Document And Entity Information (USD $)	6 Months Ended
	Jun. 30, 2011	Jul. 31, 2011
Entity Registrant Name	GAMCO INVESTORS, INC. ET AL
Entity Central Index Key	0001060349
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	No
Entity Filer Category	Accelerated Filer
Entity Public Float	$ 307,699,443
Entity Common Stock, Shares Outstanding		6,644,812
Document Fiscal Year Focus	2011
Document Fiscal Period Focus	Q2
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Aug. 03, 2011