Cohen & Steers (CNS) 10-Q 8 May 15 2015 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information Document	3 Months Ended
	Mar. 31, 2015	5-May-15
Entity Information
Entity Registrant Name	COHEN & STEERS INC
Entity Central Index Key	1284812
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	31-Mar-15
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1
Amendment Flag	FALSE
Entity Common Stock, Shares Outstanding		45,414,522

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Financial Condition (Unaudited) (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Thousands, unless otherwise specified
Assets
Cash and cash equivalents	$99,493		$124,938
Trading investments	9,395	[1]	9,509	[1]
Equity method investments	27,465		28,550
Available-for-sale investments	21,320		21,269
Accounts receivable	54,935		43,392
Due from broker	1,315		1,805
Income tax receivable	5,839		56
Property and equipment—net	10,136		11,189
Goodwill	17,862		19,120
Intangible assets—net	1,590		1,612
Deferred income tax asset—net	0		15,108
Other assets	5,652		4,173
Total assets	255,002		280,721
Liabilities:
Accrued compensation	6,651		28,300
Deferred rent	5,677		5,728
Income tax payable	1,164		4,141
Other liabilities and accrued expenses	13,074		13,964
Total liabilities	26,566		52,133
Commitments and contingencies
Redeemable noncontrolling interest	797		607
Stockholders’ equity:
Common stock, $0.01 par value; 500,000,000 shares authorized; 49,630,490 and 48,593,812 shares issued at March 31, 2015 and December 31, 2014, respectively	496		486
Additional paid-in capital	500,604		489,266
Accumulated deficit	-133,574		-142,786
Accumulated other comprehensive income, net of tax	-3,775		-1,582
Less: Treasury stock, at cost, 4,236,934 and 3,800,920 shares at March 31, 2015 and December 31, 2014, respectively	-136,112		-117,403
Total stockholders’ equity	227,639		227,981
Total liabilities and stockholders’ equity	$255,002		$280,721
[1]	Includes $622 and $650 held as collateral attributable to the consolidated balances of Cohen & Steers Active Commodities Strategy Fund, Inc. (CDF) as of March 31, 2015 and December 31, 2014, respectively.

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Financial Condition (Unaudited) (Parenthetical) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, except Share data, unless otherwise specified
Common Stock, par value	$0.01	$0.01
Common Stock, shares authorized	500,000,000	500,000,000
Common Stock, shares issued	49,630,490	48,593,812
Common Stock, Shares, Outstanding	45,393,556	44,792,892
Treasury Stock, shares	4,236,934	3,800,920
Trading investments pledged as collateral
Trading investments and pledged as collateral	$622	$650

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Operations (Unaudited) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Revenue:
Investment advisory and administration fees	$77,752	$67,564
Distribution and service fees	3,906	3,470
Portfolio consulting and other	2,157	1,801
Total revenue	83,815	72,835
Expenses:
Employee compensation and benefits	25,983	24,035
Distribution and service fees	9,251	8,304
General and administrative	12,463	11,093
Depreciation and amortization	1,052	1,262
Amortization of deferred commissions	517	545
Total expenses	49,266	45,239
Operating income	34,549	27,596
Non-operating income:
Interest and dividend income—net	299	239
(Loss) gain from trading investments—net	-451	983
Gain from available-for-sale investments—net	100	1,076
Equity in (losses) earnings of affiliates	-1,081	935
Other losses	-419	-52
Total non-operating (loss) income	-1,552	3,181
Income before provision for income taxes	32,997	30,777
Provision for income taxes	12,226	11,177
Net income	20,771	19,600
Less: Net loss (income) attributable to redeemable noncontrolling interest	45	-155
Net income attributable to common stockholders	$20,816	$19,445
Earnings per share attributable to common stockholders:
Basic (in dollars per share)	$0.46	$0.44
Diluted (in dollars per share)	$0.45	$0.43
Dividends declared per share (in dollars per share)	$0.25	$0.22
Weighted average shares outstanding:
Basic (shares)	45,241	44,633
Diluted (shares)	45,980	45,483

Condensed_Consolidated_Stateme3

Condensed Consolidated Statements of Comprehensive Income (Unaudited) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Net income	$20,771	$19,600
Less: Net loss (income) attributable to redeemable noncontrolling interest	45	-155
Net income attributable to common stockholders	20,816	19,445
Foreign currency translation (loss) gain (net of tax of $0)	-2,078	77
Net unrealized (loss) gain from available-for-sale investments (net of tax of $0)	-15	1,090
Reclassification to statements of operations of gain from available-for-sale investments (net of tax of $0)	-100	-1,076
Other comprehensive (loss) income	-2,193	91
Total comprehensive income attributable to common stockholders	$18,623	$19,536

Condensed_Consolidated_Stateme4

Condensed Consolidated Statements of Changes in Stockholders' Equity and Redeemable Noncontrolling Interest (Unaudited) (USD $)	Total	Common Stocks	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss), Net of Tax	Treasury Stock	Total Stockholders' Equity	Redeemable Noncontrolling Interest
In Thousands, except Share data
Beginning balance (redeemable noncontrolling interest) at Dec. 31, 2013								$207
Beginning balance at Dec. 31, 2013		477	457,138	-131,366	2,989	-105,681	223,557
Beginning balance (shares of common stock, net) at Dec. 31, 2013		44,254,000
Dividends		0	0	-10,015	0	0	-10,015
Issuance of common stock		8	157	0	0	0	165	0
Issuance of common stock, shares		775,000
Repurchase of common stock		0	0	0	0	-10,593	-10,593	0
Repurchase of common stock, shares		-291,000
Tax benefits associated with restricted stock units—net		0	2,533	0	0	0	2,533	0
Issuance of restricted stock units		0	272	0	0	0	272	0
Amortization of restricted stock units—net		0	5,907	0	0	0	5,907	0
Net income (loss)	19,600	0	0	19,445	0	0	19,445	155
Other comprehensive income (loss), net of tax	91	0	0	0	91	0	91	0
Contributions from redeemable noncontrolling interest	1,820	0	0	0	0	0	0	1,820
Distributions to redeemable noncontrolling interest		0	0	0	0	0	0	-130
Transfer of redeemable noncontrolling interest in consolidated entity		0	0	0	0	0	0	-209
Ending balance (redeemable noncontrolling interest) at Mar. 31, 2014								1,843
Ending balance at Mar. 31, 2014		485	466,007	-121,936	3,080	-116,274	231,362
Ending balance (shares of common stock, net) at Mar. 31, 2014		44,738,000
Beginning balance (redeemable noncontrolling interest) at Dec. 31, 2014								607
Beginning balance at Dec. 31, 2014	227,981	486	489,266	-142,786	-1,582	-117,403	227,981
Beginning balance (shares of common stock, net) at Dec. 31, 2014	44,792,892	44,793,000
Dividends		0	0	-11,604	0	0	-11,604
Issuance of common stock		10	221	0	0	0	231	0
Issuance of common stock, shares		1,037,000
Repurchase of common stock		0	0	0	0	-18,709	-18,709	0
Repurchase of common stock, shares		-436,000
Tax benefits associated with restricted stock units—net		0	4,790	0	0	0	4,790	0
Issuance of restricted stock units		0	375	0	0	0	375	0
Amortization of restricted stock units—net		0	5,952	0	0	0	5,952	0
Net income (loss)	20,771	0	0	20,816	0	0	20,816	-45
Other comprehensive income (loss), net of tax	-2,193	0	0	0	-2,193	0	-2,193	0
Contributions from redeemable noncontrolling interest	235	0	0	0	0	0	0	235
Ending balance (redeemable noncontrolling interest) at Mar. 31, 2015								797
Ending balance at Mar. 31, 2015	$227,639	$496	$500,604	($133,574)	($3,775)	($136,112)	$227,639
Ending balance (shares of common stock, net) at Mar. 31, 2015	45,393,556	45,394,000

Condensed_Consolidated_Stateme5

Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Cash flows from operating activities:
Net income	$20,771	$19,600
Adjustments to reconcile net income to net cash provided by operating activities:
Stock compensation expense	5,990	5,932
Amortization of deferred commissions	517	545
Depreciation and amortization	1,052	1,262
Deferred rent	-51	1,532
Loss (gain) from trading investments—net	451	-983
Equity in losses (earnings) of affiliates	1,081	-935
Gain from available-for-sale investments, net	-100	-1,076
Deferred income taxes	12,879	4,828
Foreign currency (gain) loss	-852	760
Changes in operating assets and liabilities:
Accounts receivable	-10,691	-9,344
Due from broker	490	225
Deferred commissions	-668	-366
Trading investments	-337	-1,204
Income tax receivable	-5,783	43
Other assets	-1,304	381
Accrued compensation	-21,624	-18,695
Income tax payable	-402	192
Other liabilities and accrued expenses	-1,077	-2,792
Net cash provided by (used in) operating activities	342	-95
Cash flows from investing activities:
Proceeds from redemptions of equity method investments—net	4	22
Purchases of available-for-sale investments	-1,409	-2,099
Proceeds from sales of available-for-sale investments	1,366	6,609
Purchases of property and equipment	0	-705
Net cash (used in) provided by investing activities	-39	3,827
Cash flows from financing activities:
Excess tax benefits associated with restricted stock units	4,674	2,427
Issuance of common stock	200	139
Repurchase of common stock	-18,709	-10,593
Dividends to stockholders	-11,354	0
Distributions to redeemable noncontrolling interest	0	-130
Contributions from redeemable noncontrolling interest	235	1,820
Net cash used in financing activities	-24,954	-6,337
Net decrease in cash and cash equivalents	-24,651	-2,605
Effect of foreign exchange rate changes on cash and cash equivalents	-794	73
Cash and cash equivalents, beginning of the period	124,938	128,277
Cash and cash equivalents, end of the period	$99,493	$125,745

Condensed_Consolidated_Stateme6

Condensed Consolidated Statements of Cash Flows (Unaudited) (Parenthetical) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Income taxes paid, net	($805)	($3,697)
Fully vested restricted stock units issued	125	104
Restricted stock unit dividend equivalents, net of forfeitures	$250	$167

Organization_and_Description_o

Organization and Description of Business	3 Months Ended
	Mar. 31, 2015
Organization and Description of Business [Abstract]
Organization and Description of Business	Organization and Description of Business
	Cohen & Steers, Inc. (CNS) was organized as a Delaware corporation on March 17, 2004. CNS is the holding company for its direct and indirect subsidiaries, including Cohen & Steers Capital Management, Inc. (CSCM), Cohen & Steers Securities, LLC (CSS), Cohen & Steers Asia Limited (CSAL), Cohen & Steers UK Limited (CSUK) and Cohen & Steers Japan, LLC (collectively, the Company).
	The Company is a leading global investment manager with a long history of innovation and a focus on real assets, including real estate, infrastructure and commodities, along with preferred securities and other income solutions. The Company serves institutional and individual investors around the world. Its clients include Company-sponsored open-end mutual funds and closed-end funds, U.S. and non-U.S. pension plans, endowment funds, foundations and subadvised funds for other financial institutions. The condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP). The condensed consolidated financial statements set forth herein include the accounts of CNS and its direct and indirect subsidiaries. Intercompany balances and transactions have been eliminated in consolidation.

