Calamos Asset Management (CLMS) 10-Q 11 May 15 2015 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 31, 2015	1-May-15
Entity Information [Line Items]
Entity Registrant Name	Calamos Asset Management, Inc. /DE/
Entity Central Index Key	1299033
Current Fiscal Year End Date	-19
Entity Filer Category	Accelerated Filer
Document Fiscal Year Focus	2015
Document Fiscal Period Focus (Q1,Q2,Q3,FY)	Q1
Document Type	10-Q
Amendment Flag	FALSE
Document Period End Date	31-Mar-15
Class A Common Stock
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		20,530,571
Class B Common Stock
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		100

CONSOLIDATED_STATEMENTS_OF_FIN

CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$72,812	$35,285
Receivables:
Affiliates and affiliated funds	16,017	16,024
Customers	3,330	2,967
Investment securities	289,645	339,959
Partnership investments	116,214	143,723
Prepaid expenses	4,201	3,188
Deferred tax assets, net	8,051	9,194
Other current assets	2,770	2,508
Total current assets	513,040	552,848
Non-current assets:
Deferred tax assets, net	31,098	31,067
Goodwill	6,380	6,380
Property and equipment, net of accumulated depreciation and amortization ($62,168 at March 31, 2015 and $61,145 at December 31, 2014)	13,740	14,246
Other non-current assets	2,252	2,615
Total non-current assets	53,470	54,308
Total assets	566,510	607,156
Current liabilities:
Distribution fees payable	8,767	10,614
Accrued compensation and benefits	10,845	24,476
Interest payable	632	1,386
Liabilities of partnership investments	1,737	10,117
Accrued expenses and other current liabilities	6,438	6,009
Total current liabilities	28,419	52,602
Non-current liabilities:
Long-term debt	45,955	45,955
Deferred rent	8,821	8,803
Other non-current liabilities	1,224	1,710
Total non-current liabilities	56,000	56,468
Total liabilities	84,419	109,070
Redeemable non-controlling interest in partnership investments	79,216	76,167
EQUITY
Additional paid-in capital	222,614	221,208
Retained earnings	86,692	89,311
Accumulated other comprehensive income	2,061	1,297
Treasury stock; 7,248,200 shares at March 31, 2015 and 7,070,059 shares at December 31, 2014	-109,062	-107,129
Calamos Asset Management, Inc. stockholders’ equity	202,556	204,937
Non-controlling interest in Calamos Investments LLC (Calamos Interests)	200,319	216,982
Total equity	402,875	421,919
Total liabilities and equity	566,510	607,156
Class A Common Stock
EQUITY
Common Stock	251	250
Class B Common Stock
EQUITY
Common Stock	$0	$0

CONSOLIDATED_STATEMENTS_OF_FIN1

CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION (Parenthetical) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, except Share data, unless otherwise specified
Non-current assets:
Property and equipment, accumulated depreciation and amortization	$62,168	$61,145
EQUITY
Treasury stock (in shares)	7,248,200	7,070,059
Class A Common Stock
EQUITY
Common Stock, par value (in dollar per share)	$0.01	$0.01
Common Stock, authorized (in shares)	600,000,000	600,000,000
Common Stock, shares issued (in shares)	25,148,222	24,990,781
Common Stock, shares outstanding (in shares)	17,900,022	17,920,722
Class B Common Stock
EQUITY
Common Stock, par value (in dollar per share)	$0.01	$0.01
Common Stock, authorized (in shares)	1,000	1,000
Common Stock, shares issued (in shares)	100	100
Common Stock, shares outstanding (in shares)	100	100

CONSOLIDATED_STATEMENTS_OF_OPE

CONSOLIDATED STATEMENTS OF OPERATIONS (USD $)	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
REVENUES
Investment management fees	$45,948	$50,278
Distribution and underwriting fees	10,847	12,989
Other	622	663
Total revenues	57,417	63,930
EXPENSES
Employee compensation and benefits	24,874	23,996
Distribution expenses	10,517	12,651
Marketing and sales promotion	13,405	3,705
General and administrative	10,126	9,502
Total operating expenses	58,922	49,854
Operating income (loss)	-1,505	14,076
NON-OPERATING INCOME
Net interest expense	-730	-1,465
Investment and other income	5,737	1,583
Total non-operating income	5,007	118
Income before income taxes	3,502	14,194
Income tax provision	465	1,362
Net income	3,037	12,832
Net (income) loss attributable to non-controlling interest in Calamos Investments LLC (Calamos Interests)	112	-10,630
Net income attributable to redeemable non-controlling interest in partnership investments	-3,048	-63
Net income attributable to Calamos Asset Management, Inc.	$101	$2,139
Earnings per share:
Basic (in dollars per share)	$0.01	$0.11
Diluted (in dollars per share)	$0.01	$0.11
Weighted average shares outstanding:
Basic (in shares)	17,872,357	19,079,163
Diluted (in shares)	18,699,641	19,805,828
Cash dividends declared per share	$0.15	$0.13

CONSOLIDATED_STATEMENTS_OF_COM

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income	$3,037	$12,832
Unrealized gains on available-for-sale securities:
Unrealized gains	9,016	2,518
Reclassification adjustment for realized gains included in net income	-853	-816
Other comprehensive income, before income tax provision	8,163	1,702
Income tax provision related to other comprehensive income	448	269
After-Tax Amount	7,715	1,433
Comprehensive income	10,752	14,265
Comprehensive income attributable to non-controlling interest in Calamos Investments LLC (Calamos Interests)	-6,839	-11,587
Comprehensive income attributable to redeemable non-controlling interest in partnership investments	-3,048	-63
Comprehensive income attributable to Calamos Asset Management, Inc.	$865	$2,615

CONSOLIDATED_STATEMENTS_OF_CHA

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (USD $)	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income	Treasury Stock	Non-controlling Interest in Calamos Investments LLC (Calamos Interests)	Redeemable Non-controlling Interest in Partnership Investments
In Thousands, unless otherwise specified
Beginning balance at Dec. 31, 2014	$421,919	$250	$221,208	$89,311	$1,297	($107,129)	$216,982	$76,167
Increase (Decrease) in Stockholders' Equity
Net income	-11			101			-112	3,048
Other comprehensive income	7,715				764		6,951
Issuance of common stock (157,441 Class A common shares)		1	-1
Repurchase of common stock by Calamos Investments LLC (178,141 Class A common shares)	-2,229					-495	-1,734
Impact of the redemption of common stock from Calamos Investments LLC by Calamos Asset Management, Inc. (157,441 Class A common shares)			1,438			-1,438
Cumulative impact of changes in ownership of Calamos Investments LLC	-432		-71				-361	1
Compensation expense recognized under stock incentive plans	1,620		360				1,260
Impact on non-controlling interests as a result of dividends paid to Calamos Investments LLC on repurchased common stock			-320				320
Dividend equivalent accrued under stock incentive plans	-233			-52			-181
Equity and tax distributions paid to non-controlling interests in Calamos Investments LLC (Calamos Interests)	-22,806						-22,806
Dividends declared	-2,668			-2,668
Ending balance at Mar. 31, 2015	$402,875	$251	$222,614	$86,692	$2,061	($109,062)	$200,319	$79,216

CONSOLIDATED_STATEMENTS_OF_CHA1

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Parenthetical) (Class A Common Stock)	3 Months Ended
	Mar. 31, 2015
Class A Common Stock
Issuance of common stock (in shares)	157,441
Repurchase of common stock (in shares)	178,141
Redemption of common stock (in shares)	157,441

CONSOLIDATED_STATEMENTS_OF_CAS

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Statement of Cash Flows [Abstract]
Cash and cash equivalents at beginning of period	$35,285,000	$39,078,000
Cash flows used in operating activities:
Net income	3,037,000	12,832,000
Adjustments to reconcile net income to net cash used in operating activities:
Amortization of deferred sales commissions	509,000	638,000
Other depreciation and amortization	1,115,000	1,121,000
Loss on disposal of property and equipment	26,000	0
Deferred rent	18,000	-81,000
Change in unrealized gains on trading securities, derivative assets, derivative liabilities and partnership investments	-9,467,000	-8,779,000
Net realized losses on sale of investment securities, derivative assets, derivative liabilities and partnership investments	3,914,000	7,992,000
Deferred taxes, net	698,000	1,989,000
Stock-based compensation	1,620,000	2,045,000
Employee taxes paid on vesting under stock incentive plans	-465,000	-335,000
Receivables:
Affiliates and affiliated funds, net	7,000	-420,000
Customers	-363,000	1,268,000
Other assets	-1,428,000	-2,836,000
Decrease in liabilities:
Distribution fees payable	-1,847,000	-743,000
Accrued compensation and benefits	-13,631,000	-11,895,000
Accrued expenses and other liabilities	-1,078,000	-3,811,000
Net cash used in operating activities	-17,335,000	-1,015,000
Cash flows provided by investing activities:
Net additions to property and equipment	-628,000	-249,000
Purchases of investment securities	-4,396,000	-8,618,000
Proceeds from sale of investment securities	64,306,000	122,875,000
Contributions to partnership investments	0	-5,059,000
Distributions from partnership investments	23,249,000	0
Net cash provided by investing activities	82,531,000	108,949,000
Cash flows used in financing activities:
Deferred tax benefit (expense) on vesting under stock incentive plans	34,000	-24,000
Repurchase of common stock by Calamos Investments LLC (178,141 at March 31, 2015, and 1,036,615 at March 31, 2014 Class A common shares)	-2,229,000	-12,206,000
Equity distributions paid to non-controlling interests (Calamos Interests)	-15,559,000	-38,897,000
Tax distributions paid to non-controlling interests (Calamos Interests)	-7,247,000	-12,136,000
Cash dividends paid to common stockholders	-2,668,000	-2,414,000
Net cash used in financing activities	-27,669,000	-65,677,000
Net increase in cash and cash equivalents	37,527,000	42,257,000
Cash and cash equivalents at end of period	72,812,000	81,335,000
Cash paid for:
Income taxes, net	21,000	111,000
Interest	$1,516,000	$2,977,000

