Cohen & Steers (CNS) 10-K 26 Feb 21 2020 FY Annual report Financial data

Cover Page

Cover Page - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2020	Feb. 22, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Document Transition Report	false
Entity File Number	001-32236
Entity Registrant Name	COHEN & STEERS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	14-1904657
Entity Address, Address Line One	280 Park Avenue
Entity Address, City or Town	New York
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10017
City Area Code	212
Local Phone Number	832-3232
Title of 12(b) Security	Common Stock, $.01 par value
Trading Symbol	CNS
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 1.7
Entity Common Stock, Shares Outstanding		48,229,251
ICFR Auditor Attestation Flag	true
Entity Central Index Key	0001284812
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	[1]
Total revenue									$ 427,536	$ 410,830	$ 381,111
Expenses:
Employee compensation and benefits									156,457	143,431	131,292
Distribution and service fees									115,084	55,237	50,043
General and administrative									56,286	47,632	48,265
Depreciation and amortization									4,652	4,396	4,473
Total expenses									332,479	250,696	234,073
Operating income (loss)	$ (11,914)	$ 43,307	$ 35,295	$ 28,369	$ 46,462	$ 40,133	$ 38,104	$ 35,435	95,057	160,134	147,038
Non-operating income (loss):
Interest and dividend income—net									3,362	6,716	10,426
Gain (loss) from investments—net									(4,116)	21,673	(14,264)
Foreign currency gains (losses)—net									(916)	(974)	579
Total non-operating income (loss)									(1,670)	27,415	(3,259)
Income before provision for income taxes									93,387	187,549	143,779
Provision for income taxes									18,222	40,565	34,257
Net income									75,165	146,984	109,522
Less: Net (income) loss attributable to redeemable noncontrolling interest									1,419	(12,363)	4,374
Net income attributable to common stockholders	$ (4,412)	$ 31,904	$ 28,520	$ 20,572	$ 36,728	$ 34,017	$ 31,333	$ 32,543	$ 76,584	$ 134,621	$ 113,896
Earnings (loss) per share attributable to common stockholders:
Basic (in dollars per share)	$ (0.09)	$ 0.67	$ 0.60	$ 0.43	$ 0.78	$ 0.72	$ 0.66	$ 0.69	$ 1.60	$ 2.85	$ 2.43
Diluted (in dollars per share)	$ (0.09)	$ 0.66	$ 0.59	$ 0.42	$ 0.75	$ 0.70	$ 0.65	$ 0.68	$ 1.57	$ 2.79	$ 2.40
Weighted average shares outstanding:
Basic (shares)	47,867	47,855	47,826	47,651	47,324	47,316	47,304	47,146	47,800	47,273	46,794
Diluted (shares)	48,857	48,681	48,572	48,591	48,703	48,412	48,175	47,642	48,676	48,297	47,381
Investment advisory and administration fees
Total revenue									$ 395,037	$ 378,578	$ 349,870
Distribution and service fees
Total revenue									30,134	30,048	29,090
Other
Total revenue									$ 2,365	$ 2,204	$ 2,151
[1]	Revenue amounts related to model-based portfolios were reclassified from other (previously reported as portfolio consulting and other) to investment advisory and administration fees.

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018		Jan. 01, 2019
Cash flows from operating activities:
Net income	$ 75,165,000	$ 146,984,000	$ 109,522,000	[1]
Adjustments to reconcile net income to net cash provided by operating activities:
Stock compensation expense	29,337,000	27,811,000	24,626,000
Amortization of deferred commissions	1,701,000	1,079,000	1,559,000
Depreciation and amortization	4,652,000	4,396,000	4,473,000	[1]
Amortization of right-of-use assets	10,128,000	10,048,000	9,364,000
Amortization (accretion) of premium (discount) on held-to-maturity investments	(208,000)	(493,000)	(246,000)
(Gain) loss from investments—net	4,116,000	(21,673,000)	14,264,000	[1]
Deferred income taxes	107,000	96,000	(1,373,000)
Foreign currency (gain) loss	(1,269,000)	9,000	211,000
Changes in operating assets and liabilities:
Accounts receivable	(9,310,000)	(8,729,000)	3,262,000
Due from brokers	(3,382,000)	989,000	(7,811,000)
Deferred commissions	(1,474,000)	(1,628,000)	(982,000)
Investments within consolidated funds	(3,605,000)	(13,997,000)	(81,182,000)
Other assets	(771,000)	(120,000)	(2,689,000)
Accrued compensation	3,951,000	4,420,000	2,341,000
Distribution and service fees payable	430,000	(1,175,000)	2,262,000
Operating lease liabilities	(11,314,000)	(10,955,000)	(9,542,000)
Due to broker	135,000	45,000	1,839,000
Income tax payable	(9,640,000)	3,531,000	(1,229,000)
Other liabilities and accrued expenses	437,000	807,000	3,929,000
Net cash provided by (used in) operating activities	89,186,000	141,445,000	72,598,000
Cash flows from investing activities:
Proceeds from redemptions of equity method investments	6,000	52,000	37,000
Purchases of investments	(70,963,000)	(50,943,000)	(63,557,000)
Proceeds from sales of investments	71,689,000	89,592,000	13,796,000
Purchases of property and equipment	(2,502,000)	(2,752,000)	(3,470,000)
Net cash provided by (used in) investing activities	(1,770,000)	35,949,000	(53,194,000)
Cash flows from financing activities:
Issuance of common stock	859,000	741,000	597,000
Repurchase of common stock	(25,937,000)	(10,408,000)	(10,599,000)
Dividends to stockholders	(122,489,000)	(162,705,000)	(178,879,000)
Distributions to redeemable noncontrolling interest	(6,024,000)	(43,483,000)	(10,862,000)
Contributions from redeemable noncontrolling interests	4,696,000	45,725,000	81,633,000
Net cash provided by (used in) financing activities	(148,895,000)	(170,130,000)	(118,110,000)
Net increase (decrease) in cash and cash equivalents	(61,479,000)	7,264,000	(98,706,000)
Effect of foreign exchange rate changes on cash and cash equivalents	1,359,000	1,355,000	(2,013,000)
Cash and cash equivalents, beginning of the year	101,352,000	92,733,000	193,452,000
Cash and cash equivalents, end of the year	41,232,000	101,352,000	92,733,000
Supplemental Cash Flow Information [Abstract]
Income taxes paid	(27,719,000)	(37,036,000)	(36,795,000)
Restricted stock unit dividend equivalents, net of forfeitures	3,176,000	5,973,000	$ 6,544,000
Investments, fair value					$ 5,370,000
The Cohen & Steers Preferred Securities and Income SMA Shares
Supplemental Cash Flow Information [Abstract]
Transfer of redeemable noncontrolling interest in consolidated entity	7,181,000
SICAV GRE
Supplemental Cash Flow Information [Abstract]
Transfer of redeemable noncontrolling interest in consolidated entity	114,192,000
SICAV GRE
Supplemental Cash Flow Information [Abstract]
Noncontrolling interest, increase from business combination	$ 45,988,000
Cohen & Steers Funds ICAV
Supplemental Cash Flow Information [Abstract]
Transfer of redeemable noncontrolling interest in consolidated entity		$ 6,411,000
[1]	Revenue amounts related to model-based portfolios were reclassified from other (previously reported as portfolio consulting and other) to investment advisory and administration fees.

Basis of Presentation

Basis of Presentation	12 Months Ended
	Dec. 31, 2020
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), Cohen & Steers Japan Limited (CSJL) and Cohen & Steers Ireland Limited (CSIL) (collectively, the Company). The Company is a global investment manager specializing in liquid real assets, including real estate securities, listed infrastructure 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, Dublin, 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.

Consolidated Statements of Fina

Consolidated Statements of Financial Condition - USD ($) $ in Thousands		Dec. 31, 2020	Dec. 31, 2019
Assets:
Cash and cash equivalents		$ 41,232	$ 101,352
Investments ($80,743 and $82,829)	[1],[2]	154,978	155,213
Accounts receivable		69,680	59,101
Due from brokers ($223 and $1,743) (1)	[1],[2]	5,125	1,743
Property and equipment—net		10,341	12,486
Operating lease right-of-use assets		31,203	38,440
Goodwill and intangible assets—net		20,495	19,560
Deferred income tax asset—net		6,995	7,091
Other assets ($637 and $1,041)	[1],[2]	8,404	7,433
Total assets		348,453	402,419
Liabilities:
Accrued compensation		52,056	48,105
Distribution and service fees payable		7,748	7,318
Operating lease liabilities		34,926	43,349
Income tax payable		12,672	22,194
Due to brokers ($128 and $366)	[1],[2]	501	366
Other liabilities and accrued expenses ($326 and $784)	[1],[2]	15,646	13,972
Total liabilities		123,549	135,304
Commitments and contingencies
Redeemable noncontrolling interest		$ 50,665	$ 53,412
Common stock, shares issued (in shares)		53,462,621	52,580,246
Common stock, shares authorized		500,000,000	500,000,000
Common stock, par value		$ 0.01	$ 0.01
Stockholders’ equity:
Common stock, $0.01 par value; 500,000,000 shares authorized; 53,462,621 and 52,580,246 shares issued at December 31, 2020 and 2019, respectively		$ 535	$ 527
Additional paid-in capital		670,142	636,788
Accumulated deficit		(291,542)	(242,461)
Accumulated other comprehensive income, net of tax		$ (4,134)	$ (6,326)
Treasury stock, shares		5,674,510	5,329,820
Less: Treasury stock, at cost, 5,674,510 and 5,329,820 shares at December 31, 2020 and 2019, respectively		$ (200,762)	$ (174,825)
Total stockholders’ equity		174,239	213,703
Total liabilities and stockholders’ equity		$ 348,453	$ 402,419
[1]	Asset and liability amounts in parentheses represent the aggregated balances at December 31, 2020 and 2019 attributable to variable interest entities consolidated by the Company. Refer to Note 4 for further discussion.
[2]	Asset and liability amounts in parentheses represent the aggregated balances at December 31, 2020 and 2019 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, 2020	Dec. 31, 2019
Investments	[1],[2]	$ 154,978	$ 155,213
Due from brokers	[1],[2]	5,125	1,743
Other assets	[1],[2]	8,404	7,433
Due to brokers	[1],[2]	501	366
Other liabilities and accrued expenses	[1],[2]	$ 15,646	$ 13,972
Common stock, par value		$ 0.01	$ 0.01
Common stock, shares authorized		500,000,000	500,000,000
Common stock, shares issued (in shares)		53,462,621	52,580,246
Common stock, shares outstanding		53,462,621	52,580,246
Treasury stock, shares		5,674,510	5,329,820
GLI SICAV, GRP-CIP, SICAV GRE and SICAV RAP [Member]
Investments		$ 80,743	$ 82,829
Due from brokers		223	1,743
Other assets		637	1,041
Due to brokers		128	366
Other liabilities and accrued expenses		$ 326	$ 784
[1]	Asset and liability amounts in parentheses represent the aggregated balances at December 31, 2020 and 2019 attributable to variable interest entities consolidated by the Company. Refer to Note 4 for further discussion.
[2]	Asset and liability amounts in parentheses represent the aggregated balances at December 31, 2020 and 2019 attributable to variable interest entities consolidated by the Company. Refer to Note 4 for further discussion.

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Net income	$ 75,165	$ 146,984	$ 109,522	[1]
Less: Net (income) loss attributable to redeemable noncontrolling interest	1,419	(12,363)	4,374	[1]
Net income attributable to common stockholders	76,584	134,621	113,896	[1]
Other comprehensive income (loss), net of tax:
Foreign currency translation income (loss)	2,192	997	(2,557)
Total comprehensive income attributable to common stockholders	$ 78,776	$ 135,618	$ 111,339
[1]	Revenue amounts related to model-based portfolios were reclassified from other (previously reported as portfolio consulting and other) to investment advisory and administration fees.