Basis_of_Presentation_and_Sign

Basis of Presentation and Significant Accounting Policies	3 Months Ended
	Mar. 31, 2015
Basis of Presentation and Significant Accounting Policies [Abstract]
Basis of Presentation and Significant Accounting Policies	Basis of Presentation and Significant Accounting Policies
	The condensed consolidated financial statements of the Company included herein are unaudited and have been prepared in accordance with the instructions to Form 10-Q pursuant to the rules and regulations of the Securities and Exchange Commission (SEC). In the opinion of management, all adjustments, consisting of normal recurring adjustments, necessary for a fair presentation of the interim results have been made. The Company’s condensed consolidated financial statements and the related notes should be read together with the consolidated financial statements and the related notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014.
	Accounting Estimates—The preparation of the condensed consolidated financial statements in conformity with GAAP requires management to make certain estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosures of contingent assets and liabilities at the dates of the condensed consolidated financial statements and the reported amounts of revenue and expenses during the reporting periods. Management believes the estimates used in preparing the condensed consolidated financial statements are reasonable and prudent. Actual results could differ from those estimates.
	Reclassifications—Certain prior year amounts have been reclassified to conform to the current year presentation.
	Consolidation—The Company consolidates operating entities deemed to be voting interest entities if the Company owns a majority of the voting interest. The Company also consolidates any variable interest entities (VIEs) in which the Company is the primary beneficiary. The Company records noncontrolling interests in consolidated subsidiaries for which the Company’s ownership is less than 100 percent. The equity method of accounting is used for investments in affiliates in which the Company’s ownership ranges from 20 to 50 percent, or in instances in which the Company is able to exercise significant influence but not control.
	A VIE is an entity in which either (a) the equity investment at risk is not sufficient to permit the entity to finance its own activities without additional financial support or (b) the group of holders of the equity investment at risk lack certain characteristics of a controlling financial interest. The primary beneficiary is the entity that has the obligation to absorb a majority of the expected losses or the right to receive the majority of the residual returns. Investments and redemptions or amendments to the governing documents of the respective entities could affect an entity's status as a VIE or the determination of the primary beneficiary. The Company assesses whether entities in which it has an interest are VIEs upon initial involvement and at each reporting date. The Company assesses whether it is the primary beneficiary of any VIEs identified by evaluating its economic interests in the entity held either directly by the Company and its affiliates or indirectly through employees. See Note 4 for further discussion about the Company’s investments.
	Cash and Cash Equivalents—Cash equivalents consist of short-term, highly liquid investments, which are readily convertible into cash and have original maturities of three months or less.
	Due from Broker—The Company conducts business, primarily through its consolidated seed investments, with brokers for certain of its investment activities. The clearing and custody operations for these investment activities are performed pursuant to contractual agreements. The due from broker balance represents cash and cash equivalents balances at brokers/custodians and net receivables and payables for unsettled security transactions.
	Investments—Management of the Company determines the appropriate classification of its investments at the time of purchase and re-evaluates such determination at each statement of financial condition date.
	Investments classified as trading represent securities held within the affiliated funds that the Company consolidates and are measured at fair value based on quoted market prices, market prices obtained from independent pricing services engaged by management or as determined by the Company’s valuation committee. Unrealized gains and losses are recorded as gain (loss) from trading investments—net in the Company’s condensed consolidated statements of operations.
	Investments classified as equity method investments are accounted for using the equity method, under which the Company recognizes its respective share of the investee’s net income or loss for the period. As of March 31, 2015, the Company's equity method investments consisted of interests in affiliated funds which measure their underlying investments at fair value and report a net asset value on a recurring basis. The carrying amounts of these investments approximate their fair value.
	Investments classified as available-for-sale are comprised of equity securities, investment-grade preferred instruments and investments in Company-sponsored open-end mutual funds. These investments are carried at fair value based on quoted market prices or market prices obtained from independent pricing services engaged by management, with unrealized gains and losses, net of tax, reported in accumulated other comprehensive income. The Company periodically reviews each individual security position that has an unrealized loss, or impairment, to determine if that impairment is other than temporary. If the Company believes an impairment of a security position is other than temporary, the loss will be recognized in the Company’s condensed consolidated statements of operations. An other than temporary impairment is presumed to have occurred if the available-for-sale investment has an unrealized loss continuously for 12 or more months.
	From time to time, the affiliated funds consolidated by the Company enter into derivative contracts to gain exposure to the underlying commodities markets or to hedge market and credit risks of the underlying portfolios utilizing options, total return swaps, credit default swaps and futures contracts. These instruments are measured at fair value with gains and losses recorded as gain (loss) from trading investments—net in the Company's condensed consolidated statements of operations. The fair values of these instruments are recorded in other assets or other liabilities and accrued expenses in the Company's condensed consolidated statements of financial condition. As of March 31, 2015, none of the outstanding derivative contracts were subject to a master netting agreement or other similar arrangement.
	Additionally, from time to time, the Company enters into foreign exchange contracts to hedge its currency exposure related to client receivables. These instruments are measured at fair value with gains and losses recorded in other non-operating income in the Company's condensed consolidated statements of operations. The fair values of these contracts are recorded in other assets or other liabilities and accrued expenses in the Company's condensed consolidated statements of financial condition.
	Goodwill and Intangible Assets—Goodwill represents the excess of the cost of the Company’s investment in the net assets of an acquired company over the fair value of the underlying identifiable net assets at the date of acquisition. Goodwill and indefinite lived intangible assets are not amortized but are tested at least annually for impairment by comparing the fair value to their carrying amounts. Finite lived intangible assets are amortized over their useful lives and are tested for impairment whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. See Note 3 for further discussion about the Company’s goodwill and intangible assets.
	Redeemable Noncontrolling Interest—Redeemable noncontrolling interest represents third-party interests in the Company's consolidated entities. This interest is redeemable at the option of the investors and therefore is not treated as permanent equity. Redeemable noncontrolling interest is remeasured at redemption value which approximates the fair value at each reporting period.
	Investment Advisory and Administration Fees—The Company earns revenue by providing asset management services to institutional accounts and to Company-sponsored open-end mutual funds and closed-end funds. Investment advisory fees are earned pursuant to the terms of underlying advisory contracts, and are based on a contractual fee rate applied to the assets in the portfolio. The Company also earns administration fees from certain Company-sponsored open-end mutual funds and closed-end funds pursuant to the terms of underlying administration contracts. Administration fees are based on the average assets under management of such funds. Investment advisory and administration fee revenue is recognized as such fees are earned.
	Distribution and Service Fee Revenue—CSS acts as the principal distributor of the Company’s sponsored open-end mutual funds which may offer the following classes: Class A (initial sales load), Class C (back end sales load), Class R (load retirement) and Class Z (no load retirement). Effective May 2007, the Company suspended sales of Class B shares and all remaining Class B shares are expected to convert to Class A shares in 2015. Distribution and service fee revenue is based on the average daily net assets of the funds as detailed below. Distribution and service fee revenue is earned daily and is recorded gross of any third-party distribution and service fee expense for applicable share classes.
	Pursuant to distribution plans with the Company's sponsored open-end mutual funds, CSS receives distribution fees of up to 25bps for Class A shares, 75bps for Class C shares and 50bps for Class R shares. CSS also receives shareholder servicing fees of up to 10bps on Class A shares, 25bps on Class C shares and 15bps on Class Z shares, pursuant to shareholder servicing plans with the funds. Effective October 1, 2014, the Company no longer receives shareholder servicing fees on Class Z shares.
	Distribution and Service Fee Expense—Distribution and service fee expense includes distribution fees, service fees and intermediary assistance payments. Distribution and service fee expense is recorded as incurred.
	Distribution fee expense represents payments made to qualified dealers/institutions for (i) assistance in connection with the distribution of the Company's sponsored open-end mutual funds' shares and (ii) for other expenses such as advertising costs and printing and distribution of prospectuses to investors. Such amounts may also be used to pay financial intermediaries for services as specified in the terms of written agreements complying with Rule 12b-1 of the Investment Company Act of 1940 (Rule 12b-1). CSS pays distribution fee expense based on the average daily net assets under management of up to 25bps on Class A shares, 75bps on Class C shares and 50bps on Class R shares.
	Shareholder servicing fee expense represents payments made to qualified dealers/institutions for shareholder account service and maintenance. These services are provided pursuant to written agreements with such qualified institutions. CSS pays service fee expenses based on the average daily net assets under management of up to 10bps on Class A shares, 25bps on Class C shares and 15bps on Class Z shares. Effective October 1, 2014, Class Z shares no longer pay shareholder service fees.
	Intermediary assistance payments represent payments to qualified dealers/institutions for activities related to distribution, shareholder servicing and marketing and support of Company-sponsored open-end mutual funds and are incremental to those described above. Intermediary assistance payments are generally based on the average assets under management or the number of accounts being serviced.
	Portfolio Consulting and Other—The Company earns portfolio consulting and other fees by: (i) providing portfolio consulting services in connection with model-based strategies accounts; (ii) earning a licensing fee for the use of the Company's proprietary indices; and (iii) providing portfolio monitoring services related to a number of unit investment trusts. This revenue is earned pursuant to the terms of the underlying contract, and the fee schedules for these relationships vary based on the type of services the Company provides for each relationship. This revenue is recognized as such fees are earned.
	Stock-based Compensation—The Company recognizes compensation expense for the grant-date fair value of awards of equity instruments granted to employees. This expense is recognized over the period during which employees are required to provide service. The Company also estimates forfeitures.
	Income Taxes—The Company records the current and deferred tax consequences of all transactions that have been recognized in the condensed consolidated financial statements in accordance with the provisions of the enacted tax laws. Deferred tax assets are recognized for temporary differences that will result in deductible amounts in future years at tax rates that are expected to apply in those years. Deferred tax liabilities are recognized for temporary differences that will result in taxable income in future years at tax rates that are expected to apply in those years. The Company records a valuation allowance, when necessary, to reduce deferred tax assets to an amount that more likely than not will be realized. The effective tax rate for interim periods represents the Company’s best estimate of the effective tax rate expected to be applied to the full fiscal year.
	Currency Translation and Transactions—Assets and liabilities of subsidiaries having non-U.S. dollar functional currencies are translated at exchange rates at the applicable condensed consolidated statement of financial condition date. Revenue and expenses of subsidiaries are translated at average exchange rates during the period. The gains or losses resulting from translating non-U.S. dollar functional currency into U.S. dollars are included in the Company's condensed consolidated statements of comprehensive income. The cumulative translation adjustment was $(3,524,000) and $(1,446,000) as of March 31, 2015 and December 31, 2014, respectively. Gains or losses resulting from non-U.S. dollar currency transactions are included in other non-operating income in the condensed consolidated statements of operations.
	Comprehensive Income—The Company reports all changes in comprehensive income in the condensed consolidated statements of comprehensive income. Comprehensive income includes net income or loss attributable to common stockholders, foreign currency translation gain and loss (net of tax), unrealized gain and loss from available-for-sale investments (net of tax) and reclassification to statements of operations of gain and loss from available-for-sale investments (net of tax).
	Recently Issued Accounting Pronouncements—In May 2015, the Financial Accounting Standards Board (FASB) issued new guidance amending the current disclosure requirement for investments in certain entities that calculate net asset value per share. The guidance requires investments for which fair value is measured using the net asset value per share practical expedient be removed from the fair value hierarchy. Instead, those investment amounts shall be provided as a separate item to permit reconciliation of the fair value of investments included in the fair value hierarchy to the line items presented in the statement of financial position. This new guidance will be effective for the Company’s first quarter of 2016. The Company is currently evaluating the potential impact on its condensed consolidated financial statements and related disclosures.
	In February 2015, the FASB issued new guidance amending the current accounting for consolidation of certain legal entities. These amendments modify the evaluation of whether limited partnerships and similar legal entities are VIEs or voting interest entities, eliminate the presumption that a general partner should consolidate a limited partnership, affect the consolidation analysis of reporting entities that are involved with VIEs, particularly those that have fee arrangements and related party relationships, and provide a scope exception from consolidation guidance for reporting entities with interests in certain investment funds. This new guidance will be effective for the Company’s first quarter of 2016. The Company is currently evaluating the potential impact on its condensed consolidated financial statements and related disclosures.
	In August 2014, the FASB issued new guidance regarding disclosure of going concern uncertainties in the financial statements. The guidance requires management to evaluate whether there are conditions or events, considered in the aggregate, that raise substantial doubt about the entity's ability to continue as a going concern within one year after the date that the financial statements are issued at each annual and interim reporting period. This new guidance will be effective for the Company’s first quarter of 2017. The Company does not anticipate that the adoption of this new guidance will have a material impact on the Company's condensed consolidated financial statements.
	In May 2014, the FASB issued new guidance which outlined a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers. The core principle of the revenue model 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. This new guidance will be effective for the Company's first quarter of 2017 and requires either a retrospective or a modified retrospective approach to adoption. Early application is prohibited. The Company is currently evaluating the potential impact on its condensed consolidated financial statements and related disclosures, as well as the available transition methods.

