Cohen & Steers (CNS) 10-K 1 Mar 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information Document - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Feb. 19, 2019	Jun. 30, 2018
Entity Information
Entity Registrant Name	COHEN & STEERS INC
Entity Central Index Key	1,284,812
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		47,221,640
Entity Well-known Seasoned Issuer	Yes
Entity Shell Company	false
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 922

Consolidated Statements of Fina

Consolidated Statements of Financial Condition - USD ($) $ in Thousands		Dec. 31, 2018	Dec. 31, 2017
Assets:
Cash and cash equivalents		$ 92,733	$ 193,452
Investments ($414) ($136,113 and $68,101)	[1]	224,932	108,106
Accounts receivable		50,381	53,854
Due from brokers ($4,906 and $2,525 )	[1]	14,240	6,429
Property and equipment—net		14,106	15,040
Goodwill and intangible assets—net		19,751	20,379
Deferred income tax asset—net		7,200	5,812
Other assets ($5,685 and $1,053)	[1]	9,208	7,053
Total assets		432,551	410,125
Liabilities:
Accrued compensation		43,685	41,370
Distribution and service fees payable		8,493	6,231
Income tax payable		18,663	19,892
Due to brokers ($1,194 and $210)	[1]	5,121	3,282
Deferred rent		5,816	5,994
Other liabilities and accrued expenses ($468 and $521)	[1]	13,935	10,025
Total liabilities		95,713	86,794
Commitments and contingencies
Redeemable noncontrolling interest		114,192	47,795
Stockholders’ equity:
Common stock, $0.01 par value; 500,000,000 shares authorized; 51,818,186 and 51,104,593 shares issued at December 31, 2018 and 2017, respectively		518	511
Additional paid-in capital		602,272	570,486
Accumulated deficit		(208,404)	(137,972)
Accumulated other comprehensive income, net of tax		(7,323)	(3,671)
Less: Treasury stock, at cost, 5,050,285 and 4,789,608 shares at December 31, 2018 and 2017, respectively		(164,417)	(153,818)
Total stockholders’ equity		222,646	275,536
Total liabilities and stockholders’ equity		$ 432,551	$ 410,125
[1]	Asset and liability amounts in parentheses represent the aggregated balances at December 31, 2018 and 2017 attributable to variable interest entities consolidated by the Company. Refer to Note 4 for further discussion.

Consolidated Statements of Fi_2

Consolidated Statements of Financial Condition (Parenthetical) - USD ($) $ in Thousands		Dec. 31, 2018	Dec. 31, 2017
Common stock, par value		$ 0.01	$ 0.01
Common stock, shares authorized		500,000,000	500,000,000
Common stock, shares issued		51,104,593	50,415,152
Common stock, shares outstanding		46,314,985	45,890,458
Treasury stock, shares		4,789,608	4,524,694
Due from brokers	[1]	$ 14,240	$ 6,429
Other assets	[1]	9,208	7,053
Due to brokers	[1]	5,121	3,282
Other liabilities and accrued expenses	[1]	13,935	10,025
Investments
Trading investment and held as collateral		1,807	414
GLI SICAV, GRP-CIP and SICAV Preferred
Trading investments			68,101
Due from brokers			5,410
Other assets			931
Due to brokers			3,203
Other liabilities and accrued expenses			$ 291
GLI SICAV, GRP-CIP, SICAV Preferred and SICAV RAP [Member]
Trading investments		136,113
Due from brokers		11,187
Other assets		2,604
Due to brokers		4,422
Other liabilities and accrued expenses		$ 440
[1]	Asset and liability amounts in parentheses represent the aggregated balances at December 31, 2018 and 2017 attributable to variable interest entities consolidated by the Company. Refer to Note 4 for further discussion.

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Total revenue	$ 381,111	$ 378,696	$ 351,497
Expenses:
Employee compensation and benefits	131,292	124,076	115,607
Distribution and service fees	50,043	53,338	53,144
General and administrative	48,265	42,219	42,989
Depreciation and amortization	4,473	4,317	4,246
Total expenses	234,073	223,950	215,986
Operating income (loss)	147,038	154,746	135,511
Non-operating income (loss):
Interest and dividend income—net	10,426	4,333	2,119
Gain (loss) from investments—net	(14,264)	2,020	4,993
Foreign currency gains (losses)—net	579	(699)	780
Total non-operating income (loss)	(3,259)	5,654	7,892
Income before provision for income taxes	143,779	160,400	143,403
Provision for income taxes	34,257	67,914	50,593
Net income	109,522	92,486	92,810
Less: Net (income) loss attributable to redeemable noncontrolling interest	4,374	(547)	126
Net income attributable to common stockholders	$ 113,896	$ 91,939	$ 92,936
Earnings per share attributable to common stockholders:
Basic (in dollars per share)	$ 2.43	$ 1.98	$ 2.02
Diluted (in dollars per share)	$ 2.40	$ 1.96	$ 2
Weighted average shares outstanding:
Basic (shares)	46,794	46,353	45,951
Diluted (shares)	47,381	46,979	46,432
Investment advisory and administration fees
Total revenue	$ 341,226	$ 336,743	$ 311,859
Expenses:
Distribution and service fees		50,538	49,780
Distribution and service fees
Total revenue	29,090	30,747	28,825
Expenses:
General and administrative		42,219	42,989
Portfolio consulting and other
Total revenue	$ 10,795	$ 11,206	$ 10,813

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Net income		$ 109,522	$ 92,486	$ 92,810
Less: Net (income) loss attributable to redeemable noncontrolling interest		4,374	(547)	126
Net income attributable to common stockholders		113,896	91,939	92,936
Other comprehensive income (loss), net of tax:
Foreign currency translation income (loss)		(2,557)	2,064	(2,937)
Net unrealized gain (loss) from available-for-sale investments	[1]	0	497	2,346
Reclassification to statements of operations of realized (gain) loss from available-for-sale investments		0	(347)	(1,451)
Other comprehensive income (loss)		(2,557)	2,214	(2,042)
Total comprehensive income attributable to common stockholders		$ 111,339	$ 94,153	$ 90,894
[1]	Due to the adoption and application of the amendments to the financial instruments accounting standard on January 1, 2018, realized and unrealized gains (losses) from equity investments at fair value are recognized through earnings rather than through other comprehensive income. See Notes 2 and 4 for further discussion of the Company's recently adopted accounting pronouncements and investments, respectively.

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity and Redeemable Noncontrolling Interest - USD ($) $ in Thousands	Total	Common stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss), Net of Tax	Treasury Stock	Total Stockholders' Equity	Redeemable Noncontrolling Interest
Beginning balance at Dec. 31, 2015		$ 497	$ 519,855	$ (148,096)	$ (3,843)	$ (136,637)	$ 231,776
Beginning balance (redeemable noncontrolling interest) at Dec. 31, 2015								$ 11,334
Beginning balance (shares of common stock, net) at Dec. 31, 2015		45,440,000
Dividends		$ 0	0	(72,797)	0	0	(72,797)
Issuance of common stock		$ 7	749	0	0	0	756	0
Issuance of common stock, shares		724,000
Repurchase of common stock		$ 0	0	0	0	(8,040)	(8,040)	0
Repurchase of common stock, shares		(274,000)
Tax benefits associated with restricted stock units—net		$ 0	(758)	0	0	0	(758)	0
Issuance of restricted stock units		0	2,457	0	0	0	2,457	0
Amortization of restricted stock units		0	21,555	0	0	0	21,555	0
Forfeitures of vested restricted stock units		0	(29)	0	0	0	(29)	0
Net income (loss)	$ 92,810	0	0	92,936	0	0	92,936	(126)
Other comprehensive income (loss)	(2,042)	0	0	0	(2,042)	0	(2,042)	0
Distributions to redeemable noncontrolling interest		0	0	0	0	0	0	(342)
Contributions from redeemable noncontrolling interest	4,023	0	0	0	0	0	0	4,023
Transfer of redeemable noncontrolling interest in consolidated entity		0	0	0	0	0	0	(14,036)
Ending balance at Dec. 31, 2016		$ 504	543,829	(127,957)	(5,885)	(144,677)	265,814
Ending balance (shares of common stock, net) at Dec. 31, 2016		45,890,000
Ending balance (redeemable noncontrolling interest) at Dec. 31, 2016								853
Dividends		$ 0	0	(101,669)	0	0	(101,669)
Issuance of common stock		$ 7	741	0	0	0	748	0
Issuance of common stock, shares		690,000
Repurchase of common stock		$ 0	0	0	0	(9,141)	(9,141)	0
Repurchase of common stock, shares		(265,000)
Issuance of restricted stock units		$ 0	3,974	0	0	0	3,974	0
Amortization of restricted stock units		0	22,042	(285)	0	0	21,757	0
Forfeitures of vested restricted stock units		0	(100)	0	0	0	(100)	0
Net income (loss)	92,486	0	0	91,939	0	0	91,939	547
Other comprehensive income (loss)	2,214	0	0	0	2,214	0	2,214	0
Distributions to redeemable noncontrolling interest		0	0	0	0	0	0	(263)
Contributions from redeemable noncontrolling interest	46,658	0	0	0	0	0	0	46,658
Ending balance at Dec. 31, 2017	$ 275,536	$ 511	570,486	(137,972)	(3,671)	(153,818)	275,536
Ending balance (shares of common stock, net) at Dec. 31, 2017	45,890,458	46,315,000
Ending balance (redeemable noncontrolling interest) at Dec. 31, 2017								47,795
Cumulative Effect of New Accounting Principle in Period of Adoption				1,095	(1,095)
Dividends		$ 0	0	(185,423)	0	0	(185,423)
Issuance of common stock		$ 7	696	0	0	0	703	0
Issuance of common stock, shares		714,000
Repurchase of common stock		$ 0	0	0	0	(10,599)	(10,599)	0
Repurchase of common stock, shares		(261,000)
Issuance of restricted stock units		$ 0	7,170	0	0	0	7,170	0
Amortization of restricted stock units		0	23,984	0	0	0	23,984	0
Forfeitures of vested restricted stock units		0	(64)	0	0	0	(64)	0
Net income (loss)	$ 109,522	0	0	113,896	0	0	113,896	(4,374)
Other comprehensive income (loss)	(2,557)	0	0	0	(2,557)	0	(2,557)	0
Distributions to redeemable noncontrolling interest		0	0	0	0	0	0	(10,862)
Contributions from redeemable noncontrolling interest	81,633	0	0	0	0	0	0	81,633
Ending balance at Dec. 31, 2018	$ 222,646	$ 518	$ 602,272	$ (208,404)	$ (7,323)	$ (164,417)	$ 222,646
Ending balance (shares of common stock, net) at Dec. 31, 2018	46,314,985	46,768,000
Ending balance (redeemable noncontrolling interest) at Dec. 31, 2018								$ 114,192

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Stockholders' Equity and Redeemable Noncontrolling Interest (parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Dividends declared per share	$ 3.82	$ 2.12	$ 1.54

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Net income	$ 109,522	$ 92,486	$ 92,810
Adjustments to reconcile net income to net cash provided by operating activities:
Stock compensation expense	24,626	22,360	22,108
Amortization of deferred commissions	1,559	2,800	3,364
Deferred rent	(178)	(235)	(139)
Amortization (accretion) of premium (discount) on held-to-maturity investments	(246)	0	0
(Gain) loss from investments—net	14,264	(2,020)	(4,993)
Deferred income taxes	(1,373)	(314)	(900)
Foreign currency (gain) loss	211	47	1,684
Changes in operating assets and liabilities:
Accounts receivable	3,262	(7,613)	(3,413)
Due from brokers	(7,811)	(4,850)	(1,261)
Deferred commissions	(982)	(1,894)	(3,909)
Trading investments	(81,182)	(60,252)	(3,956)
Other assets	(2,689)	(576)	(1,442)
Accrued compensation	2,341	6,064	4,855
Distribution and service fees payable	2,262	(221)	260
Due to broker	1,839	3,282	1,771
Income tax payable	(1,229)	10,517	2,110
Other liabilities and accrued expenses	3,929	355	1,763
Net cash provided by (used in) operating activities	72,598	64,253	114,958
Cash flows from investing activities:
Proceeds from redemptions of equity method investments	37	41	363
Purchases of investments	(63,557)	(16,901)	(8,096)
Proceeds from sales of investments	13,796	25,811	20,814
Purchases of property and equipment	(3,470)	(3,242)	(10,183)
Net cash provided by (used in) investing activities	(53,194)	5,709	2,898
Cash flows from financing activities:
Issuance of common stock	597	636	642
Repurchase of common stock	(10,599)	(9,141)	(8,040)
Dividends to stockholders	(178,879)	(98,313)	(70,825)
Distributions to redeemable noncontrolling interest	(10,862)	(263)	(342)
Contributions from redeemable noncontrolling interest	81,633	46,658	4,023
Net cash provided by (used in) financing activities	(118,110)	(60,423)	(74,542)
Net increase (decrease) in cash and cash equivalents	(98,706)	9,539	43,314
Effect of foreign exchange rate changes on cash and cash equivalents	(2,013)	679	(2,808)
Cash and cash equivalents, beginning of the year	193,452	183,234	142,728
Cash and cash equivalents, end of the year	92,733	193,452	183,234
Depreciation and amortization	$ 4,473	$ 4,317	$ 4,246

Consolidated Statements of Ca_2

Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income taxes paid, net	$ (36,795)	$ (57,726)	$ (49,331)
Restricted stock unit dividend equivalents, net of forfeitures	$ 6,544	3,356	$ 1,972
LPX
Transfer of redeemable noncontrolling interest in consolidated entity		14,036
Non-cash increase in equity method investments		14,550
Non-cash reclassification from Equity method investment to Available-for-sale investment		15,045
MLO
Non-cash reclassification from Equity method investment to Available-for-sale investment		$ 12,995

