of

As of

Financial Condition Location

December 31, 2014

December 31, 2013

Derivatives designated as hedging instruments:

Liability derivatives:

Foreign exchange contracts

Other accrued liabilities

$

(243

)

$

(156

)

Interest Rate Swaps and Derivative Instruments

The following tables present the effect of the Company’s financial derivatives and the location in which they are presented on the Company’s Consolidated Statements of Financial Condition and Consolidated Statements of Income:

Derivatives in

Amount of Gain or (Loss)

Location of  Gain

Amount of Gain  or

Location of  Gain

Amount of Gain

Cash Flow

Recognized in Accumulated

or (Loss)

(Loss) Reclassified

or (Loss)

or  (Loss) Recognized

Hedging

Other Comprehensive

Reclassified

from Accumulated Other

Recognized

in Income on Derivatives

Relationships

Income (Loss) on Derivatives

from Accumulated

Comprehensive Income (Loss)

in Income on

(Ineffective Portion

(Effective Portion) for the

Other

into Income (Effective

Derivatives

and Amount

Years Ended

Comprehensive

Portion) for the

(Ineffective

Excluded from

December 31,

Income into

Years Ended

Portion and

Effectiveness

Income

December 31,

Amount Excluded

Testing) for the

(Effective Portion)

from

Years Ended

Effectiveness

December 31,

(in thousands)

2014

2013

2012

2014

2013

2012

Testing)

2014

2013

2012

Interest rate swaps

$

—

$

—

$

(695

)

Interest expense

$

—

$

(1,364

)

$

2,437

Interest expense

$

—

$

—

$

—

Derivatives Not Designated as Hedging Instruments

Location of

Amount of Gain or (Loss)

Gain or  (Loss)

Recognized in Income on

Recognized in

Derivatives for the Years

Income on

Ended December 31,

(in thousands)

Derivatives

2014

2013

2012

Foreign exchange contracts

Other expense

$

(834

)

$

(139

)

$

(200

)

(income)

Property_Equipment_and_Leaseho1

Property, Equipment and Leasehold Improvements (Tables)	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Schedule of Property, Equipment and Leasehold Improvements	Property, equipment and leasehold improvements at December 31, 2014 and 2013 consisted of the following:
				As of
	Type		Estimated	December  31,			December 31,
			Useful Lives	2014(1)			2013
				(in thousands)
	Computer & related equipment		3 to 5 years	$	118,537		$	86,384
	Furniture & fixtures		7 years		9,569			9,108
	Leasehold improvements		1 to 21 years		49,756			52,776
	Work-in-process		—		9,020			12,691
	Subtotal				186,882			160,959
	Accumulated depreciation and amortization				(92,808	)		(75,371	)
	Property, equipment and leasehold improvements, net			$	94,074		$	85,588
	(1)	Property, equipment and leasehold improvements as of December 31, 2014 reflects the disposition and addition of property, equipment and leasehold improvements associated with the sale of ISS and acquisition of Governance Holdings Co. (“GMI Ratings”), respectively. See Note 3, “Dispositions and Discontinued Operations,” and Note 11, “Acquisitions,” for additional information.

Goodwill_and_Intangible_Assets1

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The Company carries goodwill as reflected in the table below:
			Goodwill
	(in thousands)
	Goodwill at December 31, 2012		$	1,797,753
	Changes to goodwill (1)			13,902
	Foreign exchange translation adjustment			1,509
	Goodwill at December 31, 2013		$	1,813,164
	Changes to goodwill (2)			(244,299	)
	Foreign exchange translation adjustment			(3,961	)
	Goodwill at December 31, 2014		$	1,564,904
	-1	Changes to goodwill reflect the acquisition of InvestorForce, which contributed $11.6 million, adjustments to the valuation of acquired IPD assets and liabilities, which contributed $2.7 million and the disposition of the CFRA product line, which removed $0.5 million. See Note 3, “Dispositions and Discontinued Operations,” and Note 12, “Acquisitions,” for additional information.
	-2	Changes to goodwill reflect the disposition and addition of goodwill associated with the sale of ISS, which removed $254.2 million, and the acquisition of GMI Ratings, which contributed $9.9 million. See Note 3, “Dispositions and Discontinued Operations,” and Note 12, “Acquisitions,” for additional information.
Components of Intangible Assets by Major Class	The gross carrying amounts, accumulated amortization and net intangible asset totals related to the Company’s identifiable intangible assets are as follows:
			As of
	(in thousands)		December 31,			December 31,
			2014 (1)			2013
	Gross intangible assets:
	Customer relationships		$	360,835		$	478,735
	Trademarks/trade names			223,382			257,282
	Technology/software			193,681			199,778
	Proprietary process			—			3,800
	Proprietary data			28,627			28,527
	Covenant not to compete			900			—
	Subtotal			807,425			968,122
	Foreign exchange translation adjustment			(1,588	)		1,962
	Total gross intangible assets		$	805,837		$	970,084
	Accumulated amortization:
	Customer relationships		$	(119,058	)	$	(125,359	)
	Trademarks/trade names			(81,545	)		(75,696	)
	Technology/software			(167,083	)		(168,481	)
	Proprietary process			—			(2,269	)
	Proprietary data			(4,589	)		(2,326	)
	Covenant not to compete			(187	)		—
	Subtotal			(372,462	)		(374,131	)
	Foreign exchange translation adjustment			253			(246	)
	Total accumulated amortization		$	(372,209	)	$	(374,377	)
	Net intangible assets:
	Customer relationships		$	241,777		$	353,376
	Trademarks/trade names			141,837			181,586
	Technology/software			26,598			31,297
	Proprietary process			—			1,531
	Proprietary data			24,038			26,201
	Covenant not to compete			713			—
	Subtotal			434,963			593,991
	Foreign exchange translation adjustment			(1,335	)		1,716
	Total net intangible assets		$	433,628		$	595,707
	-1	Intangible assets and the associated accumulated amortization as of December 31, 2014 reflect the disposition and addition of intangible assets associated with the sale of ISS and acquisition of GMI Ratings, respectively. See Note 3, “Dispositions and Discontinued Operations,” and Note 12, “Acquisitions,” for additional information.
Estimated Amortization Expense for Succeeding Years	Estimated amortization expense for succeeding years is presented below:
	For the Years Ending December 31,		Amortization
			Expense
			(in thousands)
	2015		$	47,111
	2016			46,684
	2017			41,457
	2018			38,721
	2019			37,420
	Thereafter			222,235
	Total		$	433,628

ShareBased_Compensation_Tables

Share-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Components of Share-Based Compensation Expense	The components of share-based compensation expense related to the awards to Company employees and directors who are not employees of the Company of restricted stock units and restricted stock awards (representing shares of common stock) and options to purchase shares of common stock, as applicable, are presented below:
			For the Years Ended
	(in thousands)		December 31,			December 31,		December 31,
			2014			2013		2012
	Deferred stock		$	25,830		$	23,910	$	23,198
	Stock options			1,201			1,643		2,398
	Total share-based compensation expense		$	27,031		$	25,553	$	25,596
Summary of Vested and Unvested Deferred Stock Awards Activity	The following table sets forth activity concerning the Company’s vested and unvested deferred stock awards applicable to its employees (share data in thousands):
	For the Year Ended December 31, 2014		Number of			Weighted
			Shares			Average
						Grant
						Date  Fair
						Value
	Vested and unvested deferred stock awards at December 31, 2013 (1)			1,237		$	33.84
	Granted			639		$	42.32
	Conversion to common stock			(567	)	$	34.54
	Canceled			(96	)	$	35.82
	Vested and unvested deferred stock awards at December 31, 2014			1,213		$	37.82
	-1	As of December 31, 2014, 1,195 restricted stock units and restricted stock awards, with a weighted average price of $37.80, were vested or expected to vest.
Summary of Unvested Deferred Stock Awards Activity	The following table sets forth activity concerning the Company’s unvested deferred stock awards related to its employees (share data in thousands):
	For the Year Ended December 31, 2014		Number of			Weighted
			Shares			Average
						Grant
						Date  Fair
						Value
	Unvested deferred stock awards at December 31, 2013			894		$	33.85
	Granted			479		$	42.35
	Vested			(412	)	$	34.39
	Canceled			(78	)	$	36.35
	Unvested deferred stock awards at December 31, 2014			883		$	37.99
	Unvested deferred stock awards expected to vest			866		$	37.96
Weighted Average Fair Value of Stock Options Assumed	The weighted average fair value of MSCI stock options issued by the Company in the year ended December 31, 2013 was $19.18 utilizing the following assumptions:
			Assumptions
	Risk free interest rate			1.87	%
	Expected option life in years			6.5
	Expected stock price volatility			46.07	%
	Expected dividend yield			—
Summary of Stock Options Activity	The following table sets forth activity concerning MSCI stock options granted to the Company’s employees for the years ended December 31, 2014 (option data and dollar values in thousands, except exercise price):
	For the Year Ended December 31, 2014		Number of			Weighted		Weighted		Aggregated
			Options			Average		Average		Intrinsic
						Exercise		Remaining		Value
						Price		Life
								(Years)
	Options outstanding at December 31, 2013			1,986		$	21.85		4.55		N/A
	Granted or assumed			—		$	—		N/A		N/A
	Forfeited			(1	)	$	24.49		N/A		N/A
	Conversion to common stock			(498	)	$	19.32		N/A		N/A
	Options outstanding at December 31, 2014			1,487		$	22.69		3.76	$	36,802
	Options exercisable at December 31, 2014			1,303		$	20.49		3.28	$	35,120
	Options vested or expected to vest			1,487		$	22.69		3.76	$	36,802
Summary of Stock Options Outstanding by Exercise Price Range	The following table presents information relating to the Company’s outstanding stock options as of December 31, 2014 (number of options outstanding and aggregate intrinsic value data in thousands):
	At December 31, 2014		Options Outstanding
	Range of Exercise Prices		Number			Weighted		Average		Aggregate
			Outstanding			Average		Remaining		Intrinsic
						Exercise		Life (Years)		Value
						Price
	$2.76 to $16.48			130		$	12.69		2.42	$	4,512
	$18.00			763		$	18		2.87	$	22,469
	$20.45 to $25.64			282		$	23.16		3.34	$	6,833
	$36.70 to $40.23			312		$	37.88		6.88	$	2,988
	Total			1,487						$	36,802
Summary of Stock Options Exercisable by Exercise Price Range	The following table presents information relating to the Company’s exercisable stock options as of December 31, 2014 (number of options outstanding and aggregate intrinsic value data in thousands):
	At December 31, 2014		Options Exercisable
	Range of Exercise Prices		Number			Weighted		Average		Aggregate
			Outstanding			Average		Remaining		Intrinsic
						Exercise		Life (Years)		Value
						Price
	$2.76 to $16.48			130		$	12.69		2.42	$	4,512
	$18.00			763		$	18		2.87	$	22,469
	$20.45 to $25.64			282		$	23.16		3.34	$	6,833
	$36.70 to $40.23			128		$	37.27		6.4	$	1,306
	Total			1,303						$	35,120