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 DeficitCumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive Income (Loss), Net of Tax	Accumulated Other Comprehensive Income (Loss), Net of TaxCumulative Effect, Period of Adoption, Adjustment	Treasury Stock	Total Stockholders' Equity	Redeemable Noncontrolling Interest
Beginning balance at Dec. 31, 2017			$ 511	$ 570,486	$ (137,972)	$ 1,095	$ (3,671)	$ (1,095)	$ (153,818)	$ 275,536
Beginning balance (redeemable noncontrolling interest) at Dec. 31, 2017											$ 47,795
Beginning balance (shares of common stock, net) at Dec. 31, 2017			46,315,000
Dividends					(185,423)					(185,423)
Issuance of common stock			$ 7	696					0	703
Issuance of common stock, shares			714,000
Repurchase of common stock									(10,599)	(10,599)
Repurchase of common stock, shares			(261,000)
Issuance of restricted stock units				7,170						7,170
Amortization of restricted stock units				23,984						23,984
Forfeitures of vested restricted stock units				(64)						(64)
Net income (loss)	$ 109,522	[1]			113,896					113,896	(4,374)
Other comprehensive income (loss)							(2,557)			(2,557)
Net contributions (distributions) attributable to redeemable noncontrolling interests	$ 81,633										70,771
Ending balance at Dec. 31, 2018			$ 518	602,272	(208,404)		(7,323)		(164,417)	222,646
Ending balance (shares of common stock, net) at Dec. 31, 2018			46,768,000
Ending balance (redeemable noncontrolling interest) at Dec. 31, 2018											114,192
Dividends declared per share	$ 3.82
Dividends			$ 0	0	(168,678)		0		0	(168,678)
Issuance of common stock			$ 9	861	0		0		0	870	0
Issuance of common stock, shares			762,000
Repurchase of common stock			$ 0	0	0		0		(10,408)	(10,408)	0
Repurchase of common stock, shares			(280,000)
Issuance of restricted stock units			$ 0	7,039	0		0		0	7,039	0
Amortization of restricted stock units			0	26,883	0		0		0	26,883	0
Forfeitures of vested restricted stock units			0	(267)	0		0		0	(267)	0
Net income (loss)	$ 146,984		0	0	134,621		0		0	134,621	12,363
Other comprehensive income (loss)			0	0	0		997		0	997	0
Net contributions (distributions) attributable to redeemable noncontrolling interests	45,725		0	0	0		0		0	0	2,242
Net consolidation (deconsolidation) of Company-sponsored funds											75,385
Ending balance at Dec. 31, 2019	$ 213,703		$ 527	636,788	(242,461)		(6,326)		(174,825)	213,703
Ending balance (shares of common stock, net) at Dec. 31, 2019	52,580,246		47,250,000
Ending balance (redeemable noncontrolling interest) at Dec. 31, 2019											53,412
Dividends declared per share	$ 3.44
Dividends			$ 0	0	(125,665)		0		0	(125,665)
Issuance of common stock			$ 8	1,002	0		0		0	1,010	0
Issuance of common stock, shares			883,000
Repurchase of common stock			$ 0	0	0		0		(25,937)	(25,937)	0
Repurchase of common stock, shares			(345,000)
Issuance of restricted stock units			$ 0	3,865	0		0		0	3,865	0
Amortization of restricted stock units			0	28,740	0		0		0	28,740	0
Forfeitures of vested restricted stock units			0	(253)	0		0		0	(253)	0
Net income (loss)	$ 75,165		0	0	76,584		0		0	76,584	(1,419)
Other comprehensive income (loss)			0	0	0		2,192		0	2,192	0
Net contributions (distributions) attributable to redeemable noncontrolling interests	4,696		0	0	0		0		0	0	(1,328)
Ending balance at Dec. 31, 2020	$ 174,239		$ 535	$ 670,142	$ (291,542)		$ (4,134)		$ (200,762)	$ 174,239
Ending balance (shares of common stock, net) at Dec. 31, 2020	53,462,621		47,788,000
Ending balance (redeemable noncontrolling interest) at Dec. 31, 2020											$ 50,665
Dividends declared per share	$ 2.56
[1]	Revenue amounts related to model-based portfolios were reclassified from other (previously reported as portfolio consulting and other) to investment advisory and administration fees.

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Stockholders' Equity and Redeemable Noncontrolling Interest (parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Dividends declared per share	$ 2.56	$ 3.44	$ 3.82

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Recently Adopted Accounting Pronouncements —In August 2018, the Financial Accounting Standards Board (FASB) issued guidance to align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. Under the new standard, implementation costs are deferred and presented in the same financial statement caption on the consolidated statements of financial condition as a prepayment of related arrangement fees. The deferred costs are recognized over the term of the arrangement in the same financial statement caption in the consolidated statements of operations as the related fees of the arrangement. This new guidance became effective on January 1, 2020. The Company has adopted this new standard using a prospective approach to all implementation costs incurred after adoption. The Company's adoption of the new standard did not have a material effect on its 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. As a result of the revised guidance, a goodwill impairment will be the amount by which a reporting unit’s carrying value exceeds its fair value. This new guidance became effective on January 1, 2020. The Company's adoption of the new standard did not have a material effect on its consolidated financial statements and related disclosures. In June 2016, the FASB issued guidance on the measurement of credit losses on financial instruments. This standard amended guidance related to reporting credit losses for financial assets measured at amortized cost and replaced the incurred loss impairment model with a current expected credit loss (CECL) model. CECL requires a company to estimate lifetime expected credit losses based on relevant information about historical events, current conditions and reasonable and supportable forecasts. This new guidance became effective on January 1, 2020. The Company's adoption of the new standard had no impact on its consolidated financial statements and related disclosures. 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 due to factors the Company cannot fully predict including the extent of the impact to the Company's business from the ongoing COVID-19 pandemic. 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 Company-sponsored funds for which the Company’s ownership is less than 100%. Cash and Cash Equivalents —Cash and cash equivalents are on deposit with several highly rated financial institutions and include short-term, highly-liquid investments, which are readily convertible into cash and have original maturities of three months or less. Due from/to Brokers —The Company, including the consolidated Company-sponsored funds, may 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/or cash collateral balances at brokers/custodians and/or receivables and payables for unsettled securities transactions with brokers. 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, 2020, the Company's investments were comprised of the following: • Equity investments at fair value, which generally represent equity securities held within the consolidated Company-sponsored funds, individual equity 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 generally represent debt securities held within the consolidated Company-sponsored funds and individual debt securities held directly for the purposes of establishing performance track records. • Held-to-maturity investments, which generally represent corporate investments in U.S. Treasury securities recorded at amortized cost. Under the CECL model, any expected credit losses are recognized as an allowance, which represents an adjustment to the amortized costs basis. The Company did not record any provision for credit losses on these securities during the year ended December 31, 2020. • Equity method investments, which generally represent seed investments in Company-sponsored funds in which the Company owns between 20-50% of the outstanding voting interests 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 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 consolidated Company-sponsored funds, may enter into derivative contracts, including options, futures and swaps contracts, to gain exposure to the underlying commodities markets or to economically hedge market risk of the underlying portfolios. Gains 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. Additionally, from time to time, the Company, including the consolidated Company-sponsored funds, may enter into forward foreign exchange contracts to economically hedge its currency exposure. These instruments are measured at fair value based on the prevailing forward exchange rate with gains and losses recorded in foreign currency gain (loss)—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. Leases —The Company determines if an arrangement is a lease at inception. The Company has operating leases for corporate offices and certain information technology equipment and these leases are included in operating lease right-of-use (ROU) assets and operating lease liabilities on the Company’s consolidated statements of financial condition. ROU assets represent the right to use an underlying asset for the lease term and lease liabilities represent obligations to make lease payments arising from the lease. Operating lease ROU assets and lease liabilities are recognized at commencement date based on the net present value of lease payments over the lease term. The majority of the Company’s lease agreements do not provide an implicit rate. As a result, the Company used an incremental borrowing rate based on the information available as of lease commencement dates in determining the present value of lease payments. The operating lease ROU asset reflects any upfront lease payments made as well as lease incentives received. The lease terms may include options to extend or terminate the lease and these are factored into the determination of the ROU asset and lease liability at lease inception when and if it is reasonably certain that the Company will exercise that option. Lease expense for fixed lease payments is recognized on a straight-line basis over the lease term. The Company has certain lease agreements with non-lease components such as maintenance and executory costs, which are accounted for separately and not included in ROU assets. ROU assets are tested for impairment whenever changes in facts or circumstances indicate that the carrying amount of an asset may not be recoverable. Modification of a lease term would result in re-measurement of the lease liability and a corresponding adjustment to the ROU asset. 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. Redeemable Noncontrolling Interests —Redeemable noncontrolling interests represent third-party interests in the consolidated Company-sponsored funds. These interests are redeemable at the option of the investors and therefore are not treated as permanent equity. Redeemable noncontrolling interest is recorded at fair value which approximates the redemption value at each reporting period. Investment Advisory and Administration Fees —The Company earns revenue by providing asset management services to institutional accounts, Company-sponsored open-end and closed-end funds as well as model-based portfolios. Investment advisory fees are earned pursuant to the terms of investment management agreements and are generally based on a contractual fee rate applied to the average daily assets under management. 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 daily 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. In certain instances, the Company may earn performance fees when specified performance hurdles are met during the performance period. Performance fees are forms of variable consideration and are not recognized until it becomes probable that there will not be a significant reversal of the cumulative revenue recognized . 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 all periods presented, a portion of the distribution fee revenue recognized in the period 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 includes distribution fees, shareholder servicing fees and intermediary assistance payments. Distribution and service fee expense is recorded on an accrual basis. Distribution fees represent 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, 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. Distribution fees are based on the average daily net assets under management of certain share classes of certain of the funds. Shareholder servicing fees represent payments made to qualified intermediaries for shareholder account service and maintenance. These services are provided pursuant to written agreements with such qualified institutions. Shareholder servicing fees are generally based on the average daily assets under management. 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. Stock-based Compensation —The Company recognizes compensation expense for the grant-date fair value of awards of equity instruments to certain 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 uncertainties in the application of complex tax laws and regulations across the Company’s global operations. A tax benefit from an uncertain tax position is 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 $(4,134,000), $(6,326,000) and $(7,323,000) as of December 31, 2020, 2019 and 2018, respectively. Gains or losses resulting from transactions denominated in currencies other than the U.S. dollar within 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 generally 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 December 2019, the FASB issued Accounting Standards Update 2019-12, Income Taxes (Topic 740): Simplifying Accounting for Income Taxes . The standard is intended to simplify various aspects related to income taxes and removes certain exceptions to the general principles in Topic 740. This new guidance will be effective on January 1, 2021. The Company does not expect the adoption of the new standard to have a material effect on its consolidated financial statements and related disclosures.

Revenue

Revenue	12 Months Ended
	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Revenue	Revenue The following tables summarize revenue recognized from contracts with customers by client domicile and by investment vehicle: Years ended December 31, (in thousands) 2020 2019 2018 Client domicile: North America $ 363,834 $ 352,629 $ 322,964 Japan 32,517 33,967 35,283 Europe, Middle East and Africa 19,869 11,087 10,371 Asia Pacific excluding Japan 11,316 13,147 12,493 Total $ 427,536 $ 410,830 $ 381,111 Years ended December 31, (in thousands) 2020 2019 2018 (2) Investment vehicle: Open-end funds (1) $ 231,269 $ 217,778 $ 197,363 Institutional accounts 115,876 110,346 104,327 Closed-end funds 78,026 80,502 77,270 Other 2,365 2,204 2,151 Total $ 427,536 $ 410,830 $ 381,111 ________________________ (1) Included distribution and service fees of $30.1 million, $30.0 million and $29.1 million for the years ended December 31, 2020, 2019 and 2018, respectively. (2) Amounts related to model-based portfolios were reclassified from other (previously reported as portfolio consulting and other) to open-end funds and institutional accounts.