Basis of Presentation

Basis of Presentation	12 Months Ended
	Dec. 31, 2018
Organization and Description of Business [Abstract]
Organization and Description of Business	Basis of Presentation 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 global investment manager specializing in liquid real assets, including real estate securities, listed infrastructure, commodities and natural resource equities, as well as preferred securities and other income solutions. Founded in 1986, the Company is headquartered in New York City, with offices in London, Hong Kong and Tokyo. The consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP). The 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.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Recently Adopted Accounting Pronouncements —In May 2017, the Financial Accounting Standards Board (FASB) issued new guidance for modification accounting related to share-based payment transactions in order to provide clarity and to reduce current diversity in practice. This new guidance does not fundamentally change the notion of a modification. Instead, the amendments clarify which changes to the terms or conditions of a share-based payment award require an entity to apply modification accounting. The amendments became effective on January 1, 2018 and required prospective application. The Company's adoption of the new guidance did not have a material effect on its consolidated financial statements and related disclosures. In August 2016, the FASB amended the current guidance on the classification of certain cash receipts and payments in the statement of cash flows. This guidance is intended to unify the currently diverse presentations and classifications, including, among other items, distributions received from equity method investees. This amended guidance became effective on January 1, 2018 and was adopted retrospectively. The Company made an accounting policy election to use the Cumulative Earnings Approach when determining whether distributions received from equity method investments should be classified as either operating or investing activities within its consolidated statements of cash flows. The Company's adoption and application of the new guidance did not have a material effect on its consolidated financial statements and related disclosures. In January 2016, the FASB issued new guidance amending the accounting for, among other items, equity investments as well as the presentation and disclosure requirements for financial instruments. This new guidance became effective on January 1, 2018 and required the Company to recognize a cumulative-effect adjustment to the beginning retained earnings of approximately $1,095,000 , net of tax. Furthermore, changes in the fair value of the Company’s equity investments carried at fair value are now reported through earnings rather than through other comprehensive income. Additionally, due to the required cumulative-effect method of adoption applied, certain disclosures for prior periods have not been recast to conform with the current period presentation. Lastly, upon adoption of the new guidance, the Company reclassified certain investments previously classified as available-for-sale to trading investments or equity investments at fair value. See Notes 4 and 5 for further discussion about the Company's investments. 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 became effective on January 1, 2018 and the Company elected to adopt the standard using the retrospective method, which required the recasting of prior period amounts. The adoption of the new standard did not have a material impact on the timing of recognition for the Company's revenue but did affect the presentation of certain revenue and expenses on either a gross or net basis. The adoption of the new revenue recognition standard resulted in the following changes to the Company's previously reported results for the periods presented (in thousands): Year Ended December 31, 2017 Year Ended December 31, 2016 Previously Reported Net Adjustments Due to New Revenue Standard Recast Previously Reported Net Adjustments Due to New Revenue Standard Recast Revenue: Investment advisory and administration fees $ 346,832 $ (10,089 ) $ 336,743 $ 319,667 $ (7,808 ) $ 311,859 Distribution and service fees $ 20,156 $ 10,591 $ 30,747 $ 19,396 $ 9,429 $ 28,825 Expenses: Distribution and service fees (1) $ 39,632 $ 10,906 $ 50,538 $ 39,590 $ 10,190 $ 49,780 General and administrative $ 52,623 $ (10,404 ) $ 42,219 $ 51,558 $ (8,569 ) $ 42,989 ________________________ (1) The amount presented in the consolidated statements of operations differs from the amount presented within this table due to the reclassification of the amortization of deferred sales commissions previously reported as depreciation and amortization. Accounting Estimates —The preparation of the 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 consolidated financial statements and the reported amounts of revenue and expenses during the reporting periods. Management believes the estimates used in preparing the consolidated financial statements are reasonable and prudent. Actual results could differ from those estimates. Reclassifications— The Company reclassified certain prior period amounts in the consolidated financial statements to conform with the current period presentation. Consolidation of Company-sponsored Funds —Investments in Company-sponsored funds and management fees are evaluated at inception and thereafter, if there is a reconsideration event, in order to determine whether to apply the Variable Interest Entity (VIE) model or the Voting Interest Entity (VOE) model. In performing this analysis, all of the Company’s management fees are presumed to be commensurate and at market and are therefore not considered variable interests. A VIE is an entity in which either (i) the equity investment at risk is not sufficient to permit the entity to finance its own activities without additional financial support or (ii) 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 (i) the power to direct the activities of the VIE that most significantly affect its performance, and (ii) the obligation to absorb losses of the entity or the right to receive benefits from the entity that could potentially be significant to the VIE. 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 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. VIEs for which the Company is deemed to be the primary beneficiary are consolidated. Investments in Company-sponsored funds that are determined to be VOEs are consolidated when the Company’s ownership interest is greater than 50% of the outstanding voting interests of the fund or when the Company is the general partner of the fund and the limited partners do not have substantive kick-out or participating rights in the fund. The Company records noncontrolling interests in consolidated funds for which the Company’s ownership is less than 100%. Cash and Cash Equivalents —Cash and cash equivalents are on deposit with major financial institutions and consist of short-term, highly liquid investments, which are readily convertible into cash and have original maturities of three months or less. Due from/to Brokers —Accounts formed for the purpose of establishing performance track records and Company-sponsored funds that are consolidated transact with brokers for certain investment activities. The clearing and custody operations for these investment activities are performed pursuant to contractual agreements. The due from/to brokers balance represents cash and cash equivalents balances at brokers/custodians and/or receivables and payables for unsettled securities transactions. Investments —Management of the Company determines the appropriate classification of its investments at the time of purchase and re-evaluates such determination no less than on a quarterly basis. At December 31, 2018, the Company's investments were comprised of the following: • Equity investments at fair value, which includes securities held within the affiliated funds that the Company consolidates, individual securities held directly for the purposes of establishing performance track records and seed investments in Company-sponsored open-end funds where the Company has neither control nor the ability to exercise significant influence. • Trading investments, which represent debt securities held within the affiliated funds that the Company consolidates and individual debt securities held directly for the purposes of establishing performance track records. • Held-to-maturity investments, which represent fixed income securities recorded at amortized cost. The Company periodically reviews held-to-maturity investments for other-than-temporary impairments (OTTI). If the Company believes an OTTI exists, an impairment charge will be recognized in the Company’s consolidated statements of operations. • Equity method investments, which represent seed investments in which the Company owns between 20-50% of the outstanding voting interests in the affiliated fund or when it is determined that the Company is able to exercise significant influence but not control over the investments. When using the equity method, the Company recognizes its respective share of the affiliated investee fund net income or loss for the period which is recorded as gain (loss) from investments—net in the Company's consolidated statements of operations. Realized and unrealized gains and losses on equity investments at fair value, trading investments and equity method investments are recorded in gain (loss) from investments—net in the Company's consolidated statements of operations. From time to time, the Company, including the Company-sponsored funds that are consolidated by the Company, enters into derivative contracts to gain exposure to the underlying commodities markets or to hedge market and credit risks of the underlying portfolios utilizing options, futures and swaps contracts. Options and futures contracts are measured at fair value based on their settlement price at the close of trading on the associated exchange or board of trade and swaps are measured at fair value based on the underlying futures contracts. Gain and losses on derivative contracts are recorded as gain (loss) from investments—net in the Company's consolidated statements of operations. The fair values of these instruments are recorded in other assets or other liabilities and accrued expenses on the Company's consolidated statements of financial condition. At December 31, 2018 , none of the outstanding derivative contracts were subject to a master netting agreement or other similar arrangement. Additionally, from time to time, the Company, including the affiliated funds consolidated by the Company, enters into foreign exchange contracts to hedge its currency exposure related to certain client receivables. These instruments are measured at fair value based on the prevailing forward exchange rate with gains and losses recorded in foreign currency gains (losses)—net in the Company’s consolidated statements of operations. The fair values of these contracts are recorded in other assets or other liabilities and accrued expenses on the Company’s 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. Redeemable Noncontrolling Interests —Redeemable noncontrolling interests represent third-party interests in the affiliated funds that the Company consolidates. 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 and closed-end funds. Investment advisory fees are earned pursuant to the terms of investment management agreements and are based on a contractual fee rate applied to the average assets in the portfolio. The Company also earns administration fees from certain Company-sponsored open-end 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 when earned and is recorded net of any fund reimbursements. The investment advisory and administration contracts each include a single performance obligation as the services provided are not separately identifiable and are accounted for as a series satisfied over time using a time-based method (days elapsed). Additionally, investment advisory and administration fees represent variable consideration, as fees are based on average assets under management which fluctuate daily. Distribution and Service Fee Revenue —Distribution and service fee revenue is based on the average daily net assets of certain share classes of the Company’s sponsored open-end funds distributed by CSS. Distribution and service fee revenue is earned daily and is generally recorded gross of any third-party distribution and service fee expense for applicable share classes. Distribution fee agreements include a single performance obligation that is satisfied at a point in time when an investor purchases shares in a Company-sponsored open-end fund. Distribution fees represent variable consideration, as fees are based on average assets under management which fluctuate daily. For the years ended December 31, 2018 , 2017 and 2016, a portion of the distribution fee revenue recognized may relate to performance obligations satisfied (or partially satisfied) in prior periods. Service fee agreements include a single performance obligation as the services provided are not separately identifiable and are accounted for as a series satisfied over time using a time-based method (days elapsed). Service fees represent variable consideration, as fees are based on average assets under management which fluctuate daily. Portfolio Consulting and Other —The Company earns portfolio consulting and other fees by (i) providing portfolio consulting services in connection with model-based strategy accounts, (ii) earning a licensing fee for the use of the Company's proprietary indexes and (iii) providing portfolio monitoring services related to a number of unit investment trusts. Revenue is earned pursuant to the terms of the underlying contracts and the fee schedules for these relationships vary based on the type of services the Company provides for each relationship. The majority of the Company's revenue from portfolio consulting and other is recognized over time and represents variable consideration, as fees are based on average assets under advisement which fluctuate daily. Distribution and Service Fee Expense —Distribution and service fee expense includes distribution fees, shareholder servicing fees and intermediary assistance payments. Distribution and service fee expense is recorded on an accrual basis. Distribution fee expense represents payments made to qualified intermediaries for (i) assistance in connection with the distribution of the Company’s sponsored open-end 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). The Company pays distribution fee expense based on the average daily net assets under management of certain share classes of certain of the funds. Shareholder servicing fee expense represents payments made to qualified intermediaries for shareholder account service and maintenance. These services are provided pursuant to written agreements with such qualified institutions. The Company pays shareholder servicing fee expense generally based on the average assets under management or the number of accounts being serviced. Intermediary assistance payments represent payments to qualified intermediaries for activities related to distribution, shareholder servicing and marketing and support of the Company’s sponsored open-end 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. Stock-based Compensation —The Company recognizes compensation expense for the grant-date fair value of awards of equity instruments to employees. This expense is recognized over the period during which employees are required to provide service. Forfeitures are recorded as incurred. Income Taxes —The Company records the current and deferred tax consequences of all transactions that have been recognized in the 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 calculation of tax liabilities involves dealing with uncertainties in the application of complex tax laws and regulations in a multitude of jurisdictions across the Company’s global operations. A tax benefit from an uncertain tax position may be recognized when it is more likely than not that the position will be sustained upon examination, including resolution of any related appeals or litigation processes, on the basis of the technical merits. The Company records potential interest and penalties related to uncertain tax positions in the provision for income taxes in the consolidated statements of operations. Currency Translation and Transactions —Assets and liabilities of subsidiaries having non-U.S. dollar functional currencies are translated at exchange rates at the applicable consolidated statement of financial condition date. Revenue and expenses of such 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 consolidated statements of comprehensive income. The cumulative translation adjustment was $(7,323,000) , $(4,781,000) and $(6,845,000) as of December 31, 2018 , 2017 and 2016, respectively. Gains or losses resulting from transactions denominated in currencies other than the U.S. dollar held by certain foreign subsidiaries are included in non-operating income (loss) in the consolidated statements of operations. Gains and losses arising on revaluation of U.S. dollar-denominated assets and liabilities held by foreign subsidiaries are also included in non-operating income (loss) in the Company’s consolidated statements of operations. Comprehensive Income —The Company reports all changes in comprehensive income in the consolidated statements of comprehensive income. Comprehensive income includes net income or loss attributable to common stockholders and amounts attributable to foreign currency translation gain (loss), net of tax. Recently Issued Accounting Pronouncements —In February 2018, the FASB issued new guidance allowing entities to reclassify certain tax effects related to the enactment of the Tax Cuts and Jobs Act (the Tax Act) from accumulated other comprehensive income (AOCI) to retained earnings. Prior to the issuance of the new guidance, a portion of the previously recognized deferred tax effects recorded in AOCI was "left stranded" in AOCI as the effect of remeasuring the deferred taxes using the reduced federal corporate income tax rate was required to be recorded through income. The new guidance allows these stranded tax effects to be reclassified from AOCI to retained earnings. The new guidance will be effective on January 1, 2019, with early adoption permitted and is to be applied either in the period of adoption or retrospectively to each period in which the effect of the change in the U.S. federal corporate income tax rate in the Tax Act is recognized. The adoption of the new guidance on a prospective basis is not expected to have a material effect on the Company's consolidated financial statements and related disclosures. In August 2017, the FASB issued new guidance amending the accounting for hedging activities. The new guidance (i) expands hedge accounting for nonfinancial and financial risk components and amends measurement methodologies to more closely align hedge accounting with an entity's risk management activities, (ii) decreases the complexity of preparing and understanding hedge results through eliminating the separate measurement and reporting of hedge ineffectiveness, (iii) enhances transparency, comparability and understandability of hedge results through enhanced disclosures and changing the presentation of hedge results to align the effects of the hedging instrument and the hedged item and (iv) reduces the cost and complexity of applying hedge accounting by simplifying the manner in which assessments of hedge effectiveness may be performed. The new guidance will be effective on January 1, 2019, with early adoption permitted. The adoption of the new guidance is not expected to have a material effect on the Company's consolidated financial statements and related disclosures. In January 2017, the FASB issued guidance to simplify the goodwill impairment test by removing the requirement to perform a hypothetical purchase price allocation. A goodwill impairment will now be the amount by which a reporting unit’s carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. This new guidance will be effective on January 1, 2020. The Company does not expect the adoption of the new guidance to have a material effect on its consolidated financial statements and related disclosures. In February 2016, the FASB issued guidance introducing a new lease model which requires lessees to recognize leases on-balance sheet and disclose key information about leasing arrangements. The new guidance establishes a right-of-use model (ROU) that requires a lessee to recognize an ROU asset and lease liability on the balance sheet for all leases with a term longer than 12 months. Leases will be classified as finance or operating which will affect expense recognition in the income statement. The guidance also requires disclosures by lessees and lessors to enable users of financial statements to assess the amount, timing, and uncertainty of cash flows arising from leases. In July and December 2018, the FASB issued amendments to the guidance intended to provide supplemental narrow-scope improvements and clarifications. The new guidance, along with the amendments, is effective on January 1, 2019, with early adoption permitted. The Company expects to adopt the new standard along with certain allowable practical expedients using the modified retrospective transition approach, which requires the recasting of prior period amounts. Upon adoption of the new standard, at January 1, 2019, the Company will record an ROU asset of $48.5 million, net of deferred rent of $5.8 million, and a lease liability of $54.3 million primarily related to real estate operating leases. The adoption of the new standard is not expected to affect the Company's consolidated statements of operations and cash flows.

Revenue Revenue

Revenue Revenue	12 Months Ended
	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Revenue	Revenue The following tables summarize revenue recognized from contracts with customers by client domicile and revenue by vehicle for the periods presented (in thousands): Year ended December 31, 2018 2017 2016 Client domicile: North America $ 322,964 $ 314,021 $ 286,957 Japan 35,283 42,303 43,458 Asia excluding Japan 12,493 11,496 9,852 Europe 10,371 10,876 11,230 Total $ 381,111 $ 378,696 $ 351,497 Year ended December 31, 2018 2017 2016 Vehicle: Open-end funds $ 192,735 $ 188,613 $ 172,371 Closed-end funds 77,270 78,670 76,108 Institutional accounts 100,311 100,207 92,205 Portfolio consulting and other 10,795 11,206 10,813 Total $ 381,111 $ 378,696 $ 351,497

Investments

Investments	12 Months Ended
	Dec. 31, 2018
Investments [Abstract]
Investment Holdings	Investments The following tables summarize the Company’s investments as of December 31, 2018 and 2017 (in thousands): December 31, 2018 Equity investments at fair value $ 66,795 Trading 108,363 Held-to-maturity (1) 49,748 Equity method 26 Total investments $ 224,932 _________________________ (1) At December 31, 2018, held-to-maturity investments had an amortized cost of approximately $49.7 million and a fair value of approximately $49.8 million , with original maturities ranging from 6 to 24 months. December 31, 2017 Trading $ 74,856 Equity method 6,176 Available-for-sale 27,074 Total investments $ 108,106 The Company seeded one new fund for the year ended December 31, 2018 and two new funds for the year ended December 31, 2017. The following tables summarize gain (loss) from investments for the years ended December 31, 2018, 2017 and 2016 (in thousands): December 31, 2018 Net realized gains (losses) during the period $ (1,486 ) Net unrealized gains (losses) during the period on investments still held at the end of the period (12,778 ) Gain (loss) from investments—net (1) $ (14,264 ) _________________________ (1) Included net income (loss) attributable to redeemable noncontrolling interests. Year Ended December 31, 2017 2016 Gain (loss) from trading investments—net (1) $ 1,915 $ 218 Equity in earnings (losses) of affiliates—net (242 ) 3,324 Gain (loss) from available-for-sale investments—net 347 1,451 Gain (loss) from investments—net $ 2,020 $ 4,993 _________________________ (1) Included net income (loss) attributable to redeemable noncontrolling interests. The following tables summarize the consolidated statements of financial condition attributable to the Company's consolidated VIEs, which included the Cohen & Steers SICAV Global Listed Infrastructure Fund (GLI SICAV), the Cohen & Steers Co-Investment Partnership, L.P. (GRP-CIP), the Cohen & Steers SICAV Global Preferred Securities Fund (SICAV Preferred) and the Cohen & Steers SICAV Diversified Real Assets Fund (SICAV RAP) for the years ended December 31, 2018 and 2017 (in thousands): December 31, 2018 GLI SICAV GRP-CIP SICAV Preferred SICAV RAP Total Assets (1) Investments $ 5,704 $ 550 $ 120,930 $ 8,929 $ 136,113 Due from brokers 49 103 10,868 167 11,187 Other assets 171 — 2,136 297 2,604 Total assets $ 5,924 $ 653 $ 133,934 $ 9,393 $ 149,904 Liabilities (1) Due to brokers $ — $ — $ 4,398 $ 24 $ 4,422 Other liabilities and accrued expenses 74 5 212 149 440 Total liabilities $ 74 $ 5 $ 4,610 $ 173 $ 4,862 December 31, 2017 GLI SICAV GRP-CIP SICAV Preferred Total Assets (1) Investments $ 5,961 $ 1,330 $ 60,810 $ 68,101 Due from brokers 285 202 4,923 5,410 Other assets 32 — 899 931 Total assets $ 6,278 $ 1,532 $ 66,632 $ 74,442 Liabilities (1) Due to brokers $ 35 $ — $ 3,168 $ 3,203 Other liabilities and accrued expenses 87 5 199 291 Total liabilities $ 122 $ 5 $ 3,367 $ 3,494 _________________________ (1) The assets may only be used to settle obligations of each VIE and the liabilities are the sole obligation of each VIE, for which creditors do not have recourse to the general credit of the Company. The following tables summarize the cost, gross unrealized gains, gross unrealized losses and fair value of available-for-sale investments for the year ended December 31, 2017 (in thousands): Cost Gross Unrealized Gains Gross (1) Fair Value Common stocks $ 6,782 $ 639 $ (183 ) $ 7,238 Company-sponsored funds 13,376 1,269 (13 ) 14,632 Fixed income securities 3,966 15 (20 ) 3,961 Preferred securities 1,100 29 (5 ) 1,124 Other 100 19 — 119 Total available-for-sale investments $ 25,324 $ 1,971 $ (221 ) $ 27,074 _________________________ (1) At December 31, 2017, there were no securities with material unrealized losses continuously for a period of more than 12 months. Available-for-sale investments with a fair value of approximately $6,086,000 at December 31, 2017 were in an unrealized loss position. At December 31, 2017, unrealized losses on available-for-sale investments were generally caused by changes in 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 as well as qualitative and quantitative information about the financial condition and near-term prospects of the issuers. Furthermore, the Company determined that it had the ability and intent to hold the remaining available-for-sale investments for which no other-than-temporary impairment has occurred until a recovery of fair value. Accordingly, impairment of these investments, if any, was considered temporary. The following table summarizes sales proceeds, gross realized gains and losses from available-for-sale investments for the years ended December 31, 2017 and 2016 (in thousands): Year Ended December 31, 2017 2016 Proceeds from sales $ 25,812 $ 20,823 Gross realized gains 714 1,879 Gross realized losses (367 ) (428 )