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Summary of Provision for Income Taxes (Benefits)	The provision for income taxes (benefits) consisted of (in thousands):
			For the Years Ended
			December 31,			December 31,			December 31,
			2014			2013			2012
	Current
	U.S. federal		$	84,959		$	97,739		$	72,786
	U.S. state and local			13,929			16,820			25,049
	Non U.S.			18,505			18,270			19,996
				117,393			132,829			117,831
	Deferred
	U.S. federal			(2,606	)		(14,362	)		(18,234	)
	U.S. state and local			(3,356	)		(3,802	)		(3,821	)
	Non U.S.			(2,035	)		(1,747	)		234
				(7,997	)		(19,911	)		(21,821	)
	Provision for income taxes from continuing operations		$	109,396		$	112,918		$	96,010
	Provision for income taxes from discontinued operations		$	1,059		$	10,146		$	9,161
Reconciliation of Provision to U.S. Federal Statutory Income Tax Rate	The following table reconciles the provision to the U.S. federal statutory income tax rate:
			For the Years Ended
			December 31,			December 31,			December 31,
			2014			2013			2012
	U.S. federal statutory income tax rate			35	%		35	%		35.00	%
	U.S. state and local income taxes, net of U.S. federal income tax benefits			2.72	%		3.05	%		2.14	%
	Change in tax rates applicable to non-U.S. earnings			(1.88	%)		(0.93	%)		(1.57	%)
	Domestic tax credits			(0.86	%)		(0.95	%)		—	%
	Other			0.5	%		(0.07	%)		1.24	%
	Effective income tax rate			35.48	%		36.1	%		36.81	%
Significant Components of Deferred Tax Assets and Liabilities	Significant components of the Company’s deferred tax assets and liabilities as of December 31, 2014 and 2013, were as follows (in thousands):
			As of
			December 31,			December 31,
			2014			2013
	Deferred tax assets:
	Employee compensation and benefit plans		$	24,765		$	26,165
	Deferred rent			7,229			9,526
	Property, equipment and leasehold improvements, net			—			1,520
	State taxes			2,322			2,323
	Pension			2,494			395
	Unearned revenue			1,117			1,238
	NOL carryforward – current			1,667			3,813
	NOL carryforward – non-current			34,249			7,506
	Other			1,979			112
	Subtotal			75,822			52,598
	Less: valuation allowance (1)			(21,232	)		(7	)
	Total deferred tax assets		$	54,590		$	52,591
	Deferred tax liabilities:
	Intangible assets		$	(154,965	)	$	(233,980	)
	Foreign currency translation			(629	)		(372	)
	Property, equipment and leasehold improvements, net			(10,435	)		—
	Other			(246	)		—
	Total deferred tax liabilities		$	(166,275	)	$	(234,352	)
	Net deferred tax liabilities		$	(111,685	)	$	(181,761	)
	(1)	The Company’s valuation allowance was not significant on December 31, 2013 or in prior periods but increased in the year ended December 31, 2014 as a result of a capital loss carryforward recognized on the sale of ISS that is not currently expected to be utilized.
Summary of Components of Income Before Provision for Income Taxes	The following table presents the components of income before provision for income taxes generated by domestic or foreign operations for the periods indicated (in thousands):
			For the Years Ended
			December 31,			December 31,			December 31,
			2014			2013			2012
	Domestic		$	269,944		$	276,549		$	220,072
	Foreign (1)			38,394			36,279			40,729
	Total income before provision for income taxes		$	308,338		$	312,828		$	260,801
	(1)	Foreign income before provision for income taxes is defined as income generated from operations located outside the U.S.
Reconciliation of Unrecognized Tax Benefits	The following table presents a reconciliation of the beginning and ending amount of the gross unrecognized tax benefits, excluding interest and penalties, for the years ended December 31, 2014, 2013 and 2012:
	Gross unrecognized tax benefits		Year Ended			Year Ended			Year Ended
			December 31,			December 31,			December 31,
			2014			2013			2012
	(amounts in thousands)
	Beginning balance		$	7,089		$	6,827		$	13,168
	Increases based on tax positions related to the current period			292			194			—
	Increases based on tax positions related to prior periods			1,969			2,690			349
	Decreases based on tax positions related to prior periods			(346	)		(2,474	)		(427	)
	Increases/ (Decreases) related to settlements with taxing authorities			(1,652	)		—			(6,263	)
	Increases/(Decreases) related to a lapse of applicable statute of limitations			(827	)		(148	)		—
	Ending balance		$	6,525		$	7,089		$	6,827

Segment_Information_Tables

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Revenue by Geographic Area	Revenue by geography is based on the shipping address of the customer. The following table sets forth revenue for the periods indicated by geographic area.
		For the Years Ended
	(in thousands)	December 31,		December 31,		December 31,
		2014		2013		2012
	Revenues
	Americas:
	United States	$	471,145	$	416,999	$	394,401
	Other		37,189		34,547		27,783
	Total Americas		508,334		451,546		422,184
	Europe, the Middle East and Africa (“EMEA”):
	United Kingdom		154,308		141,938		107,189
	Other		209,893		202,664		179,535
	Total EMEA		364,201		344,602		286,724
	Asia & Australia:
	Japan		46,642		46,752		53,649
	Other		77,503		70,464		64,433
	Total Asia & Australia		124,145		117,216		118,082
	Total	$	996,680	$	913,364	$	826,990
Long-Lived Assets by Geographic Area	The following table sets forth long-lived assets on the dates indicated by geographic area:
		As of
	(in thousands)	December 31,		December 31,
		2014		2013
	Long-lived assets
	Americas:
	United States	$	1,944,433	$	2,338,124
	Other		3,293		4,082
	Total Americas		1,947,726		2,342,206
	EMEA:
	United Kingdom		120,781		133,411
	Other		13,345		11,871
	Total EMEA		134,126		145,282
	Asia & Australia:
	Japan		837		1,543
	Other		9,917		5,428
	Total Asia & Australia		10,754		6,971
	Total	$	2,092,606	$	2,494,459