CONSOLIDATED_STATEMENTS_OF_CAS1

CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) (Class A Common Stock)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Class A Common Stock
Repurchase of common stock (in shares)	178,141	1,036,615

Organization_and_Description_o

Organization and Description of Business	3 Months Ended
	Mar. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Description of Business	Organization and Description of Business
	Calamos Asset Management, Inc. (“CAM”), representing the public shares outstanding, as of March 31, 2015, owned 22.2% of the operating company, Calamos Investments LLC (“Calamos Investments”), with the remaining 77.8% privately owned by Calamos Family Partners, Inc. (“CFP”), a Delaware corporation, and John P. Calamos, Sr., the Chairman, Chief Executive Officer and Global Co-Chief Investment Officer of CAM. CAM, together with Calamos Investments and Calamos Investments’ subsidiaries (the “Company”), operates the investment advisory and distribution services businesses reported within these consolidated financial statements. CAM operates and is the sole manager, and thus controls all of the business and affairs of Calamos Investments and, as a result of this control, consolidates the financial results of Calamos Investments with its own financial results. CFP and John P. Calamos, Sr. (collectively "Calamos Interests") ownership interest, in accordance with applicable accounting guidance, is reflected and referred to within these consolidated financial statements as "non-controlling interest in Calamos Investments LLC". As shown in the diagram below, CFP also owns all of CAM’s outstanding Class B common stock, which represents 97.4% of the combined voting power of all classes of CAM’s voting stock. The graphic below illustrates our organizational and ownership structure as of March 31, 2015:
	-1	Represents combined economic interest of Calamos Family Partners, Inc. and John P. Calamos, Sr. who is also a member of Calamos Investments LLC.
	-2	Represents combined economic interest of all public stockholders, including John P. Calamos, Sr. and John P. Calamos, Jr.’s combined 15.86% ownership interest of Class A common stock. The calculation of ownership interest includes options and restricted stock units ("RSUs") that vest within 60 days, as well as CFP’s indirect ownership interest in Class A common stock purchased by Calamos Investments LLC, pursuant to the Company’s share repurchase plan.
	The Company primarily provides investment advisory services to individuals and institutional investors through a number of investment products that include open-end funds and closed-end funds (the “Funds”), separate accounts, offshore funds, an exchange traded fund and partnerships, as well as provides model portfolio design and oversight for separately managed accounts. The subsidiaries through which the Company provides these services include: Calamos Advisors LLC (“CAL”), a Delaware limited liability company and registered investment advisor; Calamos Financial Services LLC (“CFS”), a Delaware limited liability company and registered broker-dealer; Calamos Wealth Management LLC, a Delaware limited liability company and registered investment advisor; and Calamos Investments LLP, a United Kingdom limited liability partnership, registered investment advisor with the Financial Conduct Authority in the United Kingdom, and a global distributor of the offshore funds and Company products. For reporting purposes, the offshore funds are included within the open-end funds.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2015
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies
	Basis of Presentation
	The consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”), which require the use of estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses, and the disclosure of contingent assets and liabilities. Management believes the accounting estimates are appropriate and reasonably stated; however, due to the inherent uncertainties in making estimates, actual amounts could differ from these estimates.
	The consolidated financial statements as of March 31, 2015 and for the three months ended March 31, 2015 and 2014 have not been audited by the Company’s independent registered public accounting firm. In the opinion of management, these statements contain all adjustments, including those of a normal recurring nature, necessary for fair presentation of the financial condition and results of operations. The results for the interim periods presented are not necessarily indicative of the results to be obtained for a full fiscal year. This Form 10-Q filing should be read in conjunction with the Company’s Annual Report on Form 10-K for the year ended December 31, 2014.
	Principles of Consolidation
	The Company consolidates investments in which the Company’s ownership exceeds 50% or in which the Company operates and controls the business and affairs of the entity or is deemed to be the primary beneficiary. In order to make this determination, an analysis is performed to determine if the investment in an affiliate or partnership is a variable interest entity ("VIE"). The Company has evaluated its investments in affiliates and partnerships and has concluded that they are not VIEs. With respect to partnership investments, the limited partners have no control of the business and affairs of the partnership, no substantive ability to dissolve (liquidate) the partnership, or otherwise remove the general partner (CAL and Calamos Investments) without cause or have other substantive rights.
	The consolidated financial statements include the financial statements of CAM, Calamos Investments, Calamos Investments’ wholly-owned subsidiaries, and the Company’s partnerships in which it owns a majority interest or in which it has operating control. The equity method of accounting is used for investments in which the Company has significant influence, but less than 50% ownership. All significant intercompany balances and transactions have been eliminated.
	The Calamos Interests’ combined 77.8% interest in Calamos Investments at March 31, 2015 and December 31, 2014, is represented as a non-controlling interest in Calamos Investments LLC in the Company’s consolidated financial statements. Non-controlling interest in Calamos Investments is derived by multiplying the historical equity of Calamos Investments by the Calamos Interests’ aggregate ownership percentage for the periods presented. Issuances and repurchases of CAM’s common stock may result in changes to CAM’s ownership percentage and to the non-controlling interests’ ownership percentage of Calamos Investments with resulting changes reflected in the consolidated statements of changes in equity. Income is allocated based on the average ownership interest during the period in which the income is earned.
	CAM owns certain assets to which it has exclusive economic rights. As of March 31, 2015 and December 31, 2014, these assets included cash, cash equivalents and investment securities of $58.5 million and $79.3 million, net current and non-current deferred tax assets of $39.1 million and $40.3 million, net current income taxes receivable of $2.7 million and $2.4 million, and a loan receivable from Calamos Investments of $45.0 million and $21.0 million, respectively, that are reported together with Calamos Investments’ consolidated assets in the consolidated statements of financial condition. Additionally, net income before income taxes of $3.5 million and $14.2 million for the three months ended March 31, 2015 and 2014, respectively, each included $580,000 and $403,000, respectively, of interest income, dividend income and realized gains and losses on cash and cash equivalents held solely by CAM. These portions of CAM’s income and expense are not affected by non-controlling interests.
	Calamos Investments, through its wholly owned subsidiaries and affiliates, is indirectly the general partner and controls the operations of Calamos Global Opportunities Fund LP, for which it acquired a majority interest in the partnership during the second quarter of 2014. The results of this partnership are included in the Company's consolidated financial statements for the year ended December 31, 2014 and the three months ended March 31, 2015. Calamos Investments, through a wholly owned subsidiary, was indirectly the general partner and controlled the operations of Calamos Arista Strategic Fund LP, a U.S. feeder fund, and Calamos Arista Strategic Fund Ltd, an offshore feeder fund, both to Calamos Arista Strategic Master Fund LTD, a hedge fund in the Cayman Islands. As Calamos Investments was the general partner and controlled the operations of Calamos Arista Strategic Fund LP and Calamos Arista Strategic Fund Ltd, the results of these partnerships and the master fund were included in the Company’s consolidated financial results for the year ended December 31, 2014. Calamos Arista Strategic Fund LP was liquidated on December 26, 2014. The partnership redemptions were completed during the first quarter of 2015 for proceeds of $23.1 million. For the year ended December 31, 2014, the amount due to non-controlling interest of $7.7 million related to this partnership investment was presented in liabilities of partnership investments in our consolidated statements of financial condition. The operations of Calamos International Growth Fund LP were controlled by CAL, the general partner. In December 2013, the limited partners of Calamos International Growth Fund LP redeemed all of their interests in the fund. As a result, the Company deconsolidated Calamos International Growth Fund LP and accounted for this partnership investment using the equity method as of December 31, 2014. Calamos International Growth Fund LP was dissolved on April 10, 2014. See Note 5, Partnership Investments, for more discussion regarding these funds.
	For the periods the partnerships are consolidated, the assets and liabilities of the partnerships are presented as partnership investments and liabilities of partnership investments, respectively, in the consolidated statements of financial condition. The net income for these partnerships are included in investment and other income in the consolidated statements of operations, and the change in partnership investments is included in contributions to or distributions from partnership investments in the consolidated statements of cash flows. The underlying assets and liabilities that are being consolidated are described in Note 5, Partnership Investments. The combined interests of all of the consolidated partnerships not owned by the Company and that are redeemable at the option of the holder, are presented as redeemable non-controlling interest in partnership investments in the Company’s consolidated financial statements for the periods those partnerships were consolidated.
	The Company holds non-controlling interests in certain other partnership investments that are included in partnership investments in the consolidated statements of financial condition. These other partnership investments are accounted for under the equity method.
	Restricted Cash
	The Company has a $430,000 security deposit that is restricted from the Company’s general corporate use and is being reported in other non-current assets in the consolidated statements of financial condition.
	Treasury Stock
	On November 13, 2014, the Company announced a repurchase of up to an additional 3 million shares of the Company's outstanding Class A Common Stock primarily to continue to manage the dilution from share issuances under the Company’s incentive compensation plan. During the three months ended March 31, 2015, Calamos Investments repurchased 178,141 shares of Class A common stock, at an average purchase price of $12.51 and a total cost of $2.2 million under this repurchase program. As Calamos Investments is consolidated with CAM, the repurchased shares are reported as treasury shares. As such, CAM’s 22.2% ownership interest in these shares totaling $495,000 is reported in treasury stock, with Calamos Interests’ 77.8% ownership interest in these shares totaling $1.7 million reported in non-controlling interest in the consolidated statements of financial condition. The total shares repurchased are not included in the calculation of basic and diluted earnings per share in accordance with GAAP.
	During the three months ended March 31, 2015, CAM redeemed 157,141 Class A common shares from Calamos Investments for a value of $1.8 million, which represents the fair value of the shares on the date of redemption. As Calamos Investments is consolidated with CAM, the impact of the distribution reflecting the non-controlling interest is $1.4 million.
	During the three months ended March 31, 2015, dividends on shares held by Calamos Investments totaled $411,000. The payment of these dividends increased Calamos Investments' equity resulting in a $320,000 adjustment from additional paid in capital to non-controlling interest in Calamos Investments LLC in the consolidated statement of changes in equity. This adjustments represent Calamos Interests' ownership interest in those dividend payments.
	For a comprehensive disclosure of the Company's significant accounting policies, see the Company's Annual Report on Form 10-K for the year ended December 31, 2014.