Fair Value

Fair Value	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value	Fair Value Accounting Standards 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. If the asset or liability has a specified (contractual) term, the level 2 input must be observable for substantially the full term of the asset or liability. • 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. The following table presents fair value measurements as of December 31, 2018 (in thousands): Level 1 Level 2 Level 3 Investments Measured at NAV Investments Carried at Amortized Cost Total Cash equivalents $ 78,147 $ — $ — $ — $ — $ 78,147 Equity investments at fair value Common stocks $ 21,982 $ — $ — $ — $ — $ 21,982 Company-sponsored funds 9,456 — — — — 9,456 Limited partnership interests 1,056 — — 550 — 1,606 Preferred securities 30,448 3,193 — — — 33,641 Other — — — 110 — 110 Total $ 62,942 $ 3,193 $ — $ 660 $ — $ 66,795 Trading investments Fixed income $ — $ 108,363 $ — $ — $ — $ 108,363 Total $ — $ 108,363 $ — $ — $ — $ 108,363 Held-to-maturity investments Fixed income $ — $ — $ — $ — $ 49,748 $ 49,748 Total $ — $ — $ — $ — $ 49,748 $ 49,748 Equity method investments $ — $ — $ — $ 26 $ — $ 26 Total investments $ 62,942 $ 111,556 $ — $ 686 $ 49,748 $ 224,932 Derivatives - assets Commodity contracts $ 486 $ — $ — $ — $ — $ 486 Commodity swap contracts — 739 — — — 739 Total $ 486 $ 739 $ — $ — $ — $ 1,225 Derivatives - liabilities Commodity contracts $ 2,181 $ — $ — $ — $ — $ 2,181 Foreign exchange contracts — 205 — — — 205 Total $ 2,181 $ 205 $ — $ — $ — $ 2,386 Cash equivalents were comprised of investments in actively traded U.S. Treasury money market funds measured at NAV. Equity investments at fair value classified as level 2 were comprised of certain preferred securities with predominately equity-like characteristics whose fair values are generally determined using third-party pricing services. The pricing services may utilize pricing models, and inputs into those models may include reported trades, executable bid and ask prices, broker-dealer quotations, prices or yields of similar securities, benchmark curves and other market information. The pricing services may use a matrix approach, which considers information regarding securities with similar characteristics to determine the valuation for a security. Trading investments classified as level 2 were comprised of U.S. Treasury securities held within consolidated funds carried at amortized cost, which approximates fair value, corporate debt securities, as well as certain preferred securities with predominately debt-like characteristics. The fair value amounts were generally determined using third-party pricing services. The pricing services may utilize evaluated pricing models that vary by asset class and incorporate available trade, bid and other market information. Since these securities do not trade on a daily basis, the pricing services evaluate pricing applications and apply available information through processes such as yield curves, benchmarking of like securities, sector groupings, and matrix pricing, to prepare evaluations. Investments measured at NAV were comprised of certain investments measured at fair value using NAV (or its equivalent) as a practical expedient. These investments were comprised of: • Equity investments at fair value - limited partner interests in limited partnership vehicles that invest in non-registered real estate funds and the Company's co-investment in a Cayman trust invested in global listed infrastructure securities, both of which are valued based on the NAVs of the underlying investments. At December 31, 2018 , the Company did not have the ability to redeem the interests in the limited partnership vehicles; there were no contractual restrictions on the Company's ability to redeem its interest in the Cayman trust. • Equity method investments - the Company's partnership interest in a Company-sponsored limited partnership that invests in non-registered real estate funds, which approximated its fair value based on the fund's NAV. At December 31, 2018 , the Company's ownership in this limited partnership was approximately 0.2%. The Company's risk with respect to this investment is limited to its equity ownership and any uncollected management fees. At December 31, 2018 , the Company did not have the ability to redeem this investment. Held-to-maturity investments were comprised of U.S. Treasury securities, which were directly issued by the U.S. government, with original maturities of 6 to 24 months. These securities were purchased with the intent to hold to maturity and are recorded at amortized cost. Investments measured at NAV and held-to-maturity investments have not been classified in the fair value hierarchy. The amounts presented in the above table are intended to permit reconciliation of the fair value hierarchy to the amounts presented on the consolidated statement of financial position. Commodity swap contracts classified as level 2 were valued based on the underlying futures contracts. Foreign currency exchange contracts classified as level 2 were valued based on the prevailing forward exchange rate. The following table presents fair value measurements as of December 31, 2017 (in thousands): Level 1 Level 2 Level 3 Investments Measured at NAV Total Cash equivalents $ 173,270 $ — $ — $ — $ 173,270 Trading investments Common stocks $ 5,961 $ — $ — $ — $ 5,961 Fixed income — 6,755 — — 6,755 Limited partnership interests — — 605 725 1,330 Preferred securities 7,658 53,152 — — 60,810 Total $ 13,619 $ 59,907 $ 605 $ 725 $ 74,856 Equity method investments $ — $ — $ — $ 6,176 $ 6,176 Available-for-sale investments Common stocks $ 7,238 $ — $ — $ — $ 7,238 Company-sponsored funds 14,632 — — — 14,632 Fixed income — 3,961 — — 3,961 Preferred securities 999 125 — — 1,124 Other — — — 119 119 Total $ 22,869 $ 4,086 $ — $ 119 $ 27,074 Total investments $ 36,488 $ 63,993 $ 605 $ 7,020 $ 108,106 Derivatives - assets Commodity contracts $ 487 $ — $ — $ — $ 487 Total $ 487 $ — $ — $ — $ 487 Derivatives - liabilities Commodity contracts $ 286 $ — $ — $ — $ 286 Foreign exchange contracts — 64 — — 64 Total $ 286 $ 64 $ — $ — $ 350 Cash equivalents were comprised of investments in actively traded U.S. Treasury money market funds measured at NAV. Trading investments in fixed income securities classified as level 2 in the above table were comprised of U.S. Treasury securities carried at amortized cost, which approximates fair value. Trading investments in preferred securities classified as level 2 were comprised of corporate debt and certain preferred securities. The fair value amounts were generally determined using third-party pricing services. The pricing services may utilize evaluated pricing models that vary by asset class and incorporate available trade, bid and other market information. Since these securities do not trade on a daily basis, the pricing services evaluate pricing applications and apply available information through processes such as yield curves, benchmarking of like securities, sector groupings, and matrix pricing, to prepare evaluations. Trading investments classified as level 3 in the above table were comprised of a limited partner interest in a limited partnership vehicle that invested in a private equity vehicle that invested directly in real estate which was valued using a contractual selling price. Available-for-sale investments classified as level 2 in the above table were primarily comprised of corporate bonds and certain preferred securities whose fair values are generally determined using third-party pricing services. The pricing services may utilize pricing models, and inputs into those models may include reported trades, executable bid and ask prices, broker-dealer quotations, prices or yields of similar securities, benchmark curves and other market information. The pricing services may use a matrix approach, which considers information regarding securities with similar characteristics to determine the valuation for a security. Investments measured at NAV were comprised of certain investments measured at fair value using NAV (or its equivalent) as a practical expedient. These investments have not been classified in the fair value hierarchy. The fair value amounts presented in the above table are intended to permit reconciliation of the fair value hierarchy to the amounts presented on the consolidated statement of financial position. These investments were comprised of: • Trading investments - limited partner interests in limited partnership vehicles that invest in non-registered real estate funds, which are valued based on the NAVs of the underlying funds. At December 31, 2017 , the Company did not have the ability to redeem these interests. • Equity method investments - the Company's partnership interests in Company-sponsored limited partnerships. One such partnership invests in private equity vehicles that invest directly in real estate and non-registered real estate funds and the Company did not have the ability to redeem this investment. The other partnership invests indirectly in exchange-traded commodity futures contracts and other commodity-related derivatives and the Company had the ability to redeem this investment monthly at NAV with prior written notice of 5 days. • Available-for-sale investments - the Company's co-investment in a Cayman trust invested in global listed infrastructure securities. There were no contractual restrictions on the Company's ability to redeem this investment. Foreign currency exchange contracts classified as level 2 were valued based on the prevailing forward exchange rate. The following table summarizes the changes in level 3 investments measured at fair value on a recurring basis for the years ended December 31, 2018 and 2017 (in thousands): Trading Investments Limited Partnership Interests 2018 2017 Balance at beginning of year $ 605 $ 1,196 Purchases / contributions — 419 Sales / distributions (598 ) (1,291 ) Realized gains (losses) (68 ) 162 Unrealized gains (losses) (1) 61 119 Transfers into (out of) level 3 — — Balance at end of year $ — $ 605 _________________________ (1) Pertains to unrealized gains (losses) from securities still held at December 31, 2017. Realized and unrealized gains (losses) in the above table were recorded as gain (loss) from investments—net in the Company's consolidated statements of operations. Valuation Techniques In certain instances, debt, equity and preferred securities are valued on the basis of prices from an orderly transaction between market participants provided by reputable broker-dealers or independent pricing services. In determining the value of a particular investment, independent 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 generally performs reviews of valuations provided by broker-dealers or independent pricing services. Investments in Company-sponsored funds are valued at their closing price or NAV (or its equivalent) as a practical expedient. Foreign exchange contracts are valued based on the prevailing forward exchange rate, 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. At December 31, 2017 , the valuation technique used in the fair value measurement of the Company’s level 3 investment, limited partnership interests - direct investment in real estate, of approximately $605,000 was based on a contractual selling price.

Derivatives

Derivatives	12 Months Ended
	Dec. 31, 2018
Derivatives [Abstract]
Derivatives	Derivatives The following tables summarize the notional and fair value of the derivative financial instruments. The notional amount represents the absolute value amount of all outstanding derivative contracts at December 31, 2018 and 2017 (in thousands): December 31, 2018 Assets Liabilities Notional Fair Value Notional Fair Value Commodity contracts $ 19,361 $ 486 $ 3,434 $ 2,181 Commodity swap contracts 8,761 739 — — Foreign exchange contracts — — 10,996 205 Total $ 28,122 $ 1,225 $ 14,430 $ 2,386 December 31, 2017 Assets Liabilities Notional Fair Value Notional Fair Value Commodity contracts $ 8,939 $ 487 $ 6,876 $ 286 Foreign exchange contracts — — 12,279 64 Total $ 8,939 $ 487 $ 19,155 $ 350 Cash included in due from broker on the consolidated statement of financial condition of approximately $2,002,000 at December 31, 2018 was held as collateral for futures contracts. Investments on the consolidated statement of financial condition of approximately $1,807,000 and $414,000 as of December 31, 2018 and 2017, respectively, were held as collateral for futures contracts. The following table summarizes gains (losses) from derivative financial instruments for the years ended December 31, 2018, 2017 and 2016 (in thousands): Year Ended December 31, 2018 2017 2016 Commodity contracts $ (2,093 ) $ (438 ) $ 835 Commodity swap contracts 739 — — Foreign exchange contracts (141 ) (1,481 ) 1,626 Total $ (1,495 ) $ (1,919 ) $ 2,461

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Property and Equipment	Property and Equipment The following table summarizes the Company’s property and equipment at December 31, 2018 and 2017 (in thousands): December 31, 2018 2017 Equipment $ 5,590 $ 7,503 Furniture and fixtures 3,644 3,598 Software 17,591 21,173 Leasehold improvements 16,028 16,017 Subtotal 42,853 48,291 Less: Accumulated depreciation and amortization (28,747 ) (33,251 ) Property and equipment, net $ 14,106 $ 15,040 Depreciation and amortization expense related to property and equipment was $4,378,000 , $4,229,000 and $4,155,000 for the years ended December 31, 2018, 2017 and 2016 , respectively. Depreciation and amortization expense related to property and equipment is recorded using the straight-line method over the estimated useful lives of the related assets which range from 3 - 7 years. Leasehold improvements are amortized using the straight-line method over the lease term.

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2018
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 using the treasury stock method 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 and are excluded from the computation if their effect is anti-dilutive. There were no anti-dilutive common stock equivalents for the years ended December 31, 2018 and 2017. Anti-dilutive common stock equivalents of approximately 14,000 shares were excluded from the computation for the year ended December 31, 2016. The following table is a reconciliation of the income and share data used in the basic and diluted earnings per share computations for the years ended December 31, 2018, 2017 and 2016 (in thousands, except per share data): Year Ended December 31, 2018 2017 2016 Net income $ 109,522 $ 92,486 $ 92,810 Less: Net (income) loss attributable to redeemable noncontrolling interests 4,374 (547 ) 126 Net income attributable to common stockholders $ 113,896 $ 91,939 $ 92,936 Basic weighted average shares outstanding 46,794 46,353 45,951 Dilutive potential shares from restricted stock units 587 626 481 Diluted weighted average shares outstanding 47,381 46,979 46,432 Basic earnings per share attributable to common stockholders $ 2.43 $ 1.98 $ 2.02 Diluted earnings per share attributable to common stockholders $ 2.40 $ 1.96 $ 2.00

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	Stock-Based Compensation Amended and Restated Stock Incentive Plan The Amended and Restated Cohen & Steers, Inc. Stock Incentive Plan (the SIP) provides for the issuance of Restricted Stock Units (RSUs), stock options and other stock-based awards to eligible employees and directors. A total of 20.0 million shares of common stock may be granted under the SIP. The board of directors is authorized to increase the number of shares available for issuance under the SIP, subject to shareholder approval. At December 31, 2018 , RSUs with respect to approximately 15.8 million shares of common stock had been issued under the SIP. Total compensation cost related to unvested RSUs not yet recognized was approximately $40,868,000 at December 31, 2018 and is expected to be recognized over approximately the next three years. In January 2019, the Company granted approximately 0.8 million RSUs under the SIP with a grant date fair value of approximately $29,248,000 which vest over a four-year period. Restricted Stock Units Vested Restricted Stock Unit Grants The Company grants awards of vested RSUs to the non-management directors of the Company pursuant to the SIP. The directors are entitled to receive delivery of the underlying common stock on the third anniversary of the date of grant. Dividends declared during the period are paid to the directors in cash. In connection with the grant of these vested RSUs, the Company recorded non-cash stock-based compensation expense of approximately $626,000 , $618,000 and $486,000 for the years ended December 31, 2018, 2017 and 2016 , respectively. Unvested Restricted Stock Unit Grants From time to time, the Company grants awards of unvested RSUs to certain employees pursuant to the SIP. The fair value at the date of grant is expensed on a straight-line basis over the applicable service periods, which is generally four years. Dividends declared by the Company are paid in additional RSUs and are forfeitable until they are delivered. The dividend equivalent RSUs will generally vest and be delivered on the fourth anniversary of the original grant date. The Company recorded stock-based compensation expense, net of forfeitures, of approximately $4,216,000 , $3,957,000 and $4,685,000 for the years ended December 31, 2018, 2017 and 2016 , respectively. Incentive Bonus Plans for Employees of the Company The Company has implemented a program for employees which, based upon compensation levels, automatically allocates a portion of their year-end bonuses in the form of unvested RSUs (Mandatory Program). Dividends declared by the Company are paid in additional RSUs and are forfeitable until they are delivered. The RSUs under the Mandatory Program will generally vest and be delivered ratably over four years and the dividend equivalents RSUs will generally vest and be delivered on the fourth anniversary of the original grant date. The fair value at the date of grant of the RSUs under the Mandatory Program is expensed on a straight-line basis over the vesting period. The Company recorded stock-based compensation under the Mandatory Program, net of forfeitures, of approximately $19,710,000 , $17,175,000 and $16,847,000 for the years ended December 31, 2018, 2017 and 2016 , respectively. The following table sets forth activity relating to the Company’s RSUs under the SIP (share data in thousands): Vested Restricted Stock Unit Grants Unvested Restricted Stock Unit Grants Incentive Bonus Plans Restricted Stock Unit Grants Number of Shares Weighted Average Grant Date Fair Value Number of Shares Weighted Average Grant Date Fair Value Number of Shares Weighted Average Grant Date Fair Value Balance at January 1, 2016 30 $ 36.17 296 $ 36.36 1,282 $ 37.33 Granted 13 37.17 159 30.31 722 30.02 Delivered (9 ) 34.02 (147 ) 35.52 (548 ) 35.86 Forfeited — — (1 ) 42.09 (57 ) 35.14 Balance at December 31, 2016 34 37.15 307 33.62 1,399 34.22 Granted 16 38.14 151 35.45 714 35.36 Delivered (8 ) 40.03 (140 ) 34.41 (523 ) 34.80 Forfeited — — — — (40 ) 33.87 Balance at December 31, 2017 42 36.98 318 34.14 1,550 34.60 Granted 15 38.29 134 39.02 757 39.42 Delivered (12 ) 34.95 (146 ) 35.13 (539 ) 34.94 Forfeited — — — — (23 ) 37.16 Balance at December 31, 2018 45 37.93 306 35.80 1,745 36.55 Employee Stock Purchase Plan Pursuant to the Amended and Restated Employee Stock Purchase Plan (ESPP), the Company allows eligible employees, as defined in the ESPP, to purchase common stock at a 15% discount from fair market value up to a maximum of $25,000 in annual aggregate purchases by any one individual. The number of shares of common stock authorized for purchase by eligible employees is 600,000 . As of December 31, 2018, the Company had issued approximately 413,000 shares of common stock under the ESPP. For the years ended December 31, 2018, 2017 and 2016 , approximately 18,000 , 18,000 and 19,000 shares, respectively, were purchased by eligible employees through the ESPP. For the years ended December 31, 2018, 2017 and 2016 , the Company recorded a non-cash stock-based compensation expense of approximately $105,000 , $112,000 and $114,000 , respectively, which represents the discount on the shares issued pursuant to this plan. The ESPP will terminate upon the earliest to occur of (1) termination of the ESPP by the board of directors or (2) issuance of all of the shares reserved for issuance under the ESPP. The board of directors is authorized to increase the number of shares available for issuance under the ESPP, subject to shareholder approval.

401(k) and Profit-Sharing Plan

401(k) and Profit-Sharing Plan	12 Months Ended
	Dec. 31, 2018
Compensation Related Costs [Abstract]
401 (k) and Profit-Sharing Plan	401(k) and Profit-Sharing Plan The Company sponsors a profit-sharing plan (the Plan) covering all employees who meet certain age and service requirements. Subject to limitations, the Plan permits participants to defer up to 100% of their eligible compensation pursuant to Section 401(k) of the Internal Revenue Code. Employee contributions are matched by the Company at $0.50 per $1.00 deferred. The Plan also allows the Company to make discretionary contributions, which are integrated with the taxable wage base under the Social Security Act. No discretionary contributions were made for the years ended December 31, 2018, 2017 and 2016 . Forfeitures occur when participants terminate employment before becoming entitled to their full benefits under the Plan. In accordance with the Plan document, forfeited amounts are used to reduce the Company’s contributions to the Plan or to pay Plan expenses. Forfeitures for the years ended December 31, 2018, 2017 and 2016 totaled approximately $101,000 , $128,000 and $126,000 , respectively. Matching contributions, net of forfeitures, to the Plan for the years ended December 31, 2018, 2017 and 2016 totaled approximately $1,770,000 , $1,715,000 and $1,464,000 , respectively.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2018
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions The Company is an investment adviser to, and has administration agreements with, affiliated funds for which certain employees are officers and/or directors. The following table summarizes the amount of revenue the Company earned from these affiliated funds for the years ended December 31, 2018, 2017 and 2016 (in thousands): Year Ended December 31, 2018 2017 2016 Investment advisory and administration fees (1) $ 241,255 $ 236,832 $ 220,364 Distribution and service fees 29,090 30,747 28,825 Total $ 270,345 $ 267,579 $ 249,189 _________________________ (1) Investment advisory and administration fees are reflected net of fund reimbursements of approximately $8.6 million , $8.7 million and $7.6 million for and the years ended December 31, 2018, 2017 and 2016 , respectively. Amounts for the years ended December 31, 2017 and 2016 have been recast to reflect the Company's adoption of the new revenue recognition accounting standard on January 1, 2018. See Notes 2 and 3 for further discussion of the Company's recently adopted accounting pronouncements and revenue, respectively. The following table summarizes sales proceeds, gross realized gains, gross realized losses and dividend income from investments in Company-sponsored funds for the years ended December 31, 2018, 2017 and 2016 (in thousands): Year Ended December 31, 2018 2017 2016 Proceeds from sales $ 10,872 $ 15,105 $ 13,251 Gross realized gains 28 80 1,159 Gross realized losses (4,448 ) — — Dividend income 481 675 787 Included in accounts receivable at December 31, 2018 and 2017 are receivables due from Company-sponsored funds of approximately $21,855,000 and $23,666,000 , respectively.