Quarterly_Results_of_Operation1

Quarterly Results of Operations (Tables)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Summary of Quarterly Results of Operations
			2014												2013
			First			Second			Third			Fourth			First			Second			Third			Fourth
			Quarter			Quarter			Quarter			Quarter			Quarter			Quarter			Quarter			Quarter
			(in thousands, except per share data)
	Operating revenues		$	239,688		$	254,226		$	251,661		$	251,105		$	219,469		$	228,423		$	228,608		$	236,864
	Cost of services			75,427			76,816			78,876			77,455			65,300			69,696			68,151			72,256
	Selling, general and administrative			67,658			71,516			70,833			69,345			55,515			52,842			59,917			64,174
	Amortization of intangible assets			11,270			11,442			11,574			11,591			11,166			11,222			11,193			11,217
	Depreciation and amortization of property, equipment and leasehold improvements			5,828			5,921			6,342			7,620			4,597			4,774			5,443			5,570
	Total operating expenses			160,183			165,695			167,625			166,011			136,578			138,534			144,704			153,217
	Operating income			79,505			88,531			84,036			85,094			82,891			89,889			83,904			83,647
	Interest income			(156	)		(192	)		(277	)		(226	)		(237	)		(186	)		(227	)		(239	)
	Interest expense (1)			5,059			5,366			5,604			15,791			7,016			6,499			5,828			6,913
	Other expense (income)			1,071			(726	)		(1,287	)		(1,199	)		1,922			(328	)		563			(21	)
	Other expense (income), net			5,974			4,448			4,040			14,366			8,701			5,985			6,164			6,653
	Income from continuing operations before provision for income taxes			73,531			84,083			79,996			70,728			74,190			83,904			77,740			76,994
	Provision for income taxes			26,385			27,280			28,272			27,459			21,232			27,763			27,804			36,119
	Income from continuing operations			47,146			56,803			51,724			43,269			52,958			56,141			49,936			40,875
	Income (loss) from discontinued operations, net of income taxes			33,253			50,857			(10	)		1,071			5,979			4,912			5,374			6,382
	Net income		$	80,399		$	107,660		$	51,714		$	44,340		$	58,937		$	61,053		$	55,310		$	47,257
	Earnings per basic common share
	From continuing operations		$	0.4		$	0.48		$	0.44		$	0.38		$	0.44		$	0.46		$	0.42		$	0.34
	From discontinued operations			0.28			0.44			—			0.01			0.05			0.04			0.04			0.06
	Earnings per basic common share		$	0.68		$	0.92		$	0.44		$	0.39		$	0.49		$	0.5		$	0.46		$	0.4
	Earnings per diluted common share
	From continuing operations		$	0.4		$	0.48		$	0.44		$	0.38		$	0.43		$	0.46		$	0.42		$	0.34
	From discontinued operations			0.28			0.43			—			0.01			0.05			0.04			0.04			0.05
	Earnings per diluted common share		$	0.68		$	0.91		$	0.44		$	0.39		$	0.48		$	0.5		$	0.46		$	0.39
	Weighted average shares outstanding used in computing per share data
	Basic			117,582			116,702			116,251			112,299			120,746			121,149			119,607			118,828
	Diluted			118,597			117,664			117,163			113,289			121,702			122,069			120,578			119,877
	-1	Increased interest expense during the fourth quarter of 2014 was primarily the result of the debt discount and deferred financing fees written off in association with the offering of the Senior Notes and the 2014 Revolving Facility.

Introduction_and_Basis_of_Pres3

Introduction and Basis of Presentation - Additional Information (Detail) (USD $)	0 Months Ended	12 Months Ended
	Mar. 17, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
	Segment		Segment
Introduction And Basis Of Presentation [Line Items]
Number of operating segments	1		2
Minimum percentage of voting stock for consolidation		50.00%
Maximum percentage of voting stock in variable interest entity for consolidation		20.00%
Decrease to beginning retained earnings		$1,022,695,000	$758,975,000		$352,180,000
Decrease to additional paid in capital			1,073,157,000
Decrease to prepaid taxes		29,180,000	14,568,000
Increase to long-term deferred tax liabilities		137,838,000	234,649,000
Increase to goodwill		1,564,904,000	1,813,164,000	1,797,753,000
Cumulative revenue reduction of one-time adjustment				5,200,000
Capitalized software development costs		8,216,000	3,285,000
Impairment of goodwill		0	0	0
Percentage of operating revenues accounted for by major customer		10.60%	10.00%	10.00%
Minimum [Member]
Introduction And Basis Of Presentation [Line Items]
Remaining useful life		1 year
Maximum [Member]
Introduction And Basis Of Presentation [Line Items]
Remaining useful life		20 years
Adjustment [Member]
Introduction And Basis Of Presentation [Line Items]
Decrease to beginning retained earnings			-11,281,000		-11,281,000
Decrease to additional paid in capital			-736,000
Decrease to prepaid taxes			-12,765,000
Increase to long-term deferred tax liabilities			13,595,000
Increase to goodwill			$14,343,000
Software and Software Development Costs [Member] | Minimum [Member]
Introduction And Basis Of Presentation [Line Items]
Estimates of useful lives		3 years
Software and Software Development Costs [Member] | Maximum [Member]
Introduction And Basis Of Presentation [Line Items]
Estimates of useful lives		5 years
Furniture & Fixtures [Member]
Introduction And Basis Of Presentation [Line Items]
Estimates of useful lives		7 years
Computer & Related Equipment [Member] | Minimum [Member]
Introduction And Basis Of Presentation [Line Items]
Estimates of useful lives		3 years
Computer & Related Equipment [Member] | Maximum [Member]
Introduction And Basis Of Presentation [Line Items]
Estimates of useful lives		5 years
Leasehold improvements [Member] | Minimum [Member]
Introduction And Basis Of Presentation [Line Items]
Estimates of useful lives		1 year
Leasehold improvements [Member] | Maximum [Member]
Introduction And Basis Of Presentation [Line Items]
Estimates of useful lives		21 years
Institutional Shareholder Services Inc. [Member]
Introduction And Basis Of Presentation [Line Items]
Sale completion date		30-Apr-14

Introduction_and_Basis_of_Pres4

Introduction and Basis of Presentation - Schedule of Revised Consolidated Financial Statements Amounts Previously Reported (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Thousands, unless otherwise specified
Prepaid taxes	$29,180	$14,568
Total current assets	770,632	624,270
Goodwill	1,564,904	1,813,164	1,797,753
Total assets	2,894,175	3,136,115
Deferred taxes	137,838	234,649
Total liabilities	1,461,342	1,571,768
Additional paid in capital		1,073,157
Retained earnings	1,022,695	758,975		352,180
Total shareholders' equity	1,432,833	1,564,347	1,413,950	1,294,151
Total liabilities and shareholders' equity	2,894,175	3,136,115
As Previously Reported [Member]
Prepaid taxes		27,333
Total current assets		637,035
Goodwill		1,798,821
Total assets		3,134,537
Deferred taxes		221,054
Total liabilities		1,558,173
Additional paid in capital		1,073,893
Retained earnings		770,256		363,461
Total shareholders' equity		1,576,364		1,305,432
Total liabilities and shareholders' equity		3,134,537
Adjustment [Member]
Prepaid taxes		-12,765
Total current assets		-12,765
Goodwill		14,343
Total assets		1,578
Deferred taxes		13,595
Total liabilities		13,595
Additional paid in capital		-736
Retained earnings		-11,281		-11,281
Total shareholders' equity		-12,017		-11,281
Total liabilities and shareholders' equity		$1,578

Introduction_and_Basis_of_Pres5

Introduction and Basis of Presentation - Schedule of Revised Consolidated Statement of Cash Flows Amounts Previously Reported (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Excess tax benefits from share-based compensation	($2,835)	($1,897)	($1,048)
Net cash provided by operating activities	305,673	321,183	347,075
Excess tax benefits from share-based compensation	2,835	1,897	1,048
Net cash (used in) provided by financing activities	-442,328	-146,584	-322,976
As Previously Reported [Member]
Excess tax benefits from share-based compensation		-2,633
Net cash provided by operating activities		320,447
Excess tax benefits from share-based compensation		2,633
Net cash (used in) provided by financing activities		-145,848
Adjustment [Member]
Excess tax benefits from share-based compensation		736
Net cash provided by operating activities		736
Excess tax benefits from share-based compensation		-736
Net cash (used in) provided by financing activities		($736)

Introduction_and_Basis_of_Pres6

Introduction and Basis of Presentation - Schedule of Revised Consolidated Statements of Shareholders' Equity Amounts Previously Reported (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Excess tax benefits from share-based compensation	$2,835	$1,897	$1,048
Retained earnings	1,022,695	758,975		352,180
Additional paid in capital		1,073,157
Total shareholders' equity	1,432,833	1,564,347	1,413,950	1,294,151
Additional Paid-In Capital [Member]
Excess tax benefits from share-based compensation	2,835	1,897	1,048
Total shareholders' equity	1,022,221	1,073,157	1,000,014	995,665
As Previously Reported [Member]
Retained earnings		770,256		363,461
Additional paid in capital		1,073,893
Total shareholders' equity		1,576,364		1,305,432
As Previously Reported [Member] | Additional Paid-In Capital [Member]
Excess tax benefits from share-based compensation		2,633
Adjustment [Member]
Retained earnings		-11,281		-11,281
Additional paid in capital		-736
Total shareholders' equity		-12,017		-11,281
Adjustment [Member] | Additional Paid-In Capital [Member]
Excess tax benefits from share-based compensation		($736)

Introduction_and_Basis_of_Pres7

Introduction and Basis of Presentation - Changes in Allowance for Doubtful Accounts (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Receivables [Abstract]
Balance at beginning of year	$1,280	$964	$857
Addition to provision	452	876	403
Amounts written off, net of recoveries	-875	-560	-296
Balance at ending of year	$857	$1,280	$964