Goodwill_and_Intangible_Assets

Goodwill and Intangible Assets	3 Months Ended
	Mar. 31, 2015
Goodwill and Intangible Assets [Abstract]
Goodwill and Intangible Assets	Goodwill and Intangible Assets
	Goodwill
	Goodwill represents the excess of purchase price over the net tangible assets and identifiable intangible assets of an acquired business. At March 31, 2015 and December 31, 2014, goodwill was approximately $17,862,000 and $19,120,000, respectively. The Company’s goodwill decreased by $1,258,000 for the three months ended March 31, 2015 as a result of foreign currency revaluation.
	Intangible Assets
	The following table details the gross carrying amounts and accumulated amortization for the intangible assets at March 31, 2015 and December 31, 2014 (in thousands):
		Remaining		Gross		Accumulated			Intangible
		Amortization		Carrying		Amortization			Assets, Net
		Period		Amount
		(in months)
	March 31, 2015:
	Amortized intangible assets:
	Client relationships	45		$	1,543	$	(1,203	)	$	340
	Non-amortized intangible assets:
	Mutual fund management contracts	—		1,250		—			1,250
	Total			$	2,793	$	(1,203	)	$	1,590
	December 31, 2014:
	Amortized intangible assets:
	Client relationships	48		$	1,543	$	(1,181	)	$	362
	Non-amortized intangible assets:
	Mutual fund management contracts	—		1,250		—			1,250
	Total			$	2,793	$	(1,181	)	$	1,612
	Amortization expense related to the intangible assets was approximately $22,000 for both the three months ended March 31, 2015 and 2014, respectively. Estimated future amortization expense is as follows (in thousands):
	Periods Ending December 31,	Estimated
		Amortization
		Expense
	2015	$	67
	2016	89
	2017	89
	2018	95
	2019	—
	Total	$	340

Investments_Notes

Investments (Notes)	3 Months Ended
	Mar. 31, 2015
Investments [Abstract]
Investments	Investments
	The following is a summary of the Company's investments as of March 31, 2015 and December 31, 2014 (in thousands):
		March 31,			December 31, 2014
		2015
	Trading investments	$	9,395		$	9,509
	Equity method investments	27,465			28,550
	Available-for-sale investments	21,320			21,269
	The Cohen & Steers Active Commodities Strategy Fund, Inc. (CDF), which was launched by the Company in May 2014, is an open-end mutual fund for which the Company is the investment adviser. As of March 31, 2015, the Company owned the majority of the outstanding voting interest in CDF. Accordingly, the underlying assets and liabilities and results of operations of CDF have been included in the Company's condensed consolidated financial statements with the third-party interests classified as redeemable noncontrolling interest.
	The Cohen & Steers MLP & Energy Opportunity Fund, Inc. (MLO), which was launched by the Company in December 2013, is an open-end mutual fund for which the Company is the investment adviser. The Company owned the majority of the outstanding voting interest in MLO through October 31, 2014. Accordingly, the underlying assets and liabilities and results of operations of MLO had been included in the Company's condensed consolidated financial statements with the third-party interests classified as redeemable noncontrolling interest. As a result of additional third-party subscriptions into the fund, effective November 1, 2014, the Company no longer owned the majority of the outstanding voting interest in MLO, however it was determined that the Company had significant influence over MLO. Accordingly, effective November 1, 2014, the Company began recording its investment in MLO using the equity method of accounting. As of March 31, 2015, the Company's ownership in MLO was approximately 23%.
	The Cohen & Steers Active Commodities Fund, LP (ACOM), launched by the Company in April 2013, is structured as a partnership. The Company is the investment adviser of ACOM for which it is entitled to receive a management fee. The Company owned all of the voting interest in ACOM through September 30, 2014. Accordingly, the underlying assets and liabilities and results of operations of ACOM had been included in the Company's condensed consolidated financial statements. As a result of third-party investments into the fund, effective October 1, 2014, the Company no longer held a controlling financial interest in ACOM. The Company determined that ACOM was not a VIE as the limited partners, unaffiliated with the Company, have the ability to liquidate the fund with a majority vote. As a result, the Company does not have financial control and ACOM is not consolidated into the Company's condensed consolidated financial statements. As the general partner, the Company has significant influence over the financial decisions of ACOM and therefore records its investment in ACOM using the equity method of accounting. The Company's equity interest in ACOM represents a seed investment to launch the fund, adjusted for the Company's proportionate share of the fund's earnings. As of March 31, 2015, the Company's ownership in ACOM was approximately 21%.
	Cohen & Steers Global Realty Partners III-TE, L.P. (GRP-TE), which had its closing in October 2011, is structured as a partnership. The Company is the general partner and investment adviser of GRP-TE, for which it receives a management fee and is entitled to receive an incentive distribution, if earned. GRP-TE is a VIE and the Company is not the primary beneficiary. As the general partner, the Company has significant influence over the financial decisions of GRP-TE and therefore records its investment using the equity method of accounting. The Company's equity interest in GRP-TE represents a seed investment to launch the fund, adjusted for the Company’s proportionate share of the fund’s earnings. As of March 31, 2015, the Company's ownership in GRP-TE was approximately 0.2%. The Company's risk with respect to its investment in GRP-TE is limited to its equity ownership and any uncollected management fees. In conjunction with the launch of GRP-TE, the Company established Cohen & Steers Co-Investment Partnership, L.P. (GRP-CIP), which is used by the Company to fulfill its contractual commitment to co-invest with GRP-TE. See Note 11 for further discussion regarding the Company's co-investment commitment. As of March 31, 2015, the Company owned all of the voting interest in GRP-CIP. Accordingly, the underlying assets and liabilities and results of operations of GRP-CIP have been included in the Company's condensed consolidated financial statements.
	Cohen & Steers Real Assets Fund, Inc. (RAP), which was launched by the Company on January 31, 2012, is an open-end mutual fund for which the Company is the investment adviser. During the period of August 1, 2013 through September 30, 2014, the Company did not hold a controlling financial interest in RAP, however it was determined that the Company had significant influence over RAP. Accordingly, the Company recorded its investment in RAP using the equity method of accounting. Effective September 30, 2014, the Company's ownership interest in RAP fell below 20% and the Company no longer has significant influence over RAP. Accordingly, the Company began recording its investment in RAP as an available-for-sale investment.
	Prior to its liquidation in April 2014, the Company owned the majority of the voting interests in Cohen & Steers Global Real Estate Long-Short Fund, L.P. (the Onshore Fund). Accordingly, the underlying assets and liabilities and results of operations of the Onshore Fund had been included in the Company's condensed consolidated financial statements. The Onshore Fund was structured as a partnership and the Company was the general partner and investment adviser of the fund.
	The Cohen & Steers Global Real Estate Long-Short Offshore Fund, L.P. (the Offshore Fund), which was liquidated in April 2014, was structured as a partnership. The Company was the general partner and investment adviser of the Offshore Fund for which it received a management fee and was entitled to receive a performance fee, if earned. The Company determined that the Offshore Fund was not a VIE as the limited partners, unaffiliated with the Company, had the ability to dissolve the fund with a majority vote. As a result, the Company did not have financial control and the Offshore Fund was not consolidated into the Company's condensed consolidated financial statements. As the general partner, the Company had significant influence over the financial decisions of the Offshore Fund and therefore recorded its investment in this fund using the equity method of accounting. The Company’s equity interest in the Offshore Fund represented a seed investment to launch the fund, adjusted for the Company’s proportionate share of the fund’s earnings.
	The following is a summary of the fair value of trading investments and equity method investments as of March 31, 2015 and December 31, 2014 (in thousands):
		March 31, 2015						December 31, 2014
		Trading Investments			Equity Method Investments			Trading Investments			Equity Method Investments
	ACOM	$	—		$	7,174		$	—		$	7,612
	CDF	6,950			—			7,000			—
	GRP-CIP	2,445			—			2,509			—
	GRP-TE	—			109			—			111
	MLO	—			20,182			—			20,827
	Total	$	9,395		$	27,465		$	9,509		$	28,550
	Gain (loss) from trading investments—net for the three months ended March 31, 2015 and 2014, which represent realized and unrealized gains and losses recorded by the funds the Company consolidates, are summarized below (in thousands):
		Three Months Ended
		March 31,
		2015			2014
	ACOM	$	—		$	537
	CDF	(463		)	—
	GRP-CIP	12			10
	MLO	—			412
	Onshore Fund	—			24
	Total (loss) gain from trading investments—net	$	(451	)	$	983
	Equity in earnings (losses) of affiliates for the three months ended March 31, 2015 and 2014 are summarized below (in thousands):
		Three Months Ended
		March 31,
		2015			2014
	ACOM	$	(438	)	$	—
	GRP-TE	2			20
	MLO	(645		)	—
	Offshore Fund	—			11
	RAP	—			904
	Total equity in (losses) earnings of affiliates	$	(1,081	)	$	935
	The following is a summary of the cost, gross unrealized gains, gross unrealized losses and fair value of available-for-sale investments as of March 31, 2015 and December 31, 2014 (in thousands):
		March 31, 2015
		Cost			Gross			Gross			Fair
					Unrealized			Unrealized			Value
					Gains			Losses (1)
	Preferred securities	$	1,079		$	71		$	(1	)	$	1,149
	Common stocks	5,497			590			(165		)	5,922
	Company-sponsored mutual funds	15,010			7			(768		)	14,249
	Total available-for-sale investments	$	21,586		$	668		$	(934	)	$	21,320
	_________________________
	(1)    At March 31, 2015, there were no securities with unrealized losses continuously for a period of more than 12 months.
		December 31, 2014
		Cost			Gross			Gross			Fair
					Unrealized			Unrealized			Value
					Gains			Losses (1)
	Preferred securities	$	1,043		$	54		$	(2	)	$	1,095
	Common stocks	5,366			627			(155		)	5,838
	Company-sponsored mutual funds	15,010			4			(678		)	14,336
	Total available-for-sale investments	$	21,419		$	685		$	(835	)	$	21,269
	_________________________
	(1)    At December 31, 2014, there were no securities with unrealized losses continuously for a period of more than 12 months.
The aggregate fair value of available-for-sale investments in an unrealized loss position was approximately $16,038,000 and $15,875,000 at March 31, 2015 and December 31, 2014, respectively.
Unrealized losses on available-for-sale investments as of March 31, 2015 were generally caused by market conditions. When evaluating whether an unrealized loss on an available-for-sale investment is other than temporary, the Company reviews such factors as the extent and duration of the loss, deterioration in the issuer’s credit quality, reduction or cessation of dividend payments and overall financial strength of the issuer. As of March 31, 2015, the Company determined that it had the ability and intent to hold the remaining investments for which no other-than-temporary impairment has occurred until a recovery of fair value. Accordingly, impairment of these investments is considered temporary.
Sales proceeds, gross realized gains and losses from available-for-sale investments for the three months ended March 31, 2015 and 2014 are summarized below (in thousands):
	Three Months Ended
	March 31,
	2015			2014
Proceeds from sales	$	1,390		$	6,750
Gross realized gains	169			1,106
Gross realized losses	(69		)	(30		)