Investments

Investments	12 Months Ended
	Dec. 31, 2020
Investments [Abstract]
Investment Holdings	Investments The following table summarizes the Company’s investments: (in thousands) December 31, 2020 December 31, 2019 Equity investments at fair value $ 94,089 $ 89,872 Trading 18,700 14,980 Held-to-maturity carried at amortized cost (1) 41,648 49,807 Equity method 541 554 Total investments $ 154,978 $ 155,213 _________________________ (1) Held-to-maturity investments had a fair value of approximately $41.7 million and $50.0 million at December 31, 2020 and 2019, respectively. These securities would be classified as level 2 within the fair value hierarchy if carried at fair value. Original maturities ranged from 6 to 24 months at December 31, 2020 and 2019. The Company seeded one new fund for the year ended December 31, 2020 and two new funds for the year ended December 31, 2019. The following table summarizes gain (loss)—net from investments: Years Ended December 31, (in thousands) 2020 2019 2018 Net realized gains (losses) during the period $ (5,395) $ 12,227 $ (1,486) Net unrealized gains (losses) during the period on investments 1,279 9,446 (12,778) Gain (loss) from investments—net (1) $ (4,116) $ 21,673 $ (14,264) _________________________ (1) Included net income (loss) attributable to redeemable noncontrolling interests. At December 31, 2020 and 2019, the Company's consolidated VIEs included the Cohen & Steers SICAV Global Listed Infrastructure Fund (GLI SICAV), SICAV GRE, the Cohen & Steers SICAV Diversified Real Assets Fund (SICAV RAP) and the Cohen & Steers Co-Investment Partnership, L.P. (GRP-CIP). The following tables summarize the consolidated statements of financial condition attributable to the Company's consolidated VIEs: December 31, 2020 (in thousands) GLI SICAV SICAV GRE SICAV RAP GRP-CIP Total Assets (1) Investments $ 7,140 $ 39,672 $ 33,654 $ 277 $ 80,743 Due from brokers 69 45 52 57 223 Other assets 44 359 234 — 637 Total assets $ 7,253 $ 40,076 $ 33,940 $ 334 $ 81,603 Liabilities (1) Due to brokers $ 27 $ 40 $ 61 $ — $ 128 Other liabilities and accrued expenses 29 211 81 5 326 Total liabilities $ 56 $ 251 $ 142 $ 5 $ 454 December 31, 2019 (in thousands) GLI SICAV SICAV GRE SICAV RAP GRP-CIP Total Assets (1) Investments $ 7,048 $ 45,468 $ 29,976 $ 337 $ 82,829 Due from brokers 264 663 613 203 1,743 Other assets 92 681 268 — 1,041 Total assets $ 7,404 $ 46,812 $ 30,857 $ 540 $ 85,613 Liabilities (1) Due to brokers $ 45 $ 92 $ 229 $ — $ 366 Other liabilities and accrued expenses 100 466 213 5 784 Total liabilities $ 145 $ 558 $ 442 $ 5 $ 1,150 _________________________ (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.

Fair Value

Fair Value	12 Months Ended
	Dec. 31, 2020
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. • 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. The following tables present fair value measurements: December 31, 2020 (in thousands) Level 1 Level 2 Level 3 Investments Investments Total Cash equivalents $ 23,372 $ — $ — $ — $ — $ 23,372 Equity investments at fair value Common stocks $ 91,614 $ — $ — $ — $ — $ 91,614 Company-sponsored funds 246 — — — — 246 Limited partnership interests 831 — — 277 — 1,108 Preferred securities 983 12 — — — 995 Other — — — 126 — 126 Total $ 93,674 $ 12 $ — $ 403 $ — $ 94,089 Trading investments Fixed income $ — $ 18,700 $ — $ — $ — $ 18,700 Held-to-maturity investments $ — $ — $ — $ — $ 41,648 $ 41,648 Equity method investments $ — $ — $ — $ 541 $ — $ 541 Total investments $ 93,674 $ 18,712 $ — $ 944 $ 41,648 $ 154,978 Derivatives - assets Futures - commodities $ 1,012 $ — $ — $ — $ — $ 1,012 Derivatives - liabilities Futures - commodities $ 416 $ — $ — $ — $ — $ 416 Total return swaps - commodities — 136 — — — 136 Total return swaps - equities — 1,562 — — — 1,562 Forward contracts - foreign exchange — 345 — — — 345 Total $ 416 $ 2,043 $ — $ — $ — $ 2,459 December 31, 2019 (in thousands) Level 1 Level 2 Level 3 Investments Investments Total Cash equivalents $ 85,889 $ — $ — $ — $ — $ 85,889 Equity investments at fair value Common stocks $ 87,408 $ — $ — $ — $ — $ 87,408 Company-sponsored funds 132 — — — — 132 Limited partnership interests 1,048 — — 337 — 1,385 Preferred securities 704 108 — — — 812 Other — — — 135 — 135 Total $ 89,292 $ 108 $ — $ 472 $ — $ 89,872 Trading investments Fixed income $ — $ 14,980 $ — $ — $ — $ 14,980 Held-to-maturity investments $ — $ — $ — $ — $ 49,807 $ 49,807 Equity method investments $ — $ — $ — $ 554 $ — $ 554 Total investments $ 89,292 $ 15,088 $ — $ 1,026 $ 49,807 $ 155,213 Derivatives - assets Futures - commodities $ 570 $ — $ — $ — $ — $ 570 Forward contracts - foreign exchange — 74 — — — 74 Total $ 570 $ 74 $ — $ — $ — $ 644 Derivatives - liabilities Futures - commodities $ 339 $ — $ — $ — $ — $ 339 Total return swaps - commodities — 173 — — — 173 Forward contracts - foreign exchange — 44 — — — 44 Total $ 339 $ 217 $ — $ — $ — $ 556 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 and corporate debt 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. 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 - included 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 (which is included in "Other" in the leveling table), both of which are valued based on the NAVs of the underlying investments. At December 31, 2020 and 2019, 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 - included the Company's partnership interests in the Cohen & Steers Global Realty Partners III-TE, L.P. (GRP-TE) and the Cohen & Steers Global Realty Focus Fund (GRF), a series of Cohen & Steers Series LP. GRP-TE invests in non-registered real estate funds. The Company's ownership interest was approximately 0.2% and the Company did not have the ability to redeem the investment at either December 31, 2020 or 2019. GRF invests in global real estate investment trusts and other publicly traded real estate companies. The Company's ownership interest was approximately 0.5% and the Company had the ability to redeem the investment in GRF with 15 days' notice. The Company's risk with respect to both investments is limited to its equity ownership interest and any uncollected management fees. 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 at December 31, 2020 and 2019. 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 tables are intended to permit reconciliation of the fair value hierarchy to the amounts presented on the consolidated statements of financial condition. Swap contracts classified as level 2 were valued based on the underlying futures contracts or equity indices. Foreign currency exchange contracts classified as level 2 were valued based on the prevailing forward exchange rate. 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 is an input that is observable in active markets. 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 involve a significant degree of judgment, taking into consideration a combination of internal and external factors. Such investments, which are generally immaterial, 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.

Derivatives

Derivatives	12 Months Ended
	Dec. 31, 2020
Derivatives [Abstract]
Derivatives	Derivatives The following tables summarize the notional amounts and fair value of the outstanding derivative financial instruments none of which were designated in a formal hedging relationship. As of December 31, 2020 Notional Amount Fair Value (1) (in thousands) Long Short Assets Liabilities Futures - commodities $ 13,624 $ 4,257 $ 1,012 $ 416 Total return swaps - commodities — 9,598 — 136 Total return swaps - equities — 17,688 — 1,562 Forward contracts - foreign exchange — 14,061 — 345 $ 13,624 $ 45,604 $ 1,012 $ 2,459 As of December 31, 2019 Notional Amount Fair Value (1) (in thousands) Long Short Assets Liabilities Futures - commodities $ 14,394 $ 4,623 $ 570 $ 339 Total return swaps - commodities — 8,909 — 173 Forward contracts - foreign exchange — 10,787 74 44 $ 14,394 $ 24,319 $ 644 $ 556 ________________________ (1) The fair value of derivative financial instruments is recorded in other assets and other liabilities and accrued expenses on the Company's consolidated statements of financial condition. Commodity swap contracts are utilized as economic hedges to reduce the overall risk of the Company's market exposure to seed investments in commodity futures. Equity swap contracts are utilized to economically hedge a portion of the market risk of certain seed investments. The Company enters into foreign exchange contracts to sell currency to economically hedge exposure arising from certain non-U.S. dollar investment advisory fees. Cash included in due from brokers of approximately $4,902,000 on the consolidated statement of financial condition at December 31, 2020 was held as collateral for forward and swap contracts. Investments of approximately $1,544,000 and $1,713,000 on the consolidated statements of financial condition at December 31, 2020 and 2019, respectively, comprised of U.S. Treasury securities, were held as collateral for futures and swap contracts. The following table summarizes net gains (losses) from derivative financial instruments: Years Ended December 31, (in thousands) 2020 2019 2018 Futures - commodities $ (105) $ 881 $ (2,093) Total return swaps - commodities (266) (485) 739 Total return swaps - equities (1,562) — — Forward contracts - foreign exchange (375) 235 (141) Total (1) $ (2,308) $ 631 $ (1,495) ________________________ (1) Gains and losses on derivative financial instruments are recorded in gain (loss) from investments—net in the Company's consolidated statements of operations.

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Property and Equipment	Property and Equipment The following table summarizes the Company’s property and equipment: December 31, (in thousands) 2020 2019 Equipment $ 6,725 $ 5,951 Furniture and fixtures 3,685 3,651 Software 21,789 19,988 Leasehold improvements 16,085 16,048 Subtotal 48,284 45,638 Less: Accumulated depreciation and amortization (37,943) (33,152) Property and equipment, net $ 10,341 $ 12,486 Depreciation and amortization expense related to property and equipment was $4,652,000, $4,396,000 and $4,378,000 for the years ended December 31, 2020, 2019 and 2018, 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, 2020
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share Basic earnings per share is calculated by dividing net income attributable to common stockholders by the weighted average shares outstanding. Diluted earnings per share is calculated by dividing net income attributable to common stockholders by the total weighted average shares of common stock outstanding and common stock equivalents determined using the treasury stock method. 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. The following table reconciles income and share data used in the basic and diluted earnings per share computations: Years Ended December 31, (in thousands, except per share data) 2020 2019 2018 Net income $ 75,165 $ 146,984 $ 109,522 Less: Net (income) loss attributable to redeemable noncontrolling interests 1,419 (12,363) 4,374 Net income attributable to common stockholders $ 76,584 $ 134,621 $ 113,896 Basic weighted average shares outstanding 47,800 47,273 46,794 Dilutive potential shares from restricted stock units 876 1,024 587 Diluted weighted average shares outstanding 48,676 48,297 47,381 Basic earnings per share attributable to common stockholders $ 1.60 $ 2.85 $ 2.43 Diluted earnings per share attributable to common stockholders $ 1.57 $ 2.79 $ 2.40 Anti-dilutive common stock equivalents excluded from the calculation — — —

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [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, 2020, RSUs with respect to approximately 17,248,000 shares of common stock had been issued under the SIP. As of December 31, 2020, there was $50,801,000 of unearned compensation related to unvested RSUs that has not yet been recognized in the consolidated statement of operations. The Company expects to recognize this expense over approximately the next three years. In January 2021, the Company granted approximately 691,000 RSUs under the SIP with a grant date fair value of approximately $46,030,000 which generally 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 $699,000, $614,000 and $626,000 for the years ended December 31, 2020, 2019 and 2018, 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 $4,595,000, $4,443,000 and $4,216,000 for the years ended December 31, 2020, 2019 and 2018, 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). 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, which will generally vest and be delivered ratably over 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 under the Mandatory Program, net of forfeitures, of approximately $23,884,000, $22,637,000 and $19,710,000 for the years ended December 31, 2020, 2019 and 2018, 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 (in thousands, except per share data) Number Weighted Average Grant Date Fair Value Number Weighted Average Grant Date Fair Value Number Weighted Average Grant Date Fair Value Balance at January 1, 2018 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 Granted 22 50.29 132 40.97 763 39.92 Delivered (13) 37.61 (131) 35.46 (601) 36.30 Forfeited — — (5) 38.15 (33) 38.31 Balance at December 31, 2019 54 44.06 302 38.78 1,874 38.38 Granted 12 55.71 189 63.17 437 73.29 Delivered (16) 38.22 (143) 36.96 (705) 36.30 Forfeited — — (7) 50.60 (78) 49.73 Balance at December 31, 2020 50 48.80 341 52.80 1,528 48.76 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. Through December 31, 2020, the Company had issued approximately 448,000 shares of common stock under the ESPP. For each year ended December 31, 2020, 2019 and 2018, approximately 18,000 was purchased by eligible employees through the ESPP. For the years ended December 31, 2020, 2019 and 2018, the Company recorded a non-cash stock-based compensation expense of approximately $152,000, $131,000 and $105,000, 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, 2020
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 U.S. 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, 2020, 2019 and 2018. 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, 2020, 2019 and 2018 totaled approximately $147,000, $131,000 and $101,000, respectively. Matching contributions, net of forfeitures, to the Plan for the years ended December 31, 2020, 2019 and 2018 totaled approximately $2,498,000, $2,057,000 and $1,770,000, respectively.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2020
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions The Company is an investment adviser to, and has administration agreements with, Company-sponsored 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: Years Ended December 31, (in thousands) 2020 2019 2018 Investment advisory and administration fees (1) $ 274,566 $ 264,116 $ 241,255 Distribution and service fees 30,134 30,048 29,090 Total $ 304,700 $ 294,164 $ 270,345 _________________________ (1) Investment advisory and administration fees are reflected net of fund reimbursements of $13.6 million, $11.1 million and $8.6 million for and the years ended December 31, 2020, 2019 and 2018, respectively. The following table summarizes sales proceeds, gross realized gains, gross realized losses and dividend income from investments in Company-sponsored funds that are not consolidated: Years Ended December 31, (in thousands) 2020 2019 2018 Proceeds from sales $ 7 $ 37,326 $ 10,872 Gross realized gains — 241 28 Gross realized losses — (907) (4,448) Dividend income 5 52 481 Included in accounts receivable at December 31, 2020 and 2019 are receivables due from Company-sponsored funds of approximately $30,163,000 and $26,701,000, respectively. Included in accounts payable at December 31, 2020 and December 31, 2019 are payables due to Company-sponsored funds of approximately $574,000 and $474,000, respectively.