Regulatory Requirements

Regulatory Requirements	12 Months Ended
	Dec. 31, 2018
Regulatory Capital 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 by the Rule. At December 31, 2018 , CSS had net capital of approximately $ 3.2 million , which exceeded its requirements by approximately $ 3.0 million . 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 is subject to regulation by the Hong Kong Securities and Futures Commission. At December 31, 2018 , CSAL had regulatory capital of approximately $26.0 million , which exceeded its minimum regulatory capital requirements by approximately $25.7 million . In August, 2018, CSAL paid a dividend in the amount of $32.0 million to its parent, Cohen & Steers Capital Management, Inc. In January 2019, CSAL paid an additional dividend in the amount of $15.0 million to its parent. CSUK is subject to regulation by the United Kingdom Financial Conduct Authority. At December 31, 2018 , CSUK had regulatory capital of approximately $33.0 million , which exceeded its minimum regulatory capital requirements by approximately $28.2 million .

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies Disclosure	Commitments and Contingencies The Company leases office space under noncancelable operating leases expiring at various dates through March 2024. The Company also leases certain information technology applications, market data and office equipment under noncancelable operating leases expiring at various dates through March 2024. The aggregate minimum future payments under the leases are as follows (in thousands): Year Ending December 31, Operating Leases 2019 $ 15,112 2020 13,570 2021 11,397 2022 10,882 2023 10,842 Thereafter 960 $ 62,763 Rent expense charged to operations, including escalation charges for real estate taxes and other expenses, totaled approximately $11.9 million , $11.8 million and $11.5 million for the years ended December 31, 2018, 2017 and 2016 , respectively. 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 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 Cohen & Steers Global Realty Partners III-TE, L.P. (GRP-TE), a portion of which is made through GRP-TE and the remainder of which is made through Cohen & Steers Co-Investment Partnership, L.P. (GRP-CIP) for up to 12 years through the life of GRP-TE. At December 31, 2018 , the Company has funded approximately $3.8 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 in which GRP-TE and GRP-CIP invest. At December 31, 2018 , the unfunded commitment was not recorded on the Company’s consolidated statements of financial condition.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	Goodwill and Intangible Assets The following table summarizes the changes in the Company’s goodwill and intangible assets during the years ended December 31, 2018 and 2017 (in thousands): Goodwill Finite-Lived Intangible Assets Indefinite-Lived Intangible Assets Balance at January 1, 2017 $ 17,684 $ 184 $ 1,250 Currency revaluation 1,350 — — Amortization N/A (89 ) N/A Balance at December 31, 2017 $ 19,034 $ 95 $ 1,250 Currency revaluation (533 ) — — Amortization N/A (95 ) N/A Balance at December 31, 2018 $ 18,501 $ — $ 1,250 The following table summarizes the Company’s intangible assets at December 31, 2018 and 2017 (in thousands): Remaining Amortization Period (in months) Gross Carrying Amount Accumulated Amortization Intangible Assets, Net 2018 Amortized intangible assets: Client relationships — $ 1,543 $ (1,543 ) $ — Non-amortized intangible assets: Mutual fund management contracts — 1,250 — 1,250 Total $ 2,793 $ (1,543 ) $ 1,250 2017 Amortized intangible assets: Client relationships 12 $ 1,543 $ (1,448 ) $ 95 Non-amortized intangible assets: Mutual fund management contracts — 1,250 — 1,250 Total $ 2,793 $ (1,448 ) $ 1,345 Amortization expense related to the intangible assets was approximately $95,000 , $89,000 and $89,000 for the years ended December 31, 2018, 2017 and 2016 , respectively.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The income before provision for income taxes and provision for income taxes for the years ended December 31, 2018, 2017 and 2016 are as follows (in thousands): Year Ended December 31, 2018 2017 2016 Income before provision for income taxes - U.S. $ 132,838 $ 149,338 $ 132,882 Income before provision for income taxes - Non-U.S. 10,941 11,062 10,521 Total income before provision for income taxes $ 143,779 $ 160,400 $ 143,403 Current taxes: U.S. federal $ 26,223 $ 58,082 $ 42,056 State and local 7,378 8,155 7,423 Non-U.S. 2,029 1,991 2,014 35,630 68,228 51,493 Deferred taxes: U.S. federal (748 ) (428 ) (743 ) State and local (281 ) (412 ) (86 ) Non-U.S. (344 ) 526 (71 ) (1,373 ) (314 ) (900 ) Provision for income taxes $ 34,257 $ 67,914 $ 50,593 In connection with the enactment of the Tax Cuts and Jobs Act (the Tax Act), the Company recorded a provisional transition tax of $8.4 million at December 31, 2017, which reflected a one-time tax on deemed repatriated accumulated earnings and profits of the Company’s foreign subsidiaries. The transition tax, which is payable over eight years on an interest-free basis, was included as part of income tax payable on the Company's consolidated statements of financial condition at December 31, 2018 and December 31, 2017. Based on refinement of the calculation, the Company adjusted its transition tax liability from $8.4 million at December 31, 2017 to $8.3 million during the second quarter of 2018. The transition tax liability at December 31, 2018 is as follows (in thousands): Year Ending December 31, Transition Tax Liability 2019 $ 192 2020 665 2021 665 2022 1,246 2023 1,662 2024 2,077 $ 6,507 In addition to the transition tax, the Tax Act requires certain income earned by foreign subsidiaries, referred to under the Tax Act as global intangible low-taxed income (GILTI), be included in the U.S. taxable income of the parent company. GILTI requires an accounting policy election to either (1) treat taxes due on future U.S. inclusions in taxable income related to GILTI as a current period expense when incurred or (2) factor such amounts into the measurement of deferred taxes. The Company has made an accounting policy election to account for any additional tax resulting from the GILTI provisions in the year in which it is incurred. Based upon its calculation, the Company was not required to record any additional income tax expense attributable to the GILTI provisions for the year ended December 31, 2018. 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 records a valuation allowance, when necessary, to reduce deferred tax assets to an amount that more likely than not will be realized. Significant components of the Company’s net deferred income tax asset at December 31, 2018 and 2017 consist of the following (in thousands): At December 31, 2018 2017 Deferred income tax assets (liabilities): Stock-based compensation $ 4,915 $ 5,437 Non-deductible realized losses on investments 1,539 1,030 Dividend equivalents on unvested restricted stock units 1,734 1,715 Net unrealized losses on investments 2,512 2,359 Deferred compensation 78 (1,325 ) Deferred rent 1,452 1,488 Other (760 ) (996 ) Subtotal 11,470 9,708 Less: valuation allowance (4,270 ) (3,896 ) Deferred income tax asset—net $ 7,200 $ 5,812 The Company had capital loss carryforwards of approximately $6,181,000 and $4,181,000 for the years ended December 31, 2018 and 2017 which, if unused, will expire in years 2019 to 2023. The valuation allowance on the net deferred income tax asset increased approximately $374,000 during the year ended December 31, 2018 . At December 31, 2018 , the Company had approximately $12,037,000 of total gross unrecognized tax benefits. Of this total, approximately $9,235,000 (net of the federal benefit on state issues) represents the amount of unrecognized tax benefits that, if recognized, would favorably affect the Company’s effective tax rate in future periods. The Company believes it is reasonably possible that it will reduce its unrecognized tax benefits by $5,121,000 within the next twelve months due to the lapse of the statute of limitations on certain positions. A reconciliation of the beginning and ending amount of gross unrecognized tax benefits is as follows (in thousands): Liability for Unrecognized Tax Benefits Gross unrecognized tax benefits balance at January 1, 2016 $ 7,259 Addition for tax positions of current year 1,437 Addition for tax positions of prior years 163 Reduction of tax positions from prior years (1,007 ) Gross unrecognized tax benefits balance at December 31, 2016 $ 7,852 Addition for tax positions of current year 1,724 Addition for tax positions of prior years 6,624 Reduction of tax positions from prior years (3,794 ) Gross unrecognized tax benefits balance at December 31, 2017 $ 12,406 Addition for tax positions of current year 2,233 Reduction of tax positions from prior years (2,602 ) Gross unrecognized tax benefits balance at December 31, 2018 $ 12,037 The Company records potential interest and penalties related to uncertain tax positions in the provision for income taxes. At December 31, 2018 and 2017, the Company had approximately $2,519,000 and $1,933,000 , respectively, in potential interest and penalties associated with uncertain tax positions. The tax years 2012 through 2018 remain open to examination by various taxing jurisdictions. A reconciliation of the Company’s statutory federal income tax rate and the effective tax rate for the years ended December 31, 2018, 2017 and 2016 is as follows: Year Ended December 31, 2018 2017 2016 U.S. statutory tax rate 21.0 % 35.0 % 35.0 % State and local income taxes, net of federal income taxes 3.8 % 3.1 % 3.5 % Unrecognized tax benefit adjustments (1.0 )% (1.9 )% (0.2 )% Foreign operations tax differential 0.3 % (1.4 )% (1.1 )% Non-deductible losses on investments 0.2 % 0.2 % 1.3 % Non-taxable gains on investments 0.1 % (0.2 )% (3.0 )% Tax Act (0.1 )% 8.0 % — % Other (1.2 )% (0.3 )% (0.2 )% Effective income tax rate 23.1 % 42.5 % 35.3 %

Concentration of Credit Risk

Concentration of Credit Risk	12 Months Ended
	Dec. 31, 2018
Risks and Uncertainties [Abstract]
Concentration of Credit Risk	Concentration of Credit Risk The Company’s cash and cash equivalents are principally on deposit with major financial institutions. The Company is subject to credit risk should these financial institutions be unable to fulfill their obligations. The following affiliated funds and third-party institutional separate account subadvisory relationship, which is comprised of multiple accounts, provided 10% or more of the total revenue of the Company (in thousands): Year Ended December 31, 2018 2017 2016 Cohen & Steers Realty Shares, Inc. (CSR): Investment advisory and administration fees $ 33,827 $ 38,392 $ 45,047 Percent of total revenue 9 % 10 % 13 % Cohen & Steers Preferred Securities and Income Fund, Inc. (CPX): Investment advisory and administration fees $ 53,059 $ 53,594 $ 42,420 Percent of total revenue 14 % 14 % 12 % Daiwa Asset Management: Investment advisory fees $ 30,265 $ 37,756 $ 39,377 Portfolio consulting and other 3,189 3,035 2,930 Total $ 33,454 $ 40,791 $ 42,307 Percent of total revenue 9 % 11 % 12 %