Fair_Value

Fair Value	3 Months Ended
	Mar. 31, 2015
Fair Value [Abstract]
Fair Value	Fair Value
	Codification Topic 820, Fair Value Measurement (ASC 820) specifies a hierarchy of valuation classifications based on whether the inputs to the valuation techniques used in each valuation classification are observable or unobservable. These classifications are summarized in the three broad levels listed below:
	•	Level 1—Unadjusted quoted prices for identical instruments in active markets.
	•	Level 2—Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations in which all significant inputs and significant value drivers are observable.
	•	Level 3—Valuations derived from valuation techniques in which significant inputs or significant value drivers are unobservable.
	Inputs used to measure fair value might fall in different levels of the fair value hierarchy, in which case the Company defaults to the lowest level input that is significant to the fair value measurement in its entirety. These levels are not necessarily an indication of the risk or liquidity associated with the investments. In determining the appropriate levels, the Company performed a detailed analysis of the assets and liabilities that are subject to ASC 820. Transfers among levels, if any, are recorded at the beginning of the reporting period. There were no transfers between level 1 and level 2 during the three months ended March 31, 2015.
	The following table presents fair value measurements as of March 31, 2015 (in thousands):
		Level 1			Level 2			Level 3			Total
	Cash equivalents (1)	$	58,389		$	—		$	—		$	58,389
	Trading investments
	Fixed income securities	$	—		$	6,950		$	—		$	6,950
	Limited partnership interests	—			—			2,445			2,445
	Total trading investments	$	—		$	6,950		$	2,445		$	9,395
	Equity method investments	$	20,182		$	7,174		$	109		$	27,465
	Available-for-sale investments
	Preferred securities	$	1,149		$	—		$	—		$	1,149
	Common stocks	5,922			—			—			5,922
	Company-sponsored mutual funds	14,249			—			—			14,249
	Total available-for-sale investments	$	21,320		$	—		$	—		$	21,320
	Derivatives - assets
	Foreign exchange contracts	$	—		$	563		$	—		$	563
	Commodity contracts	141			—			—			141
	Total derivatives - assets	$	141		$	563		$	—		$	704
	Derivatives - liabilities
	Commodity contracts	$	419		$	—		$	—		$	419
	Total derivatives - liabilities	$	419		$	—		$	—		$	419
	_________________________
	(1)    Comprised of investments in actively traded money market funds measured at net asset value.
	Trading investments classified as level 2 in the above table were primarily comprised of investments in United States Treasury Bills carried at amortized cost, which approximates fair value.
	Trading investments classified as level 3 in the above table were comprised of limited partnership interests which represent the Company's co-investments through GRP-CIP, which along with the Company's interest in GRP-TE, represent the Company's collective ownership interests in limited partnership vehicles that invest in non-registered real estate funds, which are valued based on the net asset values of the underlying funds, and private equity vehicles that invest directly in real estate which are generally valued using a discounted cash flow model.
	Equity method investments classified as level 2 in the above table represent the carrying amount of the Company's partnership interest in ACOM, which approximates its fair value based on the fund's net asset value. ACOM invests in exchange-traded commodity futures contracts and other commodity related derivatives. The Company has the ability to redeem its investment in the fund monthly at net asset value per share with prior written notice of 5 days and there are no significant restrictions to redemption.
	Equity method investments classified as level 3 in the above table represent the carrying amount of the Company's partnership interest in GRP-TE, which approximates its fair value based on the fund's net asset value. GRP-TE invests in non-registered real estate funds and in private equity vehicles that invest directly in real estate. As of March 31, 2015, the Company did not have the ability to redeem its investment in GRP-TE.
	The following table presents fair value measurements as of December 31, 2014 (in thousands):
		Level 1			Level 2			Level 3			Total
	Cash equivalents (1)	$	59,281		$	—		$	—		$	59,281
	Trading investments
	Fixed income securities	$	—		$	7,000		$	—		$	7,000
	Limited partnership interests	—			—			2,509			2,509
	Total trading investments	$	—		$	7,000		$	2,509		$	9,509
	Equity method investments	$	20,827		$	7,612		$	111		$	28,550
	Available-for-sale investments
	Preferred securities	$	1,095		$	—		$	—		$	1,095
	Common stocks	5,838			—			—			5,838
	Company-sponsored mutual funds	14,336			—			—			14,336
	Total available-for-sale investments	$	21,269		$	—		$	—		$	21,269
	Derivatives - assets
	Foreign exchange contracts	$	—		$	505		$	—		$	505
	Commodity contracts	234			—			—			234
	Total derivatives - assets	$	234		$	505		$	—		$	739
	Derivatives - liabilities
	Foreign exchange contracts	$	—		$	12		$	—		$	12
	Commodity contracts	754			—			—			754
	Total derivatives - liabilities	$	754		$	12		$	—		$	766
	_________________________
	(1)    Comprised of investments in actively traded money market funds measured at net asset value.
	Trading investments classified as level 2 in the above table were primarily comprised of investments in United States Treasury Bills carried at amortized cost, which approximates fair value.
	Trading investments classified as level 3 in the above table were comprised of limited partnership interests which represent the Company's co-investments through GRP-CIP, which along with the Company's interest in GRP-TE, represent the Company's collective ownership interests in limited partnership vehicles that invest in non-registered real estate funds, which are valued based on the net asset values of the underlying funds, and private equity vehicles that invest directly in real estate which are generally valued using a discounted cash flow model.
	Equity method investments classified as level 2 in the above table represent the carrying amount of the Company's partnership interest in ACOM, which approximates its fair value based on the fund's net asset value. ACOM invests in exchange-traded commodity futures contracts and other commodity related derivatives. The Company has the ability to redeem its investment in the fund monthly at net asset value per share with prior written notice of 5 days and there are no significant restrictions to redemption.
	Equity method investments classified as level 3 in the above table represent the carrying amount of the Company's partnership interest in GRP-TE, which approximates its fair value based on the fund's net asset value. GRP-TE invests in non-registered real estate funds and in private equity vehicles that invest directly in real estate. As of December 31, 2014, the Company did not have the ability to redeem its investment in GRP-TE.
	The following table summarizes the changes in level 3 investments measured at fair value on a recurring basis for the three months ended March 31, 2015 (in thousands):
		Trading			Equity Method Investments
		Investments
		Limited Partnership Interests			GRP-TE
	Balance at January 1, 2015	$	2,509		$	111
Purchases / contributions	37			2
Sales / distributions	(113		)	(6		)
Realized gains	80			2
Unrealized losses (1)	(68		)	—
Transfers into (out of) level 3	—			—
Balance at March 31, 2015	$	2,445		$	109
_________________________
(1)    Pertains to unrealized gains (losses) from securities held at March 31, 2015.
The following table summarizes the changes in level 3 investments measured at fair value on a recurring basis for the three months ended March 31, 2014 (in thousands):
	Trading						Equity Method Investments			Available-for-sale investment
	Investments
	Common Stocks			Limited Partnership Interests			GRP-TE/Offshore Fund			Preferred Securities
Balance at January 1, 2014	$	503		$	2,740		$	528		$	3,325
Purchases / contributions	—			281			7			—
Sales / distributions	(527		)	(721		)	(29		)	(4,000		)
Realized gains	24			209			—			675
Unrealized (losses) gains (1)	—			(258		)	31			—
Transfers into (out of) level 3	—			—			—			—
Balance at March 31, 2014	$	—		$	2,251		$	537		$	—
_________________________
(1)    Pertains to unrealized gains (losses) from securities held at March 31, 2014.
Realized gains (losses) from investments classified as trading investments, equity method investments and available-for-sale investments in the above tables were recorded as gain (loss) from trading investments, equity in earnings (losses) of affiliates and gain (loss) from available-for-sale investments, respectively, in the Company's condensed consolidated statements of operations. Unrealized gains (losses) from investments classified as trading investments and equity method investments in the above tables were recorded as gain (loss) from trading investments and equity in earnings (losses) of affiliates, respectively, in the Company's condensed consolidated statements of operations. Unrealized gains (losses) from available-for-sale investments in the above tables were recorded as unrealized gain (loss) from available-for-sale investments in the Company's condensed consolidated statements of comprehensive income.
Valuation Techniques
In certain instances, debt and equity securities are valued on the basis of prices from an orderly transaction between market participants provided by reputable brokers/dealers or pricing services. In determining the value of a particular investment, pricing services may use information with respect to transactions in such investments, broker quotes, pricing matrices, market transactions in comparable investments and various relationships between investments. As part of its independent price verification process, the Company selectively performs detailed reviews of valuations provided by broker/dealers or pricing services.
Foreign exchange contracts are valued by interpolating a value using the spot foreign exchange rate and forward points (based on the spot rate and currency interest rate differentials), which are all inputs that are observable in active markets (level 2).
In the absence of observable market prices, the Company values its investments using valuation methodologies applied on a consistent basis. For some investments, little market activity may exist; management's determination of fair value is then based on the best information available in the circumstances, and may incorporate management's own assumptions and involves a significant degree of judgment, taking into consideration a combination of internal and external factors. Such investments are valued on a quarterly basis, taking into consideration any changes in key inputs and changes in economic and other relevant conditions, and valuation models are updated accordingly. The valuation process also includes a review by the Company's valuation committee which is comprised of senior members from various departments within the Company, including investment management. The valuation committee provides independent oversight of the valuation policies and procedures.
The valuation techniques and significant unobservable inputs used in the fair value measurement of the following level 3 investments as of March 31, 2015 were:
	Fair Value			Fair Value		Significant	Input /
	(in thousands)			Methodology		Unobservable Inputs	Range
Limited partnership interests - direct investments in real estate	$	1,403		Discounted cash flows		Discount rate	9.5% - 15%
						Exit capitalization rates	8% - 8.5%
						Market rental rates	$15.00 - 17.00 psf
The valuation techniques and significant unobservable inputs used in the fair value measurement of the following level 3 investments as of December 31, 2014 were:
	Fair Value			Fair Value		Significant	Input /
	(in thousands)			Methodology		Unobservable Inputs	Range
Limited partnership interests - direct investments in real estate	$	1,465		Discounted cash flows		Discount rate	9% - 15%
						Exit capitalization rates	8% - 8.5%
						Market rental rates	$15.00 - 17.00 psf
Changes in the significant unobservable inputs in the tables above may result in a materially higher or lower fair value measurement. The disclosure in the above tables excludes the Company's ownership interests in limited partnership vehicles which are valued based on the net asset values of the underlying funds.

Derivatives

Derivatives	3 Months Ended
	Mar. 31, 2015
Derivatives [Abstract]
Derivatives	Derivatives
	The following is a summary of the notional and fair value of the derivative financial instruments. The notional amount represents the absolute value amount of all outstanding derivative contracts as of March 31, 2015 (in thousands):
		31-Mar-15
		Assets						Liabilities
		Notional			Fair Value			Notional		Fair Value
	Total foreign exchange contracts	$	23,103		$	563		$	—	$	—
	Total commodity contracts	4,202			141			7,571		419
	Total derivatives	$	27,305		$	704		$	7,571	$	419
	The following is a summary of the notional and fair value of the derivative financial instruments. The notional amount represents the absolute value amount of all outstanding derivative contracts as of December 31, 2014 (in thousands):
		31-Dec-14
		Assets						Liabilities
		Notional			Fair Value			Notional		Fair Value
	Total foreign exchange contracts	$	11,349		$	505		$	222	$	12
	Total commodity contracts	6,095			234			8,977		754
	Total derivatives	$	17,444		$	739		$	9,199	$	766
	Cash included in due from broker in the condensed consolidated statement of financial condition of approximately $140,000 and $422,000 as of March 31, 2015 and December 31, 2014, respectively, was held as collateral for futures contracts. Securities included in trading investments in the condensed consolidated statement of financial condition of approximately $622,000 and $650,000 as of March 31, 2015 and December 31, 2014, respectively, were held as collateral for futures contracts.
	Gains and losses from derivative financial instruments for the three months ended March 31, 2015 and 2014 are summarized below (in thousands):
		Three Months Ended
		March 31,
		2015			2014
	Foreign exchange contracts	$	71		$	(168	)
	Commodity contracts	(465		)	548
	Total derivatives	$	(394	)	$	380

Earnings_Per_Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share
	Basic earnings per share is calculated by dividing net income attributable to common stockholders by the weighted average shares outstanding. Diluted earnings per share is calculated by dividing net income attributable to common stockholders by the total weighted average shares of common stock outstanding and common stock equivalents. Common stock equivalents are comprised of dilutive potential shares from restricted stock unit awards. Common stock equivalents are excluded from the computation if their effect is anti-dilutive. Diluted earnings per share are computed using the treasury stock method.
	No anti-dilutive common stock equivalents were excluded from the computation for the three months ended March 31, 2015 and 2014.
	The following is a reconciliation of the income and share data used in the basic and diluted earnings per share computations for the three months ended March 31, 2015 and 2014 (in thousands, except per share data):
		Three Months Ended
		March 31,
		2015		2014
	Net income	$	20,771	$	19,600
	Less: Net loss (income) attributable to redeemable noncontrolling interest	45		(155		)
	Net income attributable to common stockholders	$	20,816	$	19,445
	Basic weighted average shares outstanding	45,241		44,633
	Dilutive potential shares from restricted stock units	739		850
	Diluted weighted average shares outstanding	45,980		45,483
	Basic earnings per share attributable to common stockholders	$	0.46	$	0.44
	Diluted earnings per share attributable to common stockholders	$	0.45	$	0.43

Income_Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2015
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes
	The provision for income taxes for the three months ended March 31, 2015 includes U.S. federal, state, local and foreign taxes at an approximate effective tax rate of 37%. The effective tax rate for the three months ended March 31, 2014 was approximately 36.5%. The Company expects the tax rate for the full year 2015 to approximate 37%, excluding discrete items.
	Deferred income taxes represent the tax effects of the temporary differences between book and tax bases and are measured using enacted tax rates that will be in effect when such items are expected to reverse. The Company's net deferred tax asset is primarily comprised of future income tax deductions attributable to the delivery of unvested restricted stock units. The Company records a valuation allowance, when necessary, to reduce deferred tax assets to an amount that more likely than not will be realized.

