CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Comprehensive Income [Abstract]
Net income	$ 117,365		$ 75,595		$ 69,675
Other comprehensive income/(loss), net of tax:
Foreign currency translation	20		(28)		8
Net unrealized gains/(losses) on securities available for sale (a)	3,919	[1]	3,808	[1]	(2,877)	[1]
Other comprehensive income/(loss)	3,939		3,780		(2,869)
Comprehensive income	121,304		79,375		66,806
Less: Comprehensive income/(loss) attributable to noncontrolling interests	(512)		(56)		7
Comprehensive income attributable to GAMCO Investors, Inc.	$ 120,792		$ 79,319		$ 66,813

[1] Net of income tax expense of $2,236 for 2012, income tax benefit of ($1,690) for 2011 and income tax expense of $3,710 for 2010.