Investment_Securities

Investment Securities	3 Months Ended
	Mar. 31, 2015
Investments [Abstract]
Investment Securities	Investment Securities
	The Company is required to carry all investment securities it owns at fair value and record all changes in fair value in current earnings. As such, unrealized gains and losses on trading securities, as well as realized gains and losses on all investment securities, are included in investment and other income in the consolidated statements of operations. Unrealized gains and losses on available-for-sale securities are reported, net of CAM's deferred income tax, as a separate component of accumulated other comprehensive income in equity until realized.
	The following table provides a summary of investment securities as of March 31, 2015 and December 31, 2014:
	(in thousands)
	March 31, 2015		Cost			Unrealized Gains			Unrealized Losses				Fair Value
	Available-for-sale securities:
	Funds
	Equity
	Global Growth		$	142,486		$	10,835		$	(933	)		$	152,388
	U.S. Growth		64,675			5,574			(93		)		70,156
	Value		5,098			53			(132		)		5,019
	Alternative		31,289			538			(58		)		31,769
	Fixed Income/High Yield		17,601			167			(84		)		17,684
	Convertible		5,153			166			—				5,319
	Multi-Strategy		1,520			219			(7		)		1,732
	Total Funds		267,822			17,552			(1,307		)		284,067
	Common stock		137			141			—				278
	Total available-for-sale securities		$	267,959		$	17,693		$	(1,307	)		$	284,345
	Trading securities:
	Funds
	Equity
	U.S. Growth		$	5,147		$	153		$	—			$	5,300
	Total investment securities												$	289,645
	(in thousands)
	December 31, 2014		Cost			Unrealized Gains			Unrealized Losses				Fair Value
	Available-for-sale securities:
	Funds
	Equity
	Global Growth		$	142,610		$	5,275		$	(1,872	)		$	146,013
	U.S. Growth		64,526			3,194			(410		)		67,310
	Value		9,979			286			(171		)		10,094
	Alternative		40,752			1,283			(4		)		42,031
	Fixed Income/High Yield		17,596			1			(423		)		17,174
	Convertible		10,163			15			(1		)		10,177
	Multi-Strategy		1,494			198			(9		)		1,683
	Total Funds		287,120			10,252			(2,890		)		294,482
	Common stock		136			125			—				261
	Total available-for-sale securities		$	287,256		$	10,377		$	(2,890	)		$	294,743
	Trading securities:
	Funds
	Equity
	U.S. Growth		$	52,147		$	33		$	(6,964	)		$	45,216
	Total investment securities												$	339,959
	The investments in Funds at March 31, 2015 and December 31, 2014, of $289.4 million and $339.7 million, respectively, were invested in affiliated funds and accounts that are separately managed.
	The aggregate fair value of available-for-sale investment securities that were in an unrealized loss position at March 31, 2015 and December 31, 2014 was $36.5 million and $98.1 million, respectively. As of March 31, 2015, the Company's investment securities that had been in a continuous loss position for 12 months or longer were not significant. As of December 31, 2014, the Company had no investment securities that had been in a continuous loss position for 12 months or longer.
	As of March 31, 2015 and December 31, 2014, the Company believes that the $1.3 million and $2.9 million, respectively, in unrealized losses on certain available-for-sale securities are only temporary in nature, as these losses are a result of short-term declines in the net asset value of the funds. Further, the Company has the intent and ability to hold these securities for a period of time sufficient to allow for recovery of the market value. The Company also considered current market conditions and the nature of the securities held when determining the recoverability of those securities' market value. As of March 31, 2015, no other-than-temporary impairment charge was recorded.
	The following table provides a summary of changes in investment securities for the three months ended March 31, 2015 and 2014:
		Three Months Ended March 31,
	(in thousands)	2015			2014
	Available-for-sale securities:
	Proceeds from sales	$	15,000		$	87,263
	Gross realized gains on sales	$	545		$	454
	Trading securities:
	Change in unrealized gains	$	7,820		$	8,562
	The table below summarizes the tax provision on unrealized gains and gains reclassified out of accumulated other comprehensive income (loss) on available-for-sale securities for the three months ended March 31, 2015 and 2014:
		Three Months Ended										Three Months Ended
		March 31, 2015										March 31, 2014
	(in thousands)	Before-Tax Amount			Tax Provision			After-Tax				Before-Tax Amount			Tax Provision			After-Tax
								Amount										Amount
	Available-for-sale securities:
	Changes in unrealized gains	$	9,016		$	764		$	8,252			$	2,518		$	336		$	2,182
	Reclassification adjustment for realized gains included in income	(853		)	(316		)	(537		)		(816		)	(67		)	(749		)
	Other comprehensive income	$	8,163		$	448		$	7,715			$	1,702		$	269		$	1,433
	Reclassification of realized gains out of accumulated other comprehensive income are reported in non-operating income, in investment income, in the consolidated statement of operations.  See Note 9, Non-Operating Income.

Derivative_Assets_and_Liabilit

Derivative Assets and Liabilities	3 Months Ended
	Mar. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Assets and Liabilities	Derivative Assets and Liabilities
	The Company may use exchange-traded option contracts as an economic hedge of price changes in its investment securities portfolio in order to reduce the volatility equity markets have on the fair value of the Company's corporate investment portfolio and that could result in realized or unrealized gains and losses. The Company's investment securities, totaling $289.6 million at March 31, 2015, consist primarily of positions in several Calamos equity and fixed income funds. The equity price risk in the investment portfolio may be hedged using exchange-traded option contracts that correlate most closely with the change in value of the portfolio being hedged. The use of these option contracts are part of a hedge overlay strategy to minimize downside risk in the hedged portfolio. The Company may adjust its hedge position in response to movement and volatility in prices and changes in the composition of the hedged portfolio, but generally is not actively buying and selling contracts.
	The Company has elected not to offset its derivative assets with its derivative liabilities even if a right of offset exists. When applicable, the fair value of option contracts is reported on a gross basis in derivative assets and derivative liabilities in the consolidated statements of financial condition. Net gains and losses on these contracts are reported in investment and other income in the consolidated statements of operations. The Company did not record a gain or loss for the three months ended March 31, 2015 and 2014. The Company may use these derivatives for risk management purposes but does not designate the contracts as hedges for accounting purposes. The Company had no derivative instruments outstanding as of March 31, 2015 and 2014.

Partnership_Investments

Partnership Investments	3 Months Ended
	Mar. 31, 2015
Partnership Investments [Abstract]
Partnership Investments	Partnership Investments
	Presented below are the underlying assets and liabilities of the partnerships that the Company reports on a consolidated basis, as well as partnership investments that the Company accounts for under the equity method. These investments are presented as partnership investments and liabilities of partnership investments, respectively, in its consolidated statements of financial condition as of March 31, 2015 and December 31, 2014.
	(in thousands)	March 31, 2015			December 31, 2014
	Consolidated partnerships:
	Assets
	Securities owned	$	107,488		$	103,079
	Cash and cash equivalents	6,034			39,205
	Receivables for securities sold	465			—
	Other current assets	973			1,188
	Exchange-traded option contracts, net	1,228			201
	Total assets of consolidated partnerships	$	116,188		$	143,673
	Liabilities
	Payables for securities purchased	(1,608		)	(2,256		)
	Due to non-controlling interest in partnership investments	—			(7,719		)
	Accrued expenses and other current liabilities	(129		)	(142		)
	Total	$	(1,737	)	$	(10,117	)
	Equity method investment in partnerships	$	26		$	50
	Profits and losses are allocated to the general partner and limited partners in proportion to their ownership interests at the beginning of each month. Partners' admissions, additional contributions and withdrawals are permitted on a monthly basis.
	Calamos Arista Strategic Fund LP was liquidated on December 26, 2014. The partnership redemptions were completed during the first quarter of 2015 for proceeds of $23.1 million. This investment is presented as a consolidated partnership as of the year ended December 31, 2014, in the table above.
	During the second quarter of 2014, Calamos Investments, through its wholly owned subsidiaries and affiliates, acquired a majority interest in Calamos Global Opportunities Fund LP. This investment is presented as a consolidated partnership as of the year ended December 31, 2014, and for the three months ended March 31, 2015.