Selected Quarterly Financial Da

Selected Quarterly Financial Data (unaudited)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data (unadudited)	Selected Quarterly Financial Data (unaudited) The table below presents selected quarterly financial data for 2018 and 2017 (in thousands, except per share data): Quarter 1st 2nd 3rd 4th Total 2018 Revenue $ 94,464 $ 94,410 $ 98,331 $ 93,906 $ 381,111 Operating income 37,219 36,287 39,223 34,309 147,038 Net income attributable to common stockholders (1) 27,586 29,959 30,790 25,561 113,896 Earnings per share attributable to common stockholders: Basic 0.59 0.64 0.66 0.55 2.43 Diluted 0.59 0.63 0.65 0.54 2.40 Weighted-average shares outstanding: Basic 46,683 46,819 46,830 46,842 46,794 Diluted 47,152 47,311 47,524 47,562 47,381 2017 Revenue (2) $ 89,741 $ 92,714 $ 96,787 $ 99,454 $ 378,696 Operating income 35,528 37,357 40,973 40,888 154,746 Net income attributable to common stockholders 22,985 23,474 25,082 20,398 91,939 Earnings per share attributable to common stockholders: Basic 0.50 0.51 0.54 0.44 1.98 Diluted 0.49 0.50 0.53 0.43 1.96 Weighted-average shares outstanding: Basic 46,243 46,373 46,386 46,407 46,353 Diluted 46,603 46,902 47,047 47,300 46,979 _________________________ (1) Net income for all four quarters of 2018 reflected the lower U.S. federal statutory tax rate of 21% due to the Tax Cuts and Jobs Act. (2) Amounts have been recast to reflect the Company’s adoption of the new revenue recognition accounting standard on January 1, 2018. See Notes 2 and 3 for further discussion of the Company's recently adopted accounting pronouncements and revenue, respectively.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2018
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 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 February 21, 2019, CNS declared a quarterly dividend on its common stock in the amount of $0.36 per share. This dividend will be payable on March 14, 2019 to stockholders of record at the close of business on March 4, 2019.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Accounting Estimates	Accounting Estimates —The preparation of the 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 consolidated financial statements and the reported amounts of revenue and expenses during the reporting periods. Management believes the estimates used in preparing the consolidated financial statements are reasonable and prudent. Actual results could differ from those estimates.
Reclassifications	Reclassifications— The Company reclassified certain prior period amounts in the consolidated financial statements to conform with the current period presentation.
Consolidation of Company-sponsored Funds	Consolidation of Company-sponsored Funds —Investments in Company-sponsored funds and management fees are evaluated at inception and thereafter, if there is a reconsideration event, in order to determine whether to apply the Variable Interest Entity (VIE) model or the Voting Interest Entity (VOE) model. In performing this analysis, all of the Company’s management fees are presumed to be commensurate and at market and are therefore not considered variable interests. A VIE is an entity in which either (i) the equity investment at risk is not sufficient to permit the entity to finance its own activities without additional financial support or (ii) 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 (i) the power to direct the activities of the VIE that most significantly affect its performance, and (ii) the obligation to absorb losses of the entity or the right to receive benefits from the entity that could potentially be significant to the VIE. 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 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. VIEs for which the Company is deemed to be the primary beneficiary are consolidated. Investments in Company-sponsored funds that are determined to be VOEs are consolidated when the Company’s ownership interest is greater than 50% of the outstanding voting interests of the fund or when the Company is the general partner of the fund and the limited partners do not have substantive kick-out or participating rights in the fund. The Company records noncontrolling interests in consolidated funds for which the Company’s ownership is less than 100%.
Cash and Cash Equivalents	Cash and Cash Equivalents —Cash and cash equivalents are on deposit with major financial institutions and consist of short-term, highly liquid investments, which are readily convertible into cash and have original maturities of three months or less.
Due from/to Brokers	Due from/to Brokers —
Investments	Investments —Management of the Company determines the appropriate classification of its investments at the time of purchase and re-evaluates such determination no less than on a quarterly basis. At December 31, 2018, the Company's investments were comprised of the following: • Equity investments at fair value, which includes securities held within the affiliated funds that the Company consolidates, individual securities held directly for the purposes of establishing performance track records and seed investments in Company-sponsored open-end funds where the Company has neither control nor the ability to exercise significant influence. • Trading investments, which represent debt securities held within the affiliated funds that the Company consolidates and individual debt securities held directly for the purposes of establishing performance track records. • Held-to-maturity investments, which represent fixed income securities recorded at amortized cost. The Company periodically reviews held-to-maturity investments for other-than-temporary impairments (OTTI). If the Company believes an OTTI exists, an impairment charge will be recognized in the Company’s consolidated statements of operations. • Equity method investments, which represent seed investments in which the Company owns between 20-50% of the outstanding voting interests in the affiliated fund or when it is determined that the Company is able to exercise significant influence but not control over the investments. When using the equity method, the Company recognizes its respective share of the affiliated investee fund net income or loss for the period which is recorded as gain (loss) from investments—net in the Company's consolidated statements of operations. Realized and unrealized gains and losses on equity investments at fair value, trading investments and equity method investments are recorded in gain (loss) from investments—net in the Company's consolidated statements of operations. From time to time, the Company, including the Company-sponsored funds that are consolidated by the Company, enters into derivative contracts to gain exposure to the underlying commodities markets or to hedge market and credit risks of the underlying portfolios utilizing options, futures and swaps contracts. Options and futures contracts are measured at fair value based on their settlement price at the close of trading on the associated exchange or board of trade and swaps are measured at fair value based on the underlying futures contracts. Gain and losses on derivative contracts are recorded as gain (loss) from investments—net in the Company's consolidated statements of operations. The fair values of these instruments are recorded in other assets or other liabilities and accrued expenses on the Company's consolidated statements of financial condition. At December 31, 2018 , none of the outstanding derivative contracts were subject to a master netting agreement or other similar arrangement.
Goodwill and Intangible Assets	Goodwill and Intangible Assets —
Redeemable Noncontrolling Interest	Redeemable Noncontrolling Interests —Redeemable noncontrolling interests represent third-party interests in the affiliated funds that the Company consolidates. 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	Investment Advisory and Administration Fees —The Company earns revenue by providing asset management services to institutional accounts and to Company-sponsored open-end and closed-end funds. Investment advisory fees are earned pursuant to the terms of investment management agreements and are based on a contractual fee rate applied to the average assets in the portfolio. The Company also earns administration fees from certain Company-sponsored open-end 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 when earned and is recorded net of any fund reimbursements. The investment advisory and administration contracts each include a single performance obligation as the services provided are not separately identifiable and are accounted for as a series satisfied over time using a time-based method (days elapsed). Additionally, investment advisory and administration fees represent variable consideration, as fees are based on average assets under management which fluctuate daily.
Distribution and Service Fee Revenue	Distribution and Service Fee Revenue —Distribution and service fee revenue is based on the average daily net assets of certain share classes of the Company’s sponsored open-end funds distributed by CSS. Distribution and service fee revenue is earned daily and is generally recorded gross of any third-party distribution and service fee expense for applicable share classes. Distribution fee agreements include a single performance obligation that is satisfied at a point in time when an investor purchases shares in a Company-sponsored open-end fund. Distribution fees represent variable consideration, as fees are based on average assets under management which fluctuate daily. For the years ended December 31, 2018 , 2017 and 2016, a portion of the distribution fee revenue recognized may relate to performance obligations satisfied (or partially satisfied) in prior periods. Service fee agreements include a single performance obligation as the services provided are not separately identifiable and are accounted for as a series satisfied over time using a time-based method (days elapsed). Service fees represent variable consideration, as fees are based on average assets under management which fluctuate daily.
Distribution and Service Fee Expense	Distribution and Service Fee Expense —Distribution and service fee expense includes distribution fees, shareholder servicing fees and intermediary assistance payments. Distribution and service fee expense is recorded on an accrual basis. Distribution fee expense represents payments made to qualified intermediaries for (i) assistance in connection with the distribution of the Company’s sponsored open-end 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). The Company pays distribution fee expense based on the average daily net assets under management of certain share classes of certain of the funds. Shareholder servicing fee expense represents payments made to qualified intermediaries for shareholder account service and maintenance. These services are provided pursuant to written agreements with such qualified institutions. The Company pays shareholder servicing fee expense generally based on the average assets under management or the number of accounts being serviced. Intermediary assistance payments represent payments to qualified intermediaries for activities related to distribution, shareholder servicing and marketing and support of the Company’s sponsored open-end 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 strategy accounts, (ii) earning a licensing fee for the use of the Company's proprietary indexes and (iii) providing portfolio monitoring services related to a number of unit investment trusts. Revenue is earned pursuant to the terms of the underlying contracts and the fee schedules for these relationships vary based on the type of services the Company provides for each relationship. The majority of the Company's revenue from portfolio consulting and other is recognized over time and represents variable consideration, as fees are based on average assets under advisement which fluctuate daily.
Stock-based Compensation	Stock-based Compensation —The Company recognizes compensation expense for the grant-date fair value of awards of equity instruments to employees. This expense is recognized over the period during which employees are required to provide service. Forfeitures are recorded as incurred.
Income Taxes	Income Taxes —The Company records the current and deferred tax consequences of all transactions that have been recognized in the 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 calculation of tax liabilities involves dealing with uncertainties in the application of complex tax laws and regulations in a multitude of jurisdictions across the Company’s global operations. A tax benefit from an uncertain tax position may be recognized when it is more likely than not that the position will be sustained upon examination, including resolution of any related appeals or litigation processes, on the basis of the technical merits. The Company records potential interest and penalties related to uncertain tax positions in the provision for income taxes in the consolidated statements of operations.
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 consolidated statement of financial condition date. Revenue and expenses of such 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 consolidated statements of comprehensive income. The cumulative translation adjustment was $(7,323,000) , $(4,781,000) and $(6,845,000) as of December 31, 2018 , 2017 and 2016, respectively. Gains or losses resulting from transactions denominated in currencies other than the U.S. dollar held by certain foreign subsidiaries are included in non-operating income (loss) in the consolidated statements of operations. Gains and losses arising on revaluation of U.S. dollar-denominated assets and liabilities held by foreign subsidiaries are also included in non-operating income (loss) in the Company’s consolidated statements of operations.
Comprehensive Income	Comprehensive Income —The Company reports all changes in comprehensive income in the consolidated statements of comprehensive income. Comprehensive income includes net income or loss attributable to common stockholders and amounts attributable to foreign currency translation gain (loss), net of tax.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements —In February 2018, the FASB issued new guidance allowing entities to reclassify certain tax effects related to the enactment of the Tax Cuts and Jobs Act (the Tax Act) from accumulated other comprehensive income (AOCI) to retained earnings. Prior to the issuance of the new guidance, a portion of the previously recognized deferred tax effects recorded in AOCI was "left stranded" in AOCI as the effect of remeasuring the deferred taxes using the reduced federal corporate income tax rate was required to be recorded through income. The new guidance allows these stranded tax effects to be reclassified from AOCI to retained earnings. The new guidance will be effective on January 1, 2019, with early adoption permitted and is to be applied either in the period of adoption or retrospectively to each period in which the effect of the change in the U.S. federal corporate income tax rate in the Tax Act is recognized. The adoption of the new guidance on a prospective basis is not expected to have a material effect on the Company's consolidated financial statements and related disclosures. In August 2017, the FASB issued new guidance amending the accounting for hedging activities. The new guidance (i) expands hedge accounting for nonfinancial and financial risk components and amends measurement methodologies to more closely align hedge accounting with an entity's risk management activities, (ii) decreases the complexity of preparing and understanding hedge results through eliminating the separate measurement and reporting of hedge ineffectiveness, (iii) enhances transparency, comparability and understandability of hedge results through enhanced disclosures and changing the presentation of hedge results to align the effects of the hedging instrument and the hedged item and (iv) reduces the cost and complexity of applying hedge accounting by simplifying the manner in which assessments of hedge effectiveness may be performed. The new guidance will be effective on January 1, 2019, with early adoption permitted. The adoption of the new guidance is not expected to have a material effect on the Company's consolidated financial statements and related disclosures. In January 2017, the FASB issued guidance to simplify the goodwill impairment test by removing the requirement to perform a hypothetical purchase price allocation. A goodwill impairment will now be the amount by which a reporting unit’s carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. This new guidance will be effective on January 1, 2020. The Company does not expect the adoption of the new guidance to have a material effect on its consolidated financial statements and related disclosures. In February 2016, the FASB issued guidance introducing a new lease model which requires lessees to recognize leases on-balance sheet and disclose key information about leasing arrangements. The new guidance establishes a right-of-use model (ROU) that requires a lessee to recognize an ROU asset and lease liability on the balance sheet for all leases with a term longer than 12 months. Leases will be classified as finance or operating which will affect expense recognition in the income statement. The guidance also requires disclosures by lessees and lessors to enable users of financial statements to assess the amount, timing, and uncertainty of cash flows arising from leases. In July and December 2018, the FASB issued amendments to the guidance intended to provide supplemental narrow-scope improvements and clarifications. The new guidance, along with the amendments, is effective on January 1, 2019, with early adoption permitted. The Company expects to adopt the new standard along with certain allowable practical expedients using the modified retrospective transition approach, which requires the recasting of prior period amounts. Upon adoption of the new standard, at January 1, 2019, the Company will record an ROU asset of $48.5 million, net of deferred rent of $5.8 million, and a lease liability of $54.3 million primarily related to real estate operating leases. The adoption of the new standard is not expected to affect the Company's consolidated statements of operations and cash flows.
Valuation Techniques	Accounting Standards 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. If the asset or liability has a specified (contractual) term, the level 2 input must be observable for substantially the full term of the asset or liability. • 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. The following table presents fair value measurements as of December 31, 2018 (in thousands): Level 1 Level 2 Level 3 Investments Measured at NAV Investments Carried at Amortized Cost Total Cash equivalents $ 78,147 $ — $ — $ — $ — $ 78,147 Equity investments at fair value Common stocks $ 21,982 $ — $ — $ — $ — $ 21,982 Company-sponsored funds 9,456 — — — — 9,456 Limited partnership interests 1,056 — — 550 — 1,606 Preferred securities 30,448 3,193 — — — 33,641 Other — — — 110 — 110 Total $ 62,942 $ 3,193 $ — $ 660 $ — $ 66,795 Trading investments Fixed income $ — $ 108,363 $ — $ — $ — $ 108,363 Total $ — $ 108,363 $ — $ — $ — $ 108,363 Held-to-maturity investments Fixed income $ — $ — $ — $ — $ 49,748 $ 49,748 Total $ — $ — $ — $ — $ 49,748 $ 49,748 Equity method investments $ — $ — $ — $ 26 $ — $ 26 Total investments $ 62,942 $ 111,556 $ — $ 686 $ 49,748 $ 224,932 Derivatives - assets Commodity contracts $ 486 $ — $ — $ — $ — $ 486 Commodity swap contracts — 739 — — — 739 Total $ 486 $ 739 $ — $ — $ — $ 1,225 Derivatives - liabilities Commodity contracts $ 2,181 $ — $ — $ — $ — $ 2,181 Foreign exchange contracts — 205 — — — 205 Total $ 2,181 $ 205 $ — $ — $ — $ 2,386 Cash equivalents were comprised of investments in actively traded U.S. Treasury money market funds measured at NAV. Equity investments at fair value classified as level 2 were comprised of certain preferred securities with predominately equity-like characteristics whose fair values are generally determined using third-party pricing services. The pricing services may utilize pricing models, and inputs into those models may include reported trades, executable bid and ask prices, broker-dealer quotations, prices or yields of similar securities, benchmark curves and other market information. The pricing services may use a matrix approach, which considers information regarding securities with similar characteristics to determine the valuation for a security. Trading investments classified as level 2 were comprised of U.S. Treasury securities held within consolidated funds carried at amortized cost, which approximates fair value, corporate debt securities, as well as certain preferred securities with predominately debt-like characteristics. The fair value amounts were generally determined using third-party pricing services. The pricing services may utilize evaluated pricing models that vary by asset class and incorporate available trade, bid and other market information. Since these securities do not trade on a daily basis, the pricing services evaluate pricing applications and apply available information through processes such as yield curves, benchmarking of like securities, sector groupings, and matrix pricing, to prepare evaluations. Investments measured at NAV were comprised of certain investments measured at fair value using NAV (or its equivalent) as a practical expedient. These investments were comprised of: • Equity investments at fair value - limited partner interests in limited partnership vehicles that invest in non-registered real estate funds and the Company's co-investment in a Cayman trust invested in global listed infrastructure securities, both of which are valued based on the NAVs of the underlying investments. At December 31, 2018 , the Company did not have the ability to redeem the interests in the limited partnership vehicles; there were no contractual restrictions on the Company's ability to redeem its interest in the Cayman trust. • Equity method investments - the Company's partnership interest in a Company-sponsored limited partnership that invests in non-registered real estate funds, which approximated its fair value based on the fund's NAV. At December 31, 2018 , the Company's ownership in this limited partnership was approximately 0.2%. The Company's risk with respect to this investment is limited to its equity ownership and any uncollected management fees. At December 31, 2018 , the Company did not have the ability to redeem this investment. Held-to-maturity investments were comprised of U.S. Treasury securities, which were directly issued by the U.S. government, with original maturities of 6 to 24 months. These securities were purchased with the intent to hold to maturity and are recorded at amortized cost. Investments measured at NAV and held-to-maturity investments have not been classified in the fair value hierarchy. The amounts presented in the above table are intended to permit reconciliation of the fair value hierarchy to the amounts presented on the consolidated statement of financial position. Commodity swap contracts classified as level 2 were valued based on the underlying futures contracts. Foreign currency exchange contracts classified as level 2 were valued based on the prevailing forward exchange rate. The following table presents fair value measurements as of December 31, 2017 (in thousands): Level 1 Level 2 Level 3 Investments Measured at NAV Total Cash equivalents $ 173,270 $ — $ — $ — $ 173,270 Trading investments Common stocks $ 5,961 $ — $ — $ — $ 5,961 Fixed income — 6,755 — — 6,755 Limited partnership interests — — 605 725 1,330 Preferred securities 7,658 53,152 — — 60,810 Total $ 13,619 $ 59,907 $ 605 $ 725 $ 74,856 Equity method investments $ — $ — $ — $ 6,176 $ 6,176 Available-for-sale investments Common stocks $ 7,238 $ — $ — $ — $ 7,238 Company-sponsored funds 14,632 — — — 14,632 Fixed income — 3,961 — — 3,961 Preferred securities 999 125 — — 1,124 Other — — — 119 119 Total $ 22,869 $ 4,086 $ — $ 119 $ 27,074 Total investments $ 36,488 $ 63,993 $ 605 $ 7,020 $ 108,106 Derivatives - assets Commodity contracts $ 487 $ — $ — $ — $ 487 Total $ 487 $ — $ — $ — $ 487 Derivatives - liabilities Commodity contracts $ 286 $ — $ — $ — $ 286 Foreign exchange contracts — 64 — — 64 Total $ 286 $ 64 $ — $ — $ 350 Cash equivalents were comprised of investments in actively traded U.S. Treasury money market funds measured at NAV. Trading investments in fixed income securities classified as level 2 in the above table were comprised of U.S. Treasury securities carried at amortized cost, which approximates fair value. Trading investments in preferred securities classified as level 2 were comprised of corporate debt and certain preferred securities. The fair value amounts were generally determined using third-party pricing services. The pricing services may utilize evaluated pricing models that vary by asset class and incorporate available trade, bid and other market information. Since these securities do not trade on a daily basis, the pricing services evaluate pricing applications and apply available information through processes such as yield curves, benchmarking of like securities, sector groupings, and matrix pricing, to prepare evaluations. Trading investments classified as level 3 in the above table were comprised of a limited partner interest in a limited partnership vehicle that invested in a private equity vehicle that invested directly in real estate which was valued using a contractual selling price. Available-for-sale investments classified as level 2 in the above table were primarily comprised of corporate bonds and certain preferred securities whose fair values are generally determined using third-party pricing services. The pricing services may utilize pricing models, and inputs into those models may include reported trades, executable bid and ask prices, broker-dealer quotations, prices or yields of similar securities, benchmark curves and other market information. The pricing services may use a matrix approach, which considers information regarding securities with similar characteristics to determine the valuation for a security. Investments measured at NAV were comprised of certain investments measured at fair value using NAV (or its equivalent) as a practical expedient. These investments have not been classified in the fair value hierarchy. The fair value amounts presented in the above table are intended to permit reconciliation of the fair value hierarchy to the amounts presented on the consolidated statement of financial position. These investments were comprised of: • Trading investments - limited partner interests in limited partnership vehicles that invest in non-registered real estate funds, which are valued based on the NAVs of the underlying funds. At December 31, 2017 , the Company did not have the ability to redeem these interests. • Equity method investments - the Company's partnership interests in Company-sponsored limited partnerships. One such partnership invests in private equity vehicles that invest directly in real estate and non-registered real estate funds and the Company did not have the ability to redeem this investment. The other partnership invests indirectly in exchange-traded commodity futures contracts and other commodity-related derivatives and the Company had the ability to redeem this investment monthly at NAV with prior written notice of 5 days. • Available-for-sale investments - the Company's co-investment in a Cayman trust invested in global listed infrastructure securities. There were no contractual restrictions on the Company's ability to redeem this investment. Foreign currency exchange contracts classified as level 2 were valued based on the prevailing forward exchange rate. The following table summarizes the changes in level 3 investments measured at fair value on a recurring basis for the years ended December 31, 2018 and 2017 (in thousands): Trading Investments Limited Partnership Interests 2018 2017 Balance at beginning of year $ 605 $ 1,196 Purchases / contributions — 419 Sales / distributions (598 ) (1,291 ) Realized gains (losses) (68 ) 162 Unrealized gains (losses) (1) 61 119 Transfers into (out of) level 3 — — Balance at end of year $ — $ 605 _________________________ (1) Pertains to unrealized gains (losses) from securities still held at December 31, 2017. Realized and unrealized gains (losses) in the above table were recorded as gain (loss) from investments—net in the Company's consolidated statements of operations. Valuation Techniques In certain instances, debt, equity and preferred securities are valued on the basis of prices from an orderly transaction between market participants provided by reputable broker-dealers or independent pricing services. In determining the value of a particular investment, independent 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 generally performs reviews of valuations provided by broker-dealers or independent pricing services. Investments in Company-sponsored funds are valued at their closing price or NAV (or its equivalent) as a practical expedient. Foreign exchange contracts are valued based on the prevailing forward exchange rate, 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.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Schedule of New Accounting Pronouncements and Changes in Accounting Principles	The adoption of the new revenue recognition standard resulted in the following changes to the Company's previously reported results for the periods presented (in thousands): Year Ended December 31, 2017 Year Ended December 31, 2016 Previously Reported Net Adjustments Due to New Revenue Standard Recast Previously Reported Net Adjustments Due to New Revenue Standard Recast Revenue: Investment advisory and administration fees $ 346,832 $ (10,089 ) $ 336,743 $ 319,667 $ (7,808 ) $ 311,859 Distribution and service fees $ 20,156 $ 10,591 $ 30,747 $ 19,396 $ 9,429 $ 28,825 Expenses: Distribution and service fees (1) $ 39,632 $ 10,906 $ 50,538 $ 39,590 $ 10,190 $ 49,780 General and administrative $ 52,623 $ (10,404 ) $ 42,219 $ 51,558 $ (8,569 ) $ 42,989 ________________________ (1) The amount presented in the consolidated statements of operations differs from the amount presented within this table due to the reclassification of the amortization of deferred sales commissions previously reported as depreciation and amortization.