Dispositions_and_Discontinued_2

Dispositions and Discontinued Operations - Additional Information (Detail) (USD $)	0 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Apr. 30, 2014	Dec. 31, 2014
Discontinued Operations and Disposal Groups [Abstract]
Definitive sale agreement date		3/17/14
Sale proceeds from divestiture	$367,400	$367,355

Dispositions_and_Discontinued_3

Dispositions and Discontinued Operations - Schedule of Value of Assets and Liabilities Disposed (Detail) (USD $)	0 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Apr. 30, 2014	Dec. 31, 2014
Discontinued Operations and Disposal Groups [Abstract]
Cash proceeds	$367,400	$367,355
Less: working capital adjustments		-311
Total proceeds		367,044
Less assets sold and liabilities relieved resulting from disposal:
Cash and cash equivalents		-4,544
Accounts receivable		-15,765
Deferred taxes (current)		-3,174
Prepaid income taxes		-617
Prepaid and other assets		-4,500
Property, equipment and leasehold improvements (net of accumulated depreciation and amortization of $4,213)		-8,544
Goodwill		-254,233
Intangible assets (net of accumulated amortization of $50,283)		-121,269
Other non-current assets		-1,645
Accounts payable		574
Accrued compensation and related benefits		6,783
Other accrued liabilities		4,034
Deferred revenue		51,767
Deferred taxes (non-current)		59,129
Other non-current liabilities		5,576
Other comprehensive income including currency translation adjustments and pension and other post-retirement adjustments		4,004
Net assets sold		-282,424
Less: Transaction costs		-5,946
Gain on sale of ISS		$78,674

Dispositions_and_Discontinued_4

Dispositions and Discontinued Operations - Schedule of Value of Assets and Liabilities Disposed (Parenthetical) (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Discontinued Operations and Disposal Groups [Abstract]
Property, equipment and leasehold improvements, accumulated depreciation and amortization	$4,213
Intangible assets, accumulated amortization	$50,283

Dispositions_and_Discontinued_5

Dispositions and Discontinued Operations - Schedule of Income (Loss) Amounts Associated with Discontinued Operations (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Discontinued Operations and Disposal Groups [Abstract]
Revenue from discontinued operations									$43,122	$122,303	$123,151
Income from discontinued operations before provision for income taxes									86,230	32,793	28,608
Provision for income taxes									1,059	10,146	9,161
Income from discontinued operations, net of income taxes	$1,071	($10)	$50,857	$33,253	$6,382	$5,374	$4,912	$5,979	$85,171	$22,647	$19,447

Reclassifications_out_of_Accum2

Reclassifications out of Accumulated Other Comprehensive Income (Loss) - Schedule of Reclassifications Out of Accumulated Other Comprehensive Income (Loss) (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reclassification Adjustment out of Accumulated Other Comprehensive Income (Loss) [Line Items]
Interest expense	($15,791)	($5,604)	($5,366)	($5,059)	($6,913)	($5,828)	($6,499)	($7,016)	($31,820)	($26,256)	($56,401)
Interest income	226	277	192	156	239	227	186	237	851	889	699
Net periodic benefit expense									-2,800	-2,500	-3,100
Tax benefit (expense)	-27,459	-28,272	-27,280	-26,385	-36,119	-27,804	-27,763	-21,232	-109,396	-112,918	-96,010
Net income	44,340	51,714	107,660	80,399	47,257	55,310	61,053	58,937	284,113	222,557	184,238
Amount Reclassified from Accumulated Other Comprehensive Income (Loss) [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income (Loss) [Line Items]
Foreign currency translation adjustment									4,184
Net income									4,065	-863
Amount Reclassified from Accumulated Other Comprehensive Income (Loss) [Member] | Unrealized Losses on Cash Flow Hedges [Member] | Interest Rate Contracts [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income (Loss) [Line Items]
Interest expense										-1,364
Tax benefit (expense)										524
Net income										-840
Amount Reclassified from Accumulated Other Comprehensive Income (Loss) [Member] | Unrealized Gains on Available-for-Sale Securities [Member] | Short-Term Investments [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income (Loss) [Line Items]
Interest income										5
Tax benefit (expense)										-2
Net income										3
Amount Reclassified from Accumulated Other Comprehensive Income (Loss) [Member] | Defined Benefit Pension Plans Amount Recognized as a Component of Net Periodic Benefit Expense [Member] | Curtailments and Settlements [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income (Loss) [Line Items]
Net periodic benefit expense									-104	-32
Tax benefit (expense)									-15	6
Net income									($119)	($26)

Reclassifications_out_of_Accum3

Reclassifications out of Accumulated Other Comprehensive Income (Loss) - Schedule of Reclassifications Out of Accumulated Other Comprehensive Income (Loss) (Parenthetical) (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reclassification Adjustment out of Accumulated Other Comprehensive Income (Loss) [Line Items]
Income from discontinued operation, before taxes									$86,230	$32,793	$28,608
Income from discontinued operation, taxes									1,059	10,146	9,161
Income from discontinued operation, net of taxes	1,071	-10	50,857	33,253	6,382	5,374	4,912	5,979	85,171	22,647	19,447
Curtailments and Settlements [Member] | Defined Benefit Pension Plans Amount Recognized as a Component of Net Periodic Benefit Expense [Member] | Amount Reclassified from Accumulated Other Comprehensive Income (Loss) [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income (Loss) [Line Items]
Income from discontinued operation, before taxes									-186
Income from discontinued operation, taxes									6
Income from discontinued operation, net of taxes									($180)

Earnings_Per_Common_Share_Addi

Earnings Per Common Share - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Earnings Per Share [Abstract]
Anti-dilutive securities excluded from the calculation of diluted EPS	78,260	26,407	6,714

Earnings_Per_Common_Share_Comp

Earnings Per Common Share - Computation of Basic and Diluted EPS (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Earnings Per Share [Abstract]
Income from continuing operations, net of income taxes	$43,269	$51,724	$56,803	$47,146	$40,875	$49,936	$56,141	$52,958	$198,942	$199,910	$164,791
Income (loss) from discontinued operations, net of income taxes	1,071	-10	50,857	33,253	6,382	5,374	4,912	5,979	85,171	22,647	19,447
Net income	44,340	51,714	107,660	80,399	47,257	55,310	61,053	58,937	284,113	222,557	184,238
Less: Allocations of earnings to unvested restricted stock units									-368	-633	-1,547
Earnings available to MSCI common shareholders									$283,745	$221,924	$182,691
Basic weighted average common shares outstanding	112,299	116,251	116,702	117,582	118,828	119,607	121,149	120,746	115,737	120,100	122,023
Effect of dilutive securities:
Stock options and restricted stock units									969	974	1,181
Diluted weighted average common shares outstanding	113,289	117,163	117,664	118,597	119,877	120,578	122,069	121,702	116,706	121,074	123,204
Earnings per basic common share from continuing operations	$0.38	$0.44	$0.48	$0.40	$0.34	$0.42	$0.46	$0.44	$1.72	$1.66	$1.34
Earnings per basic common share from discontinued operations									$0.73	$0.19	$0.16
Earnings per basic common share	$0.39	$0.44	$0.92	$0.68	$0.40	$0.46	$0.50	$0.49	$2.45	$1.85	$1.50
Earnings per diluted common share from continuing operations	$0.38	$0.44	$0.48	$0.40	$0.34	$0.42	$0.46	$0.43	$1.70	$1.64	$1.32
Earnings per diluted common share from discontinued operations									$0.73	$0.19	$0.16
Earnings per diluted common share	$0.39	$0.44	$0.91	$0.68	$0.39	$0.46	$0.50	$0.48	$2.43	$1.83	$1.48

Commitments_and_Contingencies_1

Commitments and Contingencies - Additional Information (Detail) (USD $)

0 Months Ended

12 Months Ended

0 Months Ended

Share data in Millions, except Per Share data, unless otherwise specified

Oct. 31, 2014

Sep. 17, 2014

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

Nov. 20, 2014

Mar. 31, 2013

Dec. 12, 2013

Jul. 31, 2013

Dec. 14, 2012

Dec. 30, 2013

Aug. 02, 2013

5-May-14

Feb. 07, 2014

Sep. 19, 2014

Dec. 13, 2012

4-May-12

Aug. 01, 2013

Feb. 04, 2014

Schedule Of Commitments And Contingencies [Line Items]

Annual rent expense

$27,000,000

$24,200,000

$22,100,000

Repurchase program authorizing the purchase of shares

300,000,000

Quarterly cash dividend, approved date

17-Sep-14

Quarterly cash dividend, payment rate on common stock

$0.18

$0.18

Quarterly cash dividend, to be paid date

31-Oct-14

Quarterly cash dividend, record date

15-Oct-14

Expected annual dividend, payment rate on common stock

$0.72

Aggregate Cash dividend paid

20,400,000

Term loan description

The Company is required to repay $5.1 million in quarterly payments over the first two years and $10.1 million in quarterly payments over the following three years, with the exception of the final payment in December 2018, which will be $658.1 million (assuming no further prepayments).