Fair_Value_Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements
	The Company utilizes a three-tier fair value hierarchy which prioritizes the inputs used in measuring fair value as follows: Level 1 — observable inputs such as quoted prices for identical assets and liabilities in active markets; Level 2 — inputs, other than the quoted prices in active markets, that are observable either directly or indirectly (including quoted prices of similar securities, interest rates, credit risk, fair value adjustments to quoted foreign securities, etc.); and Level 3 — unobservable inputs in which there is little or no market data, and require the reporting entity to develop its own assumptions. For each period presented, the Company did not have any assets or liabilities measured at fair value using Level 3 measurements. Transfers between levels are measured at the end of the reporting period. The Company had no transfers between levels during the period.
	Investments are presented in the consolidated financial statements at fair value in accordance with GAAP. Investments in open-end funds are stated at fair value based on end of day published net asset values of shares owned by the Company. The fair value of investments in open-end funds was $250.3 million and $297.0 million at the end of March 31, 2015 and December 31, 2014, respectively. There are no unfunded commitments related to these investments. These investments may be redeemed daily with a redemption notice period of up to seven days. Investments in securities traded on a national securities exchange are stated at the last reported sales price on the day of valuation. Other securities, including derivatives, traded in the over-the-counter market and listed securities for which no sale was reported on that date are stated at the last quoted bid price. However, short sales positions and call options written are reported at the last quoted ask price. Convertible bonds, fixed income securities and other securities for which quotations are not readily available are valued at fair value based on observable inputs such as market prices for similar instruments as validated by third party pricing agencies and the Company’s prime broker. Debt securities are valued based upon prices received from an independent pricing service or from a dealer or broker who makes markets in such securities. Pricing services utilize various observable market data and as such, debt securities are generally categorized as Level 2.
	The following tables provide the hierarchy of inputs used to derive the fair value of the Company’s assets and liabilities measured at fair value on a recurring basis as of March 31, 2015 and December 31, 2014, respectively. Foreign currency contracts are carried in the Company's partnership investments and are presented on a net basis where the right of offset exists, and had no impact for either period presented.
					Fair Value Measurements Using
	(in thousands)	March 31, 2015			Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1)			Significant Other Observable Inputs (Level 2)
	Description
	Cash and cash equivalents
	Money market funds	$	26,213		$	26,213		$	—
	Investment securities (Note 3)
	Funds
	Equity
	Global Growth	152,388			152,388			—
	U.S. Growth	75,456			75,456			—
	Value	5,019			5,019			—
	Alternative	31,764			31,764			—
	Fixed Income/High Yield	17,684			12,572			5,112
	Convertible	6,180			6,180			—
	Multi-Strategy	1,732			1,732			—
	Total Funds	290,223			285,111			5,112
	Common stock	278			278			—
	Investment securities	290,501			285,389			5,112
	Securities and derivatives owned by partnership investments (Note 5)
	Common stocks	54,927			26,671			28,256
	Preferred stocks	5,853			5,853			—
	Convertible bonds	42,661			—			42,661
	Corporate bonds	4,047			—			4,047
	Money market funds	5,992			5,737			255
	Exchange-traded put option contracts	1,228			1,228			—
		114,708			39,489			75,219
	Securities sold but not yet purchased (Note 3)
	Common stocks	(856		)	(856		)	—
	Total	$	430,566		$	350,235		$	80,331
					Fair Value Measurements Using
	(in thousands)	December 31, 2014			Quoted Prices in Active Markets for Identical Assets			Significant Other Observable Inputs
					and Liabilities			(Level 2)
	Description				(Level 1)
	Cash and cash equivalents
	Money market funds	$	1,209		$	1,209		$	—
	Investment securities (Note 3)
	Funds
	Equity
	Global Growth	146,013			146,013			—
	U.S. Growth	112,526			112,526			—
	Value	12,218			12,218			—
	Alternative	42,031			42,031			—
	Fixed Income/High Yield	17,174			12,174			5,000
	Convertible	11,021			11,021			—
	Multi-Strategy	1,683			1,683			—
	Total Funds	342,666			337,666			5,000
	Common stock	261			261			—
	Investment securities	342,927			337,927			5,000
	Securities and derivatives owned by partnership investments (Note 5)
	Common stocks	51,403			26,237			25,166
	Preferred stocks	5,736			2,281			3,455
	Convertible bonds	41,119			—			41,119
	Corporate bonds	4,821			—			4,821
	Money market funds	37,060			7,851			29,209
	Foreign currency	513			513			—
	Exchange-traded put option contracts	201			201			—
		140,853			37,083			103,770
	Securities sold but not yet purchased (Note 3)
	Common stocks	(2,968		)	(2,968		)	—
	Total	$	482,021		$	373,251		$	108,770
The fair value of the Company’s long-term debt, which has a total carrying value of $46.0 million at March 31, 2015 and December 31, 2014, was $53.4 million and $54.2 million, respectively. During the third quarter of 2014, $46.2 million of senior notes outstanding were repaid. The fair value and carrying value of the Company’s payment obligation was $1.7 million at March 31, 2015, and December 31, 2014. This obligation is associated with the Company's purchase of Black Capital LLC in 2012, reported in other current liabilities in the consolidated statements of financial condition. These fair value estimates are calculated using discounted cash flows based on the Company’s incremental borrowing rates and market inputs for similar bonds for the debt, and the treasury yield curve plus market spread for the payment obligation. The fair values of the debt and payment obligation are based on Level 2 inputs within the fair value hierarchy.
The carrying value of all other financial instruments approximates fair value due to the short maturities of these financial instruments.

Loans_Payable

Loans Payable	3 Months Ended
	Mar. 31, 2015
Loans Payable [Abstract]
Loans Payable	Loans Payable
	The Company has access to margin loans for the settlement of call options, as well as an additional source of liquidity. The interest rate that can be charged on margin loans is 1.5% per annum, based on the brokerage firm’s lending rate. These loans are due on demand. The Company can borrow up to 70% of its marginable securities on deposit with its brokerage firm. The Company had no margin loan balances outstanding at March 31, 2015 and December 31, 2014.

Stock_Based_Compensation

Stock Based Compensation	3 Months Ended
	Mar. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock Based Compensation	Stock-Based Compensation
	Under the Company’s incentive compensation plan, certain employees of the Company receive stock-based compensation comprised of stock options and restricted stock units (“RSUs”). Historically, RSUs have been settled with newly issued shares so that no cash was used by the Company to settle awards; however, the Company may also use treasury shares upon the exercise of stock options and upon conversion of RSUs. The Company’s Annual Report on Form 10-K for the year ended December 31, 2014 provides details of this plan and its provisions.
	During the three months ended March 31, 2015, the Company granted 780,649 RSUs and there were 139,037 RSUs forfeited. During the same period, the Company granted no stock options and there were 251,806 stock options forfeited.
	During the three months ended March 31, 2015, 193,486 RSUs vested with 36,045 units withheld for taxes and 157,441 RSUs converted into an equal number of shares of CAM’s Class A common stock. The total intrinsic value and the fair value of the converted shares was $2.1 million. The total tax benefit realized in connection with the vesting of the RSUs during the three months ended March 31, 2015 was $240,000, as the Company receives tax benefits based upon the portion of Calamos Investments’ expense that it recognizes.
	During the three months ended March 31, 2015 and 2014, compensation expense recorded in connection with the RSUs and stock options was $1.6 million and $2.0 million, respectively, of which $360,000 and $455,000, respectively, was credited as additional paid-in capital after giving effect to the non-controlling interests. The amount of deferred tax asset created was $133,000 and $168,000 during the three months ended March 31, 2015 and 2014, respectively. As of March 31, 2015, $22.5 million of total unrecognized compensation expense related to unvested stock option and RSU awards is expected to be recognized over a weighted-average period of 3.2 years.

NonOperating_Income

Non-Operating Income	3 Months Ended
	Mar. 31, 2015
Other Income and Expenses [Abstract]
Non-Operating Income	Non-Operating Income
	Non-operating income was comprised of the following components for the three months ended March 31, 2015 and 2014:
		Three Months Ended March 31,
	(in thousands)	2015			2014
	Interest income	$	44		$	39
	Interest expense	(774		)	(1,504		)
	Net interest expense	(730		)	(1,465		)
	Investment income	5,526			857
	Dividend income	227			663
	Miscellaneous other loss	(16		)	63
	Investment and other income	5,737			1,583
	Non-operating income	$	5,007		$	118

Income_Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2015
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes
	Calamos Investments is subject to certain income-based state taxes; therefore, income taxes reflect not only the portion attributed to CAM stockholders but also a portion of income taxes attributable to non-controlling interests.
		Three Months Ended March 31,
		2015			2014
	(in thousands)
	Income tax provision	$	465		$	1,362
	Income tax (provision) benefit attributable to non-controlling interest in Calamos Investments	(14		)	(45		)
	Income tax provision attributable to CAM	451			1,317
	Net income attributable to CAM	101			2,139
	Income before taxes attributable to CAM	$	552		$	3,456
	CAM’s effective income tax rate	81.7		%	38.1		%
	CAM's effective income tax rate was 81.7% for the first quarter of 2015, compared with 38.1% for the first quarter of 2014, a result of $238,000 of deferred tax expense related to expired employee stock options.
	As of December 31, 2014, the Company's total capital loss carryforward was $456,000 which will expire in 2017, if not used before the expiration dates. As of March 31, 2015, the Company did not have a valuation allowance on this deferred tax asset.

Earnings_Per_Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share
	The following table reflects the calculation of basic and diluted earnings per share:
		Three Months Ended
		March 31,
	(in thousands, except per share amounts)	2015			2014
	Earnings per share – basic:
	Earnings available to common shareholders	$	101		$	2,139
	Weighted average shares outstanding	17,872			19,079
	Earnings per share – basic	$	0.01		$	0.11
	Earnings per share – diluted:
	Earnings available to common shareholders	$	101		$	2,139
	Weighted average shares outstanding	17,872			19,079
	Dilutive impact of restricted stock units	828			727
	Weighted average shares outstanding	18,700			19,806
	Earnings per share – diluted	$	0.01		$	0.11
	When dilutive, diluted shares outstanding are calculated (a) assuming that Calamos Interests exchanged all of their ownership interest in Calamos Investments and their CAM Class B common stock for shares of CAM’s Class A common stock (the "Exchange") and (b) including the effect of outstanding dilutive equity incentive compensation awards. As of March 31, 2015, and 2014, the impact of the Exchange was anti-dilutive and, therefore, excluded from the calculation of diluted earnings per share.
	The Company uses the treasury stock method to reflect the dilutive effect of unvested RSUs and unexercised stock options on diluted earnings per share. Under the treasury stock method, if the average market price of common stock increases above the option’s exercise price, the proceeds that would be assumed to be realized from the exercise of the option would be used to acquire outstanding shares of common stock. However, the awards may be anti-dilutive even when the market price of the underlying stock exceeds the option’s exercise price. This result is possible because compensation cost attributed to future services and not yet recognized is included as a component of the assumed proceeds upon exercise. The dilutive effect of such options and RSUs would increase the weighted average number of shares used in the calculation of diluted earnings per share.
	The Company amended its certificate of incorporation requiring that the Exchange be based on a fair value approach (details of the amendment are set forth in the Company’s Schedule 14C filed with the Securities and Exchange Commission on January 12, 2009). The amendment results in the same or fewer shares of Class A common stock being issuable at the time of the Exchange.
	The shares issuable upon the Exchange as presented are estimated solely on the formula as described in Schedule 14C that does not necessarily reflect all inputs used in a fair valuation. It is critical to note that this formula does not incorporate certain economic factors and as such, in the event of an actual Exchange, the majority of the Company’s independent directors may determine the fair market value of CAM’s net assets and its ownership in Calamos Investments. For example, premiums and/or discounts for control and marketability as well as a different discount rate for future cash flows may be applied. Therefore, the directors’ valuation may result in the actual number of shares being materially different from the shares presented. Further, based upon currently available information, the Company believes it is unlikely that any Exchange would transpire without a fair market valuation of CAM’s net assets and possibly an agreement by Calamos Interests to Exchange, based upon that fair market valuation.
	The following table shows the number of shares which were excluded from the computation of diluted earnings per share as they were anti-dilutive:
		Three Months Ended
		March 31,
		2015		2014
	Shares of Class A common stock issuable upon an Exchange of Calamos Interests’ ownership in Calamos Investments*	27,631,947		31,167,271
	Stock options	1,177,361		1,978,857
	Total	28,809,308		33,146,128
	* Number of shares calculated with the value of Calamos Investments determined by using the closing price of our shares as of March 31, 2015 ($13.45) and March 31, 2014 ($12.93) as well as assuming said closing prices fully reflect all of CAM's assets; including the application of a 12% discount rate to certain deferred tax assets at each of March 31, 2015 and 2014. The value of Calamos Investments is then multiplied by Calamos Interests' percentage ownership in Calamos Investments, with the result divided by the applicable period-end closing price. See Note 2, Summary of Significant Accounting Policies - Principles of Consolidation, for a description of certain assets owned by CAM.