Regulatory Requirements

Regulatory Requirements	12 Months Ended
	Dec. 31, 2020
Broker-Dealer, Net Capital Requirement, SEC Regulation [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, 2020, CSS had net capital of approximately $4,332,000, which exceeded its requirements by approximately $4,099,000. The Rule also provides that equity capital may not be withdrawn or cash dividends paid if the resulting net capital of a broker-dealer is less than the amount required under the Rule and requires prior notice to the SEC for certain withdrawals of capital. CSS does not carry customer accounts and has no possession or control obligations under SEA Rule 15c3-3(b) or reserve deposit obligations under SEA Rule 153-3(e). During 2020, CSCM, its parent, made a capital contribution of $2,000,000 to CSS. CSAL is subject to regulation by the Hong Kong Securities and Futures Commission. At December 31, 2020, CSAL had regulatory capital of approximately $5,000,000, which exceeded its minimum regulatory capital requirement by approximately $4,613,000. During 2020, CSAL paid dividends in the amount of approximately $12,935,000 to its parent, CSCM. CSUK is subject to regulation by the United Kingdom Financial Conduct Authority. At December 31, 2020, CSUK had regulatory capital of approximately $28,929,000, which exceeded its minimum regulatory capital requirement by approximately $23,597,000. During 2020, CSUK paid a dividend in the amount of approximately $14,800,000 to its parent, CNS. CSIL is subject to regulation by the Central Bank of Ireland. At December 31, 2020, CSIL had regulatory capital of approximately $2,854,000, which exceeded its minimum regulatory capital requirement by approximately $2,630,000. During 2020, CNS, its parent, made a capital contribution of $2,854,000 to CSIL. CSJL is registered with the Financial Services Agency of Japan and the Kanto Local Finance Bureau and is subject to the Financial Instruments and Exchange Act. In accordance with its license, CSJL is required to maintain regulatory capital, as defined, of approximately $630,000. At December 31, 2020, CSJL had stated capital in excess of this requirement.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies Disclosure	Commitments and ContingenciesFrom 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 $5,100,000 alongside GRP-TE, a portion of which is made through GRP-TE and the remainder of which is made through GRP-CIP for up to 12 years through the life of GRP-TE. As of December 31, 2020, the Company had funded approximately $3,800,000 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. The unfunded commitment is not recorded on the Company’s consolidated statements of financial condition.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2020
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 non-amortized intangible assets: (in thousands) Goodwill Indefinite-Lived Intangible Assets Balance at January 1, 2019 $ 18,501 $ 1,250 Currency revaluation (191) — Balance at December 31, 2019 $ 18,310 $ 1,250 Currency revaluation 935 — Balance at December 31, 2020 $ 19,245 $ 1,250

Leases

Leases	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Leases	Leases The Company has operating leases for corporate offices and certain information technology equipment. The following table summarizes the Company's lease cost included in general and administrative expense in the consolidated statements of operations: Years Ended December 31, (in thousands) 2020 2019 2018 Operating lease cost $ 11,247 $ 11,495 $ 11,552 Supplemental information related to operating leases is summarized below: Years Ended December 31, (in thousands) 2020 2019 2018 Supplemental cash flow information: Cash paid for amounts included in the measurement of lease liabilities $ 12,408 $ 12,365 $ 11,709 Supplemental non-cash information: Right-of-use assets obtained in exchange for new lease liabilities 3,026 — 614 Other information related to operating leases is summarized below: Years Ended December 31, 2020 2019 2018 Weighted-average remaining lease term (years) 3 4 5 Weighted-average discount rate 2.8 % 2.8 % 2.8 % The following table summarizes the maturities of lease liabilities at December 31, 2020 (in thousands): Year Ending December 31, Operating Leases 2021 $ 12,173 2022 11,875 2023 11,428 2024 966 Total remaining undiscounted lease payments 36,442 Less: imputed interest 1,516 Total remaining discounted lease payments $ 34,926

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The income before provision for income taxes and provision for income taxes are as follows: Years Ended December 31, (in thousands) 2020 2019 2018 Income before provision for income taxes - U.S. (1) $ 83,617 $ 171,497 $ 132,838 Income before provision for income taxes - Non-U.S. 9,770 16,052 10,941 Total income before provision for income taxes $ 93,387 $ 187,549 $ 143,779 _________________________ (1) Included loss of $1.4 million, income of $12.4 million and loss of $4.4 million attributable to third-party interests for the years ended December 31, 2020, 2019 and 2018, respectively. Current tax expense: U.S. federal $ 12,859 $ 30,818 $ 26,223 State and local 3,291 7,627 7,378 Non-U.S. 1,965 2,024 2,029 18,115 40,469 35,630 Deferred tax (benefit) expense: U.S. federal (67) (133) (748) State and local (32) (74) (281) Non-U.S. 206 303 (344) 107 96 (1,373) Provision for income taxes $ 18,222 $ 40,565 $ 34,257 A reconciliation of the Company’s statutory federal income tax rate and the effective tax rate is as follows: Years Ended December 31, 2020 2019 2018 U.S. statutory tax rate 21.0 % 21.0 % 21.0 % Stock-based compensation (9.0) % (0.1) % (0.6) % State and local income taxes, net of federal income taxes 4.1 % 3.4 % 3.8 % Unrecognized tax benefit adjustments 2.4 % (1.0) % (1.0) % Foreign operations tax differential 0.1 % (0.5) % 0.3 % Non-deductible (gains) losses on investments 0.1 % (1.6) % 0.2 % Non-taxable (gains) losses on investments 0.3 % 0.9 % 0.1 % Tax Cuts and Jobs Act — % — % (0.1) % Other 0.2 % 1.1 % (0.6) % Effective income tax rate 19.2 % 23.2 % 23.1 % 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 consist of the following: At December 31, (in thousands) 2020 2019 Deferred income tax assets (liabilities): Stock-based compensation $ 5,329 $ 5,310 Realized losses on investments 3,567 4,218 Dividend equivalents on unvested restricted stock units 1,735 1,725 Net unrealized (gains) losses on investments (1,364) (1,632) Deferred compensation 52 290 Deferred rent 904 1,205 Other (530) (824) Subtotal 9,693 10,292 Less: valuation allowance (2,698) (3,201) Deferred income tax asset—net $ 6,995 $ 7,091 The Company had capital loss carryforwards of approximately $14,311,000 and $17,027,000 for the years ended December 31, 2020 and 2019 which, if unused, will expire in years 2021 to 2025. The valuation allowance on the net deferred income tax asset decreased by approximately $503,000 during the year ended December 31, 2020. At December 31, 2020, the Company had approximately $13,616,000 of total gross unrecognized tax benefits. Of this total, approximately $10,027,000 (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 net unrecognized tax benefits by $9,000,000 to $10,000,000 within the next twelve months due to the expected conclusion of jurisdictional reviews and 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, 2018 $ 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 Addition for tax positions of current year 2,430 Addition for tax positions of prior years 133 Reduction of tax positions from prior years (1,720) Gross unrecognized tax benefits balance at December 31, 2019 $ 12,880 Addition for tax positions of current year 1,697 Addition for tax positions of prior years 3,599 Reduction of tax positions from prior years (4,560) Gross unrecognized tax benefits balance at December 31, 2020 $ 13,616 The Company records potential interest and penalties related to uncertain tax positions in the provision for income taxes. At December 31, 2020 and 2019, the Company had approximately $6,778,000 and $3,179,000, respectively, in potential interest and penalties associated with uncertain tax positions. The tax years 2013 through 2020 remain open to examination by various taxing jurisdictions. In connection with the enactment of the Tax Cuts and Jobs Act (the Tax Act), the Company recorded a provisional transition tax of $8,432,000 at December 31, 2017, which reflected a one-time tax on deemed repatriated accumulated earnings and profits of the Company’s foreign subsidiaries. Based on refinement of the calculation, the Company adjusted its transition tax liability from $8,432,000 at December 31, 2017 to $8,310,000 during the second quarter of 2018. This tax liability, paid 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, 2020 and 2019. The following table summarizes the remaining transition tax liability at December 31, 2020 (in thousands): 2021 $ 665 2022 665 2023 1,246 2024 1,662 2025 2,077 $ 6,315

Concentration of Credit Risk

Concentration of Credit Risk	12 Months Ended
	Dec. 31, 2020
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 provided 10% or more of the total revenue of the Company: Years Ended December 31, (in thousands, except percentages) 2020 2019 2018 Cohen & Steers Preferred Securities and Income Fund, Inc. (CPX): Investment advisory and administration fees $ 69,197 $ 56,638 $ 53,059 Distribution and service fees 13,499 12,753 13,525 Total $ 82,696 $ 69,391 $ 66,584 Percent of total revenue 19.3 % 16.9 % 17.5 % Cohen & Steers Real Estate Securities Fund, Inc. (CSI): Investment advisory and administration fees $ 38,961 $ 41,971 $ 31,759 Distribution and service fees 6,943 8,128 6,841 Total $ 45,904 $ 50,099 $ 38,600 Percent of total revenue 10.7 % 12.2 % 10.1 %

Selected Quarterly Financial Da

Selected Quarterly Financial Data (unaudited)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data (unadudited)	Selected Quarterly Financial Data (unaudited) The following table presents selected quarterly financial data: Quarter (in thousands, except per share data) 1st 2nd 3rd 4th Total 2020 Revenue $ 105,830 $ 94,087 $ 111,159 $ 116,460 $ 427,536 Operating income (loss) 28,369 35,295 43,307 (11,914) 95,057 Net income (loss) attributable to common stockholders 20,572 28,520 31,904 (4,412) 76,584 Earnings (loss) per share attributable to common stockholders: Basic 0.43 0.60 0.67 (0.09) 1.60 Diluted 0.42 0.59 0.66 (0.09) 1.57 Weighted-average shares outstanding: Basic 47,651 47,826 47,855 47,867 47,800 Diluted 48,591 48,572 48,681 48,857 48,676 2019 Revenue $ 94,226 $ 101,792 $ 104,965 $ 109,847 $ 410,830 Operating income 35,435 38,104 40,133 46,462 160,134 Net income attributable to common stockholders 32,543 31,333 34,017 36,728 134,621 Earnings per share attributable to common stockholders: Basic 0.69 0.66 0.72 0.78 2.85 Diluted 0.68 0.65 0.70 0.75 2.79 Weighted-average shares outstanding: Basic 47,146 47,304 47,316 47,324 47,273 Diluted 47,642 48,175 48,412 48,703 48,297

