CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME UNAUDITED - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME UNAUDITED [Abstract]
Net income		$ 30,861	$ 14,969	$ 84,429	$ 63,846
Other comprehensive loss, net of tax:
Foreign currency translation		(28)	(35)	(121)	(22)
Net unrealized losses on securities available for sale	[1]	506	(6,696)	323	(7,417)
Other comprehensive loss		478	(6,731)	202	(7,439)
Comprehensive income attributable to GAMCO Investors, Inc.		$ 31,339	$ 8,238	$ 84,631	$ 56,407

[1] Net of income tax expense/(benefit) of ($1,624), ($150), ($107) and ($424), respectively.