Commitments_and_Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies
	On March 27, 2015, Calamos Investments completed the initial public offering of a closed-end fund, which includes a share repurchase program after expiration of the underwriters' option to purchase additional shares. Under this program, Calamos Advisors LLC has committed to purchase up to $20 million of common shares of the fund within one year of the offering subject to a variety of market and discount conditions and a daily purchase limit.
	In the normal course of business, the Company may be party to various legal proceedings from time to time. Management believes that a current complaint filed against CAL and CFS, alleging breaches of fiduciary duties with respect to the receipt of advisory, distribution and servicing fees paid by an open-end investment company advised by CAL, is without merit and CAL and CFS intend to defend themselves vigorously against the allegations. Currently, management believes that the ultimate resolution of this complaint will not materially affect the Company’s business, financial position or results of operations and that the likelihood of a material adverse impact is remote.

Recently_Issued_Accounting_Pro

Recently Issued Accounting Pronouncements	3 Months Ended
	Mar. 31, 2015
Accounting Policies [Abstract]
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements
	The Company has reviewed all newly issued accounting pronouncements that are applicable to its business and to the preparation of its consolidated financial statements, including those not yet required to be adopted. The Company does not believe any such pronouncements will have a material effect on the Company’s financial position or results of operations. Accounting guidance that will become effective in future years, with respect to the Company’s consolidated financial statements, is described below:
	In February 2015, the Financial Accounting Standards Board ("FASB") issued an accounting update amending the consolidation requirements under GAAP. This standard modifies existing consolidation guidance for reporting organizations that are required to evaluate whether they should consolidate certain legal entities. This guidance is effective for annual and interim periods beginning after December 15, 2015, and requires either a retrospective or a modified retrospective approach to adoption. Early adoption is permitted. The Company is currently evaluating the potential impact of this standard on its results of operations, cash flows or financial position, as well as the available transition methods.
	In May 2014, the FASB issued new guidance on revenue from contracts with customers. The new revenue recognition standard provides a five-step analysis of transactions to determine when and how revenue is recognized. The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. In April 2015, the FASB tentatively decided to defer the effective date of the new revenue guidance by one year to annual reporting periods beginning after December 15, 2017, with early adoption being permitted for annual periods beginning after December 15, 2016. The Company's effective date is January 1, 2018. The Company is evaluating the effect of adopting this new accounting guidance but does not expect adoption will have a material impact on its results of operations, cash flows or financial position.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2015
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation
	The consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”), which require the use of estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses, and the disclosure of contingent assets and liabilities. Management believes the accounting estimates are appropriate and reasonably stated; however, due to the inherent uncertainties in making estimates, actual amounts could differ from these estimates.
Principles of Consolidation	Principles of Consolidation
	The Company consolidates investments in which the Company’s ownership exceeds 50% or in which the Company operates and controls the business and affairs of the entity or is deemed to be the primary beneficiary. In order to make this determination, an analysis is performed to determine if the investment in an affiliate or partnership is a variable interest entity ("VIE"). The Company has evaluated its investments in affiliates and partnerships and has concluded that they are not VIEs. With respect to partnership investments, the limited partners have no control of the business and affairs of the partnership, no substantive ability to dissolve (liquidate) the partnership, or otherwise remove the general partner (CAL and Calamos Investments) without cause or have other substantive rights.
	The consolidated financial statements include the financial statements of CAM, Calamos Investments, Calamos Investments’ wholly-owned subsidiaries, and the Company’s partnerships in which it owns a majority interest or in which it has operating control. The equity method of accounting is used for investments in which the Company has significant influence, but less than 50% ownership. All significant intercompany balances and transactions have been eliminated.
	The Calamos Interests’ combined 77.8% interest in Calamos Investments at March 31, 2015 and December 31, 2014, is represented as a non-controlling interest in Calamos Investments LLC in the Company’s consolidated financial statements. Non-controlling interest in Calamos Investments is derived by multiplying the historical equity of Calamos Investments by the Calamos Interests’ aggregate ownership percentage for the periods presented. Issuances and repurchases of CAM’s common stock may result in changes to CAM’s ownership percentage and to the non-controlling interests’ ownership percentage of Calamos Investments with resulting changes reflected in the consolidated statements of changes in equity. Income is allocated based on the average ownership interest during the period in which the income is earned.
	CAM owns certain assets to which it has exclusive economic rights. As of March 31, 2015 and December 31, 2014, these assets included cash, cash equivalents and investment securities of $58.5 million and $79.3 million, net current and non-current deferred tax assets of $39.1 million and $40.3 million, net current income taxes receivable of $2.7 million and $2.4 million, and a loan receivable from Calamos Investments of $45.0 million and $21.0 million, respectively, that are reported together with Calamos Investments’ consolidated assets in the consolidated statements of financial condition. Additionally, net income before income taxes of $3.5 million and $14.2 million for the three months ended March 31, 2015 and 2014, respectively, each included $580,000 and $403,000, respectively, of interest income, dividend income and realized gains and losses on cash and cash equivalents held solely by CAM. These portions of CAM’s income and expense are not affected by non-controlling interests.
	Calamos Investments, through its wholly owned subsidiaries and affiliates, is indirectly the general partner and controls the operations of Calamos Global Opportunities Fund LP, for which it acquired a majority interest in the partnership during the second quarter of 2014. The results of this partnership are included in the Company's consolidated financial statements for the year ended December 31, 2014 and the three months ended March 31, 2015. Calamos Investments, through a wholly owned subsidiary, was indirectly the general partner and controlled the operations of Calamos Arista Strategic Fund LP, a U.S. feeder fund, and Calamos Arista Strategic Fund Ltd, an offshore feeder fund, both to Calamos Arista Strategic Master Fund LTD, a hedge fund in the Cayman Islands. As Calamos Investments was the general partner and controlled the operations of Calamos Arista Strategic Fund LP and Calamos Arista Strategic Fund Ltd, the results of these partnerships and the master fund were included in the Company’s consolidated financial results for the year ended December 31, 2014. Calamos Arista Strategic Fund LP was liquidated on December 26, 2014. The partnership redemptions were completed during the first quarter of 2015 for proceeds of $23.1 million. For the year ended December 31, 2014, the amount due to non-controlling interest of $7.7 million related to this partnership investment was presented in liabilities of partnership investments in our consolidated statements of financial condition. The operations of Calamos International Growth Fund LP were controlled by CAL, the general partner. In December 2013, the limited partners of Calamos International Growth Fund LP redeemed all of their interests in the fund. As a result, the Company deconsolidated Calamos International Growth Fund LP and accounted for this partnership investment using the equity method as of December 31, 2014. Calamos International Growth Fund LP was dissolved on April 10, 2014. See Note 5, Partnership Investments, for more discussion regarding these funds.
	For the periods the partnerships are consolidated, the assets and liabilities of the partnerships are presented as partnership investments and liabilities of partnership investments, respectively, in the consolidated statements of financial condition. The net income for these partnerships are included in investment and other income in the consolidated statements of operations, and the change in partnership investments is included in contributions to or distributions from partnership investments in the consolidated statements of cash flows. The underlying assets and liabilities that are being consolidated are described in Note 5, Partnership Investments. The combined interests of all of the consolidated partnerships not owned by the Company and that are redeemable at the option of the holder, are presented as redeemable non-controlling interest in partnership investments in the Company’s consolidated financial statements for the periods those partnerships were consolidated.
	The Company holds non-controlling interests in certain other partnership investments that are included in partnership investments in the consolidated statements of financial condition. These other partnership investments are accounted for under the equity method.
Restricted Cash	Restricted Cash
	The Company has a $430,000 security deposit that is restricted from the Company’s general corporate use and is being reported in other non-current assets in the consolidated statements of financial condition.