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2020
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 25, 2021, CNS declared a quarterly dividend on its common stock in the amount of $0.45 per share. This dividend will be payable on March 18, 2021 to stockholders of record at the close of business on March 8, 2021.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements —In August 2018, the Financial Accounting Standards Board (FASB) issued guidance to align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. Under the new standard, implementation costs are deferred and presented in the same financial statement caption on the consolidated statements of financial condition as a prepayment of related arrangement fees. The deferred costs are recognized over the term of the arrangement in the same financial statement caption in the consolidated statements of operations as the related fees of the arrangement. This new guidance became effective on January 1, 2020. The Company has adopted this new standard using a prospective approach to all implementation costs incurred after adoption. The Company's adoption of the new standard did not have a material effect on its 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. As a result of the revised guidance, a goodwill impairment will be the amount by which a reporting unit’s carrying value exceeds its fair value. This new guidance became effective on January 1, 2020. The Company's adoption of the new standard did not have a material effect on its consolidated financial statements and related disclosures. In June 2016, the FASB issued guidance on the measurement of credit losses on financial instruments. This standard amended guidance related to reporting credit losses for financial assets measured at amortized cost and replaced the incurred loss impairment model with a current expected credit loss (CECL) model. CECL requires a company to estimate lifetime expected credit losses based on relevant information about historical events, current conditions and reasonable and supportable forecasts. This new guidance became effective on January 1, 2020. The Company's adoption of the new standard had no impact on its consolidated financial statements and related disclosures.
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 due to factors the Company cannot fully predict including the extent of the impact to the Company's business from the ongoing COVID-19 pandemic.
Reclassifications [Text Block]	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 Company-sponsored 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 several highly rated financial institutions and include 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 —The Company, including the consolidated Company-sponsored funds, may 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/or cash collateral balances at brokers/custodians and/or receivables and payables for unsettled securities transactions with 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, 2020, the Company's investments were comprised of the following: • Equity investments at fair value, which generally represent equity securities held within the consolidated Company-sponsored funds, individual equity 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 generally represent debt securities held within the consolidated Company-sponsored funds and individual debt securities held directly for the purposes of establishing performance track records. • Held-to-maturity investments, which generally represent corporate investments in U.S. Treasury securities recorded at amortized cost. Under the CECL model, any expected credit losses are recognized as an allowance, which represents an adjustment to the amortized costs basis. The Company did not record any provision for credit losses on these securities during the year ended December 31, 2020. • Equity method investments, which generally represent seed investments in Company-sponsored funds in which the Company owns between 20-50% of the outstanding voting interests 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 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 consolidated Company-sponsored funds, may enter into derivative contracts, including options, futures and swaps contracts, to gain exposure to the underlying commodities markets or to economically hedge market risk of the underlying portfolios. Gains 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. Additionally, from time to time, the Company, including the consolidated Company-sponsored funds, may enter into forward foreign exchange contracts to economically hedge its currency exposure. These instruments are measured at fair value based on the prevailing forward exchange rate with gains and losses recorded in foreign currency gain (loss)—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 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.
Redeemable Noncontrolling Interest	Redeemable Noncontrolling Interests —Redeemable noncontrolling interests represent third-party interests in the consolidated Company-sponsored funds. These interests are redeemable at the option of the investors and therefore are not treated as permanent equity. Redeemable noncontrolling interest is recorded at fair value which approximates the redemption 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, Company-sponsored open-end and closed-end funds as well as model-based portfolios. Investment advisory fees are earned pursuant to the terms of investment management agreements and are generally based on a contractual fee rate applied to the average daily assets under management. 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 daily 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. In certain instances, the Company may earn performance fees when specified performance hurdles are met during the performance period. Performance fees are forms of variable consideration and are not recognized until it becomes probable that there will not be a significant reversal of the cumulative revenue recognized .
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 all periods presented, a portion of the distribution fee revenue recognized in the period 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 fees represent 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, 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. Distribution fees are based on the average daily net assets under management of certain share classes of certain of the funds. Shareholder servicing fees represent payments made to qualified intermediaries for shareholder account service and maintenance. These services are provided pursuant to written agreements with such qualified institutions. Shareholder servicing fees are generally based on the average daily assets under management. 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.
Stock-based Compensation	Stock-based Compensation —The Company recognizes compensation expense for the grant-date fair value of awards of equity instruments to certain 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 uncertainties in the application of complex tax laws and regulations across the Company’s global operations. A tax benefit from an uncertain tax position is 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 $(4,134,000), $(6,326,000) and $(7,323,000) as of December 31, 2020, 2019 and 2018, respectively. Gains or losses resulting from transactions denominated in currencies other than the U.S. dollar within 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 generally 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 December 2019, the FASB issued Accounting Standards Update 2019-12, Income Taxes (Topic 740): Simplifying Accounting for Income Taxes . The standard is intended to simplify various aspects related to income taxes and removes certain exceptions to the general principles in Topic 740. This new guidance will be effective on January 1, 2021. The Company does not expect the adoption of the new standard to have a material effect on its consolidated financial statements and related disclosures.
Valuation Techniques	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 is an input that is observable in active markets. 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 involve a significant degree of judgment, taking into consideration a combination of internal and external factors. Such investments, which are generally immaterial, 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.
Lessee, Leases	Leases —The Company determines if an arrangement is a lease at inception. The Company has operating leases for corporate offices and certain information technology equipment and these leases are included in operating lease right-of-use (ROU) assets and operating lease liabilities on the Company’s consolidated statements of financial condition. ROU assets represent the right to use an underlying asset for the lease term and lease liabilities represent obligations to make lease payments arising from the lease. Operating lease ROU assets and lease liabilities are recognized at commencement date based on the net present value of lease payments over the lease term. The majority of the Company’s lease agreements do not provide an implicit rate. As a result, the Company used an incremental borrowing rate based on the information available as of lease commencement dates in determining the present value of lease payments. The operating lease ROU asset reflects any upfront lease payments made as well as lease incentives received. The lease terms may include options to extend or terminate the lease and these are factored into the determination of the ROU asset and lease liability at lease inception when and if it is reasonably certain that the Company will exercise that option. Lease expense for fixed lease payments is recognized on a straight-line basis over the lease term. The Company has certain lease agreements with non-lease components such as maintenance and executory costs, which are accounted for separately and not included in ROU assets.

Revenue (Tables)

Revenue (Tables)	12 Months Ended
	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following tables summarize revenue recognized from contracts with customers by client domicile and by investment vehicle: Years ended December 31, (in thousands) 2020 2019 2018 Client domicile: North America $ 363,834 $ 352,629 $ 322,964 Japan 32,517 33,967 35,283 Europe, Middle East and Africa 19,869 11,087 10,371 Asia Pacific excluding Japan 11,316 13,147 12,493 Total $ 427,536 $ 410,830 $ 381,111 Years ended December 31, (in thousands) 2020 2019 2018 (2) Investment vehicle: Open-end funds (1) $ 231,269 $ 217,778 $ 197,363 Institutional accounts 115,876 110,346 104,327 Closed-end funds 78,026 80,502 77,270 Other 2,365 2,204 2,151 Total $ 427,536 $ 410,830 $ 381,111 ________________________ (1) Included distribution and service fees of $30.1 million, $30.0 million and $29.1 million for the years ended December 31, 2020, 2019 and 2018, respectively. (2) Amounts related to model-based portfolios were reclassified from other (previously reported as portfolio consulting and other) to open-end funds and institutional accounts.

Investments (Tables)

Investments (Tables)	12 Months Ended
	Dec. 31, 2020
Investments [Abstract]
Summary of Investment Holdings	The following table summarizes the Company’s investments: (in thousands) December 31, 2020 December 31, 2019 Equity investments at fair value $ 94,089 $ 89,872 Trading 18,700 14,980 Held-to-maturity carried at amortized cost (1) 41,648 49,807 Equity method 541 554 Total investments $ 154,978 $ 155,213 _________________________ (1) Held-to-maturity investments had a fair value of approximately $41.7 million and $50.0 million at December 31, 2020 and 2019, respectively. These securities would be classified as level 2 within the fair value hierarchy if carried at fair value. Original maturities ranged from 6 to 24 months at December 31, 2020 and 2019. The Company seeded one new fund for the year ended December 31, 2020 and two new funds for the year ended December 31, 2019.
Gain (Loss) on Investments	The following table summarizes gain (loss)—net from investments: Years Ended December 31, (in thousands) 2020 2019 2018 Net realized gains (losses) during the period $ (5,395) $ 12,227 $ (1,486) Net unrealized gains (losses) during the period on investments 1,279 9,446 (12,778) Gain (loss) from investments—net (1) $ (4,116) $ 21,673 $ (14,264) _________________________ (1) Included net income (loss) attributable to redeemable noncontrolling interests.
Schedule of Variable Interest Entities	At December 31, 2020 and 2019, the Company's consolidated VIEs included the Cohen & Steers SICAV Global Listed Infrastructure Fund (GLI SICAV), SICAV GRE, the Cohen & Steers SICAV Diversified Real Assets Fund (SICAV RAP) and the Cohen & Steers Co-Investment Partnership, L.P. (GRP-CIP). The following tables summarize the consolidated statements of financial condition attributable to the Company's consolidated VIEs: December 31, 2020 (in thousands) GLI SICAV SICAV GRE SICAV RAP GRP-CIP Total Assets (1) Investments $ 7,140 $ 39,672 $ 33,654 $ 277 $ 80,743 Due from brokers 69 45 52 57 223 Other assets 44 359 234 — 637 Total assets $ 7,253 $ 40,076 $ 33,940 $ 334 $ 81,603 Liabilities (1) Due to brokers $ 27 $ 40 $ 61 $ — $ 128 Other liabilities and accrued expenses 29 211 81 5 326 Total liabilities $ 56 $ 251 $ 142 $ 5 $ 454 December 31, 2019 (in thousands) GLI SICAV SICAV GRE SICAV RAP GRP-CIP Total Assets (1) Investments $ 7,048 $ 45,468 $ 29,976 $ 337 $ 82,829 Due from brokers 264 663 613 203 1,743 Other assets 92 681 268 — 1,041 Total assets $ 7,404 $ 46,812 $ 30,857 $ 540 $ 85,613 Liabilities (1) Due to brokers $ 45 $ 92 $ 229 $ — $ 366 Other liabilities and accrued expenses 100 466 213 5 784 Total liabilities $ 145 $ 558 $ 442 $ 5 $ 1,150 _________________________ (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.

Fair Value (Tables)

Fair Value (Tables)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements, Recurring and Nonrecurring	The following tables present fair value measurements: December 31, 2020 (in thousands) Level 1 Level 2 Level 3 Investments Investments Total Cash equivalents $ 23,372 $ — $ — $ — $ — $ 23,372 Equity investments at fair value Common stocks $ 91,614 $ — $ — $ — $ — $ 91,614 Company-sponsored funds 246 — — — — 246 Limited partnership interests 831 — — 277 — 1,108 Preferred securities 983 12 — — — 995 Other — — — 126 — 126 Total $ 93,674 $ 12 $ — $ 403 $ — $ 94,089 Trading investments Fixed income $ — $ 18,700 $ — $ — $ — $ 18,700 Held-to-maturity investments $ — $ — $ — $ — $ 41,648 $ 41,648 Equity method investments $ — $ — $ — $ 541 $ — $ 541 Total investments $ 93,674 $ 18,712 $ — $ 944 $ 41,648 $ 154,978 Derivatives - assets Futures - commodities $ 1,012 $ — $ — $ — $ — $ 1,012 Derivatives - liabilities Futures - commodities $ 416 $ — $ — $ — $ — $ 416 Total return swaps - commodities — 136 — — — 136 Total return swaps - equities — 1,562 — — — 1,562 Forward contracts - foreign exchange — 345 — — — 345 Total $ 416 $ 2,043 $ — $ — $ — $ 2,459	December 31, 2019 (in thousands) Level 1 Level 2 Level 3 Investments Investments Total Cash equivalents $ 85,889 $ — $ — $ — $ — $ 85,889 Equity investments at fair value Common stocks $ 87,408 $ — $ — $ — $ — $ 87,408 Company-sponsored funds 132 — — — — 132 Limited partnership interests 1,048 — — 337 — 1,385 Preferred securities 704 108 — — — 812 Other — — — 135 — 135 Total $ 89,292 $ 108 $ — $ 472 $ — $ 89,872 Trading investments Fixed income $ — $ 14,980 $ — $ — $ — $ 14,980 Held-to-maturity investments $ — $ — $ — $ — $ 49,807 $ 49,807 Equity method investments $ — $ — $ — $ 554 $ — $ 554 Total investments $ 89,292 $ 15,088 $ — $ 1,026 $ 49,807 $ 155,213 Derivatives - assets Futures - commodities $ 570 $ — $ — $ — $ — $ 570 Forward contracts - foreign exchange — 74 — — — 74 Total $ 570 $ 74 $ — $ — $ — $ 644 Derivatives - liabilities Futures - commodities $ 339 $ — $ — $ — $ — $ 339 Total return swaps - commodities — 173 — — — 173 Forward contracts - foreign exchange — 44 — — — 44 Total $ 339 $ 217 $ — $ — $ — $ 556

Derivatives (Tables)

Derivatives (Tables)	12 Months Ended
	Dec. 31, 2020
Derivatives [Abstract]
Schedule of Derivative Instruments	The following tables summarize the notional amounts and fair value of the outstanding derivative financial instruments none of which were designated in a formal hedging relationship. As of December 31, 2020 Notional Amount Fair Value (1) (in thousands) Long Short Assets Liabilities Futures - commodities $ 13,624 $ 4,257 $ 1,012 $ 416 Total return swaps - commodities — 9,598 — 136 Total return swaps - equities — 17,688 — 1,562 Forward contracts - foreign exchange — 14,061 — 345 $ 13,624 $ 45,604 $ 1,012 $ 2,459 As of December 31, 2019 Notional Amount Fair Value (1) (in thousands) Long Short Assets Liabilities Futures - commodities $ 14,394 $ 4,623 $ 570 $ 339 Total return swaps - commodities — 8,909 — 173 Forward contracts - foreign exchange — 10,787 74 44 $ 14,394 $ 24,319 $ 644 $ 556 ________________________ (1) The fair value of derivative financial instruments is recorded in other assets and other liabilities and accrued expenses on the Company's consolidated statements of financial condition.
Gains (Losses) on Derivatives	The following table summarizes net gains (losses) from derivative financial instruments: Years Ended December 31, (in thousands) 2020 2019 2018 Futures - commodities $ (105) $ 881 $ (2,093) Total return swaps - commodities (266) (485) 739 Total return swaps - equities (1,562) — — Forward contracts - foreign exchange (375) 235 (141) Total (1) $ (2,308) $ 631 $ (1,495) ________________________ (1) Gains and losses on derivative financial instruments are recorded in gain (loss) from investments—net in the Company's consolidated statements of operations.