Revenue (Tables)

Revenue (Tables)	12 Months Ended
	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following tables summarize revenue recognized from contracts with customers by client domicile and revenue by vehicle for the periods presented (in thousands): Year ended December 31, 2018 2017 2016 Client domicile: North America $ 322,964 $ 314,021 $ 286,957 Japan 35,283 42,303 43,458 Asia excluding Japan 12,493 11,496 9,852 Europe 10,371 10,876 11,230 Total $ 381,111 $ 378,696 $ 351,497 Year ended December 31, 2018 2017 2016 Vehicle: Open-end funds $ 192,735 $ 188,613 $ 172,371 Closed-end funds 77,270 78,670 76,108 Institutional accounts 100,311 100,207 92,205 Portfolio consulting and other 10,795 11,206 10,813 Total $ 381,111 $ 378,696 $ 351,497

Investments (Tables)

Investments (Tables)	12 Months Ended
	Dec. 31, 2018
Investments [Abstract]
Summary of Investment Holdings	The following tables summarize the Company’s investments as of December 31, 2018 and 2017 (in thousands): December 31, 2018 Equity investments at fair value $ 66,795 Trading 108,363 Held-to-maturity (1) 49,748 Equity method 26 Total investments $ 224,932 _________________________ (1) At December 31, 2018, held-to-maturity investments had an amortized cost of approximately $49.7 million and a fair value of approximately $49.8 million , with original maturities ranging from 6 to 24 months. December 31, 2017 Trading $ 74,856 Equity method 6,176 Available-for-sale 27,074 Total investments $ 108,106
Gain (Loss) on Investments	The following tables summarize gain (loss) from investments for the years ended December 31, 2018, 2017 and 2016 (in thousands): December 31, 2018 Net realized gains (losses) during the period $ (1,486 ) Net unrealized gains (losses) during the period on investments still held at the end of the period (12,778 ) Gain (loss) from investments—net (1) $ (14,264 ) _________________________ (1) Included net income (loss) attributable to redeemable noncontrolling interests. Year Ended December 31, 2017 2016 Gain (loss) from trading investments—net (1) $ 1,915 $ 218 Equity in earnings (losses) of affiliates—net (242 ) 3,324 Gain (loss) from available-for-sale investments—net 347 1,451 Gain (loss) from investments—net $ 2,020 $ 4,993 _________________________ (1) Included net income (loss) attributable to redeemable noncontrolling interests.
Schedule of Variable Interest Entities	The following tables summarize the consolidated statements of financial condition attributable to the Company's consolidated VIEs, which included the Cohen & Steers SICAV Global Listed Infrastructure Fund (GLI SICAV), the Cohen & Steers Co-Investment Partnership, L.P. (GRP-CIP), the Cohen & Steers SICAV Global Preferred Securities Fund (SICAV Preferred) and the Cohen & Steers SICAV Diversified Real Assets Fund (SICAV RAP) for the years ended December 31, 2018 and 2017 (in thousands): December 31, 2018 GLI SICAV GRP-CIP SICAV Preferred SICAV RAP Total Assets (1) Investments $ 5,704 $ 550 $ 120,930 $ 8,929 $ 136,113 Due from brokers 49 103 10,868 167 11,187 Other assets 171 — 2,136 297 2,604 Total assets $ 5,924 $ 653 $ 133,934 $ 9,393 $ 149,904 Liabilities (1) Due to brokers $ — $ — $ 4,398 $ 24 $ 4,422 Other liabilities and accrued expenses 74 5 212 149 440 Total liabilities $ 74 $ 5 $ 4,610 $ 173 $ 4,862 December 31, 2017 GLI SICAV GRP-CIP SICAV Preferred Total Assets (1) Investments $ 5,961 $ 1,330 $ 60,810 $ 68,101 Due from brokers 285 202 4,923 5,410 Other assets 32 — 899 931 Total assets $ 6,278 $ 1,532 $ 66,632 $ 74,442 Liabilities (1) Due to brokers $ 35 $ — $ 3,168 $ 3,203 Other liabilities and accrued expenses 87 5 199 291 Total liabilities $ 122 $ 5 $ 3,367 $ 3,494 _________________________ (1) The assets may only be used to settle obligations of each VIE and the liabilities are the sole obligation of each VIE, for which creditors do not have recourse to the general credit of the Company.
Schedule of Available-for-Sale Investments Reconciliation	The following tables summarize the cost, gross unrealized gains, gross unrealized losses and fair value of available-for-sale investments for the year ended December 31, 2017 (in thousands): Cost Gross Unrealized Gains Gross (1) Fair Value Common stocks $ 6,782 $ 639 $ (183 ) $ 7,238 Company-sponsored funds 13,376 1,269 (13 ) 14,632 Fixed income securities 3,966 15 (20 ) 3,961 Preferred securities 1,100 29 (5 ) 1,124 Other 100 19 — 119 Total available-for-sale investments $ 25,324 $ 1,971 $ (221 ) $ 27,074 _________________________ (1) At December 31, 2017, there were no securities with material unrealized losses continuously for a period of more than 12 months.
Schedule of Realized Gains (Losses) on Available-for-sale investments	The following table summarizes sales proceeds, gross realized gains and losses from available-for-sale investments for the years ended December 31, 2017 and 2016 (in thousands): Year Ended December 31, 2017 2016 Proceeds from sales $ 25,812 $ 20,823 Gross realized gains 714 1,879 Gross realized losses (367 ) (428 )

Fair Value (Tables)

Fair Value (Tables)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements, Recurring and Nonrecurring	The following table presents fair value measurements as of December 31, 2018 (in thousands): Level 1 Level 2 Level 3 Investments Measured at NAV Investments Carried at Amortized Cost Total Cash equivalents $ 78,147 $ — $ — $ — $ — $ 78,147 Equity investments at fair value Common stocks $ 21,982 $ — $ — $ — $ — $ 21,982 Company-sponsored funds 9,456 — — — — 9,456 Limited partnership interests 1,056 — — 550 — 1,606 Preferred securities 30,448 3,193 — — — 33,641 Other — — — 110 — 110 Total $ 62,942 $ 3,193 $ — $ 660 $ — $ 66,795 Trading investments Fixed income $ — $ 108,363 $ — $ — $ — $ 108,363 Total $ — $ 108,363 $ — $ — $ — $ 108,363 Held-to-maturity investments Fixed income $ — $ — $ — $ — $ 49,748 $ 49,748 Total $ — $ — $ — $ — $ 49,748 $ 49,748 Equity method investments $ — $ — $ — $ 26 $ — $ 26 Total investments $ 62,942 $ 111,556 $ — $ 686 $ 49,748 $ 224,932 Derivatives - assets Commodity contracts $ 486 $ — $ — $ — $ — $ 486 Commodity swap contracts — 739 — — — 739 Total $ 486 $ 739 $ — $ — $ — $ 1,225 Derivatives - liabilities Commodity contracts $ 2,181 $ — $ — $ — $ — $ 2,181 Foreign exchange contracts — 205 — — — 205 Total $ 2,181 $ 205 $ — $ — $ — $ 2,386	The following table presents fair value measurements as of December 31, 2017 (in thousands): Level 1 Level 2 Level 3 Investments Measured at NAV Total Cash equivalents $ 173,270 $ — $ — $ — $ 173,270 Trading investments Common stocks $ 5,961 $ — $ — $ — $ 5,961 Fixed income — 6,755 — — 6,755 Limited partnership interests — — 605 725 1,330 Preferred securities 7,658 53,152 — — 60,810 Total $ 13,619 $ 59,907 $ 605 $ 725 $ 74,856 Equity method investments $ — $ — $ — $ 6,176 $ 6,176 Available-for-sale investments Common stocks $ 7,238 $ — $ — $ — $ 7,238 Company-sponsored funds 14,632 — — — 14,632 Fixed income — 3,961 — — 3,961 Preferred securities 999 125 — — 1,124 Other — — — 119 119 Total $ 22,869 $ 4,086 $ — $ 119 $ 27,074 Total investments $ 36,488 $ 63,993 $ 605 $ 7,020 $ 108,106 Derivatives - assets Commodity contracts $ 487 $ — $ — $ — $ 487 Total $ 487 $ — $ — $ — $ 487 Derivatives - liabilities Commodity contracts $ 286 $ — $ — $ — $ 286 Foreign exchange contracts — 64 — — 64 Total $ 286 $ 64 $ — $ — $ 350
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 years ended December 31, 2018 and 2017 (in thousands): Trading Investments Limited Partnership Interests 2018 2017 Balance at beginning of year $ 605 $ 1,196 Purchases / contributions — 419 Sales / distributions (598 ) (1,291 ) Realized gains (losses) (68 ) 162 Unrealized gains (losses) (1) 61 119 Transfers into (out of) level 3 — — Balance at end of year $ — $ 605 _________________________ (1) Pertains to unrealized gains (losses) from securities still held at December 31, 2017.

Derivatives (Tables)

Derivatives (Tables)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Derivatives [Abstract]
Schedule of Derivative Instruments	The notional amount represents the absolute value amount of all outstanding derivative contracts at December 31, 2018 and 2017 (in thousands): December 31, 2018 Assets Liabilities Notional Fair Value Notional Fair Value Commodity contracts $ 19,361 $ 486 $ 3,434 $ 2,181 Commodity swap contracts 8,761 739 — — Foreign exchange contracts — — 10,996 205 Total $ 28,122 $ 1,225 $ 14,430 $ 2,386	December 31, 2017 Assets Liabilities Notional Fair Value Notional Fair Value Commodity contracts $ 8,939 $ 487 $ 6,876 $ 286 Foreign exchange contracts — — 12,279 64 Total $ 8,939 $ 487 $ 19,155 $ 350
Gains (Losses) on Derivatives	Year Ended December 31, 2018 2017 2016 Commodity contracts $ (2,093 ) $ (438 ) $ 835 Commodity swap contracts 739 — — Foreign exchange contracts (141 ) (1,481 ) 1,626 Total $ (1,495 ) $ (1,919 ) $ 2,461

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Property and Equipment	The following table summarizes the Company’s property and equipment at December 31, 2018 and 2017 (in thousands): December 31, 2018 2017 Equipment $ 5,590 $ 7,503 Furniture and fixtures 3,644 3,598 Software 17,591 21,173 Leasehold improvements 16,028 16,017 Subtotal 42,853 48,291 Less: Accumulated depreciation and amortization (28,747 ) (33,251 ) Property and equipment, net $ 14,106 $ 15,040

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following table is a reconciliation of the income and share data used in the basic and diluted earnings per share computations for the years ended December 31, 2018, 2017 and 2016 (in thousands, except per share data): Year Ended December 31, 2018 2017 2016 Net income $ 109,522 $ 92,486 $ 92,810 Less: Net (income) loss attributable to redeemable noncontrolling interests 4,374 (547 ) 126 Net income attributable to common stockholders $ 113,896 $ 91,939 $ 92,936 Basic weighted average shares outstanding 46,794 46,353 45,951 Dilutive potential shares from restricted stock units 587 626 481 Diluted weighted average shares outstanding 47,381 46,979 46,432 Basic earnings per share attributable to common stockholders $ 2.43 $ 1.98 $ 2.02 Diluted earnings per share attributable to common stockholders $ 2.40 $ 1.96 $ 2.00

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Disclosure of Share-based Compensation Arrangements by Share-based Payment Award	The following table sets forth activity relating to the Company’s RSUs under the SIP (share data in thousands): Vested Restricted Stock Unit Grants Unvested Restricted Stock Unit Grants Incentive Bonus Plans Restricted Stock Unit Grants Number of Shares Weighted Average Grant Date Fair Value Number of Shares Weighted Average Grant Date Fair Value Number of Shares Weighted Average Grant Date Fair Value Balance at January 1, 2016 30 $ 36.17 296 $ 36.36 1,282 $ 37.33 Granted 13 37.17 159 30.31 722 30.02 Delivered (9 ) 34.02 (147 ) 35.52 (548 ) 35.86 Forfeited — — (1 ) 42.09 (57 ) 35.14 Balance at December 31, 2016 34 37.15 307 33.62 1,399 34.22 Granted 16 38.14 151 35.45 714 35.36 Delivered (8 ) 40.03 (140 ) 34.41 (523 ) 34.80 Forfeited — — — — (40 ) 33.87 Balance at December 31, 2017 42 36.98 318 34.14 1,550 34.60 Granted 15 38.29 134 39.02 757 39.42 Delivered (12 ) 34.95 (146 ) 35.13 (539 ) 34.94 Forfeited — — — — (23 ) 37.16 Balance at December 31, 2018 45 37.93 306 35.80 1,745 36.55

Related Party Transactions (Tab

Related Party Transactions (Tables)	12 Months Ended
	Dec. 31, 2018
Related Party Transactions [Abstract]
Schedule of Related Party Transactions	the years ended December 31, 2018, 2017 and 2016 (in thousands): Year Ended December 31, 2018 2017 2016 Proceeds from sales $ 10,872 $ 15,105 $ 13,251 Gross realized gains 28 80 1,159 Gross realized losses (4,448 ) — — Dividend income 481 675 787 The following table summarizes the amount of revenue the Company earned from these affiliated funds for the years ended December 31, 2018, 2017 and 2016 (in thousands): Year Ended December 31, 2018 2017 2016 Investment advisory and administration fees (1) $ 241,255 $ 236,832 $ 220,364 Distribution and service fees 29,090 30,747 28,825 Total $ 270,345 $ 267,579 $ 249,189

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Rental Payments for Operating Leases	The Company also leases certain information technology applications, market data and office equipment under noncancelable operating leases expiring at various dates through March 2024. The aggregate minimum future payments under the leases are as follows (in thousands): Year Ending December 31, Operating Leases 2019 $ 15,112 2020 13,570 2021 11,397 2022 10,882 2023 10,842 Thereafter 960 $ 62,763

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Changes in Goodwill and Intangible Assets	The following table summarizes the changes in the Company’s goodwill and intangible assets during the years ended December 31, 2018 and 2017 (in thousands): Goodwill Finite-Lived Intangible Assets Indefinite-Lived Intangible Assets Balance at January 1, 2017 $ 17,684 $ 184 $ 1,250 Currency revaluation 1,350 — — Amortization N/A (89 ) N/A Balance at December 31, 2017 $ 19,034 $ 95 $ 1,250 Currency revaluation (533 ) — — Amortization N/A (95 ) N/A Balance at December 31, 2018 $ 18,501 $ — $ 1,250
Schedule of Intangible Assets	The following table summarizes the Company’s intangible assets at December 31, 2018 and 2017 (in thousands): Remaining Amortization Period (in months) Gross Carrying Amount Accumulated Amortization Intangible Assets, Net 2018 Amortized intangible assets: Client relationships — $ 1,543 $ (1,543 ) $ — Non-amortized intangible assets: Mutual fund management contracts — 1,250 — 1,250 Total $ 2,793 $ (1,543 ) $ 1,250 2017 Amortized intangible assets: Client relationships 12 $ 1,543 $ (1,448 ) $ 95 Non-amortized intangible assets: Mutual fund management contracts — 1,250 — 1,250 Total $ 2,793 $ (1,448 ) $ 1,345

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Schedule of Income before Taxes	The income before provision for income taxes and provision for income taxes for the years ended December 31, 2018, 2017 and 2016 are as follows (in thousands): Year Ended December 31, 2018 2017 2016 Income before provision for income taxes - U.S. $ 132,838 $ 149,338 $ 132,882 Income before provision for income taxes - Non-U.S. 10,941 11,062 10,521 Total income before provision for income taxes $ 143,779 $ 160,400 $ 143,403 Current taxes: U.S. federal $ 26,223 $ 58,082 $ 42,056 State and local 7,378 8,155 7,423 Non-U.S. 2,029 1,991 2,014 35,630 68,228 51,493 Deferred taxes: U.S. federal (748 ) (428 ) (743 ) State and local (281 ) (412 ) (86 ) Non-U.S. (344 ) 526 (71 ) (1,373 ) (314 ) (900 ) Provision for income taxes $ 34,257 $ 67,914 $ 50,593
Components of Deferred Tax Assets and Liabilities	Significant components of the Company’s net deferred income tax asset at December 31, 2018 and 2017 consist of the following (in thousands): At December 31, 2018 2017 Deferred income tax assets (liabilities): Stock-based compensation $ 4,915 $ 5,437 Non-deductible realized losses on investments 1,539 1,030 Dividend equivalents on unvested restricted stock units 1,734 1,715 Net unrealized losses on investments 2,512 2,359 Deferred compensation 78 (1,325 ) Deferred rent 1,452 1,488 Other (760 ) (996 ) Subtotal 11,470 9,708 Less: valuation allowance (4,270 ) (3,896 ) Deferred income tax asset—net $ 7,200 $ 5,812
Reconciliation of Gross Unrecognized Tax Benefits	A reconciliation of the beginning and ending amount of gross unrecognized tax benefits is as follows (in thousands): Liability for Unrecognized Tax Benefits Gross unrecognized tax benefits balance at January 1, 2016 $ 7,259 Addition for tax positions of current year 1,437 Addition for tax positions of prior years 163 Reduction of tax positions from prior years (1,007 ) Gross unrecognized tax benefits balance at December 31, 2016 $ 7,852 Addition for tax positions of current year 1,724 Addition for tax positions of prior years 6,624 Reduction of tax positions from prior years (3,794 ) Gross unrecognized tax benefits balance at December 31, 2017 $ 12,406 Addition for tax positions of current year 2,233 Reduction of tax positions from prior years (2,602 ) Gross unrecognized tax benefits balance at December 31, 2018 $ 12,037
Reconciliation of Federal Statutory Income Tax Rate to Effective Rate	A reconciliation of the Company’s statutory federal income tax rate and the effective tax rate for the years ended December 31, 2018, 2017 and 2016 is as follows: Year Ended December 31, 2018 2017 2016 U.S. statutory tax rate 21.0 % 35.0 % 35.0 % State and local income taxes, net of federal income taxes 3.8 % 3.1 % 3.5 % Unrecognized tax benefit adjustments (1.0 )% (1.9 )% (0.2 )% Foreign operations tax differential 0.3 % (1.4 )% (1.1 )% Non-deductible losses on investments 0.2 % 0.2 % 1.3 % Non-taxable gains on investments 0.1 % (0.2 )% (3.0 )% Tax Act (0.1 )% 8.0 % — % Other (1.2 )% (0.3 )% (0.2 )% Effective income tax rate 23.1 % 42.5 % 35.3 %
Schedule of Transition Tax Liability, Fiscal Year Maturity Schedule	Year Ending December 31, Transition Tax Liability 2019 $ 192 2020 665 2021 665 2022 1,246 2023 1,662 2024 2,077 $ 6,507

Concentration of Credit Risk (T

Concentration of Credit Risk (Tables)	12 Months Ended
	Dec. 31, 2018
Risks and Uncertainties [Abstract]
Schedules of Concentration of Risk, by Risk Factor	The following affiliated funds and third-party institutional separate account subadvisory relationship, which is comprised of multiple accounts, provided 10% or more of the total revenue of the Company (in thousands): Year Ended December 31, 2018 2017 2016 Cohen & Steers Realty Shares, Inc. (CSR): Investment advisory and administration fees $ 33,827 $ 38,392 $ 45,047 Percent of total revenue 9 % 10 % 13 % Cohen & Steers Preferred Securities and Income Fund, Inc. (CPX): Investment advisory and administration fees $ 53,059 $ 53,594 $ 42,420 Percent of total revenue 14 % 14 % 12 % Daiwa Asset Management: Investment advisory fees $ 30,265 $ 37,756 $ 39,377 Portfolio consulting and other 3,189 3,035 2,930 Total $ 33,454 $ 40,791 $ 42,307 Percent of total revenue 9 % 11 % 12 %

Selected Quarterly Financial _2

Selected Quarterly Financial Data (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	The table below presents selected quarterly financial data for 2018 and 2017 (in thousands, except per share data): Quarter 1st 2nd 3rd 4th Total 2018 Revenue $ 94,464 $ 94,410 $ 98,331 $ 93,906 $ 381,111 Operating income 37,219 36,287 39,223 34,309 147,038 Net income attributable to common stockholders (1) 27,586 29,959 30,790 25,561 113,896 Earnings per share attributable to common stockholders: Basic 0.59 0.64 0.66 0.55 2.43 Diluted 0.59 0.63 0.65 0.54 2.40 Weighted-average shares outstanding: Basic 46,683 46,819 46,830 46,842 46,794 Diluted 47,152 47,311 47,524 47,562 47,381 2017 Revenue (2) $ 89,741 $ 92,714 $ 96,787 $ 99,454 $ 378,696 Operating income 35,528 37,357 40,973 40,888 154,746 Net income attributable to common stockholders 22,985 23,474 25,082 20,398 91,939 Earnings per share attributable to common stockholders: Basic 0.50 0.51 0.54 0.44 1.98 Diluted 0.49 0.50 0.53 0.43 1.96 Weighted-average shares outstanding: Basic 46,243 46,373 46,386 46,407 46,353 Diluted 46,603 46,902 47,047 47,300 46,979