Recently_Issued_Accounting_Pro1

Recently Issued Accounting Pronouncements (Policies)	3 Months Ended
	Mar. 31, 2015
Accounting Policies [Abstract]
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements
	The Company has reviewed all newly issued accounting pronouncements that are applicable to its business and to the preparation of its consolidated financial statements, including those not yet required to be adopted. The Company does not believe any such pronouncements will have a material effect on the Company’s financial position or results of operations. Accounting guidance that will become effective in future years, with respect to the Company’s consolidated financial statements, is described below:
	In February 2015, the Financial Accounting Standards Board ("FASB") issued an accounting update amending the consolidation requirements under GAAP. This standard modifies existing consolidation guidance for reporting organizations that are required to evaluate whether they should consolidate certain legal entities. This guidance is effective for annual and interim periods beginning after December 15, 2015, and requires either a retrospective or a modified retrospective approach to adoption. Early adoption is permitted. The Company is currently evaluating the potential impact of this standard on its results of operations, cash flows or financial position, as well as the available transition methods.
	In May 2014, the FASB issued new guidance on revenue from contracts with customers. The new revenue recognition standard provides a five-step analysis of transactions to determine when and how revenue is recognized. The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. In April 2015, the FASB tentatively decided to defer the effective date of the new revenue guidance by one year to annual reporting periods beginning after December 15, 2017, with early adoption being permitted for annual periods beginning after December 15, 2016. The Company's effective date is January 1, 2018. The Company is evaluating the effect of adopting this new accounting guidance but does not expect adoption will have a material impact on its results of operations, cash flows or financial position.

Investment_Securities_Tables

Investment Securities (Tables)	3 Months Ended
	Mar. 31, 2015
Investments [Abstract]
Summary of investment securities	The following table provides a summary of investment securities as of March 31, 2015 and December 31, 2014:
	(in thousands)
	March 31, 2015		Cost			Unrealized Gains			Unrealized Losses				Fair Value
	Available-for-sale securities:
	Funds
	Equity
	Global Growth		$	142,486		$	10,835		$	(933	)		$	152,388
	U.S. Growth		64,675			5,574			(93		)		70,156
	Value		5,098			53			(132		)		5,019
	Alternative		31,289			538			(58		)		31,769
	Fixed Income/High Yield		17,601			167			(84		)		17,684
	Convertible		5,153			166			—				5,319
	Multi-Strategy		1,520			219			(7		)		1,732
	Total Funds		267,822			17,552			(1,307		)		284,067
	Common stock		137			141			—				278
	Total available-for-sale securities		$	267,959		$	17,693		$	(1,307	)		$	284,345
	Trading securities:
	Funds
	Equity
	U.S. Growth		$	5,147		$	153		$	—			$	5,300
	Total investment securities												$	289,645
	(in thousands)
	December 31, 2014		Cost			Unrealized Gains			Unrealized Losses				Fair Value
	Available-for-sale securities:
	Funds
	Equity
	Global Growth		$	142,610		$	5,275		$	(1,872	)		$	146,013
	U.S. Growth		64,526			3,194			(410		)		67,310
	Value		9,979			286			(171		)		10,094
	Alternative		40,752			1,283			(4		)		42,031
	Fixed Income/High Yield		17,596			1			(423		)		17,174
	Convertible		10,163			15			(1		)		10,177
	Multi-Strategy		1,494			198			(9		)		1,683
	Total Funds		287,120			10,252			(2,890		)		294,482
	Common stock		136			125			—				261
	Total available-for-sale securities		$	287,256		$	10,377		$	(2,890	)		$	294,743
	Trading securities:
	Funds
	Equity
	U.S. Growth		$	52,147		$	33		$	(6,964	)		$	45,216
	Total investment securities												$	339,959
Changes in investment securities	The following table provides a summary of changes in investment securities for the three months ended March 31, 2015 and 2014:
		Three Months Ended March 31,
	(in thousands)	2015			2014
	Available-for-sale securities:
	Proceeds from sales	$	15,000		$	87,263
	Gross realized gains on sales	$	545		$	454
	Trading securities:
	Change in unrealized gains	$	7,820		$	8,562
Summary of tax (provision) benefit on unrealized gains	The table below summarizes the tax provision on unrealized gains and gains reclassified out of accumulated other comprehensive income (loss) on available-for-sale securities for the three months ended March 31, 2015 and 2014:
		Three Months Ended										Three Months Ended
		March 31, 2015										March 31, 2014
	(in thousands)	Before-Tax Amount			Tax Provision			After-Tax				Before-Tax Amount			Tax Provision			After-Tax
								Amount										Amount
	Available-for-sale securities:
	Changes in unrealized gains	$	9,016		$	764		$	8,252			$	2,518		$	336		$	2,182
	Reclassification adjustment for realized gains included in income	(853		)	(316		)	(537		)		(816		)	(67		)	(749		)
	Other comprehensive income	$	8,163		$	448		$	7,715			$	1,702		$	269		$	1,433

Partnership_Investments_Tables

Partnership Investments (Tables)	3 Months Ended
	Mar. 31, 2015
Partnership Investments [Abstract]
Partnership investments	These investments are presented as partnership investments and liabilities of partnership investments, respectively, in its consolidated statements of financial condition as of March 31, 2015 and December 31, 2014.
	(in thousands)	March 31, 2015			December 31, 2014
	Consolidated partnerships:
	Assets
	Securities owned	$	107,488		$	103,079
	Cash and cash equivalents	6,034			39,205
	Receivables for securities sold	465			—
	Other current assets	973			1,188
	Exchange-traded option contracts, net	1,228			201
	Total assets of consolidated partnerships	$	116,188		$	143,673
	Liabilities
	Payables for securities purchased	(1,608		)	(2,256		)
	Due to non-controlling interest in partnership investments	—			(7,719		)
	Accrued expenses and other current liabilities	(129		)	(142		)
	Total	$	(1,737	)	$	(10,117	)
	Equity method investment in partnerships	$	26		$	50

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Fair value of assets and liabilities measured on recurring basis	Foreign currency contracts are carried in the Company's partnership investments and are presented on a net basis where the right of offset exists, and had no impact for either period presented.
					Fair Value Measurements Using
	(in thousands)	March 31, 2015			Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1)			Significant Other Observable Inputs (Level 2)
	Description
	Cash and cash equivalents
	Money market funds	$	26,213		$	26,213		$	—
	Investment securities (Note 3)
	Funds
	Equity
	Global Growth	152,388			152,388			—
	U.S. Growth	75,456			75,456			—
	Value	5,019			5,019			—
	Alternative	31,764			31,764			—
	Fixed Income/High Yield	17,684			12,572			5,112
	Convertible	6,180			6,180			—
	Multi-Strategy	1,732			1,732			—
	Total Funds	290,223			285,111			5,112
	Common stock	278			278			—
	Investment securities	290,501			285,389			5,112
	Securities and derivatives owned by partnership investments (Note 5)
	Common stocks	54,927			26,671			28,256
	Preferred stocks	5,853			5,853			—
	Convertible bonds	42,661			—			42,661
	Corporate bonds	4,047			—			4,047
	Money market funds	5,992			5,737			255
	Exchange-traded put option contracts	1,228			1,228			—
		114,708			39,489			75,219
	Securities sold but not yet purchased (Note 3)
	Common stocks	(856		)	(856		)	—
	Total	$	430,566		$	350,235		$	80,331
					Fair Value Measurements Using
	(in thousands)	December 31, 2014			Quoted Prices in Active Markets for Identical Assets			Significant Other Observable Inputs
					and Liabilities			(Level 2)
	Description				(Level 1)
	Cash and cash equivalents
	Money market funds	$	1,209		$	1,209		$	—
	Investment securities (Note 3)
	Funds
	Equity
	Global Growth	146,013			146,013			—
	U.S. Growth	112,526			112,526			—
	Value	12,218			12,218			—
	Alternative	42,031			42,031			—
	Fixed Income/High Yield	17,174			12,174			5,000
	Convertible	11,021			11,021			—
	Multi-Strategy	1,683			1,683			—
	Total Funds	342,666			337,666			5,000
	Common stock	261			261			—
	Investment securities	342,927			337,927			5,000
	Securities and derivatives owned by partnership investments (Note 5)
	Common stocks	51,403			26,237			25,166
	Preferred stocks	5,736			2,281			3,455
	Convertible bonds	41,119			—			41,119
	Corporate bonds	4,821			—			4,821
	Money market funds	37,060			7,851			29,209
	Foreign currency	513			513			—
	Exchange-traded put option contracts	201			201			—
		140,853			37,083			103,770
	Securities sold but not yet purchased (Note 3)
	Common stocks	(2,968		)	(2,968		)	—
	Total	$	482,021		$	373,251		$	108,770

NonOperating_Income_Tables

Non-Operating Income (Tables)	3 Months Ended
	Mar. 31, 2015
Other Income and Expenses [Abstract]
Non-operating income	Non-operating income was comprised of the following components for the three months ended March 31, 2015 and 2014:
		Three Months Ended March 31,
	(in thousands)	2015			2014
	Interest income	$	44		$	39
	Interest expense	(774		)	(1,504		)
	Net interest expense	(730		)	(1,465		)
	Investment income	5,526			857
	Dividend income	227			663
	Miscellaneous other loss	(16		)	63
	Investment and other income	5,737			1,583
	Non-operating income	$	5,007		$	118

Income_Taxes_Tables

Income Taxes (Tables)	3 Months Ended
	Mar. 31, 2015
Income Tax Disclosure [Abstract]
Schedule of components of income tax expense (benefit)
		Three Months Ended March 31,
		2015			2014
	(in thousands)
	Income tax provision	$	465		$	1,362
	Income tax (provision) benefit attributable to non-controlling interest in Calamos Investments	(14		)	(45		)
	Income tax provision attributable to CAM	451			1,317
	Net income attributable to CAM	101			2,139
	Income before taxes attributable to CAM	$	552		$	3,456
	CAM’s effective income tax rate	81.7		%	38.1		%

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Calculation of basic and diluted earnings per share	The following table reflects the calculation of basic and diluted earnings per share:
		Three Months Ended
		March 31,
	(in thousands, except per share amounts)	2015			2014
	Earnings per share – basic:
	Earnings available to common shareholders	$	101		$	2,139
	Weighted average shares outstanding	17,872			19,079
	Earnings per share – basic	$	0.01		$	0.11
	Earnings per share – diluted:
	Earnings available to common shareholders	$	101		$	2,139
	Weighted average shares outstanding	17,872			19,079
	Dilutive impact of restricted stock units	828			727
	Weighted average shares outstanding	18,700			19,806
	Earnings per share – diluted	$	0.01		$	0.11
Schedule of antidilutive securities excluded from computation of earnings per share	The following table shows the number of shares which were excluded from the computation of diluted earnings per share as they were anti-dilutive:
		Three Months Ended
		March 31,
		2015		2014
	Shares of Class A common stock issuable upon an Exchange of Calamos Interests’ ownership in Calamos Investments*	27,631,947		31,167,271
	Stock options	1,177,361		1,978,857
	Total	28,809,308		33,146,128
	* Number of shares calculated with the value of Calamos Investments determined by using the closing price of our shares as of March 31, 2015 ($13.45) and March 31, 2014 ($12.93) as well as assuming said closing prices fully reflect all of CAM's assets; including the application of a 12% discount rate to certain deferred tax assets at each of March 31, 2015 and 2014. The value of Calamos Investments is then multiplied by Calamos Interests' percentage ownership in Calamos Investments, with the result divided by the applicable period-end closing price. See Note 2, Summary of Significant Accounting Policies - Principles of Consolidation, for a description of certain assets owned by CAM.