Regulatory_Requirements

Regulatory Requirements	3 Months Ended
	Mar. 31, 2015
Regulatory Requirements [Abstract]
Regulatory Requirements	Regulatory Requirements
	CSS, a registered broker/dealer in the U.S., is subject to the SEC’s Uniform Net Capital Rule 15c3-1 (the Rule), which requires that broker/dealers maintain a minimum level of net capital, as prescribed under the Rule. As of March 31, 2015, CSS had net capital of approximately $1,258,000, which exceeded its requirements by approximately $1,078,000. The Rule also provides that equity capital may not be withdrawn or cash dividends paid if the resulting net capital of a broker/dealer is less than the amount required under the Rule and requires prior notice to the SEC for certain withdrawals of capital.
	CSS does not carry customer accounts and is exempt from SEC Rule 15c3-3 pursuant to provisions (k)(1) and (k)(2)(i) of such rule.
	CSAL and CSUK are regulated outside the U.S. by the Hong Kong Securities and Futures Commission and the United Kingdom Financial Conduct Authority, respectively. As of March 31, 2015, CSAL and CSUK had aggregate regulatory capital of approximately $64,826,000, which exceeded requirements by approximately $62,718,000.

Related_Party_Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2015
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions
	The Company is an investment adviser to, and has administrative agreements with, affiliated funds for which certain employees are officers and/or directors. The following table sets forth the amount of revenue the Company earned from these affiliated funds for the three months ended March 31, 2015 and 2014 (in thousands):
		Three Months Ended
		March 31,
		2015		2014
	Investment advisory and administration fees	$	56,109	$	48,137
	Distribution and service fees	3,906		3,470
		$	60,015	$	51,607
	Sales proceeds, gross realized gains, gross realized losses and dividend income from available-for-sale investments in Company-sponsored mutual funds for the three months ended March 31, 2015 and 2014 are summarized below (in thousands):
		Three Months Ended
		March 31,
		2015		2014
	Proceeds from sales	$	—	$	192
	Gross realized gains	—		—
	Gross realized losses	—		(3		)
	Dividend income	—		—
	The Company has agreements with certain affiliated open-end mutual funds and closed-end funds to reimburse certain fund expenses. For the three months ended March 31, 2015 and 2014, expenses of approximately $2,394,000 and $2,116,000, respectively, were incurred by the Company pursuant to these agreements and are included in general and administrative expenses.
	Included in accounts receivable at March 31, 2015 and December 31, 2014 are receivables due from Company-sponsored mutual funds of approximately $20,559,000 and $19,750,000, respectively.

Commitments_and_Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2015
Commitments and Contingencies [Abstract]
Commitments and Contingencies	Commitments and Contingencies
	From time to time, the Company is involved in legal matters relating to claims arising in the ordinary course of business. There are currently no such matters pending that the Company believes could have a material adverse effect on its condensed consolidated results of operations, cash flows or financial position.
	The Company periodically commits to fund a portion of the equity in certain of its sponsored investment products. The Company has committed to co-invest up to $5.1 million alongside GRP-TE, a portion of which is made through GRP-TE and the remainder of which is made through GRP-CIP for up to 12 years through the life of GRP-TE. As of March 31, 2015, the Company has funded approximately $3.2 million with respect to this commitment. The actual timing for funding the unfunded portion of this commitment is currently unknown, as the drawdown of the Company's unfunded commitment is contingent on the timing of drawdowns by the underlying funds and co-investments in which GRP-TE invests. The unfunded commitment was not recorded on the Company's condensed consolidated statements of financial condition as of March 31, 2015.

Concentration_of_Credit_Risk

Concentration of Credit Risk	3 Months Ended
	Mar. 31, 2015
Concentration of Credit Risk [Abstract]
Concentration of Credit Risk	Concentration of Credit Risk
	The Company's cash and cash equivalents are principally on deposit with three major financial institutions. The Company is subject to credit risk should these financial institutions be unable to fulfill their obligations.

Subsequent_Events

Subsequent Events	3 Months Ended
	Mar. 31, 2015
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events
	The Company has evaluated the need for disclosures and/or adjustments resulting from subsequent events through the date the condensed consolidated financial statements were issued. Other than the items described below, the Company determined that there were no additional subsequent events that require disclosure and/or adjustment.
	On May 7, 2015, CNS declared a quarterly dividend on its common stock in the amount of $0.25 per share. The dividend will be payable on June 25, 2015 to stockholders of record at the close of business on June 2, 2015.

Basis_of_Presentation_and_Sign1

Basis of Presentation and Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2015
Basis of Presentation and Significant Accounting Policies [Abstract]
Accounting Estimates	Accounting Estimates—The preparation of the condensed consolidated financial statements in conformity with GAAP requires management to make certain estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosures of contingent assets and liabilities at the dates of the condensed consolidated financial statements and the reported amounts of revenue and expenses during the reporting periods. Management believes the estimates used in preparing the condensed consolidated financial statements are reasonable and prudent. Actual results could differ from those estimates.
Reclassifications	Reclassifications—Certain prior year amounts have been reclassified to conform to the current year presentation.
Consolidation	Consolidation—The Company consolidates operating entities deemed to be voting interest entities if the Company owns a majority of the voting interest. The Company also consolidates any variable interest entities (VIEs) in which the Company is the primary beneficiary. The Company records noncontrolling interests in consolidated subsidiaries for which the Company’s ownership is less than 100 percent. The equity method of accounting is used for investments in affiliates in which the Company’s ownership ranges from 20 to 50 percent, or in instances in which the Company is able to exercise significant influence but not control.
VIE	A VIE is an entity in which either (a) the equity investment at risk is not sufficient to permit the entity to finance its own activities without additional financial support or (b) the group of holders of the equity investment at risk lack certain characteristics of a controlling financial interest. The primary beneficiary is the entity that has the obligation to absorb a majority of the expected losses or the right to receive the majority of the residual returns. Investments and redemptions or amendments to the governing documents of the respective entities could affect an entity's status as a VIE or the determination of the primary beneficiary. The Company assesses whether entities in which it has an interest are VIEs upon initial involvement and at each reporting date. The Company assesses whether it is the primary beneficiary of any VIEs identified by evaluating its economic interests in the entity held either directly by the Company and its affiliates or indirectly through employees.
Cash and Cash Equivalents	Cash and Cash Equivalents—Cash equivalents consist of short-term, highly liquid investments, which are readily convertible into cash and have original maturities of three months or less.
Due from Broker	Due from Broker—The Company conducts business, primarily through its consolidated seed investments, with brokers for certain of its investment activities. The clearing and custody operations for these investment activities are performed pursuant to contractual agreements. The due from broker balance represents cash and cash equivalents balances at brokers/custodians and net receivables and payables for unsettled security transactions.
Investments	Investments—Management of the Company determines the appropriate classification of its investments at the time of purchase and re-evaluates such determination at each statement of financial condition date.
	Investments classified as trading represent securities held within the affiliated funds that the Company consolidates and are measured at fair value based on quoted market prices, market prices obtained from independent pricing services engaged by management or as determined by the Company’s valuation committee. Unrealized gains and losses are recorded as gain (loss) from trading investments—net in the Company’s condensed consolidated statements of operations.
	Investments classified as equity method investments are accounted for using the equity method, under which the Company recognizes its respective share of the investee’s net income or loss for the period. As of March 31, 2015, the Company's equity method investments consisted of interests in affiliated funds which measure their underlying investments at fair value and report a net asset value on a recurring basis. The carrying amounts of these investments approximate their fair value.
	Investments classified as available-for-sale are comprised of equity securities, investment-grade preferred instruments and investments in Company-sponsored open-end mutual funds. These investments are carried at fair value based on quoted market prices or market prices obtained from independent pricing services engaged by management, with unrealized gains and losses, net of tax, reported in accumulated other comprehensive income. The Company periodically reviews each individual security position that has an unrealized loss, or impairment, to determine if that impairment is other than temporary. If the Company believes an impairment of a security position is other than temporary, the loss will be recognized in the Company’s condensed consolidated statements of operations. An other than temporary impairment is presumed to have occurred if the available-for-sale investment has an unrealized loss continuously for 12 or more months.
	From time to time, the affiliated funds consolidated by the Company enter into derivative contracts to gain exposure to the underlying commodities markets or to hedge market and credit risks of the underlying portfolios utilizing options, total return swaps, credit default swaps and futures contracts. These instruments are measured at fair value with gains and losses recorded as gain (loss) from trading investments—net in the Company's condensed consolidated statements of operations. The fair values of these instruments are recorded in other assets or other liabilities and accrued expenses in the Company's condensed consolidated statements of financial condition. As of March 31, 2015, none of the outstanding derivative contracts were subject to a master netting agreement or other similar arrangement.
	Additionally, from time to time, the Company enters into foreign exchange contracts to hedge its currency exposure related to client receivables. These instruments are measured at fair value with gains and losses recorded in other non-operating income in the Company's condensed consolidated statements of operations. The fair values of these contracts are recorded in other assets or other liabilities and accrued expenses in the Company's condensed consolidated statements of financial condition.
Goodwill and Intangible Assets	Goodwill and Intangible Assets—Goodwill represents the excess of the cost of the Company’s investment in the net assets of an acquired company over the fair value of the underlying identifiable net assets at the date of acquisition. Goodwill and indefinite lived intangible assets are not amortized but are tested at least annually for impairment by comparing the fair value to their carrying amounts. Finite lived intangible assets are amortized over their useful lives and are tested for impairment whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. See Note 3 for further discussion about the Company’s goodwill and intangible assets.
Redeemable Noncontrolling Interest	Redeemable Noncontrolling Interest—Redeemable noncontrolling interest represents third-party interests in the Company's consolidated entities. This interest is redeemable at the option of the investors and therefore is not treated as permanent equity. Redeemable noncontrolling interest is remeasured at redemption value which approximates the fair value at each reporting period.
Investment Advisory and Administrative Fees	Investment Advisory and Administration Fees—The Company earns revenue by providing asset management services to institutional accounts and to Company-sponsored open-end mutual funds and closed-end funds. Investment advisory fees are earned pursuant to the terms of underlying advisory contracts, and are based on a contractual fee rate applied to the assets in the portfolio. The Company also earns administration fees from certain Company-sponsored open-end mutual funds and closed-end funds pursuant to the terms of underlying administration contracts. Administration fees are based on the average assets under management of such funds. Investment advisory and administration fee revenue is recognized as such fees are earned.
Distribution and Service Fee Revenue	Distribution and Service Fee Revenue—CSS acts as the principal distributor of the Company’s sponsored open-end mutual funds which may offer the following classes: Class A (initial sales load), Class C (back end sales load), Class R (load retirement) and Class Z (no load retirement). Effective May 2007, the Company suspended sales of Class B shares and all remaining Class B shares are expected to convert to Class A shares in 2015. Distribution and service fee revenue is based on the average daily net assets of the funds as detailed below. Distribution and service fee revenue is earned daily and is recorded gross of any third-party distribution and service fee expense for applicable share classes.
	Pursuant to distribution plans with the Company's sponsored open-end mutual funds, CSS receives distribution fees of up to 25bps for Class A shares, 75bps for Class C shares and 50bps for Class R shares. CSS also receives shareholder servicing fees of up to 10bps on Class A shares, 25bps on Class C shares and 15bps on Class Z shares, pursuant to shareholder servicing plans with the funds. Effective October 1, 2014, the Company no longer receives shareholder servicing fees on Class Z shares.
Distribution and Service Fee Expense	Distribution and Service Fee Expense—Distribution and service fee expense includes distribution fees, service fees and intermediary assistance payments. Distribution and service fee expense is recorded as incurred.
	Distribution fee expense represents payments made to qualified dealers/institutions for (i) assistance in connection with the distribution of the Company's sponsored open-end mutual funds' shares and (ii) for other expenses such as advertising costs and printing and distribution of prospectuses to investors. Such amounts may also be used to pay financial intermediaries for services as specified in the terms of written agreements complying with Rule 12b-1 of the Investment Company Act of 1940 (Rule 12b-1). CSS pays distribution fee expense based on the average daily net assets under management of up to 25bps on Class A shares, 75bps on Class C shares and 50bps on Class R shares.
	Shareholder servicing fee expense represents payments made to qualified dealers/institutions for shareholder account service and maintenance. These services are provided pursuant to written agreements with such qualified institutions. CSS pays service fee expenses based on the average daily net assets under management of up to 10bps on Class A shares, 25bps on Class C shares and 15bps on Class Z shares. Effective October 1, 2014, Class Z shares no longer pay shareholder service fees.
	Intermediary assistance payments represent payments to qualified dealers/institutions for activities related to distribution, shareholder servicing and marketing and support of Company-sponsored open-end mutual funds and are incremental to those described above. Intermediary assistance payments are generally based on the average assets under management or the number of accounts being serviced.
Portfolio Consulting and Other	Portfolio Consulting and Other—The Company earns portfolio consulting and other fees by: (i) providing portfolio consulting services in connection with model-based strategies accounts; (ii) earning a licensing fee for the use of the Company's proprietary indices; and (iii) providing portfolio monitoring services related to a number of unit investment trusts. This revenue is earned pursuant to the terms of the underlying contract, and the fee schedules for these relationships vary based on the type of services the Company provides for each relationship. This revenue is recognized as such fees are earned.
Stock-based Compensation	Stock-based Compensation—The Company recognizes compensation expense for the grant-date fair value of awards of equity instruments granted to employees. This expense is recognized over the period during which employees are required to provide service. The Company also estimates forfeitures.
Income Taxes	Income Taxes—The Company records the current and deferred tax consequences of all transactions that have been recognized in the condensed consolidated financial statements in accordance with the provisions of the enacted tax laws. Deferred tax assets are recognized for temporary differences that will result in deductible amounts in future years at tax rates that are expected to apply in those years. Deferred tax liabilities are recognized for temporary differences that will result in taxable income in future years at tax rates that are expected to apply in those years. The Company records a valuation allowance, when necessary, to reduce deferred tax assets to an amount that more likely than not will be realized. The effective tax rate for interim periods represents the Company’s best estimate of the effective tax rate expected to be applied to the full fiscal year.
Currency Translation and Transactions	Currency Translation and Transactions—Assets and liabilities of subsidiaries having non-U.S. dollar functional currencies are translated at exchange rates at the applicable condensed consolidated statement of financial condition date. Revenue and expenses of subsidiaries are translated at average exchange rates during the period. The gains or losses resulting from translating non-U.S. dollar functional currency into U.S. dollars are included in the Company's condensed consolidated statements of comprehensive income. The cumulative translation adjustment was $(3,524,000) and $(1,446,000) as of March 31, 2015 and December 31, 2014, respectively. Gains or losses resulting from non-U.S. dollar currency transactions are included in other non-operating income in the condensed consolidated statements of operations.
Comprehensive Income	Comprehensive Income—The Company reports all changes in comprehensive income in the condensed consolidated statements of comprehensive income. Comprehensive income includes net income or loss attributable to common stockholders, foreign currency translation gain and loss (net of tax), unrealized gain and loss from available-for-sale investments (net of tax) and reclassification to statements of operations of gain and loss from available-for-sale investments (net of tax).
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements—In May 2015, the Financial Accounting Standards Board (FASB) issued new guidance amending the current disclosure requirement for investments in certain entities that calculate net asset value per share. The guidance requires investments for which fair value is measured using the net asset value per share practical expedient be removed from the fair value hierarchy. Instead, those investment amounts shall be provided as a separate item to permit reconciliation of the fair value of investments included in the fair value hierarchy to the line items presented in the statement of financial position. This new guidance will be effective for the Company’s first quarter of 2016. The Company is currently evaluating the potential impact on its condensed consolidated financial statements and related disclosures.
	In February 2015, the FASB issued new guidance amending the current accounting for consolidation of certain legal entities. These amendments modify the evaluation of whether limited partnerships and similar legal entities are VIEs or voting interest entities, eliminate the presumption that a general partner should consolidate a limited partnership, affect the consolidation analysis of reporting entities that are involved with VIEs, particularly those that have fee arrangements and related party relationships, and provide a scope exception from consolidation guidance for reporting entities with interests in certain investment funds. This new guidance will be effective for the Company’s first quarter of 2016. The Company is currently evaluating the potential impact on its condensed consolidated financial statements and related disclosures.
	In August 2014, the FASB issued new guidance regarding disclosure of going concern uncertainties in the financial statements. The guidance requires management to evaluate whether there are conditions or events, considered in the aggregate, that raise substantial doubt about the entity's ability to continue as a going concern within one year after the date that the financial statements are issued at each annual and interim reporting period. This new guidance will be effective for the Company’s first quarter of 2017. The Company does not anticipate that the adoption of this new guidance will have a material impact on the Company's condensed consolidated financial statements.
	In May 2014, the FASB issued new guidance which outlined a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers. The core principle of the revenue model 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. This new guidance will be effective for the Company's first quarter of 2017 and requires either a retrospective or a modified retrospective approach to adoption. Early application is prohibited. The Company is currently evaluating the potential impact on its condensed consolidated financial statements and related disclosures, as well as the available transition methods.
Valuation Techniques	Valuation Techniques
	In certain instances, debt and equity securities are valued on the basis of prices from an orderly transaction between market participants provided by reputable brokers/dealers or pricing services. In determining the value of a particular investment, pricing services may use information with respect to transactions in such investments, broker quotes, pricing matrices, market transactions in comparable investments and various relationships between investments. As part of its independent price verification process, the Company selectively performs detailed reviews of valuations provided by broker/dealers or pricing services.
	Foreign exchange contracts are valued by interpolating a value using the spot foreign exchange rate and forward points (based on the spot rate and currency interest rate differentials), which are all inputs that are observable in active markets (level 2).
	In the absence of observable market prices, the Company values its investments using valuation methodologies applied on a consistent basis. For some investments, little market activity may exist; management's determination of fair value is then based on the best information available in the circumstances, and may incorporate management's own assumptions and involves a significant degree of judgment, taking into consideration a combination of internal and external factors. Such investments are valued on a quarterly basis, taking into consideration any changes in key inputs and changes in economic and other relevant conditions, and valuation models are updated accordingly. The valuation process also includes a review by the Company's valuation committee which is comprised of senior members from various departments within the Company, including investment management. The valuation committee provides independent oversight of the valuation policies and procedures.