Summary of Significant Accoun_4

Summary of Significant Accounting Policies New Accountings Pronouncements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total revenue	$ 381,111	$ 378,696	$ 351,497
Distribution and service fees	50,043	53,338	53,144
General and administrative	48,265	42,219	42,989
Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption		1,095
Investment advisory and administration fees
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total revenue	341,226	336,743	311,859
Distribution and service fees		50,538	49,780
Distribution and service fees
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total revenue	$ 29,090	30,747	28,825
General and administrative		42,219	42,989
Previously Reported | Investment advisory and administration fees
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total revenue		346,832	319,667
Distribution and service fees		39,632	39,590
Previously Reported | Distribution and service fees
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total revenue		20,156	19,396
General and administrative		52,623	51,558
Net Adjustments Due to New Revenue Standard | Investment advisory and administration fees | Accounting Standards Update 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total revenue		(10,089)	(7,808)
Distribution and service fees		10,906	10,190
Net Adjustments Due to New Revenue Standard | Distribution and service fees | Accounting Standards Update 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total revenue		10,591	9,429
General and administrative		$ (10,404)	$ (8,569)

Summary of Significant Accoun_5

Summary of Significant Accounting Policies Cumulative Translation Adjustments Balance (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accumulated Translation Adjustment
Cumulative Translation Adjustments balance [Line Items]
Cumulative Foreign Currency Translation Adjustment, Net of Tax	$ (7,323)	$ (4,781)	$ (6,845)

Revenue (Details)

Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation of Revenue [Line Items]
Total revenue	$ 381,111	$ 378,696	$ 351,497
North America
Disaggregation of Revenue [Line Items]
Total revenue	322,964	314,021	286,957
Japan
Disaggregation of Revenue [Line Items]
Total revenue	35,283	42,303	43,458
Asia, excluding Japan
Disaggregation of Revenue [Line Items]
Total revenue	12,493	11,496	9,852
Europe
Disaggregation of Revenue [Line Items]
Total revenue	10,371	10,876	11,230
Open-end funds
Disaggregation of Revenue [Line Items]
Total revenue	192,735	188,613	172,371
Closed-end funds
Disaggregation of Revenue [Line Items]
Total revenue	77,270	78,670	76,108
Institutional accounts
Disaggregation of Revenue [Line Items]
Total revenue	100,311	100,207	92,205
Portfolio consulting and other
Disaggregation of Revenue [Line Items]
Total revenue	$ 10,795	$ 11,206	$ 10,813

Investments Trading, Equity Met

Investments Trading, Equity Method Investments and Available-for-Sale Investments (Details) $ in Thousands		12 Months Ended
		Dec. 31, 2018USD ($)new_funds_seeded	Dec. 31, 2017USD ($)new_funds_seeded	Dec. 31, 2016USD ($)
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading Securities, Equity			$ 74,856
Summary of Investments [Abstract]
Equity investments at fair value		$ 66,795
Trading		108,363
Held-to-maturity		49,748
Equity method		26	6,176
Available-for-sale			27,074
Total investments	[1]	224,932	$ 108,106
Debt Securities, Held-to-maturity, Fair Value		$ 49,800
Number of new funds seeded | new_funds_seeded		1	2
Gain (Loss) on Investments [Abstract]
Cost-method Investments, Realized Gain (Loss)		$ (1,486)
Marketable Securities, Unrealized Gain (Loss)		(12,778)
Gain (loss) from investments—net		(14,264)	$ 2,020	$ 4,993
Available-for-sale investments, unrealized loss position, fair value			6,086
Trading, Equity Method Investments and Available-for-Sale Investments [Abstract]
Gain (loss) from trading investments—net			1,915	218
Equity in earnings (losses) of affiliates—net			(242)	3,324
Gain (loss) from available-for-sale investments—net			347	1,451
Gain (loss) from investments—net		(14,264)	2,020	4,993
Available-for-sale investments [Abstract]
Cost			25,324
Gross Unrealized Gains			1,971
Gross Unrealized Losses			(221)
Fair Value			27,074
Proceeds from investing activities [Abstract]
Proceeds from sales			25,812	20,823
Gross realized gains			714	1,879
Gross realized losses			(367)	$ (428)
Fair Value, Measurements, Recurring
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading Securities, Equity			74,856
Summary of Investments [Abstract]
Equity investments at fair value		66,795	6,176
Trading		108,363
Available-for-sale			27,074
Available-for-sale investments [Abstract]
Fair Value			27,074
Common stock
Summary of Investments [Abstract]
Available-for-sale			7,238
Available-for-sale investments [Abstract]
Cost			6,782
Gross Unrealized Gains			639
Gross Unrealized Losses			(183)
Fair Value			7,238
Common stock | Fair Value, Measurements, Recurring
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading Securities, Equity			5,961
Summary of Investments [Abstract]
Equity investments at fair value		21,982
Available-for-sale			7,238
Available-for-sale investments [Abstract]
Fair Value			7,238
Company-sponsored funds
Summary of Investments [Abstract]
Available-for-sale			14,632
Available-for-sale investments [Abstract]
Cost			13,376
Gross Unrealized Gains			1,269
Gross Unrealized Losses			(13)
Fair Value			14,632
Company-sponsored funds | Fair Value, Measurements, Recurring
Summary of Investments [Abstract]
Equity investments at fair value		9,456
Available-for-sale			14,632
Available-for-sale investments [Abstract]
Fair Value			14,632
Fixed income securities
Summary of Investments [Abstract]
Available-for-sale			3,961
Available-for-sale investments [Abstract]
Cost			3,966
Gross Unrealized Gains			15
Gross Unrealized Losses			(20)
Fair Value			3,961
Fixed income securities | Fair Value, Measurements, Recurring
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading Securities, Equity			6,755
Summary of Investments [Abstract]
Trading		108,363
Held-to-maturity		49,748
Preferred securities
Summary of Investments [Abstract]
Available-for-sale			1,124
Available-for-sale investments [Abstract]
Cost			1,100
Gross Unrealized Gains			29
Gross Unrealized Losses			(5)
Fair Value			1,124
Preferred securities | Fair Value, Measurements, Recurring
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading Securities, Equity			60,810
Summary of Investments [Abstract]
Equity investments at fair value		$ 33,641
Available-for-sale			1,124
Available-for-sale investments [Abstract]
Fair Value			1,124
Other
Summary of Investments [Abstract]
Available-for-sale			119
Available-for-sale investments [Abstract]
Cost			100
Gross Unrealized Gains			19
Gross Unrealized Losses			0
Fair Value			119
Other | Fair Value, Measurements, Recurring
Summary of Investments [Abstract]
Available-for-sale			119
Available-for-sale investments [Abstract]
Fair Value			$ 119
[1]	Asset and liability amounts in parentheses represent the aggregated balances at December 31, 2018 and 2017 attributable to variable interest entities consolidated by the Company. Refer to Note 4 for further discussion.

Investments Variable Interest E

Investments Variable Interest Entity (Details) - USD ($) $ in Thousands		Dec. 31, 2018	Dec. 31, 2017
Variable Interest Entity [Line Items]
Investments	[1]	$ 224,932	$ 108,106
Due from brokers	[1]	14,240	6,429
Other assets	[1]	9,208	7,053
Total assets		432,551	410,125
Due to brokers	[1]	5,121	3,282
Other liabilities and accrued expenses	[1]	13,935	10,025
Total liabilities		95,713	86,794
SICAV RAP
Variable Interest Entity [Line Items]
Investments		8,929
Due from brokers		167
Other assets		297
Total assets		9,393
Due to brokers		24
Other liabilities and accrued expenses		149
Total liabilities		173
GLI SICAV
Variable Interest Entity [Line Items]
Investments		5,704	5,961
Due from brokers		49	285
Other assets		171	32
Total assets		5,924	6,278
Due to brokers		0	35
Other liabilities and accrued expenses		74	87
Total liabilities		74	122
GRP-CIP
Variable Interest Entity [Line Items]
Investments		550	1,330
Due from brokers		103	202
Other assets		0	0
Total assets		653	1,532
Due to brokers		0	0
Other liabilities and accrued expenses		5	5
Total liabilities		5	5
SICAV Preferred
Variable Interest Entity [Line Items]
Investments		120,930	60,810
Due from brokers		10,868	4,923
Other assets		2,136	899
Total assets		133,934	66,632
Due to brokers		4,398
Other liabilities and accrued expenses		212
Total liabilities		4,610	3,367
GLI SICAV, GRP-CIP and SICAV Preferred
Variable Interest Entity [Line Items]
Investments			68,101
Due from brokers			5,410
Other assets			931
Total assets			74,442
Due to brokers			3,203
Other liabilities and accrued expenses			291
Total liabilities			$ 3,494
GLI SICAV, GRP-CIP, SICAV Preferred and SICAV RAP [Member]
Variable Interest Entity [Line Items]
Investments		136,113
Due from brokers		11,187
Other assets		2,604
Total assets		149,904
Due to brokers		4,422
Other liabilities and accrued expenses		440
Total liabilities		$ 4,862
[1]	Asset and liability amounts in parentheses represent the aggregated balances at December 31, 2018 and 2017 attributable to variable interest entities consolidated by the Company. Refer to Note 4 for further discussion.

Fair Value (Details)

Fair Value (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		$ 74,856
Equity investments at fair value	$ 66,795
Available-for-sale		27,074
Held-to-maturity	49,748
Equity method investments	26	6,176
Derivative - assets		0
Derivative - liabilities		0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Debt Securities, Trading	108,363
Commodity contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative - assets		0
Derivative - liabilities		0
Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative - liabilities		0
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	78,147	173,270
Trading Securities, Equity		74,856
Equity investments at fair value	66,795	6,176
Available-for-sale		27,074
Total investments	224,932	108,106
Derivative - assets	1,225	487
Derivative - liabilities	2,386	350
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Debt Securities, Trading	108,363
Fair Value, Measurements, Recurring | Commodity contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative - assets	486	487
Derivative - liabilities	2,181	286
Fair Value, Measurements, Recurring | Commodity Swap Contract
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative - assets	739
Fair Value, Measurements, Recurring | Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative - assets	3,081
Derivative - liabilities	205	64
Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	78,147	173,270
Trading Securities, Equity		13,619
Equity investments at fair value	62,942	0
Available-for-sale		22,869
Total investments	62,942	36,488
Derivative - assets	486	487
Derivative - liabilities	2,181	286
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Debt Securities, Trading	0
Fair Value, Measurements, Recurring | Level 1 | Commodity contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative - assets	486	487
Derivative - liabilities	2,181	286
Fair Value, Measurements, Recurring | Level 1 | Commodity Swap Contract
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative - assets	0
Fair Value, Measurements, Recurring | Level 1 | Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative - liabilities	0	0
Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Trading Securities, Equity		59,907
Equity investments at fair value	3,193	0
Available-for-sale		4,086
Total investments	111,556	63,993
Derivative - assets	739	0
Derivative - liabilities	205	64
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Debt Securities, Trading	108,363
Fair Value, Measurements, Recurring | Level 2 | Commodity contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative - assets	0	0
Derivative - liabilities	0	0
Fair Value, Measurements, Recurring | Level 2 | Commodity Swap Contract
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative - assets	739
Fair Value, Measurements, Recurring | Level 2 | Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative - assets	3,081	0
Derivative - liabilities	205	64
Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Trading Securities, Equity		605
Equity investments at fair value	0	0
Available-for-sale		0
Total investments	0	605
Derivative - assets	0	0
Derivative - liabilities	0	0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Debt Securities, Trading	0
Fair Value, Measurements, Recurring | Level 3 | Commodity contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative - assets	0	0
Derivative - liabilities	0	0
Fair Value, Measurements, Recurring | Level 3 | Commodity Swap Contract
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative - assets	0
Fair Value, Measurements, Recurring | Level 3 | Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative - liabilities	0	0
Fair Value, Measurements, Recurring | Investments Measured at NAV
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Trading Securities, Equity		725
Equity investments at fair value	660	6,176
Available-for-sale		119
Total investments	686	7,020
Derivative - assets	0
Derivative - liabilities	0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Debt Securities, Trading	0
Fair Value, Measurements, Recurring | Investments Measured at NAV | Commodity contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative - assets	0
Derivative - liabilities	0
Fair Value, Measurements, Recurring | Investments Measured at NAV | Commodity Swap Contract
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative - assets	0
Fair Value, Measurements, Recurring | Investments Measured at NAV | Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative - liabilities	0
Common stocks
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale		7,238
Common stocks | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		5,961
Equity investments at fair value	21,982
Available-for-sale		7,238
Common stocks | Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		5,961
Equity investments at fair value	21,982
Available-for-sale		7,238
Common stocks | Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		0
Equity investments at fair value	0
Available-for-sale		0
Common stocks | Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		0
Equity investments at fair value	0
Available-for-sale		0
Common stocks | Fair Value, Measurements, Recurring | Investments Measured at NAV
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		0
Equity investments at fair value	0
Available-for-sale		0
Fixed income securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale		3,961
Fixed income securities | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		6,755
Held-to-maturity	49,748
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Debt Securities, Trading	108,363
Fixed income securities | Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Debt Securities, Trading	0
Fixed income securities | Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		6,755
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Debt Securities, Trading	108,363
Fixed income securities | Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Debt Securities, Trading	0
Fixed income securities | Fair Value, Measurements, Recurring | Investments Measured at NAV
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Debt Securities, Trading	0
Company-sponsored funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale		14,632
Company-sponsored funds | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity investments at fair value	9,456
Available-for-sale		14,632
Company-sponsored funds | Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity investments at fair value	9,456
Available-for-sale		14,632
Company-sponsored funds | Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity investments at fair value	0
Available-for-sale		0
Company-sponsored funds | Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity investments at fair value	0
Available-for-sale		0
Company-sponsored funds | Fair Value, Measurements, Recurring | Investments Measured at NAV
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity investments at fair value	0
Available-for-sale		0
Limited partnership interests | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		1,330
Equity investments at fair value	1,606
Available-for-sale		3,961
Limited partnership interests | Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		0
Equity investments at fair value	1,056
Available-for-sale		0
Limited partnership interests | Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		0
Equity investments at fair value	0
Available-for-sale		3,961
Limited partnership interests | Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		605
Equity investments at fair value	0
Available-for-sale		0
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	605	1,196
Purchases / contributions	0	419
Sales / distributions	598	1,291
Realized gains	68	(162)
Unrealized gains (losses)	(61)	(119)
Transfers into (out of) level 3	0	0
Ending Balance	0	605
Limited partnership interests | Fair Value, Measurements, Recurring | Investments Measured at NAV
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		725
Equity investments at fair value	550
Available-for-sale		0
Preferred securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale		1,124
Preferred securities | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		60,810
Equity investments at fair value	33,641
Available-for-sale		1,124
Preferred securities | Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		7,658
Equity investments at fair value	30,448
Available-for-sale		999
Preferred securities | Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		53,152
Equity investments at fair value	3,193
Available-for-sale		125
Preferred securities | Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		0
Equity investments at fair value	0
Available-for-sale		0
Preferred securities | Fair Value, Measurements, Recurring | Investments Measured at NAV
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		0
Equity investments at fair value	0
Available-for-sale		0
Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale		119
Other | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale		119
Other | Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity investments at fair value	0
Available-for-sale		0
Other | Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity investments at fair value	0
Available-for-sale		0
Other | Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity investments at fair value	0
Available-for-sale		0
Other | Fair Value, Measurements, Recurring | Investments Measured at NAV
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity investments at fair value	110
Available-for-sale		$ 119
Other Investment Companies [Member] | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity investments at fair value	110
Held-to-maturity Securities [Member] | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity	49,748
Held-to-maturity Securities [Member] | Fixed income securities | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity	49,748
Equity Method Investments | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity method investments	26
Equity Method Investments | Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity method investments	0
Equity Method Investments | Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity method investments	0
Equity Method Investments | Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity method investments	0
Equity Method Investments | Fair Value, Measurements, Recurring | Investments Measured at NAV
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity method investments	$ 26

Derivatives (Details)

Derivatives (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Derivative [Line Items]
Derivative Assets, Notional Amount	$ 28,122,000	$ 8,939,000
Derivative Assets, Fair Value	1,225,000	487,000
Derivative Liabilities, Notional Amount	14,430,000	19,155,000
Derivative Liabilities, Fair Value	2,386,000	350,000
Derivative, Gain (Loss) on Derivative, Net	(1,495,000)	(1,919,000)	$ 2,461,000
Investments
Derivative [Line Items]
Trading investment and held as collateral	1,807,000	414,000
Foreign exchange contracts
Derivative [Line Items]
Derivative Assets, Notional Amount	0	0
Derivative Assets, Fair Value	0	0
Derivative Liabilities, Notional Amount	10,996,000	12,279,000
Derivative Liabilities, Fair Value	205,000	64,000
Derivative, Gain (Loss) on Derivative, Net	(141,000)	(1,481,000)	1,626,000
Commodity contracts
Derivative [Line Items]
Derivative Assets, Notional Amount	19,361,000	8,939,000
Derivative Assets, Fair Value	486,000	487,000
Derivative Liabilities, Notional Amount	3,434,000	6,876,000
Derivative Liabilities, Fair Value	2,181,000	286,000
Derivative, Gain (Loss) on Derivative, Net	(2,093,000)	(438,000)	835,000
Commodity Swap Contract
Derivative [Line Items]
Derivative Assets, Notional Amount	8,761,000
Derivative Assets, Fair Value	739,000
Derivative Liabilities, Notional Amount	0
Derivative Liabilities, Fair Value	0
Derivative, Gain (Loss) on Derivative, Net	739,000	$ 0	$ 0
Due From Broker
Derivative [Line Items]
Trading investment and held as collateral	$ 2,002,000