Organization_and_Description_o1

Organization and Description of Business (Details)	3 Months Ended
	Mar. 31, 2015
Corporate Structure [Line Items]
Options and RSU awards vesting period (in days)	60 days
Calamos Asset Management, Inc.
Corporate Structure [Line Items]
Percentage ownership interest in Calamos Investments LLC (as a percent)	22.20%
Calamos Family Partners, Inc.
Corporate Structure [Line Items]
Percentage ownership interest in Calamos Investments LLC (as a percent)	77.80%
Class A Common Stock
Corporate Structure [Line Items]
Percentage of ownership (including vested stock options) by noncontrolling owners (as a percent)	15.86%
Class B Common Stock | Calamos Family Partners, Inc.
Corporate Structure [Line Items]
Percentage of voting power owned in Calamos Asset Management (as a percent)	97.40%
Percentage of economic interest (as a percent)	1.00%
Public Stockholders | Class A Common Stock
Corporate Structure [Line Items]
Percentage of public shareholders voting power (as a percent)	2.60%
Percentage of public shareholders economic interest (as a percent)	99.00%

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Related Party Transaction [Line Items]
Percentage of combined interest in subsidiary that is considered to be noncontrolling interest (as a percent)	77.80%		77.80%
Deferred tax assets	$133,000		$168,000
Interest income	44,000	39,000
Liabilities of partnership investments	1,737,000		10,117,000
Restricted cash	430,000
Calamos Asset Management, Inc.
Related Party Transaction [Line Items]
Cash and cash equivalents and investment securities	58,500,000		79,300,000
Deferred tax assets	39,100,000		40,300,000
Net current income taxes receivable	2,700,000		2,400,000
Loan receivable	45,000,000		21,000,000
Net income before income taxes	3,500,000	14,200,000
Interest income	580,000	403,000
Non-controlling Interest in Calamos Investments LLC | Subsidiaries
Related Party Transaction [Line Items]
Proceeds from partnership redemptions	23,100,000
Liabilities of partnership investments			$7,700,000

Summary_of_Significant_Account3

Summary of Significant Accounting Policies - Treasury Stock (Details) (USD $)	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Nov. 13, 2013
Class of Stock [Line Items]
Repurchase of common stock by Calamos Investments LLC	2,229
Ownership interest (as a percent)	77.80%
Dividends on shares held	411
Class A Common Stock
Class of Stock [Line Items]
Number of shares authorized to be repurchased (in shares)			3,000,000
Repurchase of common stock (in shares)	178,141	1,036,615
Issuance of common stock (in shares)	157,441
Calamos Asset Management, Inc.
Class of Stock [Line Items]
Percentage ownership interest in Calamos Investments LLC (as a percent)	22.20%
Calamos Asset Management, Inc. | Class A Common Stock
Class of Stock [Line Items]
Issuance of common stock (in shares)	157,141
Issuance of common stock	1,800
Treasury Stock
Class of Stock [Line Items]
Repurchase of common stock by Calamos Investments LLC	495
Noncontrolling interest	1,438
Non-controlling Interest in Calamos Investments LLC (Calamos Interests)
Class of Stock [Line Items]
Repurchase of common stock by Calamos Investments LLC	1,734
Impact on non-controlling interests as a result of dividends paid to Calamos Investments LLC on repurchased common stock	320
2014 Share Repurchase Program | Non-controlling Interest in Calamos Investments LLC | Common stock
Class of Stock [Line Items]
Repurchase of common stock (in shares)	178,141
Average purchase price of shares (in dollars per share)	12.51
Repurchase of common stock by Calamos Investments LLC	2,200

Investment_Securities_Summary_

Investment Securities - Summary (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Trading securities:
Total investment securities	$289,645	$339,959
Available-for-sale securities
Available-for-sale securities:
Cost	267,959	287,256
Unrealized Gains	17,693	10,377
Unrealized Losses	-1,307	-2,890
Fair Value	284,345	294,743
Available-for-sale securities | Global Growth
Available-for-sale securities:
Cost	142,486	142,610
Unrealized Gains	10,835	5,275
Unrealized Losses	-933	-1,872
Fair Value	152,388	146,013
Available-for-sale securities | U.S. Growth
Available-for-sale securities:
Cost	64,675	64,526
Unrealized Gains	5,574	3,194
Unrealized Losses	-93	-410
Fair Value	70,156	67,310
Available-for-sale securities | Value
Available-for-sale securities:
Cost	5,098	9,979
Unrealized Gains	53	286
Unrealized Losses	-132	-171
Fair Value	5,019	10,094
Available-for-sale securities | Alternative
Available-for-sale securities:
Cost	31,289	40,752
Unrealized Gains	538	1,283
Unrealized Losses	-58	-4
Fair Value	31,769	42,031
Available-for-sale securities | Fixed Income/High Yield
Available-for-sale securities:
Cost	17,601	17,596
Unrealized Gains	167	1
Unrealized Losses	-84	-423
Fair Value	17,684	17,174
Available-for-sale securities | Convertible
Available-for-sale securities:
Cost	5,153	10,163
Unrealized Gains	166	15
Unrealized Losses	0	-1
Fair Value	5,319	10,177
Available-for-sale securities | Multi-Strategy
Available-for-sale securities:
Cost	1,520	1,494
Unrealized Gains	219	198
Unrealized Losses	-7	-9
Fair Value	1,732	1,683
Available-for-sale securities | Total Funds
Available-for-sale securities:
Cost	267,822	287,120
Unrealized Gains	17,552	10,252
Unrealized Losses	-1,307	-2,890
Fair Value	284,067	294,482
Available-for-sale securities | Common stock
Available-for-sale securities:
Cost	137	136
Unrealized Gains	141	125
Unrealized Losses	0	0
Fair Value	278	261
Trading securities
Trading securities:
Cost		52,147
Unrealized Gains		33
Unrealized Losses		-6,964
Fair Value		45,216
Trading securities | U.S. Growth
Trading securities:
Cost	5,147
Unrealized Gains	153
Unrealized Losses	0
Fair Value	$5,300

Investment_Securities_Changes_

Investment Securities - Changes in Investment Securities (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Available-for-sale securities:
Proceeds from sales	$15,000	$87,263
Gross realized gains on sales	545	454
Trading securities:
Change in unrealized gains	$7,820	$8,562

Investment_Securities_Tax_Prov

Investment Securities - Tax (Provision) Benefit on Unrealized Gains (Losses) and Gains (Losses) Reclassified out of AOCI (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Changes in unrealized gains
Unrealized gains	$9,016	$2,518
Tax Provision	764	336
After-Tax Amount	8,252	2,182
Reclassification adjustment for realized gains included in income
Before-Tax Amount	-853	-816
Tax Provision (Benefit)	-316	-67
After-Tax Amount	-537	-749
Other comprehensive income
Other comprehensive income, before income tax provision	8,163	1,702
Tax Provision (Benefit)	448	269
After-Tax Amount	$7,715	$1,433

Investment_Securities_Narrativ

Investment Securities - Narrative (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Investments [Abstract]
Investments in funds	$289.40	$339.70
Aggregate fair value of available-for-sale securities in unrealized loss position	$36.50	$98.10

Derivative_Assets_and_Liabilit1

Derivative Assets and Liabilities (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Investment securities	$289,645	$339,959

Partnership_Investments_Detail

Partnership Investments (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
Consolidated partnerships:
Cash and cash equivalents	$72,812,000	$35,285,000	$81,335,000	$39,078,000
Due to non-controlling interest in partnership investments	-1,737,000	-10,117,000
Total	-84,419,000	-109,070,000
Consolidated partnerships:
Consolidated partnerships:
Securities owned	107,488,000	103,079,000
Cash and cash equivalents	6,034,000	39,205,000
Receivables for securities sold	465,000	0
Other current assets	973,000	1,188,000
Exchange-traded option contracts, net	1,228,000	201,000
Total	116,188,000	143,673,000
Payables for securities purchased	-1,608,000	-2,256,000
Due to non-controlling interest in partnership investments	0	-7,719,000
Accrued expenses and other current liabilities	-129,000	-142,000
Total	-1,737,000	-10,117,000
Equity method investment in partnerships	26,000	50,000
Subsidiaries | Non-controlling Interest in Calamos Investments LLC
Consolidated partnerships:
Due to non-controlling interest in partnership investments		-7,700,000
Proceeds from partnership redemptions	$23,100,000