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Property and Equipment	The following table summarizes the Company’s property and equipment: December 31, (in thousands) 2020 2019 Equipment $ 6,725 $ 5,951 Furniture and fixtures 3,685 3,651 Software 21,789 19,988 Leasehold improvements 16,085 16,048 Subtotal 48,284 45,638 Less: Accumulated depreciation and amortization (37,943) (33,152) Property and equipment, net $ 10,341 $ 12,486

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following table reconciles income and share data used in the basic and diluted earnings per share computations: Years Ended December 31, (in thousands, except per share data) 2020 2019 2018 Net income $ 75,165 $ 146,984 $ 109,522 Less: Net (income) loss attributable to redeemable noncontrolling interests 1,419 (12,363) 4,374 Net income attributable to common stockholders $ 76,584 $ 134,621 $ 113,896 Basic weighted average shares outstanding 47,800 47,273 46,794 Dilutive potential shares from restricted stock units 876 1,024 587 Diluted weighted average shares outstanding 48,676 48,297 47,381 Basic earnings per share attributable to common stockholders $ 1.60 $ 2.85 $ 2.43 Diluted earnings per share attributable to common stockholders $ 1.57 $ 2.79 $ 2.40 Anti-dilutive common stock equivalents excluded from the calculation — — —

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [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 (in thousands, except per share data) Number Weighted Average Grant Date Fair Value Number Weighted Average Grant Date Fair Value Number Weighted Average Grant Date Fair Value Balance at January 1, 2018 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 Granted 22 50.29 132 40.97 763 39.92 Delivered (13) 37.61 (131) 35.46 (601) 36.30 Forfeited — — (5) 38.15 (33) 38.31 Balance at December 31, 2019 54 44.06 302 38.78 1,874 38.38 Granted 12 55.71 189 63.17 437 73.29 Delivered (16) 38.22 (143) 36.96 (705) 36.30 Forfeited — — (7) 50.60 (78) 49.73 Balance at December 31, 2020 50 48.80 341 52.80 1,528 48.76

Related Party Transactions (Tab

Related Party Transactions (Tables)	12 Months Ended
	Dec. 31, 2020
Related Party Transactions [Abstract]
Schedule of Related Party Transactions	The following table summarizes the amount of revenue the Company earned from these affiliated funds: Years Ended December 31, (in thousands) 2020 2019 2018 Investment advisory and administration fees (1) $ 274,566 $ 264,116 $ 241,255 Distribution and service fees 30,134 30,048 29,090 Total $ 304,700 $ 294,164 $ 270,345 The following table summarizes sales proceeds, gross realized gains, gross realized losses and dividend income from investments in Company-sponsored funds that are not consolidated: Years Ended December 31, (in thousands) 2020 2019 2018 Proceeds from sales $ 7 $ 37,326 $ 10,872 Gross realized gains — 241 28 Gross realized losses — (907) (4,448) Dividend income 5 52 481

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2020
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 non-amortized intangible assets: (in thousands) Goodwill Indefinite-Lived Intangible Assets Balance at January 1, 2019 $ 18,501 $ 1,250 Currency revaluation (191) — Balance at December 31, 2019 $ 18,310 $ 1,250 Currency revaluation 935 — Balance at December 31, 2020 $ 19,245 $ 1,250

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Lease, Cost	The following table summarizes the Company's lease cost included in general and administrative expense in the consolidated statements of operations: Years Ended December 31, (in thousands) 2020 2019 2018 Operating lease cost $ 11,247 $ 11,495 $ 11,552 Supplemental information related to operating leases is summarized below: Years Ended December 31, (in thousands) 2020 2019 2018 Supplemental cash flow information: Cash paid for amounts included in the measurement of lease liabilities $ 12,408 $ 12,365 $ 11,709 Supplemental non-cash information: Right-of-use assets obtained in exchange for new lease liabilities 3,026 — 614
Assets And Liabilities, Lessee	Other information related to operating leases is summarized below: Years Ended December 31, 2020 2019 2018 Weighted-average remaining lease term (years) 3 4 5 Weighted-average discount rate 2.8 % 2.8 % 2.8 %
Lessee, Operating Lease, Liability, Maturity	The following table summarizes the maturities of lease liabilities at December 31, 2020 (in thousands): Year Ending December 31, Operating Leases 2021 $ 12,173 2022 11,875 2023 11,428 2024 966 Total remaining undiscounted lease payments 36,442 Less: imputed interest 1,516 Total remaining discounted lease payments $ 34,926

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Schedule of Income before Taxes	The income before provision for income taxes and provision for income taxes are as follows: Years Ended December 31, (in thousands) 2020 2019 2018 Income before provision for income taxes - U.S. (1) $ 83,617 $ 171,497 $ 132,838 Income before provision for income taxes - Non-U.S. 9,770 16,052 10,941 Total income before provision for income taxes $ 93,387 $ 187,549 $ 143,779 _________________________ (1) Included loss of $1.4 million, income of $12.4 million and loss of $4.4 million attributable to third-party interests for the years ended December 31, 2020, 2019 and 2018, respectively. Current tax expense: U.S. federal $ 12,859 $ 30,818 $ 26,223 State and local 3,291 7,627 7,378 Non-U.S. 1,965 2,024 2,029 18,115 40,469 35,630 Deferred tax (benefit) expense: U.S. federal (67) (133) (748) State and local (32) (74) (281) Non-U.S. 206 303 (344) 107 96 (1,373) Provision for income taxes $ 18,222 $ 40,565 $ 34,257
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 is as follows: Years Ended December 31, 2020 2019 2018 U.S. statutory tax rate 21.0 % 21.0 % 21.0 % Stock-based compensation (9.0) % (0.1) % (0.6) % State and local income taxes, net of federal income taxes 4.1 % 3.4 % 3.8 % Unrecognized tax benefit adjustments 2.4 % (1.0) % (1.0) % Foreign operations tax differential 0.1 % (0.5) % 0.3 % Non-deductible (gains) losses on investments 0.1 % (1.6) % 0.2 % Non-taxable (gains) losses on investments 0.3 % 0.9 % 0.1 % Tax Cuts and Jobs Act — % — % (0.1) % Other 0.2 % 1.1 % (0.6) % Effective income tax rate 19.2 % 23.2 % 23.1 %
Components of Deferred Tax Assets and Liabilities	Significant components of the Company’s net deferred income tax asset consist of the following: At December 31, (in thousands) 2020 2019 Deferred income tax assets (liabilities): Stock-based compensation $ 5,329 $ 5,310 Realized losses on investments 3,567 4,218 Dividend equivalents on unvested restricted stock units 1,735 1,725 Net unrealized (gains) losses on investments (1,364) (1,632) Deferred compensation 52 290 Deferred rent 904 1,205 Other (530) (824) Subtotal 9,693 10,292 Less: valuation allowance (2,698) (3,201) Deferred income tax asset—net $ 6,995 $ 7,091
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, 2018 $ 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 Addition for tax positions of current year 2,430 Addition for tax positions of prior years 133 Reduction of tax positions from prior years (1,720) Gross unrecognized tax benefits balance at December 31, 2019 $ 12,880 Addition for tax positions of current year 1,697 Addition for tax positions of prior years 3,599 Reduction of tax positions from prior years (4,560) Gross unrecognized tax benefits balance at December 31, 2020 $ 13,616
Schedule of Transition Tax Liability, Fiscal Year Maturity Schedule	The following table summarizes the remaining transition tax liability at December 31, 2020 (in thousands): 2021 $ 665 2022 665 2023 1,246 2024 1,662 2025 2,077 $ 6,315

Concentration of Credit Risk (T

Concentration of Credit Risk (Tables)	12 Months Ended
	Dec. 31, 2020
Risks and Uncertainties [Abstract]
Schedules of Concentration of Risk, by Risk Factor	The following affiliated funds provided 10% or more of the total revenue of the Company: Years Ended December 31, (in thousands, except percentages) 2020 2019 2018 Cohen & Steers Preferred Securities and Income Fund, Inc. (CPX): Investment advisory and administration fees $ 69,197 $ 56,638 $ 53,059 Distribution and service fees 13,499 12,753 13,525 Total $ 82,696 $ 69,391 $ 66,584 Percent of total revenue 19.3 % 16.9 % 17.5 % Cohen & Steers Real Estate Securities Fund, Inc. (CSI): Investment advisory and administration fees $ 38,961 $ 41,971 $ 31,759 Distribution and service fees 6,943 8,128 6,841 Total $ 45,904 $ 50,099 $ 38,600 Percent of total revenue 10.7 % 12.2 % 10.1 %

Selected Quarterly Financial _2

Selected Quarterly Financial Data (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	The following table presents selected quarterly financial data: Quarter (in thousands, except per share data) 1st 2nd 3rd 4th Total 2020 Revenue $ 105,830 $ 94,087 $ 111,159 $ 116,460 $ 427,536 Operating income (loss) 28,369 35,295 43,307 (11,914) 95,057 Net income (loss) attributable to common stockholders 20,572 28,520 31,904 (4,412) 76,584 Earnings (loss) per share attributable to common stockholders: Basic 0.43 0.60 0.67 (0.09) 1.60 Diluted 0.42 0.59 0.66 (0.09) 1.57 Weighted-average shares outstanding: Basic 47,651 47,826 47,855 47,867 47,800 Diluted 48,591 48,572 48,681 48,857 48,676 2019 Revenue $ 94,226 $ 101,792 $ 104,965 $ 109,847 $ 410,830 Operating income 35,435 38,104 40,133 46,462 160,134 Net income attributable to common stockholders 32,543 31,333 34,017 36,728 134,621 Earnings per share attributable to common stockholders: Basic 0.69 0.66 0.72 0.78 2.85 Diluted 0.68 0.65 0.70 0.75 2.79 Weighted-average shares outstanding: Basic 47,146 47,304 47,316 47,324 47,273 Diluted 47,642 48,175 48,412 48,703 48,297

Summary of Significant Accoun_3

Summary of Significant Accounting Policies Cumulative Translation Adjustments Balance (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accumulated Translation Adjustment
Cumulative Translation Adjustments balance [Line Items]
Cumulative Foreign Currency Translation Adjustment, Net of Tax	$ (4,134)	$ (6,326)	$ (7,323)

Revenue (Details)

Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Total revenue	$ 427,536	$ 410,830	$ 381,111	[1]
North America
Disaggregation of Revenue [Line Items]
Total revenue	363,834	352,629	322,964
Japan
Disaggregation of Revenue [Line Items]
Total revenue	32,517	33,967	35,283
Asia Pacific, excluding Japan
Disaggregation of Revenue [Line Items]
Total revenue	11,316	13,147	12,493
Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
Total revenue	19,869	11,087	10,371
Open-end funds
Disaggregation of Revenue [Line Items]
Total revenue	231,269	217,778	197,363
Institutional accounts
Disaggregation of Revenue [Line Items]
Total revenue	115,876	110,346	104,327
Closed-end funds
Disaggregation of Revenue [Line Items]
Total revenue	78,026	80,502	77,270
Other
Disaggregation of Revenue [Line Items]
Total revenue	2,365	2,204	2,151
Distribution and service fees
Disaggregation of Revenue [Line Items]
Total revenue	$ 30,134	$ 30,048	$ 29,090	[1]
[1]	Revenue amounts related to model-based portfolios were reclassified from other (previously reported as portfolio consulting and other) to investment advisory and administration fees.