Long-term debt, net of current maturities

800,000,000

788,010,000

Current maturities of long-term debt

0

19,772,000

Discount on long-term debt current

500,000

Discount on long-term debt non current

1,700,000

Deferred financing fees unamortized

14,700,000

Amortized deferred financing fees

7,748,000

3,348,000

18,065,000

Amortization of discount on long-term debt

2,218,000

1,066,000

5,305,000

Fair market value of debt obligations

831,000,000

812,000,000

Foreign Currency Forwards [Member] | Derivatives not Designated as Hedging Instruments [Member]

Schedule Of Commitments And Contingencies [Line Items]

Foreign currency forwards, notional amount

11,600,000

Prepaid and Other Assets [Member]

Schedule Of Commitments And Contingencies [Line Items]

Deferred financing fees unamortized

1,800,000

Other Non-Current Assets [Member]

Schedule Of Commitments And Contingencies [Line Items]

Deferred financing fees unamortized

12,900,000

2014 Revolving Credit Agreement [Member]

Schedule Of Commitments And Contingencies [Line Items]

Revolving credit facility, maximum borrowing

200,000,000

Revolving credit agreement, term

5 years

Revolving credit agreement, conditional description

The 2014 Revolving Credit Agreement has an initial term of five years that may be extended, at the Company's request, for two additional one year terms.

Senior Notes [Member]

Schedule Of Commitments And Contingencies [Line Items]

Debt instrument interest rate

5.25%

Maturity date

20-Nov-24

Redemption description

At any time prior to November 15, 2019, the Company may redeem all or part of the Senior Notes upon not less than 30 nor more than 60 days' prior notice at a redemption price equal to the sum of (i) 100% of the principal amount thereof, plus (ii) a make-whole premium as of the date of redemption, plus (iii) accrued and unpaid interest and additional interest, if any, thereon, to the date of redemption.

Percentage of aggregate principal amount redeemed

35.00%

Redemption price

105.25%

Debt instrument description

Interest on the Senior Notes accrues at a fixed rate of 5.25% per annum and is payable semiannually in arrears on May 15 and November 15 of each year, commencing May 15, 2015. The Company will make each interest payment to holders of record of the Senior Notes on the immediately preceding May 1 and November 1.

New Amended and Restated Credit Facility [Member]

Schedule Of Commitments And Contingencies [Line Items]

Outstanding indebtedness, amount

794,800,000

Term Loan A [Member]

Schedule Of Commitments And Contingencies [Line Items]

Prepayment of Term Loan

15,000,000

Term Loan A [Member] | New Amended and Restated Credit Facility [Member]

Schedule Of Commitments And Contingencies [Line Items]

Aggregate amount of debt

880,000,000

Senior Secured Revolving Facility [Member]

Schedule Of Commitments And Contingencies [Line Items]

Maturity period of the facility

31-Dec-18

Senior Secured Revolving Facility [Member] | New Amended and Restated Credit Facility [Member]

Schedule Of Commitments And Contingencies [Line Items]

Aggregate amount of debt

100,000,000

Quarterly Periods from December 12, 2013 through December 31, 2015 [Member]

Schedule Of Commitments And Contingencies [Line Items]

Debt principal repayment

5,100,000

Quarterly Periods from January 1, 2016 through September 30, 2018 [Member]

Schedule Of Commitments And Contingencies [Line Items]

Debt principal repayment

10,100,000

Quarter Ending December 31, 2018 [Member]

Schedule Of Commitments And Contingencies [Line Items]

Debt principal repayment

658,100,000

5.250% Senior Unsecured Notes Due 2024 [Member] | Private Placement [Member]

Schedule Of Commitments And Contingencies [Line Items]

Aggregate amount of debt

800,000,000

Debt instrument interest rate

5.25%

December 2012 ASR Agreement [Member] | Accelerated Share Repurchase Program [Member]

Schedule Of Commitments And Contingencies [Line Items]

Shares repurchases, value

100,000,000

Repurchased common shares

0.8

2.2

Repurchased common shares, average purchase price paid per share

$33.47

August 2013 ASR Agreement [Member] | Accelerated Share Repurchase Program [Member]

Schedule Of Commitments And Contingencies [Line Items]

Shares repurchases, value

100,000,000

Repurchased common shares

0.5

1.9

Repurchased common shares, average purchase price paid per share

$41.06

February 2014 ASR Agreement [Member] | Accelerated Share Repurchase Program [Member]

Schedule Of Commitments And Contingencies [Line Items]

Shares repurchases, value

100,000,000

Repurchased common shares

0.6

1.7

Repurchased common shares, average purchase price paid per share

$43.10

2014 Repurchase Program [Member]

Schedule Of Commitments And Contingencies [Line Items]

Repurchase program authorizing the purchase of shares

850,000,000

300,000,000

September 2014 ASR Agreement [Member]

Schedule Of Commitments And Contingencies [Line Items]

Shares repurchases, value

300,000,000

Accelerated share repurchase agreement, description

On September 18, 2014, the Company entered into a $300.0 million accelerated share repurchase agreement (the "September 2014 ASR Program") with Goldman Sachs & Co. ("GS&Co."), under which, on September 19, 2014, the Company paid GS&Co. $300.0 million in cash and received approximately 4.5 million shares of the Company's common stock and may also receive from GS&Co. additional shares at or prior to maturity of the ASR Agreement.

September 2014 ASR Agreement [Member] | Accelerated Share Repurchase Program [Member]

Schedule Of Commitments And Contingencies [Line Items]

Repurchased common shares

4.5

Stockholders equity period increase (decrease)

300,000,000

September 2014 ASR Agreement [Member] | Accelerated Share Repurchase Program [Member] | Treasury Stock [Member]

Schedule Of Commitments And Contingencies [Line Items]

Stockholders equity period increase (decrease)

210,000,000

September 2014 ASR Agreement [Member] | Accelerated Share Repurchase Program [Member] | Additional Paid-In Capital [Member]

Schedule Of Commitments And Contingencies [Line Items]

Stockholders equity period increase (decrease)

($90,000,000)

Commitments_and_Contingencies_2

Commitments and Contingencies - Summary of Future Minimum Commitments Under Operating Leases (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Commitments and Contingencies Disclosure [Abstract]
2015	$30,511
2016	29,890
2017	26,633
2018	25,142
2019	20,662
Thereafter	155,036
Total	$287,874

Commitments_and_Contingencies_3

Commitments and Contingencies - Summary of Fair Values of Derivative Instruments (Detail) (Derivatives Designated as Hedging Instruments [Member], Other Accrued Liabilities [Member], Foreign Exchange Contracts [Member], USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Derivatives Designated as Hedging Instruments [Member] | Other Accrued Liabilities [Member] | Foreign Exchange Contracts [Member]
Derivatives, Fair Value [Line Items]
Liability derivatives	($243)	($156)

Commitments_and_Contingencies_4

Commitments and Contingencies - Interest Rate Swaps and Derivative Instruments (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Other Expense (Income) [Member] | Derivatives not Designated as Hedging Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in Accumulated Other Comprehensive Income on Derivatives (Effective Portion)	($834)	($139)	($200)
Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (Effective Portion)		-1,364	2,437
Amount of Gain or (Loss) Recognized in Income on Derivatives (Ineffective Portion and Amount Excluded from Effectiveness Testing)	0	0	0
Interest Rate Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in Accumulated Other Comprehensive Income (Loss) on Derivatives (Effective Portion)			($695)

Property_Equipment_and_Leaseho2

Property, Equipment and Leasehold Improvements - Schedule of Property, Equipment and Leasehold Improvements (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Computer & related equipment	118,537	$86,384
Furniture & fixtures	9,569	9,108
Leasehold improvements	49,756	52,776
Work-in-process	9,020	12,691
Subtotal	186,882	160,959
Accumulated depreciation and amortization	-92,808	-75,371
Property, equipment and leasehold improvements, net	94,074	$85,588
Computer & Related Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	3 years
Computer & Related Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	5 years
Furniture & Fixtures [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	7 years
Leasehold improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	1 year
Leasehold improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	21 years
Work-in-process [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	0 years

Property_Equipment_and_Leaseho3

Property, Equipment and Leasehold Improvements - Additional Information (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Abstract]
Depreciation and amortization of property, equipment and leasehold improvements	$25,711	$20,384	$16,584

Goodwill_and_Intangible_Assets2

Goodwill and Intangible Assets - Schedule of Goodwill (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill, Beginning balance	$1,813,164	$1,797,753
Changes to goodwill	-244,299	13,902
Foreign exchange translation adjustment	-3,961	1,509
Goodwill, Ending balance	$1,564,904	$1,813,164