Property and Equipment (Details

Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property and Equipment [Line Items]
Depreciation and amortization	$ 4,378	$ 4,229	$ 4,155
Property and equipment, gross	42,853	48,291
Accumulated depreciation and amortization	(28,747)	(33,251)
Property and equipment, net	$ 14,106	15,040
Minimum
Property and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Maximum
Property and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	7 years
Equipment
Property and Equipment [Line Items]
Property and equipment, gross	$ 5,590	7,503
Furniture and fixtures
Property and Equipment [Line Items]
Property and equipment, gross	3,644	3,598
Software
Property and Equipment [Line Items]
Property and equipment, gross	17,591	21,173
Leasehold improvements
Property and Equipment [Line Items]
Property and equipment, gross	$ 16,028	$ 16,017

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Earnings Per Share [Abstract]
Anti-dilutive common stock equivalents excluded from computation (in shares)									0	0	14
Net income									$ 109,522	$ 92,486	$ 92,810
Less: Net (income) loss attributable to redeemable noncontrolling interest									4,374	(547)	126
Net income attributable to common stockholders	$ 25,561	$ 30,790	$ 29,959	$ 27,586	$ 20,398	$ 25,082	$ 23,474	$ 22,985	$ 113,896	$ 91,939	$ 92,936
Basic weighted average shares outstanding (in shares)	46,842	46,830	46,819	46,683	46,407	46,386	46,373	46,243	46,794	46,353	45,951
Dilutive potential shares from restricted stock units (in shares)									587	626	481
Diluted weighted average shares outstanding (in shares)	47,562	47,524	47,311	47,152	47,300	47,047	46,902	46,603	47,381	46,979	46,432
Basic earnings per share attributable to common stockholders (in dollars per share)	$ 0.55	$ 0.66	$ 0.64	$ 0.59	$ 0.44	$ 0.54	$ 0.51	$ 0.50	$ 2.43	$ 1.98	$ 2.02
Diluted earnings per share attributable to common stockholders (in dollars per share)	$ 0.54	$ 0.65	$ 0.63	$ 0.59	$ 0.43	$ 0.53	$ 0.50	$ 0.49	$ 2.40	$ 1.96	$ 2

Stock-Based Compensation Vested

Stock-Based Compensation Vested RSUs (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Requisite Service Period	4 years
Common stock, shares issued	51,104,593	50,415,152
Restricted Stock Units (RSUs) | Common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	$ 40,868
Stock Incentive Plan | Common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares Authorized	20,000,000
Stock Incentive Plan | Restricted Stock Units (RSUs) | Common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, shares issued	15,800,000
Allocated Share-based Compensation Expense	$ 4,216	$ 3,957	$ 4,685
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested, Number of Shares [Roll Forward] [Roll Forward]
Balance at Beginning of Period (shares)	42,000	34,000	30,000
Granted (shares)	15,000	16,000	13,000
Delivered (shares)	(12,000)	8,000	9,000
Balance at End of Period (shares)	45,000	42,000	34,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested, Weighted Average Grant Date Fair Value [Abstract] [Abstract]
Balance at beginning of period, Weighted Average Grant Date Fair Value (usd per share)	$ 36.98	$ 37.15	$ 36.17
Granted, Weighted Average Grant Date Fair Value (usd per share)	38.29	38.14	37.17
Delivered, Weighted Average Grant Date Fair Value (usd per share)	34.95	40.03	34.02
Balance at end of period, Weighted Average Grant Date Fair Value (usd per share)	$ 37.93	$ 36.98	$ 37.15
Stock Incentive Plan | Vested Restricted Stock Units (RSUs) | Common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	$ 626	$ 618	$ 486

Stock-Based Compensation Unvest

Stock-Based Compensation Unvested RSUs and Incentive Bonus Plans (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Common stock, shares issued	51,104,593	50,415,152
Share-based Compensation Arrangement by Share-based Payment Award, Incentive Bonus Plans, Weighted Average Grant Date Fair Value [Roll Forward]
Employee stock purchase plans	18,000	18,000	19,000
Vesting period of unvested employee stock compensation, number of years	3 years
Common stock | Incentive Bonus Plans for Employees
Share-based Compensation Arrangement by Share-based Payment Award, Incentive Bonus Plans, Weighted Average Grant Date Fair Value [Roll Forward]
Share-based Compensation Arrangement by Share-based Payment Award, Annual Aggregate Purchases Per Employee	$ 25,000
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Number of Shares Per Employee	600,000
Restricted Stock Units (RSUs) | Common stock
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Allocated Share-based Compensation Expense	$ 40,868,000
Restricted Stock Units (RSUs) | Common stock | Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (shares)	15,000	16,000	13,000
Granted, Weighted Average Grant Date Fair Value (usd per share)	$ 38.29	$ 38.14	$ 37.17
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested, Number	45,000	42,000	34,000	30,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Balance at beginning of period (shares)	318,000	307,000	296,000
Granted (shares)	134,000	151,000	159,000
Delivered (shares)	(146,000)	(140,000)	(147,000)
Forfeited (shares)	0	0	(1,000)
Balance at end of period (shares)	306,000	318,000	307,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Balance at beginning of period, Weighted Average Grant Date Fair Value (usd per share)	$ 34.14	$ 33.62	$ 36.36
Granted, Weighted Average Grant Date Fair Value (usd per share)	39.02	35.45	30.31
Delivered, Weighted Average Grant Date Fair Value (usd per share)	35.13	34.41	35.52
Forfeited, Weighted Average Grant Date Fair Value (usd per share)	0	0	42.09
Balance at end of period, Weighted Average Grant Date Fair Value (usd per share)	$ 35.80	$ 34.14	$ 33.62
Common stock, shares issued	15,800,000
Allocated Share-based Compensation Expense	$ 4,216,000	$ 3,957,000	$ 4,685,000
Share-based Compensation Arrangement by Share-based Payment Award, Incentive Bonus Plans, Weighted Average Grant Date Fair Value [Roll Forward]
Delivered, Weighted Average Grant Date Fair Value (usd per share)	$ 35.13	$ 34.41	$ 35.52
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested, Delivered	12,000	(8,000)	(9,000)
Delivered, Weighted Average Grant Date Fair Value (usd per share)	$ 34.95	$ 40.03	$ 34.02
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested, Weighted Average Grant Date Fair Value	37.93	36.98	37.15	$ 36.17
Restricted Stock Units (RSUs) | Common stock | Incentive Bonus Plans for Employees
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Delivered, Weighted Average Grant Date Fair Value (usd per share)	$ 34.94	$ 34.80	$ 35.86
Share-based Compensation Arrangement by Share-based Payment Award, Incentive Bonus Plans [Roll Forward]
Balance at beginning of period (shares)	1,550,000	1,399,000	1,282,000
Granted (shares)	757,000	714,000	722,000
Delivered (shares)	539,000	523,000	(548,000)
Forfeited (shares)	(23,000)	(40,000)	(57,000)
Balance at end of period (shares)	1,745,000	1,550,000	1,399,000
Share-based Compensation Arrangement by Share-based Payment Award, Incentive Bonus Plans, Weighted Average Grant Date Fair Value [Roll Forward]
Balance at beginning of period, Weighted Average Grant Date Fair Value (usd per share)	$ 34.60	$ 34.22	$ 37.33
Granted, Weighted Average Grant Date Fair Value (usd per share)	39.42	35.36	30.02
Delivered, Weighted Average Grant Date Fair Value (usd per share)	34.94	34.80	35.86
Forfeited, Weighted Average Grant Date Fair Value (usd per share)	37.16	33.87	35.14
Balance at end of period, Weighted Average Grant Date Fair Value (usd per share)	$ 36.55	$ 34.60	$ 34.22
Discount from market price, purchase date	15.00%
Restricted Stock Units (RSUs) | Common stock | Mandatory Plan
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Allocated Share-based Compensation Expense	$ 19,710,000	$ 17,175,000	$ 16,847,000
Restricted Stock Units (RSUs) | Common stock | Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Allocated Share-based Compensation Expense	105,000	112,000	114,000
Vested Restricted Stock Units (RSUs) | Common stock | Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Allocated Share-based Compensation Expense	$ 626,000	$ 618,000	$ 486,000

401(k) and Profit-Sharing Plan

401(k) and Profit-Sharing Plan (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Employer Matching Contribution, Percent of Match	50.00%
The Plan
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Maximum Employee Subscription Rate	100.00%
Forfeitures during period	$ 101	$ 128	$ 126
Employer matching contributions	1,770	$ 1,715	$ 1,464
Common stock | Restricted Stock Units (RSUs)
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Allocated Share-based Compensation Expense	$ 40,868

Related Party Transactions (Det

Related Party Transactions (Details) - Affiliated Entity - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Related Party Transactions Revenue [Abstract]
Investment advisory and administrative fees	$ 241,255	$ 236,832	$ 220,364
Distribution and service fees	29,090	30,747	28,825
Total	270,345	267,579	249,189
Related Party Transactions Summary [Abstract]
Proceeds from sales	10,872	15,105	13,251
Gross realized gains	28	80	1,159
Gross realized losses, including other-than-temporary impairment	(4,448)	0	0
Dividend income	481	675	787
Fund expenses, included in general and administrative expenses	8,600	8,700	$ 7,600
Receivables, company sponsored mutual funds	$ 21,855	$ 23,666

Regulatory Requirements (Detail

Regulatory Requirements (Details) $ in Millions	Dec. 31, 2018USD ($)
Securities Registered Domestically
Regulatory Requirements
Net Capital	$ 3.2
Excess Capital	3
Foreign Country
Regulatory Requirements
Net Capital	26
Excess Capital	$ 25.7

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)
Commitments
Loss Contingencies [Line Items]
Long-term Purchase Commitments, Time Period	12 years
Commitment to invest
Loss Contingencies [Line Items]
Other Commitment	$ 5.1
Long-term committment, funded amount	$ 3.8

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Goodwill and Intangible Assets (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Goodwill
Beginning balance	$ 19,034,000	$ 17,684,000
Currency revaluation	(533,000)	1,350,000
Ending balance	18,501,000	19,034,000	$ 17,684,000
Finite-Lived Intangible Assets
Finite-lived intangible assets, gross	2,793,000	2,793,000	184,000
Amortization	95,000	89,000	89,000
Finite-Lived Intangible Assets	0	95,000
Indefinite-Lived Intangible Assets
Fund management contracts	$ 1,250,000	$ 1,250,000	$ 1,250,000

Commitments and Contingencies_2

Commitments and Contingencies - Other Obligations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Aggregate Minimum Future Payments [Line Items]
Rent expense	$ 11,900	$ 11,800	$ 11,500
Rent Obligations
Aggregate Minimum Future Payments [Line Items]
2,017	15,112
2,018	13,570
2,019	11,397
2,020	10,882
2,021	10,842
Thereafter	960
Other Commitment	$ 62,763

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Amortization Period Remaining	12
Client relationships, Gross Carrying Amount	$ 2,793	$ 2,793	$ 184
Client relationships, Accumulated Amortization	1,448	1,543
Client relationships, Net	95	0
Fund management contracts	1,250	1,250	$ 1,250
Intangible assets—net	1,345	1,250
Client Relationships
Finite-Lived Intangible Assets [Line Items]
Client relationships, Gross Carrying Amount	1,543	1,543
Client relationships, Accumulated Amortization		1,543
Client relationships, Net	95	0
Fund Management Contracts Member
Finite-Lived Intangible Assets [Line Items]
Fund management contracts	1,250	1,250
Intangible assets—net	$ 1,250	$ 1,250

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets - Estimated Future Amortization Expense (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense related to intangible assets	$ 95,000	$ 89,000	$ 89,000

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Effective tax rate	23.10%	42.50%	35.30%
Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Change in Tax Rate, Deferred Tax Liability	$ 6,507
Gross unrecognized tax benefits	12,037	$ 12,406	$ 7,852	$ 7,259
Unrecognized tax benefits that impact effective tax rate in future periods	9,235
Reduction in unrecognized tax benefits	5,121
Uncertain tax positions, accrued interest and penalties	$ 2,519	$ 1,933

Income Taxes - Schedule of Inco

Income Taxes - Schedule of Income before Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income before provision for income taxes
U.S. income before provision for income taxes	$ 132,838	$ 149,338	$ 132,882
Foreign income before provision for income taxes	10,941	11,062	10,521
Income before provision for income taxes	143,779	160,400	143,403
Current taxes:
U.S. federal	26,223	58,082	42,056
State and local	7,378	8,155	7,423
Non-U.S.	2,029	1,991	2,014
Total	35,630	68,228	51,493
Deferred taxes:
U.S. federal	(748)	(428)	(743)
State and local	(281)	(412)	(86)
Non-U.S.	(344)	526	(71)
Deferred income taxes	(1,373)	(314)	(900)
Provision for income taxes	$ 34,257	$ 67,914	$ 50,593

Income Taxes - Components of De

Income Taxes - Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Stock-based compensation	$ 4,915	$ 5,437
Non-deductible realized losses on investments	1,539	1,030
Dividend equivalents on unvested restricted stock units	1,734	1,715
Deferred Tax Assets, Unrealized Losses on Trading Securities	2,512	2,359
Deferred compensation	78	(1,325)
Deferred rent	1,452	1,488
Other	(760)	(996)
Subtotal	11,470	9,708
Less: valuation allowance	(4,270)	(3,896)
Deferred income tax asset—net	7,200	5,812
Capital Loss Carryforward	6,181	$ 4,181
Changes in Valuation Allowance	$ (374)

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Gross Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Unrecognized Tax Benefits [Roll Forward]
Gross unrecognized tax benefits balance	$ 12,406	$ 7,852	$ 7,259
Addition for tax positions of current year	2,233	1,724	1,437
Addition for tax positions of prior years		6,624	163
Reduction of tax positions from prior years	(2,602)	(3,794)	(1,007)
Gross unrecognized tax benefits balance	$ 12,037	$ 12,406	$ 7,852

Income Taxes - Reconciliation_2

Income Taxes - Reconciliation of Federal Statutory Income Tax Rate to Effective Rate (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
U.S. statutory tax rate	21.00%	35.00%	35.00%
Tax Act	(0.10%)	8.00%	0.00%
State and local income taxes, net of federal income taxes	3.80%	3.10%	3.50%
Non-deductible losses on investments	0.20%	0.20%	1.30%
Unrecognized tax benefits adjustments	(1.00%)	(1.90%)	(0.20%)
Non-taxable gains on investments	0.10%	(0.20%)	(3.00%)
Foreign operations tax differential	0.30%	(1.40%)	(1.10%)
Other	(1.20%)	(0.30%)	(0.20%)
Effective income tax rate	23.10%	42.50%	35.30%

Income Taxes - Schedule of Tran

Income Taxes - Schedule of Transition Tax Liabilities by Fiscal Year (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)
Income Tax Disclosure [Abstract]
2,019	$ 192
2,020	665
2,021	665
2,022	1,246
2,023	1,662
2,024	2,077
Total	$ 6,507

Concentration of Credit Risk (D

Concentration of Credit Risk (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Concentration Risk (Line Items)
Revenues	$ 93,906	$ 98,331	$ 94,410	$ 94,464	$ 99,454	$ 96,787	$ 92,714	$ 89,741	$ 381,111	$ 378,696
Cohen & Steers Realty Shares, Inc. (CSR) | Sales Revenue, Services | Customer Concentration Risk
Concentration Risk (Line Items)
Percent of total revenue									9.00%	10.00%	13.00%
Cohen & Steers Realty Shares, Inc. (CSR) | Sales Revenue, Services | Investment advisory and administration fees | Customer Concentration Risk
Concentration Risk (Line Items)
Revenues									$ 33,827	$ 38,392	$ 45,047
Cohen & Steers Preferred Securities and Income Fund, Inc. (CPX) | Sales Revenue, Services | Customer Concentration Risk
Concentration Risk (Line Items)
Percent of total revenue									14.00%	14.00%	12.00%
Cohen & Steers Preferred Securities and Income Fund, Inc. (CPX) | Sales Revenue, Services | Investment advisory and administration fees | Customer Concentration Risk
Concentration Risk (Line Items)
Revenues									$ 53,059	$ 53,594	$ 42,420
Daiwa Asset Management | Sales Revenue, Services | Customer Concentration Risk
Concentration Risk (Line Items)
Revenues									$ 33,454	$ 40,791	$ 42,307
Percent of total revenue									9.00%	11.00%	12.00%
Daiwa Asset Management | Sales Revenue, Services | Investment advisory and administration fees | Customer Concentration Risk
Concentration Risk (Line Items)
Revenues									$ 30,265	$ 37,756	$ 39,377
Daiwa Asset Management | Sales Revenue, Services | Portfolio consulting and other | Customer Concentration Risk
Concentration Risk (Line Items)
Revenues									$ 3,189	$ 3,035	$ 2,930

Selected Quarterly Financial _3

Selected Quarterly Financial Data (unaudited) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 93,906	$ 98,331	$ 94,410	$ 94,464	$ 99,454	$ 96,787	$ 92,714	$ 89,741	$ 381,111	$ 378,696
Operating income (loss)	34,309	39,223	36,287	37,219	40,888	40,973	37,357	35,528	147,038	154,746	$ 135,511
Net income attributable to common stockholders	$ 25,561	$ 30,790	$ 29,959	$ 27,586	$ 20,398	$ 25,082	$ 23,474	$ 22,985	$ 113,896	$ 91,939	$ 92,936
Earnings per share attributable to common stockholders:
Basic (in dollars per share)	$ 0.55	$ 0.66	$ 0.64	$ 0.59	$ 0.44	$ 0.54	$ 0.51	$ 0.50	$ 2.43	$ 1.98	$ 2.02
Diluted (in dollars per share)	$ 0.54	$ 0.65	$ 0.63	$ 0.59	$ 0.43	$ 0.53	$ 0.50	$ 0.49	$ 2.40	$ 1.96	$ 2
Weighted-average shares outstanding:
Basic (shares)	46,842	46,830	46,819	46,683	46,407	46,386	46,373	46,243	46,794	46,353	45,951
Diluted (shares)	47,562	47,524	47,311	47,152	47,300	47,047	46,902	46,603	47,381	46,979	46,432

Subsequent Events (Details)

Subsequent Events (Details) - $ / shares	Feb. 21, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Subsequent Event [Line Items]
Dividends declared per share		$ 3.82	$ 2.12	$ 1.54
Dividend Declared | Subsequent Event
Subsequent Event [Line Items]
Dividends declared per share	$ 0.36