Goodwill_and_Intangible_Assets1

Goodwill and Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2015
Goodwill and Intangible Assets [Abstract]
Schedule of Intangible Assets	The following table details the gross carrying amounts and accumulated amortization for the intangible assets at March 31, 2015 and December 31, 2014 (in thousands):
		Remaining		Gross		Accumulated			Intangible
		Amortization		Carrying		Amortization			Assets, Net
		Period		Amount
		(in months)
	March 31, 2015:
	Amortized intangible assets:
	Client relationships	45		$	1,543	$	(1,203	)	$	340
	Non-amortized intangible assets:
	Mutual fund management contracts	—		1,250		—			1,250
	Total			$	2,793	$	(1,203	)	$	1,590
	December 31, 2014:
	Amortized intangible assets:
	Client relationships	48		$	1,543	$	(1,181	)	$	362
	Non-amortized intangible assets:
	Mutual fund management contracts	—		1,250		—			1,250
	Total			$	2,793	$	(1,181	)	$	1,612
Schedule Future Amortization Expense	Estimated future amortization expense is as follows (in thousands):
	Periods Ending December 31,	Estimated
		Amortization
		Expense
	2015	$	67
	2016	89
	2017	89
	2018	95
	2019	—
	Total	$	340

Investments_Tables

Investments (Tables)	3 Months Ended
	Mar. 31, 2015
Investments [Abstract]
Summary Investment Holdings	The following is a summary of the Company's investments as of March 31, 2015 and December 31, 2014 (in thousands):
		March 31,			December 31, 2014
		2015
	Trading investments	$	9,395		$	9,509
	Equity method investments	27,465			28,550
	Available-for-sale investments	21,320			21,269
Schedule of Fair Value of Trading Investments and Equity Method Investments	The following is a summary of the fair value of trading investments and equity method investments as of March 31, 2015 and December 31, 2014 (in thousands):
		March 31, 2015						December 31, 2014
		Trading Investments			Equity Method Investments			Trading Investments			Equity Method Investments
	ACOM	$	—		$	7,174		$	—		$	7,612
	CDF	6,950			—			7,000			—
	GRP-CIP	2,445			—			2,509			—
	GRP-TE	—			109			—			111
	MLO	—			20,182			—			20,827
	Total	$	9,395		$	27,465		$	9,509		$	28,550
Trading Investments	Gain (loss) from trading investments—net for the three months ended March 31, 2015 and 2014, which represent realized and unrealized gains and losses recorded by the funds the Company consolidates, are summarized below (in thousands):
		Three Months Ended
		March 31,
		2015			2014
	ACOM	$	—		$	537
	CDF	(463		)	—
	GRP-CIP	12			10
	MLO	—			412
	Onshore Fund	—			24
	Total (loss) gain from trading investments—net	$	(451	)	$	983
Schedule of Equity in Earnings (Losses) of Affiliates	Equity in earnings (losses) of affiliates for the three months ended March 31, 2015 and 2014 are summarized below (in thousands):
		Three Months Ended
		March 31,
		2015			2014
	ACOM	$	(438	)	$	—
	GRP-TE	2			20
	MLO	(645		)	—
	Offshore Fund	—			11
	RAP	—			904
	Total equity in (losses) earnings of affiliates	$	(1,081	)	$	935
Schedule of Available-for-sale Investments Reconciliation	The following is a summary of the cost, gross unrealized gains, gross unrealized losses and fair value of available-for-sale investments as of March 31, 2015 and December 31, 2014 (in thousands):
		March 31, 2015
		Cost			Gross			Gross			Fair
					Unrealized			Unrealized			Value
					Gains			Losses (1)
	Preferred securities	$	1,079		$	71		$	(1	)	$	1,149
	Common stocks	5,497			590			(165		)	5,922
	Company-sponsored mutual funds	15,010			7			(768		)	14,249
	Total available-for-sale investments	$	21,586		$	668		$	(934	)	$	21,320
	_________________________
	(1)    At March 31, 2015, there were no securities with unrealized losses continuously for a period of more than 12 months.
		December 31, 2014
		Cost			Gross			Gross			Fair
					Unrealized			Unrealized			Value
					Gains			Losses (1)
	Preferred securities	$	1,043		$	54		$	(2	)	$	1,095
	Common stocks	5,366			627			(155		)	5,838
	Company-sponsored mutual funds	15,010			4			(678		)	14,336
	Total available-for-sale investments	$	21,419		$	685		$	(835	)	$	21,269
	_________________________
	(1)    At December 31, 2014, there were no securities with unrealized losses continuously for a period of more than 12 months.
Realized Gain (Loss) on Investments	Sales proceeds, gross realized gains and losses from available-for-sale investments for the three months ended March 31, 2015 and 2014 are summarized below (in thousands):
		Three Months Ended
		March 31,
		2015			2014
	Proceeds from sales	$	1,390		$	6,750
	Gross realized gains	169			1,106
	Gross realized losses	(69		)	(30		)