Goodwill_and_Intangible_Assets3

Goodwill and Intangible Assets - Schedule of Goodwill (Parenthetical) (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2014
CFRA Product Line [Member]
Goodwill [Line Items]
Adjustments to goodwill from sale of business unit	$0.50
Institutional Shareholder Services Inc. [Member]
Goodwill [Line Items]
Adjustments to goodwill from sale of business unit		254.2
Investor Force Holdings, Inc. [Member]
Goodwill [Line Items]
Adjustments to goodwill from acquisitions	11.6
IPD [Member]
Goodwill [Line Items]
Adjustments to goodwill from acquisitions	2.7
GMI Ratings [Member]
Goodwill [Line Items]
Adjustments to goodwill from acquisitions		$9.90

Goodwill_and_Intangible_Assets4

Goodwill and Intangible Assets - Additional Information (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of intangible assets	$11,591	$11,574	$11,442	$11,270	$11,217	$11,193	$11,222	$11,166	$45,877	$44,798	$50,017

Goodwill_and_Intangible_Assets5

Goodwill and Intangible Assets - Components of Intangible Assets by Major Class (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Acquired Finite-Lived Intangible Assets [Line Items]
Gross carrying value	$805,837	$970,084
Accumulated amortization	-372,209	-374,377
Net carrying value	433,628	595,707
Customer Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross carrying value	360,835	478,735
Accumulated amortization	-119,058	-125,359
Net carrying value	241,777	353,376
Trademarks/Trade Names [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross carrying value	223,382	257,282
Accumulated amortization	-81,545	-75,696
Net carrying value	141,837	181,586
Technology/Software [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross carrying value	193,681	199,778
Accumulated amortization	-167,083	-168,481
Net carrying value	26,598	31,297
Proprietary Process [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross carrying value		3,800
Accumulated amortization		-2,269
Net carrying value		1,531
Proprietary Data [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross carrying value	28,627	28,527
Accumulated amortization	-4,589	-2,326
Net carrying value	24,038	26,201
Covenant Not to Compete [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross carrying value	900
Accumulated amortization	-187
Net carrying value	713
Subtotal [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross carrying value	807,425	968,122
Accumulated amortization	-372,462	-374,131
Net carrying value	434,963	593,991
Foreign Exchange Translation Adjustment [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross carrying value	-1,588	1,962
Accumulated amortization	253	-246
Net carrying value	($1,335)	$1,716

Goodwill_and_Intangible_Assets6

Goodwill and Intangible Assets - Estimated Amortization Expense for Succeeding Years (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Goodwill and Intangible Assets Disclosure [Abstract]
2015	$47,111
2016	46,684
2017	41,457
2018	38,721
2019	37,420
Thereafter	222,235
Total	$433,628	$595,707

Employee_Benefits_Additional_I

Employee Benefits - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Employee Benefit Plans [Line Items]
Pension and post-retirement benefit expenses	$22,200,000	$18,200,000	$16,200,000
Percentage of additional contribution from the Company to employees' cash compensation	3.00%
Defined contribution plan expenses	19,300,000	15,700,000	13,100,000
Net periodic benefit expense	2,800,000	2,500,000	3,100,000
Fair value of the defined benefit plan assets	14,300,000	15,700,000
Other Non-current Liabilities [Member]
Employee Benefit Plans [Line Items]
Defined benefit plan, liability	16,700,000	7,700,000
Cost of Services [Member]
Employee Benefit Plans [Line Items]
Pension and post-retirement benefit expenses	13,100,000	10,900,000	9,600,000
Selling, General and Administrative [Member]
Employee Benefit Plans [Line Items]
Pension and post-retirement benefit expenses	$9,100,000	$7,300,000	$6,600,000

ShareBased_Compensation_Additi

Share-Based Compensation - Additional Information (Detail) (USD $)	12 Months Ended			0 Months Ended			1 Months Ended	0 Months Ended	12 Months Ended	0 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014	Nov. 14, 2007	Dec. 10, 2010	Jan. 31, 2015	Dec. 14, 2010	Dec. 31, 2011	Jan. 27, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares grants in period	0		0
Tax benefits for share-based compensation expense related to deferred stock and stock options	$2.80	$2.60	$1
Compensation cost related to unvested share-based awards not yet recognized	11.6			11.6
Number of shares available for future grants	6,300,000			6,300,000
Total fair value of restricted stock units and restricted stock awards converted or vested to common stock	24.5	28.2	15.3
Weighted average fair value of stock options assumed		$19.18
Intrinsic value of the stock options exercised	12.8	13.9	14.5
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost related to unvested share-based awards not yet recognized, period for recognition				1 year
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost related to unvested share-based awards not yet recognized, period for recognition				3 years
Cost of Services [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation expense	10.8	9.8	8.8
Selling, General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation expense	14.8	12.9	14.1
Income from Discontinued Operations, Net of Income Taxes [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share based compensation expense	1.4	2.8	2.7
Founders Grant Award [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of awards					4 years
Director RSU Award [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares granted/awarded	27,447	20,514
Director Common Stock Award [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares granted/awarded	5,371	4,688
2010 CEO Award [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of awards						5 years
Stock option award value						3.6
Award vesting rights, percentage vested						25.00%
2014 Bonus Award [Member] | Subsequent Events [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amount of the award granted to retirement-eligible employees							7.2
Aggregate fair value							26.5
Number of shares grants in period							485,170
2010 Bonus Award [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amount of the award granted to retirement-eligible employees								6.2
Aggregate fair value								18.9
2010 Bonus Award [Member] | RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of awards								3 years
Fraction of bonus award vested per year								0.33
2010 Bonus Award [Member] | PSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fraction of bonus award vested per year								0.5
2011 Bonus Award [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amount of the award granted to retirement-eligible employees									6.7
Aggregate fair value									21.2
2011 Bonus Award [Member] | RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of awards									3 years
Fraction of bonus award vested per year									0.33
2011 Bonus Award [Member] | PSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fraction of bonus award vested per year									0.5
2012 Bonus Award [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amount of the award granted to retirement-eligible employees			6.2
Aggregate fair value			21.7
2012 Bonus Award [Member] | RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of awards			3 years
Fraction of bonus award vested per year			0.33
2012 Bonus Award [Member] | PSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fraction of bonus award vested per year			0.5
2013 Bonus Award [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amount of the award granted to retirement-eligible employees		6.8
Aggregate fair value		24.3
2013 Bonus Award [Member] | RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of awards		3 years
Fraction of bonus award vested per year		0.33
2013 Bonus Award [Member] | PSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fraction of bonus award vested per year		0.5
2015 Special Incentive Award [Member] | Subsequent Events [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of awards										5 years
Aggregate fair value										$5
Fraction of bonus award vested per year										0.33
Number of shares grants in period										91,657

ShareBased_Compensation_Compon

Share-Based Compensation - Components of Share-Based Compensation Expense (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	$27,031	$25,553	$25,596
Deferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	25,830	23,910	23,198
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	$1,201	$1,643	$2,398

ShareBased_Compensation_Summar

Share-Based Compensation - Summary of Vested and Unvested Deferred Stock Awards Activity (Detail) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Vested and unvested deferred stock awards at the beginning of period, Number of Shares	1,237
Granted, Number of Shares	639
Conversion to common stock, Number of Shares	-567
Canceled, Number of Shares	-96
Vested and unvested deferred stock awards at the end of period, Number of Shares	1,213
Vested and unvested deferred stock awards at the beginning of period, Weighted Average Grant Date Fair Value	$33.84
Granted, Weighted Average Grant Date Fair Value	$42.32
Conversion to common stock, Weighted Average Grant Date Fair Value	$34.54
Canceled, Weighted Average Grant Date Fair Value	$35.82
Vested and unvested deferred stock awards at the end of period, Weighted Average Grant Date Fair Value	$37.82

ShareBased_Compensation_Summar1

Share-Based Compensation - Summary of Vested and Unvested Deferred Stock Awards Activity (Parenthetical) (Detail) (USD $)	Dec. 31, 2014
In Thousands, except Per Share data, unless otherwise specified
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Restricted stock units and restricted stock awards, vested or expected to vest	1,195
Restricted stock units and restricted stock awards vested or expected to vest, weighted average price	$37.80

ShareBased_Compensation_Summar2

Share-Based Compensation - Summary of Unvested Deferred Stock Awards Activity (Detail) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted Average Grant Date Fair Value, balance at the beginning of the period	$33.85
Weighted Average Grant Date Fair Value, Granted	$42.35
Weighted Average Grant Date Fair Value, Vested	$34.39
Weighted Average Grant Date Fair Value, Canceled	$36.35
Weighted Average Grant Date Fair Value, balance at the end of the period	$37.99
Weighted Average Grant Date Fair Value, Expected to vest	$37.96
Unvested Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested deferred stock awards, balance at the beginning of period	894
Number of Shares, Granted	479
Number of Shares, Vested	-412
Number of Shares, Canceled	-78
Unvested deferred stock awards, balance at the end of period	883
Number of shares, Expected to vest	866