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (USD $)	3 Months Ended
	Sep. 30, 2014	Mar. 31, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Open-end funds		$250,300,000	$297,000,000
Securities and derivatives owned by partnership investments (Note 5)		116,214,000	143,723,000
Carrying value of long-term debt		46,000,000	46,000,000
Long-term debt fair value		53,400,000	54,200,000
Repayment of long-term debt	-46,200,000
Payment obligation associated with acquisition		1,700,000	1,700,000
Recurring | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents		26,213,000	1,209,000
Investment securities (Note 3)		285,389,000	337,927,000
Securities and derivatives owned by partnership investments (Note 5)			37,083,000
Fair Value, Net Asset (Liability)		350,235,000	373,251,000
Recurring | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) | Global Growth
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities (Note 3)		152,388,000	146,013,000
Recurring | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) | U.S. Growth
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities (Note 3)		75,456,000	112,526,000
Recurring | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) | Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities (Note 3)		5,019,000	12,218,000
Recurring | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) | Alternative
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities (Note 3)		31,764,000	42,031,000
Recurring | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) | Fixed Income/High Yield
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities (Note 3)		12,572,000	12,174,000
Recurring | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) | Convertible
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities (Note 3)		6,180,000	11,021,000
Recurring | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) | Multi-Strategy
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities (Note 3)		1,732,000	1,683,000
Recurring | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) | Total Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities (Note 3)		285,111,000	337,666,000
Recurring | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) | Common stock
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities (Note 3)		278,000	261,000
Securities and derivatives owned by partnership investments (Note 5)		26,671,000	26,237,000
Securities sold but not yet purchased (Note 3)		-856,000	-2,968,000
Recurring | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) | Preferred stocks
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities and derivatives owned by partnership investments (Note 5)		5,853,000	2,281,000
Recurring | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) | Convertible bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities and derivatives owned by partnership investments (Note 5)		0	0
Recurring | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities and derivatives owned by partnership investments (Note 5)		0	0
Recurring | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities and derivatives owned by partnership investments (Note 5)		1,228,000	7,851,000
Recurring | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) | Foreign currency
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities and derivatives owned by partnership investments (Note 5)		5,737,000	513,000
Recurring | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) | Exchange-traded put option contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities and derivatives owned by partnership investments (Note 5)		39,489,000	201,000
Recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents		0	0
Investment securities (Note 3)		5,112,000	5,000,000
Securities and derivatives owned by partnership investments (Note 5)			103,770,000
Fair Value, Net Asset (Liability)		80,331,000	108,770,000
Recurring | Significant Other Observable Inputs (Level 2) | Global Growth
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities (Note 3)		0	0
Recurring | Significant Other Observable Inputs (Level 2) | U.S. Growth
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities (Note 3)		0	0
Recurring | Significant Other Observable Inputs (Level 2) | Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities (Note 3)		0	0
Recurring | Significant Other Observable Inputs (Level 2) | Alternative
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities (Note 3)		0	0
Recurring | Significant Other Observable Inputs (Level 2) | Fixed Income/High Yield
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities (Note 3)		5,112,000	5,000,000
Recurring | Significant Other Observable Inputs (Level 2) | Convertible
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities (Note 3)		0	0
Recurring | Significant Other Observable Inputs (Level 2) | Multi-Strategy
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities (Note 3)		0	0
Recurring | Significant Other Observable Inputs (Level 2) | Total Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities (Note 3)		5,112,000	5,000,000
Recurring | Significant Other Observable Inputs (Level 2) | Common stock
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities (Note 3)		0	0
Securities and derivatives owned by partnership investments (Note 5)		28,256,000	25,166,000
Securities sold but not yet purchased (Note 3)		0	0
Recurring | Significant Other Observable Inputs (Level 2) | Preferred stocks
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities and derivatives owned by partnership investments (Note 5)		0	3,455,000
Recurring | Significant Other Observable Inputs (Level 2) | Convertible bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities and derivatives owned by partnership investments (Note 5)		42,661,000	41,119,000
Recurring | Significant Other Observable Inputs (Level 2) | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities and derivatives owned by partnership investments (Note 5)		4,047,000	4,821,000
Recurring | Significant Other Observable Inputs (Level 2) | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities and derivatives owned by partnership investments (Note 5)		0	29,209,000
Recurring | Significant Other Observable Inputs (Level 2) | Foreign currency
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities and derivatives owned by partnership investments (Note 5)		255,000	0
Recurring | Significant Other Observable Inputs (Level 2) | Exchange-traded put option contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities and derivatives owned by partnership investments (Note 5)		75,219,000	0
Fair Value | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents		26,213,000	1,209,000
Investment securities (Note 3)		290,501,000	342,927,000
Securities and derivatives owned by partnership investments (Note 5)			140,853,000
Fair Value, Net Asset (Liability)		430,566,000	482,021,000
Fair Value | Recurring | Global Growth
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities (Note 3)		152,388,000	146,013,000
Fair Value | Recurring | U.S. Growth
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities (Note 3)		75,456,000	112,526,000
Fair Value | Recurring | Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities (Note 3)		5,019,000	12,218,000
Fair Value | Recurring | Alternative
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities (Note 3)		31,764,000	42,031,000
Fair Value | Recurring | Fixed Income/High Yield
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities (Note 3)		17,684,000	17,174,000
Fair Value | Recurring | Convertible
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities (Note 3)		6,180,000	11,021,000
Fair Value | Recurring | Multi-Strategy
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities (Note 3)		1,732,000	1,683,000
Fair Value | Recurring | Total Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities (Note 3)		290,223,000	342,666,000
Fair Value | Recurring | Common stock
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities (Note 3)		278,000	261,000
Securities and derivatives owned by partnership investments (Note 5)		54,927,000	51,403,000
Securities sold but not yet purchased (Note 3)		-856,000	-2,968,000
Fair Value | Recurring | Preferred stocks
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities and derivatives owned by partnership investments (Note 5)		5,853,000	5,736,000
Fair Value | Recurring | Convertible bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities and derivatives owned by partnership investments (Note 5)		42,661,000	41,119,000
Fair Value | Recurring | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities and derivatives owned by partnership investments (Note 5)		4,047,000	4,821,000
Fair Value | Recurring | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities and derivatives owned by partnership investments (Note 5)		1,228,000	37,060,000
Fair Value | Recurring | Foreign currency
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities and derivatives owned by partnership investments (Note 5)		5,992,000	513,000
Fair Value | Recurring | Exchange-traded put option contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities and derivatives owned by partnership investments (Note 5)		$114,708,000	$201,000

Loans_Payable_Details

Loans Payable (Details) (Margin Loan)	Mar. 31, 2015
Margin Loan
Short-term Debt [Line Items]
Margin loan interest rate effective percentage rate, maximum (as a percent)	1.50%
Percentage of borrowing upon marginal securities, maximum (as a percent)	70.00%

Stock_Based_Compensation_Detai

Stock Based Compensation (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense recorded in connection with RSUs and stock options	$1,620,000	$2,045,000
Deferred tax assets	133,000		168,000
Total unrecognized compensation expense	22,500,000
Unrecognized compensation expense, expected weighted-average period to be recognized (in years)	3 years 2 months 0 days
Additional paid-in capital
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense recognized under stock incentive plans credited to additional paid-in capital	360,000	455,000
RSU
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units, granted (in shares)	780,649
Restricted stock units, forfeited (in shares)	139,037
Restricted stock units, vested (in shares)	193,486
Number of RSUs withheld for taxes (in shares)	36,045
Number of RSUs converted on a one-for-one basis for shares of company's Class A common stock (in shares)	157,441
Total intrinsic value and fair value of converted shares	2,100,000
Total tax benefit realized in connection with the vesting of RSUs	$240,000
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted (in shares)	0
Stock options forfeited (in shares)	251,806

NonOperating_Income_Details

Non-Operating Income (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Other Income and Expenses [Abstract]
Interest income	$44	$39
Interest expense	-774	-1,504
Net interest expense	-730	-1,465
Investment income	5,526	857
Dividend income	227	663
Miscellaneous other loss	-16	63
Investment and other income	5,737	1,583
Total non-operating income	$5,007	$118

Income_Taxes_Details

Income Taxes (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Income tax expense (benefit) [Abstract]
Income tax provision	$465	$1,362
Net income attributable to CAM	101	2,139
Income before taxes attributable to CAM	552	3,456
CAM’s effective income tax rate	81.70%	38.10%
Non-controlling Interest in Calamos Investments LLC
Income tax expense (benefit) [Abstract]
Income tax provision	-14	-45
Calamos Asset Management, Inc.
Income tax expense (benefit) [Abstract]
Income tax provision	$451	$1,317

Income_Taxes_Narrative_Details

Income Taxes - Narrative (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Income Tax Disclosure [Abstract]
CAM’s effective income tax rate	81.70%	38.10%
Expired employee stock options		$238
Capital loss carryforward			$456

Earnings_Per_Share_Details

Earnings Per Share (Details) (USD $)	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Earnings per share – basic:
Earnings available to common shareholders	$101	$2,139
Weighted average shares outstanding	17,872,357	19,079,163
Earnings per share – basic	$0.01	$0.11
Earnings per share – diluted:
Earnings available to common shareholders	$101	$2,139
Weighted average shares outstanding	17,872,357	19,079,163
Dilutive impact of restricted stock units	828,000	727,000
Weighted average shares outstanding	18,699,641	19,805,828
Earnings per share – diluted	$0.01	$0.11
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive (in shares)	28,809,308	33,146,128
Shares of Class A common stock issuable upon an Exchange of Calamos Interests’ ownership in Calamos Investments | Class A Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive (in shares)	27,631,947	31,167,271
Closing price of shares (in dollars per share)	$13.45	$12.93
Discount rate (as a percent)	12.00%	12.00%
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive (in shares)	1,177,361	1,978,857

Commitments_and_Contingencies_

Commitments and Contingencies (Details) (Purchase of Common Shares, USD $)	Mar. 27, 2015
Purchase of Common Shares
Other Commitments [Line Items]
Commitment to purchase shares	$20,000,000