Fair_Value_Tables

Fair Value (Tables)	3 Months Ended
	Mar. 31, 2015
Fair Value [Abstract]
Fair Value Measurements, Recurring and Nonrecurring	The following table presents fair value measurements as of December 31, 2014 (in thousands):
		Level 1			Level 2			Level 3			Total
	Cash equivalents (1)	$	59,281		$	—		$	—		$	59,281
	Trading investments
	Fixed income securities	$	—		$	7,000		$	—		$	7,000
	Limited partnership interests	—			—			2,509			2,509
	Total trading investments	$	—		$	7,000		$	2,509		$	9,509
	Equity method investments	$	20,827		$	7,612		$	111		$	28,550
	Available-for-sale investments
	Preferred securities	$	1,095		$	—		$	—		$	1,095
	Common stocks	5,838			—			—			5,838
	Company-sponsored mutual funds	14,336			—			—			14,336
	Total available-for-sale investments	$	21,269		$	—		$	—		$	21,269
	Derivatives - assets
	Foreign exchange contracts	$	—		$	505		$	—		$	505
	Commodity contracts	234			—			—			234
	Total derivatives - assets	$	234		$	505		$	—		$	739
	Derivatives - liabilities
	Foreign exchange contracts	$	—		$	12		$	—		$	12
	Commodity contracts	754			—			—			754
	Total derivatives - liabilities	$	754		$	12		$	—		$	766
	_________________________
	(1)    Comprised of investments in actively traded money market funds measured at net asset value.
	The following table presents fair value measurements as of March 31, 2015 (in thousands):
		Level 1			Level 2			Level 3			Total
	Cash equivalents (1)	$	58,389		$	—		$	—		$	58,389
	Trading investments
	Fixed income securities	$	—		$	6,950		$	—		$	6,950
	Limited partnership interests	—			—			2,445			2,445
	Total trading investments	$	—		$	6,950		$	2,445		$	9,395
	Equity method investments	$	20,182		$	7,174		$	109		$	27,465
	Available-for-sale investments
	Preferred securities	$	1,149		$	—		$	—		$	1,149
	Common stocks	5,922			—			—			5,922
	Company-sponsored mutual funds	14,249			—			—			14,249
	Total available-for-sale investments	$	21,320		$	—		$	—		$	21,320
	Derivatives - assets
	Foreign exchange contracts	$	—		$	563		$	—		$	563
	Commodity contracts	141			—			—			141
	Total derivatives - assets	$	141		$	563		$	—		$	704
	Derivatives - liabilities
	Commodity contracts	$	419		$	—		$	—		$	419
	Total derivatives - liabilities	$	419		$	—		$	—		$	419
	_________________________
	(1)    Comprised of investments in actively traded money market funds measured at net asset value.
Fair Value, Valuation Technique, Unobservable Inputs	The following table summarizes the changes in level 3 investments measured at fair value on a recurring basis for the three months ended March 31, 2015 (in thousands):
		Trading			Equity Method Investments
		Investments
		Limited Partnership Interests			GRP-TE
	Balance at January 1, 2015	$	2,509		$	111
	Purchases / contributions	37			2
	Sales / distributions	(113		)	(6		)
	Realized gains	80			2
	Unrealized losses (1)	(68		)	—
	Transfers into (out of) level 3	—			—
	Balance at March 31, 2015	$	2,445		$	109
	_________________________
	(1)    Pertains to unrealized gains (losses) from securities held at March 31, 2015.
	The following table summarizes the changes in level 3 investments measured at fair value on a recurring basis for the three months ended March 31, 2014 (in thousands):
		Trading						Equity Method Investments			Available-for-sale investment
		Investments
		Common Stocks			Limited Partnership Interests			GRP-TE/Offshore Fund			Preferred Securities
	Balance at January 1, 2014	$	503		$	2,740		$	528		$	3,325
	Purchases / contributions	—			281			7			—
	Sales / distributions	(527		)	(721		)	(29		)	(4,000		)
	Realized gains	24			209			—			675
	Unrealized (losses) gains (1)	—			(258		)	31			—
	Transfers into (out of) level 3	—			—			—			—
	Balance at March 31, 2014	$	—		$	2,251		$	537		$	—
	_________________________
	(1)    Pertains to unrealized gains (losses) from securities held at March 31, 2014.
	The valuation techniques and significant unobservable inputs used in the fair value measurement of the following level 3 investments as of March 31, 2015 were:
		Fair Value			Fair Value		Significant	Input /
		(in thousands)			Methodology		Unobservable Inputs	Range
	Limited partnership interests - direct investments in real estate	$	1,403		Discounted cash flows		Discount rate	9.5% - 15%
							Exit capitalization rates	8% - 8.5%
							Market rental rates	$15.00 - 17.00 psf
	The valuation techniques and significant unobservable inputs used in the fair value measurement of the following level 3 investments as of December 31, 2014 were:
		Fair Value			Fair Value		Significant	Input /
		(in thousands)			Methodology		Unobservable Inputs	Range
	Limited partnership interests - direct investments in real estate	$	1,465		Discounted cash flows		Discount rate	9% - 15%
							Exit capitalization rates	8% - 8.5%
							Market rental rates	$15.00 - 17.00 psf

Derivatives_Tables

Derivatives (Tables)	3 Months Ended
	Mar. 31, 2015
Derivatives [Abstract]
Schedule of Derivative Instruments	The following is a summary of the notional and fair value of the derivative financial instruments. The notional amount represents the absolute value amount of all outstanding derivative contracts as of March 31, 2015 (in thousands):
		31-Mar-15
		Assets						Liabilities
		Notional			Fair Value			Notional		Fair Value
	Total foreign exchange contracts	$	23,103		$	563		$	—	$	—
	Total commodity contracts	4,202			141			7,571		419
	Total derivatives	$	27,305		$	704		$	7,571	$	419
	The following is a summary of the notional and fair value of the derivative financial instruments. The notional amount represents the absolute value amount of all outstanding derivative contracts as of December 31, 2014 (in thousands):
		31-Dec-14
		Assets						Liabilities
		Notional			Fair Value			Notional		Fair Value
	Total foreign exchange contracts	$	11,349		$	505		$	222	$	12
	Total commodity contracts	6,095			234			8,977		754
	Total derivatives	$	17,444		$	739		$	9,199	$	766
Gains (losses) on Derivatives	Gains and losses from derivative financial instruments for the three months ended March 31, 2015 and 2014 are summarized below (in thousands):
		Three Months Ended
		March 31,
		2015			2014
	Foreign exchange contracts	$	71		$	(168	)
	Commodity contracts	(465		)	548
	Total derivatives	$	(394	)	$	380

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following is a reconciliation of the income and share data used in the basic and diluted earnings per share computations for the three months ended March 31, 2015 and 2014 (in thousands, except per share data):
		Three Months Ended
		March 31,
		2015		2014
	Net income	$	20,771	$	19,600
	Less: Net loss (income) attributable to redeemable noncontrolling interest	45		(155		)
	Net income attributable to common stockholders	$	20,816	$	19,445
	Basic weighted average shares outstanding	45,241		44,633
	Dilutive potential shares from restricted stock units	739		850
	Diluted weighted average shares outstanding	45,980		45,483
	Basic earnings per share attributable to common stockholders	$	0.46	$	0.44
	Diluted earnings per share attributable to common stockholders	$	0.45	$	0.43

Related_Party_Transactions_Tab

Related Party Transactions (Tables)	3 Months Ended
	Mar. 31, 2015
Related Party Transactions [Abstract]
Schedule of Related Party Transactions	The Company is an investment adviser to, and has administrative agreements with, affiliated funds for which certain employees are officers and/or directors. The following table sets forth the amount of revenue the Company earned from these affiliated funds for the three months ended March 31, 2015 and 2014 (in thousands):
		Three Months Ended
		March 31,
		2015		2014
	Investment advisory and administration fees	$	56,109	$	48,137
	Distribution and service fees	3,906		3,470
		$	60,015	$	51,607
Schedule of Realized Gain (Loss)	Sales proceeds, gross realized gains, gross realized losses and dividend income from available-for-sale investments in Company-sponsored mutual funds for the three months ended March 31, 2015 and 2014 are summarized below (in thousands):
		Three Months Ended
		March 31,
		2015		2014
	Proceeds from sales	$	—	$	192
	Gross realized gains	—		—
	Gross realized losses	—		(3		)
	Dividend income	—		—

Basis_of_Presentation_and_Sign2

Basis of Presentation and Significant Accounting Policies (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Minimum
Schedule of Equity Method Investments [Line Items]
Ownership percentage range	20.00%
Maximum
Schedule of Equity Method Investments [Line Items]
Ownership percentage range	50.00%
Accumulated Translation Adjustment
Cumulative Translation Adjustments balance [Line Items]
Cumulative Foreign Currency Translation Adjustment, Net of Tax	($3,524)	($1,446)

Basis_of_Presentation_and_Sign3

Basis of Presentation and Significant Accounting Policies (Distribution Rates - Phantom) (Details)	3 Months Ended
	Mar. 31, 2015
Class C Shares
Investment [Line Items]
Distribution fees revenue, Percent	0.75%
Shareholder service fee revenue, Percent	0.25%
Distribution fee expense, Percent	0.75%
Shareholder service fee expense, Percent	0.25%
Class R Shares
Investment [Line Items]
Distribution fees revenue, Percent	0.50%
Distribution fee expense, Percent	0.50%
Class Z Shares
Investment [Line Items]
Shareholder service fee revenue, Percent	0.15%
Shareholder service fee expense, Percent	0.15%
Maximum | Class A Shares
Investment [Line Items]
Distribution fees revenue, Percent	0.25%
Shareholder service fee revenue, Percent	0.10%
Distribution fee expense, Percent	0.25%
Shareholder service fee expense, Percent	0.10%

Goodwill_and_Intangible_Assets2

Goodwill and Intangible Assets (Details) (USD $)	3 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Schedule of Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Goodwill	$17,862		$19,120
Goodwill, Translation Adjustments	-1,258
Finite-Lived Intangible Assets, Accumulated Amortization	-1,203		-1,181
Intangible Assets, Net	340
Intangible Assets, Gross	2,793		2,793
Intangible Assets, Net	1,590		1,612
Amortization of Intangible Assets	22	22
Remaining Amortization Period	45 months		48 months
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2015	67
2016	89
2017	89
2018	95
2019	0
Total	340
Client Relationships
Schedule of Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	1,543		1,543
Finite-Lived Intangible Assets, Accumulated Amortization	-1,203		-1,181
Intangible Assets, Net	340		362
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Total	340		362
Mutual Fund Management Contracts
Schedule of Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Indefinite-lived Intangible Assets	$1,250		$1,250

Investments_Trading_and_Equity

Investments Trading and Equity Investments (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014	Dec. 31, 2014
Trading Investments and Other Trading Assets [Line Items]
Trading investments	$9,395	[1]		$9,509	[1]
Equity Method Investments, Fair Value Disclosure	27,465			28,550
Available-for-sale investments	21,320			21,269
Gain from trading investments—net	-451		983
Equity in earnings of affiliates	-1,081		935
Minimum
Trading Investments and Other Trading Assets [Line Items]
Ownership percentage range	20.00%
ACOM
Trading Investments and Other Trading Assets [Line Items]
Trading investments	0			0
Equity Method Investments, Fair Value Disclosure	7,174			7,612
Ownership percentage range	21.00%
Gain from trading investments—net	0		537
Equity in earnings of affiliates	-438		0
CDF
Trading Investments and Other Trading Assets [Line Items]
Trading investments	6,950			7,000
Equity Method Investments, Fair Value Disclosure	0			0
Gain from trading investments—net	-463		0
GRP-CIP
Trading Investments and Other Trading Assets [Line Items]
Trading investments	2,445			2,509
Equity Method Investments, Fair Value Disclosure	0			0
Gain from trading investments—net	12		10
GRP-TE
Trading Investments and Other Trading Assets [Line Items]
Trading investments	0			0
Equity Method Investments, Fair Value Disclosure	109			111
Ownership percentage range	0.20%
Equity in earnings of affiliates	2		20
MLO
Trading Investments and Other Trading Assets [Line Items]
Trading investments	0			0
Equity Method Investments, Fair Value Disclosure	20,182			20,827
Ownership percentage range	23.00%
Gain from trading investments—net	0		412
Equity in earnings of affiliates	-645		0
Onshore Fund
Trading Investments and Other Trading Assets [Line Items]
Gain from trading investments—net	0		24
Offshore Fund
Trading Investments and Other Trading Assets [Line Items]
Equity in earnings of affiliates	0		11
RAP
Trading Investments and Other Trading Assets [Line Items]
Equity in earnings of affiliates	$0		$904
[1]	Includes $622 and $650 held as collateral attributable to the consolidated balances of Cohen & Steers Active Commodities Strategy Fund, Inc. (CDF) as of March 31, 2015 and December 31, 2014, respectively.