Investments (Details)

Investments (Details) $ in Thousands		12 Months Ended
		Dec. 31, 2020USD ($)new_funds_seeded	Dec. 31, 2019USD ($)new_funds_seeded	Dec. 31, 2018USD ($)
Summary of Investments [Abstract]
Equity investments at fair value		$ 94,089	$ 89,872
Trading		18,700	14,980
Held-to-maturity		41,648	49,807
Equity method		541	554
Total investments	[1],[2]	154,978	155,213
Debt Securities, Held-to-maturity, Fair Value		$ 41,700	$ 50,000
Number of new funds seeded | new_funds_seeded		1	2
Gain (Loss) on Investments [Abstract]
Net realized gains (losses) during the period		$ (5,395)	$ 12,227	$ (1,486)
Net unrealized gains (losses) during the period on investments still held at the end of the period		1,279	9,446	(12,778)
Gain (loss) from investments—net (1)		$ (4,116)	$ 21,673	$ (14,264)	[3]
[1]	Asset and liability amounts in parentheses represent the aggregated balances at December 31, 2020 and 2019 attributable to variable interest entities consolidated by the Company. Refer to Note 4 for further discussion.
[2]	Asset and liability amounts in parentheses represent the aggregated balances at December 31, 2020 and 2019 attributable to variable interest entities consolidated by the Company. Refer to Note 4 for further discussion.
[3]	Revenue amounts related to model-based portfolios were reclassified from other (previously reported as portfolio consulting and other) to investment advisory and administration fees.

Investments Variable Interest E

Investments Variable Interest Entity (Details) - USD ($) $ in Thousands		Dec. 31, 2020	Dec. 31, 2019
Variable Interest Entity [Line Items]
Investments	[1],[2]	$ 154,978	$ 155,213
Other assets	[1],[2]	8,404	7,433
Total assets		348,453	402,419
Due to brokers	[1],[2]	501	366
Other liabilities and accrued expenses	[1],[2]	15,646	13,972
Total liabilities		123,549	135,304
GLI SICAV
Variable Interest Entity [Line Items]
Investments		7,140	7,048
Due from brokers		69	264
Other assets		44	92
Total assets		7,253	7,404
Due to brokers		27	45
Other liabilities and accrued expenses		29	100
Total liabilities		56	145
SICAV GRE
Variable Interest Entity [Line Items]
Investments		39,672
Due from brokers		45
Other assets		359
Total assets		40,076
Due to brokers		40
Other liabilities and accrued expenses		211
Total liabilities		251
SICAV GRE
Variable Interest Entity [Line Items]
Investments			45,468
Due from brokers			663
Other assets			681
Total assets			46,812
Due to brokers			92
Other liabilities and accrued expenses			466
Total liabilities			558
SICAV RAP
Variable Interest Entity [Line Items]
Investments		33,654	29,976
Due from brokers		52	613
Other assets		234	268
Total assets		33,940	30,857
Due to brokers		61	229
Other liabilities and accrued expenses		81	213
Total liabilities		142	442
GRP-CIP
Variable Interest Entity [Line Items]
Investments		277	337
Due from brokers		57	203
Other assets		0	0
Total assets		334	540
Due to brokers		0	0
Other liabilities and accrued expenses		5	5
Total liabilities		5	5
Total
Variable Interest Entity [Line Items]
Investments		80,743	82,829
Other assets		637	1,041
Total assets		81,603	85,613
Due to brokers		128	366
Other liabilities and accrued expenses		326	784
Total liabilities		$ 454	$ 1,150
[1]	Asset and liability amounts in parentheses represent the aggregated balances at December 31, 2020 and 2019 attributable to variable interest entities consolidated by the Company. Refer to Note 4 for further discussion.
[2]	Asset and liability amounts in parentheses represent the aggregated balances at December 31, 2020 and 2019 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	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity investments at fair value	$ 94,089	$ 89,872
Trading	18,700	14,980
Held-to-maturity	41,648	49,807
Equity method investments	541	554
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	23,372	85,889
Equity investments at fair value	94,089	89,872
Total investments	154,978	155,213
Derivative - assets		644
Derivative - liabilities	2,459	556
Fair Value, Measurements, Recurring | Futures - commodity
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative - assets	1,012	570
Derivative - liabilities	416	339
Fair Value, Measurements, Recurring | Total return swaps - commodities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative - liabilities	136	173
Fair Value, Measurements, Recurring | Forward contracts - foreign exchange
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative - assets		74
Derivative - liabilities	345	44
Fair Value, Measurements, Recurring | Total return swaps - equities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative - liabilities	1,562
Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	23,372	85,889
Equity investments at fair value	93,674	89,292
Total investments	93,674	89,292
Derivative - assets		570
Derivative - liabilities	416	339
Fair Value, Measurements, Recurring | Level 1 | Futures - commodity
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative - assets	1,012	570
Derivative - liabilities	416	339
Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity investments at fair value	12	108
Total investments	18,712	15,088
Derivative - assets		74
Derivative - liabilities	2,043	217
Fair Value, Measurements, Recurring | Level 2 | Total return swaps - commodities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative - liabilities	136	173
Fair Value, Measurements, Recurring | Level 2 | Forward contracts - foreign exchange
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative - assets		74
Derivative - liabilities	345	44
Fair Value, Measurements, Recurring | Level 2 | Total return swaps - equities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative - liabilities	1,562
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	403	472
Total investments	944	1,026
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	246	132
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	246	132
Common stocks | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity investments at fair value	91,614	87,408
Common stocks | Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity investments at fair value	91,614	87,408
Fixed income | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading	18,700	14,980
Total investments	41,648	49,807
Fixed income | Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading	18,700	14,980
Limited partnership interests | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity investments at fair value	1,108	1,385
Limited partnership interests | Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity investments at fair value	831	1,048
Limited partnership interests | 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	277	337
Preferred securities | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity investments at fair value	995	812
Preferred securities | Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity investments at fair value	983	704
Preferred securities | Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity investments at fair value	12	108
Other | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity investments at fair value	126	135
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	126	135
Held-to-maturity Securities [Member] | Fixed income | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity	41,648	49,807
Equity Method Investments [Member] | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity method investments	541	554
Equity Method Investments [Member] | Fair Value, Measurements, Recurring | Investments Measured at NAV
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity method investments	$ 541	$ 554
The Cohen & Steers Global Realty Partners III-TE, L.P.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Ownership percentage	0.20%	0.20%
The Cohen & Steers Global Realty Focus Fund, a series of Cohen & Steers Series LP (GRF)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Ownership percentage	0.50%

Derivatives (Details)

Derivatives (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Derivative [Line Items]
Notional Amount, Long	$ 13,624	$ 14,394
Notional Amount, Short	45,604	24,319
Fair Value, Assets	1,012	644
Fair Value, Liabilities	2,459	556
Gain (loss) from derivatives	(2,308)	631	$ (1,495)
Futures - commodity
Derivative [Line Items]
Notional Amount, Long	13,624	14,394
Notional Amount, Short	4,257	4,623
Fair Value, Assets	1,012	570
Fair Value, Liabilities	416	339
Gain (loss) from derivatives	(105)	881	(2,093)
Total return swaps - commodities
Derivative [Line Items]
Notional Amount, Long	0	0
Notional Amount, Short	9,598	8,909
Fair Value, Assets	0	0
Fair Value, Liabilities	136	173
Gain (loss) from derivatives	(266)	(485)	739
Total return swaps - equities
Derivative [Line Items]
Notional Amount, Long	0
Notional Amount, Short	17,688
Fair Value, Assets	0
Fair Value, Liabilities	1,562
Gain (loss) from derivatives	(1,562)	0	0
Forward contracts - foreign exchange
Derivative [Line Items]
Notional Amount, Long	0	0
Notional Amount, Short	14,061	10,787
Fair Value, Assets	0	74
Fair Value, Liabilities	345	44
Gain (loss) from derivatives	(375)	235	$ (141)
Investments
Derivative [Line Items]
Trading investment and held as collateral	1,544	$ 1,713
Cash | Interest Rate Swap
Derivative [Line Items]
Trading investment and held as collateral	$ 4,902

Property and Equipment (Details

Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property and Equipment [Line Items]
Depreciation and amortization	$ 4,652	$ 4,396	$ 4,378
Property and equipment, gross	48,284	45,638
Accumulated depreciation and amortization	(37,943)	(33,152)
Property and equipment, net	$ 10,341	12,486
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	$ 6,725	5,951
Furniture and fixtures
Property and Equipment [Line Items]
Property and equipment, gross	3,685	3,651
Software
Property and Equipment [Line Items]
Property and equipment, gross	21,789	19,988
Leasehold improvements
Property and Equipment [Line Items]
Property and equipment, gross	$ 16,085	$ 16,048

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, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Earnings Per Share [Abstract]
Anti-dilutive common stock equivalents excluded from computation (in shares)									0	0	0
Net income									$ 75,165	$ 146,984	$ 109,522	[1]
Less: Net (income) loss attributable to redeemable noncontrolling interest									1,419	(12,363)	4,374	[1]
Net income attributable to common stockholders	$ (4,412)	$ 31,904	$ 28,520	$ 20,572	$ 36,728	$ 34,017	$ 31,333	$ 32,543	$ 76,584	$ 134,621	$ 113,896	[1]
Basic weighted average shares outstanding (in shares)	47,867	47,855	47,826	47,651	47,324	47,316	47,304	47,146	47,800	47,273	46,794	[1]
Dilutive potential shares from restricted stock units (in shares)									876	1,024	587
Diluted weighted average shares outstanding (in shares)	48,857	48,681	48,572	48,591	48,703	48,412	48,175	47,642	48,676	48,297	47,381	[1]
Basic earnings per share attributable to common stockholders (in dollars per share)	$ (0.09)	$ 0.67	$ 0.60	$ 0.43	$ 0.78	$ 0.72	$ 0.66	$ 0.69	$ 1.60	$ 2.85	$ 2.43	[1]
Diluted earnings per share attributable to common stockholders (in dollars per share)	$ (0.09)	$ 0.66	$ 0.59	$ 0.42	$ 0.75	$ 0.70	$ 0.65	$ 0.68	$ 1.57	$ 2.79	$ 2.40	[1]
[1]	Revenue amounts related to model-based portfolios were reclassified from other (previously reported as portfolio consulting and other) to investment advisory and administration fees.

Stock-Based Compensation - Narr

Stock-Based Compensation - Narrative (Details) - USD ($)	1 Months Ended	12 Months Ended
	Jan. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, shares issued (in shares)		53,462,621	52,580,246
Vesting period of unvested employee stock compensation, number of years		3 years
Award requisite service period		4 years
Employee stock purchase plans		18,000
Restricted Stock Units (RSUs) | Common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share-based compensation expense		$ 50,801,000
Stock Incentive Plan | Common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)		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 (in shares)		17,248,000
Allocated share-based compensation expense		$ 4,595,000	$ 4,443,000	$ 4,216,000
Stock Incentive Plan | Restricted Stock Units (RSUs) | Common stock | Subsequent Event
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, shares issued (in shares)	691,000
Allocated share-based compensation expense	$ 46,030,000
Vesting period of unvested employee stock compensation, number of years	4 years
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		$ 699,000	614,000	626,000
Incentive Bonus Plans for Employees | Common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, shares issued (in shares)		448,000
Annual aggregate purchases per employee		$ 25,000
Maximum number of shares per employee (in shares)		600,000
Incentive Bonus Plans for Employees | Restricted Stock Units (RSUs) | Common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Discount from market price, purchase date, percent		15.00%
Mandatory Plan | Restricted Stock Units (RSUs) | Common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share-based compensation expense		$ 23,884,000	22,637,000	19,710,000
Employee Stock Purchase Plan | Restricted Stock Units (RSUs) | Common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share-based compensation expense		$ 152,000	$ 131,000	$ 105,000