ShareBased_Compensation_Weight

Share-Based Compensation - Weighted Average Fair Value of Stock Options Assumed (Detail)	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Risk free interest rate	1.87%
Expected option life in years	6 years 6 months
Expected stock price volatility	46.07%
Expected dividend yield	0.00%

ShareBased_Compensation_Summar3

Share-Based Compensation - Summary of Stock Options Activity (Detail) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Number of Options, Options outstanding, Beginning balance	1,986,000
Number of Options, Granted or assumed	0		0
Number of Options, Forfeited	-1,000
Number of Options, Conversion to common stock	-498,000
Number of Options, Options outstanding, Ending balance	1,487,000	1,986,000
Number of Options, Options exercisable	1,303,000
Number of Options, Options vested or expected to vest	1,487,000
Weighted Average Exercise Price, Options outstanding, Beginning balance	$21.85
Weighted Average Exercise Price, Granted or assumed	$0
Weighted Average Exercise Price, Forfeited	$24.49
Weighted Average Exercise Price, Conversion to common stock	$19.32
Weighted Average Exercise Price, Options outstanding, Ending balance	$22.69	$21.85
Weighted Average Exercise Price, Options Exercisable	$20.49
Weighted Average Exercise Price, Options vested or expected to vest	$22.69
Weighted Average Remaining Life (Years), Options outstanding	3 years 9 months 4 days	4 years 6 months 18 days
Weighted Average Remaining Life (Years), Options exercisable	3 years 3 months 11 days
Weighted Average Remaining Life (Years), Options vested or expected to vest	3 years 9 months 4 days
Aggregated Intrinsic Value, Options outstanding	$36,802
Aggregated Intrinsic Value, Options exercisable	35,120
Aggregated Intrinsic Value, Options vested or expected to vest	$36,802

ShareBased_Compensation_Summar4

Share-Based Compensation - Summary of Stock Options Outstanding by Exercise Price Range (Detail) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number Outstanding, Options Outstanding	1,487
Aggregate Intrinsic Value, Options Outstanding	$36,802
First Exercise Price Range [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Price, Minimum	$2.76
Range of Exercise Price, Maximum	$16.48
Number Outstanding, Options Outstanding	130
Weighted Average Exercise Price, Options Outstanding	$12.69
Average Remaining Life (Years), Options Outstanding	2 years 5 months 1 day
Aggregate Intrinsic Value, Options Outstanding	4,512
Second Exercise Price Range [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices	$18
Number Outstanding, Options Outstanding	763
Weighted Average Exercise Price, Options Outstanding	$18
Average Remaining Life (Years), Options Outstanding	2 years 10 months 13 days
Aggregate Intrinsic Value, Options Outstanding	22,469
Third Exercise Price Range [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Price, Minimum	$20.45
Range of Exercise Price, Maximum	$25.64
Number Outstanding, Options Outstanding	282
Weighted Average Exercise Price, Options Outstanding	$23.16
Average Remaining Life (Years), Options Outstanding	3 years 4 months 2 days
Aggregate Intrinsic Value, Options Outstanding	6,833
Fourth Exercise Price Range [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Price, Minimum	$36.70
Range of Exercise Price, Maximum	$40.23
Number Outstanding, Options Outstanding	312
Weighted Average Exercise Price, Options Outstanding	$37.88
Average Remaining Life (Years), Options Outstanding	6 years 10 months 17 days
Aggregate Intrinsic Value, Options Outstanding	$2,988

ShareBased_Compensation_Summar5

Share-Based Compensation - Summary of Stock Options Exercisable by Exercise Price Range (Detail) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number Outstanding, Options Exercisable	1,303
Weighted Average Exercise Price, Options Exercisable	$20.49
Aggregate Intrinsic Value, Options Exercisable	$35,120
First Exercise Price Range [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Price, Minimum	$2.76
Range of Exercise Price, Maximum	$16.48
Number Outstanding, Options Exercisable	130
Weighted Average Exercise Price, Options Exercisable	$12.69
Average Remaining Life (Years), Options Exercisable	2 years 5 months 1 day
Aggregate Intrinsic Value, Options Exercisable	4,512
Second Exercise Price Range [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices	$18
Number Outstanding, Options Exercisable	763
Weighted Average Exercise Price, Options Exercisable	$18
Average Remaining Life (Years), Options Exercisable	2 years 10 months 13 days
Aggregate Intrinsic Value, Options Exercisable	22,469
Third Exercise Price Range [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Price, Minimum	$20.45
Range of Exercise Price, Maximum	$25.64
Number Outstanding, Options Exercisable	282
Weighted Average Exercise Price, Options Exercisable	$23.16
Average Remaining Life (Years), Options Exercisable	3 years 4 months 2 days
Aggregate Intrinsic Value, Options Exercisable	6,833
Fourth Exercise Price Range [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Price, Minimum	$36.70
Range of Exercise Price, Maximum	$40.23
Number Outstanding, Options Exercisable	128
Weighted Average Exercise Price, Options Exercisable	$37.27
Average Remaining Life (Years), Options Exercisable	6 years 4 months 24 days
Aggregate Intrinsic Value, Options Exercisable	$1,306

Income_Taxes_Summary_of_Provis

Income Taxes - Summary of Provision for Income Taxes (Benefits) (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Current, U.S. federal									$84,959	$97,739	$72,786
Current, U.S. state and local									13,929	16,820	25,049
Current, Non U.S.									18,505	18,270	19,996
Current provision for income taxes (benefits)									117,393	132,829	117,831
Deferred, U.S. federal									-2,606	-14,362	-18,234
Deferred, U.S. state and local									-3,356	-3,802	-3,821
Deferred, Non U.S.									-2,035	-1,747	234
Deferred provision for income taxes (benefits)									-7,997	-19,911	-21,821
Provision for income taxes from continuing operations	27,459	28,272	27,280	26,385	36,119	27,804	27,763	21,232	109,396	112,918	96,010
Provision for income taxes from discontinued operations									$1,059	$10,146	$9,161

Income_Taxes_Reconciliation_of

Income Taxes - Reconciliation of Provision to U.S. Federal Statutory Income Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
U.S. federal statutory income tax rate	35.00%	35.00%	35.00%
U.S. state and local income taxes, net of U.S. federal income tax benefits	2.72%	3.05%	2.14%
Change in tax rates applicable to non-U.S. earnings	-1.88%	-0.93%	-1.57%
Domestic tax credits	-0.86%	-0.95%
Other	0.50%	-0.07%	1.24%
Effective income tax rate	35.48%	36.10%	36.81%

Income_Taxes_Significant_Compo

Income Taxes - Significant Components of Deferred Tax Assets and Liabilities (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Deferred tax assets:
Employee compensation and benefit plans	$24,765	$26,165
Deferred rent	7,229	9,526
Property, equipment and leasehold improvements, net		1,520
State taxes	2,322	2,323
Pension	2,494	395
Unearned revenue	1,117	1,238
NOL carryforward - current	1,667	3,813
NOL carryforward - non-current	34,249	7,506
Other	1,979	112
Subtotal	75,822	52,598
Less: valuation allowance	-21,232	-7
Total deferred tax assets	54,590	52,591
Deferred tax liabilities:
Intangible assets	-154,965	-233,980
Foreign currency translation	-629	-372
Property, equipment and leasehold improvements, net	-10,435
Other	-246
Total deferred tax liabilities	-166,275	-234,352
Net deferred tax liabilities	($111,685)	($181,761)

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Examination [Line Items]
Non-current net operating loss ("NOL") carryforward	$34,249,000	$7,506,000
Valuation allowance	21,232,000	7,000
NOL carryforward - current	1,667,000	3,813,000
Deferred tax liability	137,838,000	234,649,000
Earnings attributable to foreign subsidiaries	149,100,000	188,600,000	164,900,000
Significant change in unrecognized tax benefits, reasonably possible (in months)	12
Significant change in unrecognized tax benefits, not possible (in months)	12
Total amount of unrecognized tax benefits	5,500,000
Penalties recognized during the year	0
As Previously Reported [Member]
Income Tax Examination [Line Items]
Non-current net operating loss ("NOL") carryforward		34,700,000
Valuation allowance		23,400,000
Deferred tax liability		221,054,000
Adjustment [Member]
Income Tax Examination [Line Items]
Non-current net operating loss ("NOL") carryforward		7,300,000
NOL carryforward - current		3,800,000
Deferred tax liability		13,595,000
Adjustment [Member] | United States [Member]
Income Tax Examination [Line Items]
Net operating loss ("NOL") expiration, beginning year	2026
Minimum [Member]
Income Tax Examination [Line Items]
Tax years under examination	2005
Maximum [Member]
Income Tax Examination [Line Items]
Unrecognized tax benefits, interest on income tax expenses	100,000
Tax years under examination	2013
Maximum [Member] | Adjustment [Member]
Income Tax Examination [Line Items]
Valuation allowance		100,000
NOL carryforward		$11,300,000
Internal Revenue Service (IRS) [Member] | Minimum [Member] | Morgan Stanley [Member]
Income Tax Examination [Line Items]
Tax years under examination	2006
Internal Revenue Service (IRS) [Member] | Maximum [Member] | Morgan Stanley [Member]
Income Tax Examination [Line Items]
Tax years under examination	2008
New York State and City [Member] | Minimum [Member] | Morgan Stanley [Member]
Income Tax Examination [Line Items]
Tax years under examination	2007
New York State and City [Member] | Maximum [Member] | Morgan Stanley [Member]
Income Tax Examination [Line Items]
Tax years under examination	2008