Investments_AvailableforSale_I

Investments Available-for-Sale Investments (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014	Dec. 31, 2014
Available-for-sale Investments [Abstract]
Cost	$21,586			$21,419
Gross Unrealized Gains	668			685
Gross Unrealized Losses	-934	[1]		-835	[2]
Fair Value	21,320			21,269
Available-for-sale investments in an unrealized loss position	16,038			15,875
Proceeds from Investing Activities [Abstract]
Proceeds from sales	1,390		6,750
Gross realized gains	169		1,106
Gross realized losses	-69		-30
Preferred securities
Available-for-sale Investments [Abstract]
Cost	1,079			1,043
Gross Unrealized Gains	71			54
Gross Unrealized Losses	-1	[1]		-2	[2]
Fair Value	1,149			1,095
Common stocks
Available-for-sale Investments [Abstract]
Cost	5,497			5,366
Gross Unrealized Gains	590			627
Gross Unrealized Losses	-165	[1]		-155	[2]
Fair Value	5,922			5,838
Company-sponsored mutual funds
Available-for-sale Investments [Abstract]
Cost	15,010			15,010
Gross Unrealized Gains	7			4
Gross Unrealized Losses	-768	[1]		-678	[2]
Fair Value	$14,249			$14,336
[1]	At March 31, 2015, there were no securities with unrealized losses continuously for a period of more than 12 months.
[2]	At December 31, 2014, there were no securities with unrealized losses continuously for a period of more than 12 months.

Fair_Value_Details

Fair Value (Details) (USD $)	3 Months Ended				12 Months Ended		3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015		Dec. 31, 2014		Dec. 31, 2014		Mar. 31, 2014
	fair_value_hierarchy
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment redemption notice period	5 days		5 days
Number of fair value hierarchy	3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Trading investments	$9,395	[1]	$9,509	[1]	9,509	[1]
Equity method investments	27,465		28,550		28,550
Available-for-sale investments	21,320		21,269		21,269
Common stocks
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Available-for-sale investments	5,922		5,838		5,838
Preferred securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Available-for-sale investments	1,149		1,095		1,095
GRP-TE
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Trading investments	0		0		0
Equity method investments	109		111		111
Company-sponsored mutual funds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Available-for-sale investments	14,249		14,336		14,336
Level 3 | Minimum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value Inputs, Discount Rate	9.50%				9.00%
Fair Value Inputs, Exit Capitalization Rates	8.00%				8.00%
Fair Value Inputs, Market Rental Rates	15				15
Level 3 | Maximum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value Inputs, Discount Rate	15.00%				15.00%
Fair Value Inputs, Exit Capitalization Rates	8.50%				8.50%
Fair Value Inputs, Market Rental Rates	18.5				17
Level 3 | Limited partnership interests
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Level 3 Fair Value			1,465		1,465		1,403
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Cash equivalents	58,389		59,281		59,281
Trading investments	9,395		9,509		9,509
Equity method investments	27,465		28,550		28,550
Available-for-sale investments	21,320		21,269		21,269
Derivative - assets	704		739		739
Derivative - liabilities	419		766		766
Fair Value, Measurements, Recurring | Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Derivative - assets	563		505		505
Derivative - liabilities			12		12
Fair Value, Measurements, Recurring | Commodity contracts
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Derivative - assets	141		234		234
Derivative - liabilities	419		754		754
Fair Value, Measurements, Recurring | Common stocks
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Available-for-sale investments	5,922		5,838		5,838
Fair Value, Measurements, Recurring | Fixed income securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Trading investments	6,950		7,000		7,000
Fair Value, Measurements, Recurring | Limited partnership interests
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Trading investments	2,445		2,509		2,509
Fair Value, Measurements, Recurring | Preferred securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Available-for-sale investments	1,149		1,095		1,095
Fair Value, Measurements, Recurring | Company-sponsored mutual funds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Available-for-sale investments	14,249		14,336		14,336
Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Cash equivalents	58,389		59,281		59,281
Trading investments	0		0		0
Equity method investments	20,182		20,827		20,827
Available-for-sale investments	21,320		21,269		21,269
Derivative - assets	141		234		234
Derivative - liabilities	419		754		754
Fair Value, Measurements, Recurring | Level 1 | Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Derivative - assets	0		0		0
Derivative - liabilities			0		0
Fair Value, Measurements, Recurring | Level 1 | Commodity contracts
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Derivative - assets	141		234		234
Derivative - liabilities	419		754		754
Fair Value, Measurements, Recurring | Level 1 | Common stocks
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Available-for-sale investments	5,922		5,838		5,838
Fair Value, Measurements, Recurring | Level 1 | Fixed income securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Trading investments	0		0		0
Fair Value, Measurements, Recurring | Level 1 | Limited partnership interests
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Trading investments	0		0		0
Fair Value, Measurements, Recurring | Level 1 | Preferred securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Available-for-sale investments	1,149		1,095		1,095
Fair Value, Measurements, Recurring | Level 1 | Company-sponsored mutual funds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Available-for-sale investments	14,249		14,336		14,336
Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Cash equivalents	0		0		0
Trading investments	6,950		7,000		7,000
Equity method investments	7,174		7,612		7,612
Available-for-sale investments	0		0		0
Derivative - assets	563		505		505
Derivative - liabilities	0		12		12
Fair Value, Measurements, Recurring | Level 2 | Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Derivative - assets	563		505		505
Derivative - liabilities			12		12
Fair Value, Measurements, Recurring | Level 2 | Commodity contracts
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Derivative - assets	0		0		0
Derivative - liabilities	0		0		0
Fair Value, Measurements, Recurring | Level 2 | Common stocks
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Available-for-sale investments	0		0		0
Fair Value, Measurements, Recurring | Level 2 | Fixed income securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Trading investments	6,950		7,000		7,000
Fair Value, Measurements, Recurring | Level 2 | Limited partnership interests
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Trading investments	0		0		0
Fair Value, Measurements, Recurring | Level 2 | Preferred securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Available-for-sale investments	0		0		0
Fair Value, Measurements, Recurring | Level 2 | Company-sponsored mutual funds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Available-for-sale investments	0		0		0
Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Cash equivalents	0		0		0
Trading investments	2,445		2,509		2,509
Equity method investments	109		111		111
Available-for-sale investments	0		0		0
Derivative - assets	0		0		0
Derivative - liabilities	0		0		0
Fair Value, Measurements, Recurring | Level 3 | Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Derivative - assets	0		0		0
Derivative - liabilities			0		0
Fair Value, Measurements, Recurring | Level 3 | Commodity contracts
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Derivative - assets	0		0		0
Derivative - liabilities	0		0		0
Fair Value, Measurements, Recurring | Level 3 | Common stocks
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Available-for-sale investments	0		0		0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period					503		503
Purchases / contributions							0
Sales / distributions							-527
Realized gains (losses)							24
Unrealized gains (losses)							0	[2]
Transfers into (out of) level 3							0
Balance at end of period							0
Fair Value, Measurements, Recurring | Level 3 | Fixed income securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Trading investments	0		0		0
Fair Value, Measurements, Recurring | Level 3 | Limited partnership interests
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Trading investments	2,445		2,509		2,509
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	2,509				2,740		2,740
Purchases / contributions	37						281
Sales / distributions	-113						-721
Realized gains (losses)	80						209
Unrealized gains (losses)	-68	[3]					-258	[2]
Transfers into (out of) level 3	0						0
Balance at end of period	2,445						2,251
Fair Value, Measurements, Recurring | Level 3 | Preferred securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Available-for-sale investments	0		0		0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period					3,325		3,325
Purchases / contributions							0
Sales / distributions							-4,000
Realized gains (losses)							675
Unrealized gains (losses)							0	[2]
Transfers into (out of) level 3							0
Balance at end of period							0
Fair Value, Measurements, Recurring | Level 3 | GRP-TE
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	111
Purchases / contributions	2
Sales / distributions	-6
Realized gains (losses)	2
Unrealized gains (losses)	0	[3]
Transfers into (out of) level 3	0
Balance at end of period	109
Fair Value, Measurements, Recurring | Level 3 | Company-sponsored mutual funds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]
Available-for-sale investments	0		0		0
Fair Value, Measurements, Recurring | Level 3 | GRP-TE/Offshore Fund
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period					528		528
Purchases / contributions							7
Sales / distributions							-29
Realized gains (losses)							0
Unrealized gains (losses)							31	[2]
Transfers into (out of) level 3							0
Balance at end of period							$537
[1]	Includes $622 and $650 held as collateral attributable to the consolidated balances of Cohen & Steers Active Commodities Strategy Fund, Inc. (CDF) as of March 31, 2015 and December 31, 2014, respectively.
[2]	Pertains to unrealized gains (losses) from securities held at March 31, 2014.
[3]	Pertains to unrealized gains (losses) from securities held at March 31, 2015.

Derivatives_Details

Derivatives (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Derivative [Line Items]
Derivative Assets, Notional	$27,305		$17,444
Derivative Assets, Fair Value	704		739
Derivative Liabilities, Notional	7,571		9,199
Derivative Liabilities, Fair Value	419		766
Derivative, Gains (Losses) on derivative, net	-394	380
Due from broker
Derivative [Line Items]
Cash included in due from broker pledged as collateral	140		422
Trading investments
Derivative [Line Items]
Trading investments and pledged as collateral	622		650
Foreign exchange contracts
Derivative [Line Items]
Derivative Assets, Notional	23,103		11,349
Derivative Assets, Fair Value	563		505
Derivative Liabilities, Notional	0		222
Derivative Liabilities, Fair Value	0		12
Derivative, Gains (Losses) on derivative, net	71	-168
Commodity contracts
Derivative [Line Items]
Derivative Assets, Notional	4,202		6,095
Derivative Assets, Fair Value	141		234
Derivative Liabilities, Notional	7,571		8,977
Derivative Liabilities, Fair Value	419		754
Derivative, Gains (Losses) on derivative, net	($465)	$548

Earnings_Per_Share_Details

Earnings Per Share (Details) (USD $)	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Earnings Per Share [Abstract]
Net income	$20,771	$19,600
Less: Net loss (income) attributable to redeemable noncontrolling interest	45	-155
Net income attributable to common stockholders	$20,816	$19,445
Basic weighted average shares outstanding (shares)	45,241,000	44,633,000
Dilutive potential shares from restricted stock units (shares)	739,000	850,000
Diluted weighted average shares outstanding (shares)	45,980,000	45,483,000
Basic earnings per share attributable to common stockholders (in dollars per share)	$0.46	$0.44
Diluted earnings per share attributable to common stockholders (in dollars per share)	$0.45	$0.43
Anti-dilutive common stock equivalents excluded from computation (in shares)	0	0

Income_Taxes_Details

Income Taxes (Details) (U.S. Federal, State, Local and Foreign Taxes)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
U.S. Federal, State, Local and Foreign Taxes
Income Taxes [Line Items]
Effective income tax rate reconciliation, percent	37.00%	36.50%
Effective income tax rate, expected for fiscal year	37.00%

Regulatory_Requirements_Detail

Regulatory Requirements (Details) (USD $)	Mar. 31, 2015
In Thousands, unless otherwise specified
Securities Registered Domestically
Financial Instruments Owned and Pledged as Collateral [Line Items]
Net Capital	$1,258
Excess Capital	1,078
Securities Regulated By Foreign Entities
Financial Instruments Owned and Pledged as Collateral [Line Items]
Net Capital	64,826
Excess Capital	$62,718

Related_Party_Transactions_Det

Related Party Transactions (Details) (Affiliated Funds, USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Affiliated Funds
Related Party Transactions, Revenue [Abstract]
Investment advisory and administrative fees	$56,109	$48,137
Distribution and service fees	3,906	3,470
Total	60,015	51,607
Related Party Transactions Summary [Abstract]
Proceeds from sales	0	192
Gross realized gains	0	0
Gross realized losses	0	-3
Dividend income	0	0
Fund expenses, included in general and administrative expenses	2,394	2,116
Receivables due from company-sponsored mutual funds	$20,559		$19,750

Commitments_and_Contingencies_

Commitments and Contingencies (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015
Commitments
Loss Contingencies [Line Items]
Long-term purchase commitment, time period	12 years
Commitment to invest
Loss Contingencies [Line Items]
Long-term purchase commitment	5.1
Long-term committment, funded amount	3.2

Concentration_of_Credit_Risk_D

Concentration of Credit Risk (Details)	Mar. 31, 2015
	financial_institution
Concentration of Credit Risk [Abstract]
Number of financial institutions	3

Subsequent_Events_Details

Subsequent Events (Details) (Dividend Declared, Subsequent Event, USD $)	0 Months Ended
	7-May-15
Dividend Declared | Subsequent Event
Subsequent Event [Line Items]
Cash dividends paid, per share	$0.25