Stock-Based Compensation Unvest

Stock-Based Compensation Unvested RSUs and Incentive Bonus Plans (Details) - Restricted Stock Units (RSUs) - Common stock - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Stock Incentive Plan
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)	54	45	42
Granted (shares)	12	22	15
Delivered (in shares)	16	(13)	(12)
Balance at End of Period (shares)	50	54	45
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)	$ 44.06	$ 37.93	$ 36.98
Delivered, Weighted Average Grant Date Fair Value (usd per share)	38.22	37.61	34.95
Granted, Weighted Average Grant Date Fair Value (usd per share)	55.71	50.29	38.29
Balance at end of period, Weighted Average Grant Date Fair Value (usd per share)	$ 48.80	$ 44.06	$ 37.93
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)	302	306	318
Granted (shares)	189	132	134
Delivered (shares)	(143)	(131)	(146)
Forfeited (shares)	(7)	(5)	0
Balance at end of period (shares)	341	302	306
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)	$ 38.78	$ 35.80	$ 34.14
Granted, Weighted Average Grant Date Fair Value (usd per share)	63.17	40.97	39.02
Delivered, Weighted Average Grant Date Fair Value (usd per share)	36.96	35.46	35.13
Forfeited, Weighted Average Grant Date Fair Value (usd per share)	50.60	38.15	0
Balance at end of period, Weighted Average Grant Date Fair Value (usd per share)	52.80	38.78	35.80
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)	36.96	35.46	35.13
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)	$ 36.30	$ 36.30	$ 34.94
Share-based Compensation Arrangement by Share-based Payment Award, Incentive Bonus Plans [Roll Forward]
Balance at beginning of period (shares)	1,874	1,745	1,550
Granted (shares)	437	763	757
Delivered (shares)	705	601	(539)
Forfeited (shares)	(78)	(33)	(23)
Balance at end of period (shares)	1,528	1,874	1,745
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)	$ 38.38	$ 36.55	$ 34.60
Granted, Weighted Average Grant Date Fair Value (usd per share)	73.29	39.92	39.42
Delivered, Weighted Average Grant Date Fair Value (usd per share)	36.30	36.30	34.94
Forfeited, Weighted Average Grant Date Fair Value (usd per share)	49.73	38.31	37.16
Balance at end of period, Weighted Average Grant Date Fair Value (usd per share)	$ 48.76	$ 38.38	$ 36.55

401(k) and Profit-Sharing Plan

401(k) and Profit-Sharing Plan (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
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	$ 147	$ 131	$ 101
Employer matching contributions	2,498	$ 2,057	$ 1,770
Common stock | Restricted Stock Units (RSUs)
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Allocated share-based compensation expense	$ 50,801

Related Party Transactions (Det

Related Party Transactions (Details) - Affiliated Entity - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Related Party Transactions Revenue [Abstract]
Investment advisory and administrative fees	$ 274,566,000	$ 264,116,000	$ 241,255,000
Distribution and service fees	30,134,000	30,048,000	29,090,000
Total	304,700,000	294,164,000	270,345,000
Related Party Transactions Summary [Abstract]
Proceeds from sales	7,000	37,326,000	10,872,000
Gross realized gains	0	241,000	28,000
Gross realized losses, including other-than-temporary impairment	0	(907,000)	(4,448,000)
Dividend income	5,000	52,000	481,000
Fund expenses, included in general and administrative expenses	13,600,000	11,100,000	$ 8,600,000
Receivables, Company sponsored mutual funds	30,163,000	26,701,000
Accounts Payable, Company sponsored mutual funds	$ 574,000	$ 474,000

Regulatory Requirements (Detail

Regulatory Requirements (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)
Regulatory Requirements
Proceeds from Contributions from Parent	$ 2,000
Securities Registered Domestically
Regulatory Requirements
Net Capital	4,332
Excess Capital	4,099
Securities Regulated By Foreign Entities - Asia
Regulatory Requirements
Net Capital	5,000
Excess Capital	4,613
Dividends	12,935
Securities Regulated By Foreign Entities - UK
Regulatory Requirements
Net Capital	28,929
Excess Capital	23,597
Dividends	14,800
Securities Regulated By Foreign Entities - Ireland
Regulatory Requirements
Net Capital	2,854
Excess Capital	2,630
Dividends	2,854
Securities Regulated By Foreign Entities - Japan
Regulatory Requirements
Net Capital	$ 630

Commitments and Contingencies (

Commitments and Contingencies (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)
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 ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Goodwill
Beginning balance	$ 18,310	$ 18,501
Currency revaluation	935	(191)
Ending balance	19,245	18,310
Indefinite-Lived Intangible Assets
Fund management contracts	$ 1,250	$ 1,250	$ 1,250

Leases - Schedule of Lease Cost

Leases - Schedule of Lease Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Leases [Abstract]
Operating lease cost	$ 11,247	$ 11,495	$ 11,552
Right-of-use assets obtained in exchange for new lease liabilities	3,026	0	614
Operating Lease, Payments	$ 12,408	$ 12,365	$ 11,709

Leases - Schedule of Operating

Leases - Schedule of Operating Leases, Other Information (Details)	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Leases [Abstract]
Weighted-average remaining lease term (years)	3 years	4 years	5 years
Weighted-average discount rate	2.80%	2.80%	2.80%

Leases - Schedule of Lease Liab

Leases - Schedule of Lease Liability Maturity (Details) $ in Thousands	Dec. 31, 2020USD ($)
Leases [Abstract]
2021	$ 12,173
2022	11,875
2023	11,428
2024	966
Total remaining undiscounted lease payments	36,442
Less: imputed interest	1,516
Total remaining discounted lease payments	$ 34,926

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Income Tax Contingency [Line Items]
Effective tax rate	19.20%	23.20%	23.10%
Gross unrecognized tax benefits	$ 13,616	$ 12,880	$ 12,037		$ 12,406
Unrecognized tax benefits that impact effective tax rate in future periods	10,027
Uncertain tax positions, accrued interest and penalties	6,778	$ 3,179
Tax Cuts and Jobs Act of 2017, provisional tax liability					8,432
Tax Cuts and Jobs Act, transition tax for accumulated foreign earnings, liability				$ 8,310	$ 8,432
Minimum
Income Tax Contingency [Line Items]
Reduction in unrecognized tax benefits	9,000
Maximum
Income Tax Contingency [Line Items]
Reduction in unrecognized tax benefits	$ 10,000

Income Taxes - Schedule of Inco

Income Taxes - Schedule of Income before Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income before provision for income taxes
U.S. income before provision for income taxes	$ 83,617	$ 171,497	$ 132,838
Foreign income before provision for income taxes	9,770	16,052	10,941
Income before provision for income taxes	93,387	187,549	143,779	[1]
Current taxes:
U.S. federal	12,859	30,818	26,223
State and local	3,291	7,627	7,378
Non-U.S.	1,965	2,024	2,029
Total	18,115	40,469	35,630
Deferred taxes:
U.S. federal	(67)	(133)	(748)
State and local	(32)	(74)	(281)
Non-U.S.	206	303	(344)
Deferred income taxes	107	96	(1,373)
Provision for income taxes	$ 18,222	$ 40,565	$ 34,257	[1]
[1]	Revenue amounts related to model-based portfolios were reclassified from other (previously reported as portfolio consulting and other) to investment advisory and administration fees.

Income Taxes - Components of De

Income Taxes - Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Stock-based compensation	$ 5,329	$ 5,310
Realized losses on investments	3,567	4,218
Dividend equivalents on unvested restricted stock units	1,735	1,725
Net unrealized (gains) losses on investments	(1,364)	(1,632)
Deferred compensation	52	290
Lease liabilities	904	1,205
Other	(530)	(824)
Subtotal	9,693	10,292
Less: valuation allowance	(2,698)	(3,201)
Deferred income tax asset—net	6,995	7,091
Capital Loss Carryforward	14,311	$ 17,027
Changes in Valuation Allowance	$ 503

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Gross Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of Unrecognized Tax Benefits [Roll Forward]
Gross unrecognized tax benefits balance	$ 12,880	$ 12,037	$ 12,406
Addition for tax positions of current year	1,697	2,430	2,233
Addition for tax positions of prior years	3,599	133
Reduction of tax positions from prior years	(4,560)	(1,720)	(2,602)
Gross unrecognized tax benefits balance	$ 13,616	$ 12,880	$ 12,037

Income Taxes - Reconciliation_2

Income Taxes - Reconciliation of Federal Statutory Income Tax Rate to Effective Rate (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
U.S. statutory tax rate	21.00%	21.00%	21.00%
Stock-based compensation	(9.00%)	(0.10%)	(0.60%)
State and local income taxes, net of federal income taxes	4.10%	3.40%	3.80%
Unrecognized tax benefit adjustments	2.40%	(1.00%)	(1.00%)
Foreign operations tax differential	0.10%	(0.50%)	0.30%
Non-deductible (gains) losses on investments	0.10%	(1.60%)	0.20%
Non-taxable (gains) losses on investments	0.30%	0.90%	0.10%
Tax Cuts and Jobs Act	0.00%	0.00%	(0.10%)
Other	0.20%	1.10%	(0.60%)
Effective income tax rate	19.20%	23.20%	23.10%

Income Taxes - Schedule of Tran

Income Taxes - Schedule of Transition Tax Liabilities by Fiscal Year (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)
Income Tax Disclosure [Abstract]
2021	$ 665
2022	665
2023	1,246
2024	1,662
2025	2,077
Total	$ 6,315

Concentration of Credit Risk (D

Concentration of Credit Risk (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Concentration Risk (Line Items)
Revenues	$ 116,460	$ 111,159	$ 94,087	$ 105,830	$ 109,847	$ 104,965	$ 101,792	$ 94,226	$ 427,536	$ 410,830
Customer Concentration Risk | Cohen & Steers Preferred Securities and Income Fund, Inc. (CPX)
Concentration Risk (Line Items)
Revenues									$ 82,696	$ 69,391	$ 66,584
Percent of total revenue									19.30%	16.90%	17.50%
Customer Concentration Risk | Cohen & Steers Preferred Securities and Income Fund, Inc. (CPX) | Investment advisory and administration fees
Concentration Risk (Line Items)
Revenues									$ 69,197	$ 56,638	$ 53,059
Customer Concentration Risk | Cohen & Steers Preferred Securities and Income Fund, Inc. (CPX) | Distribution and service fees
Concentration Risk (Line Items)
Revenues									13,499	12,753	13,525
Customer Concentration Risk | Cohen & Steers Real Estate Securities Fund, Inc. (CSI)
Concentration Risk (Line Items)
Revenues									$ 45,904	$ 50,099	$ 38,600
Percent of total revenue									10.70%	12.20%	10.10%
Customer Concentration Risk | Cohen & Steers Real Estate Securities Fund, Inc. (CSI) | Investment advisory and administration fees
Concentration Risk (Line Items)
Revenues									$ 38,961	$ 41,971	$ 31,759
Customer Concentration Risk | Cohen & Steers Real Estate Securities Fund, Inc. (CSI) | Distribution and service fees
Concentration Risk (Line Items)
Revenues									$ 6,943	$ 8,128	$ 6,841

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, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	[1]
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 116,460	$ 111,159	$ 94,087	$ 105,830	$ 109,847	$ 104,965	$ 101,792	$ 94,226	$ 427,536	$ 410,830
Operating income (loss)	(11,914)	43,307	35,295	28,369	46,462	40,133	38,104	35,435	95,057	160,134	$ 147,038
Net income attributable to common stockholders	$ (4,412)	$ 31,904	$ 28,520	$ 20,572	$ 36,728	$ 34,017	$ 31,333	$ 32,543	$ 76,584	$ 134,621	$ 113,896
Earnings (loss) per share attributable to common stockholders:
Basic (in dollars per share)	$ (0.09)	$ 0.67	$ 0.60	$ 0.43	$ 0.78	$ 0.72	$ 0.66	$ 0.69	$ 1.60	$ 2.85	$ 2.43
Diluted (in dollars per share)	$ (0.09)	$ 0.66	$ 0.59	$ 0.42	$ 0.75	$ 0.70	$ 0.65	$ 0.68	$ 1.57	$ 2.79	$ 2.40
Weighted-average shares outstanding:
Basic (shares)	47,867	47,855	47,826	47,651	47,324	47,316	47,304	47,146	47,800	47,273	46,794
Diluted (shares)	48,857	48,681	48,572	48,591	48,703	48,412	48,175	47,642	48,676	48,297	47,381
[1]	Revenue amounts related to model-based portfolios were reclassified from other (previously reported as portfolio consulting and other) to investment advisory and administration fees.

Subsequent Events (Details)

Subsequent Events (Details) - $ / shares	Feb. 25, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Subsequent Event [Line Items]
Dividends declared per share		$ 2.56	$ 3.44	$ 3.82
Dividend Declared | Subsequent Event
Subsequent Event [Line Items]
Dividends declared per share	$ 0.45