Income_Taxes_Summary_of_Compon

Income Taxes - Summary of Components of Income Before Provision for Income Taxes (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Domestic									$269,944	$276,549	$220,072
Foreign									38,394	36,279	40,729
Income from continuing operations before provision for income taxes	$70,728	$79,996	$84,083	$73,531	$76,994	$77,740	$83,904	$74,190	$308,338	$312,828	$260,801

Income_Taxes_Reconciliation_of1

Income Taxes - Reconciliation of Unrecognized Tax Benefits (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Beginning balance	$7,089	$6,827	$13,168
Increases based on tax positions related to the current period	292	194
Increases based on tax positions related to prior periods	1,969	2,690	349
Decreases based on tax positions related to prior periods	-346	-2,474	-427
Increases/ (Decreases) related to settlements with taxing authorities	-1,652		-6,263
Increases/(Decreases) related to a lapse of applicable statute of limitations	-827	-148
Ending balance	$6,525	$7,089	$6,827

Acquisitions_Additional_Inform

Acquisitions - Additional Information (Detail) (USD $)	0 Months Ended	12 Months Ended	0 Months Ended
	Aug. 11, 2014	Dec. 31, 2014	Jan. 29, 2013	Nov. 30, 2012	Dec. 31, 2013	Dec. 31, 2012
Business Acquisition [Line Items]
Purchase price allocated to goodwill		$1,564,904,000			$1,813,164,000	$1,797,753,000
GMI Ratings [Member]
Business Acquisition [Line Items]
Company paid cash to acquire property	15,500,000
Date of acquisition		11-Aug-14
Purchase price allocated to goodwill		9,900,000
Purchase price allocated to identifiable intangible assets		3,600,000
Purchase price allocated for assets other than identifiable intangible assets		6,700,000
Purchase price allocated to other liabilities		4,700,000
Investor Force Holdings, Inc. [Member]
Business Acquisition [Line Items]
Company paid cash to acquire property			23,600,000
Date of acquisition		29-Jan-13
Purchase price allocated to goodwill			11,600,000
Purchase price allocated to identifiable intangible assets			9,100,000
Purchase price allocated for assets other than identifiable intangible assets			6,400,000
Purchase price allocated to other liabilities			3,500,000
IPD [Member]
Business Acquisition [Line Items]
Company paid cash to acquire property				124,800,000
Date of acquisition		30-Nov-12
Purchase price allocated to goodwill				76,500,000
Purchase price allocated to identifiable intangible assets				58,700,000
Purchase price allocated for assets other than identifiable intangible assets				18,600,000
Purchase price allocated to other liabilities				$29,000,000

Segment_Information_Additional

Segment Information - Additional Information (Detail)	0 Months Ended	12 Months Ended
	Mar. 17, 2014	Dec. 31, 2013	Dec. 31, 2014
	Segment	Segment
Segment Reporting Information [Line Items]
Number of operating segments	1	2
Institutional Shareholder Services Inc. [Member]
Segment Reporting Information [Line Items]
Sale completion date			30-Apr-14
CFRA Product Line [Member]
Segment Reporting Information [Line Items]
Sale completion date			31-Mar-13

Segment_Information_Revenue_by

Segment Information - Revenue by Geographic Area (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$251,105	$251,661	$254,226	$239,688	$236,864	$228,608	$228,423	$219,469	$996,680	$913,364	$826,990
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									471,145	416,999	394,401
Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									37,189	34,547	27,783
Total Americas [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									508,334	451,546	422,184
United Kingdom [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									154,308	141,938	107,189
Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									209,893	202,664	179,535
Total EMEA [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									364,201	344,602	286,724
Japan [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									46,642	46,752	53,649
Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									77,503	70,464	64,433
Total Asia & Australia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									$124,145	$117,216	$118,082

Segment_Information_LongLived_

Segment Information - Long-Lived Assets by Geographic Area (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$2,092,606	$2,494,459
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	1,944,433	2,338,124
Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	3,293	4,082
Total Americas [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	1,947,726	2,342,206
United Kingdom [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	120,781	133,411
Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	13,345	11,871
Total EMEA [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	134,126	145,282
Japan [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	837	1,543
Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	9,917	5,428
Total Asia & Australia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$10,754	$6,971

Quarterly_Results_of_Operation2

Quarterly Results of Operations - Summary of Quarterly Results of Operations (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Information Disclosure [Abstract]
Operating revenues	$251,105	$251,661	$254,226	$239,688	$236,864	$228,608	$228,423	$219,469	$996,680	$913,364	$826,990
Cost of services	77,455	78,876	76,816	75,427	72,256	68,151	69,696	65,300	308,574	275,403	230,282
Selling, general and administrative	69,345	70,833	71,516	67,658	64,174	59,917	52,842	55,515	279,352	232,448	211,905
Amortization of intangible assets	11,591	11,574	11,442	11,270	11,217	11,193	11,222	11,166	45,877	44,798	50,017
Depreciation and amortization of property, equipment and leasehold improvements	7,620	6,342	5,921	5,828	5,570	5,443	4,774	4,597	25,930	22,302	18,700
Total operating expenses	166,011	167,625	165,695	160,183	153,217	144,704	138,534	136,578	659,514	573,033	508,755
Operating income	85,094	84,036	88,531	79,505	83,647	83,904	89,889	82,891	337,166	340,331	318,235
Interest income	-226	-277	-192	-156	-239	-227	-186	-237	-851	-889	-699
Interest expense	15,791	5,604	5,366	5,059	6,913	5,828	6,499	7,016	31,820	26,256	56,401
Other expense (income)	-1,199	-1,287	-726	1,071	-21	563	-328	1,922	-2,141	2,136	1,732
Other expense (income), net	14,366	4,040	4,448	5,974	6,653	6,164	5,985	8,701	28,828	27,503	57,434
Income from continuing operations before provision for income taxes	70,728	79,996	84,083	73,531	76,994	77,740	83,904	74,190	308,338	312,828	260,801
Provision for income taxes	27,459	28,272	27,280	26,385	36,119	27,804	27,763	21,232	109,396	112,918	96,010
Income from continuing operations	43,269	51,724	56,803	47,146	40,875	49,936	56,141	52,958	198,942	199,910	164,791
Income (loss) from discontinued operations, net of income taxes	1,071	-10	50,857	33,253	6,382	5,374	4,912	5,979	85,171	22,647	19,447
Net income	$44,340	$51,714	$107,660	$80,399	$47,257	$55,310	$61,053	$58,937	$284,113	$222,557	$184,238
Earnings per basic common share
From continuing operations	$0.38	$0.44	$0.48	$0.40	$0.34	$0.42	$0.46	$0.44	$1.72	$1.66	$1.34
From discontinued operations	$0.01		$0.44	$0.28	$0.06	$0.04	$0.04	$0.05
Earnings per basic common share	$0.39	$0.44	$0.92	$0.68	$0.40	$0.46	$0.50	$0.49	$2.45	$1.85	$1.50
Earnings per diluted common share
From continuing operations	$0.38	$0.44	$0.48	$0.40	$0.34	$0.42	$0.46	$0.43	$1.70	$1.64	$1.32
From discontinued operations	$0.01		$0.43	$0.28	$0.05	$0.04	$0.04	$0.05
Earnings per diluted common share	$0.39	$0.44	$0.91	$0.68	$0.39	$0.46	$0.50	$0.48	$2.43	$1.83	$1.48
Weighted average shares outstanding used in computing per share data
Basic	112,299	116,251	116,702	117,582	118,828	119,607	121,149	120,746	115,737	120,100	122,023
Diluted	113,289	117,163	117,664	118,597	119,877	120,578	122,069	121,702	116,706	121,074	123,204

Subsequent_Events_Additional_I

Subsequent Events - Additional Information (Detail) (USD $)	0 Months Ended	12 Months Ended	0 Months Ended
	Sep. 17, 2014	Dec. 31, 2014	Feb. 03, 2015
Subsequent Event [Line Items]
Quarterly dividend declared	$0.18	$0.18
Quarterly dividend declared date		17-Sep-14
Quarterly dividend payable date		31-Oct-14
Quarterly dividend record date		15-Oct-14
Subsequent Events [Member]
Subsequent Event [Line Items]
Quarterly dividend declared			$0.18
Quarterly dividend declared date			3-Feb-15
Quarterly dividend payable date			13-Mar-15
Quarterly dividend record date			20-Feb-15