Related Party Transactions (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Related Party Transaction [Line Items]
Percentage of ownership (in hundredths)	55.00%
GGCP Holdings LLC [Member] | Common Class B [Member]
Related Party Transaction [Line Items]
Ownership percentage of voting rights (in hundredths)	93.00%
Percentage of ownership (in hundredths)	72.00%
Entity controlled by members of the Chairman's family [Member]
Capital Lease [Abstract]
Area of lease space (in square feet)	60,000
LICT Corporation [Member]
Capital Lease [Abstract]
Area of lease space (in square feet)	3,300
Sublease rental base rate	$ 116,527	$ 114,716	$ 119,025
Sublease rental base rate (in dollars per square foot)	28
Sublease rental rate for utilities and taxes on sublease property (in dollars per square foot)	3
Teton [Member]
Capital Lease [Abstract]
Area of lease space (in square feet)	1,600
Sublease rental base rate	68,189	67,361	69,330
Sublease rental base rate (in dollars per square foot)	37.75
Sublease rental rate for utilities and taxes on sublease property (in dollars per square foot)	3
MJG Associates, Inc [Member] | G B L [Member] | Advisory fees [Member]
Investment Advisory Services [Abstract]
Revenue from related parties	10,000	10,000	10,000
Manhattan Partners I, L.P [Member] | G B L [Member] | Management fee [Member]
Investment Advisory Services [Abstract]
Fees paid	0	0	10,665
Manhattan Partners I, L.P [Member] | G B L [Member] | Advisory fees [Member]
Investment Advisory Services [Abstract]
Revenue from related parties	21,601	21,660	19,608
S.W.A.N. Partners, LP [Member] | G B L [Member] | Advisory fees [Member]
Investment Advisory Services [Abstract]
Revenue from related parties	32,740	35,649	36,466
GSI [Member]
Related Party Transaction [Line Items]
Percentage of ownership (in hundredths)	45.00%
GSI [Member] | Management fee [Member]
Investment Advisory Services [Abstract]
Revenue from related parties				45,928
Fees paid				15,680
GSI [Member] | Incentive fees from related party [Member]
Investment Advisory Services [Abstract]
Revenue from related parties	31,217	0		61,808
Fees paid				28,197
GSI [Member] | Gabelli Global Partners Ltd [Member] | Advisory fees [Member]
Investment Advisory Services [Abstract]
Due from Affiliates	0	59,390
GSI [Member] | Gemini Capital Management, LLC [Member] | Management fee [Member]
Investment Advisory Services [Abstract]
Revenue from related parties	148,909	80,761	45,668
Gabelli International Gold Fund Limited [Member] | Management fee [Member]
Investment Advisory Services [Abstract]
Revenue from related parties	13,478	23,192	32,203
Due to Affiliate	50,639	11,957
Gabelli International Gold Fund Limited [Member] | Incentive fees from related party [Member]
Investment Advisory Services [Abstract]
Revenue from related parties	0	0	0	0
Gemini Capital Management, LLC [Member] | Gabelli Global Partners Ltd [Member] | Incentive fees from related party [Member]
Investment Advisory Services [Abstract]
Revenue from related parties	15,018	0	0
Gemini Capital Management, LLC [Member] | Gabelli Global Partners Ltd [Member] | Advisory fees [Member]
Investment Advisory Services [Abstract]
Due from Affiliates	36,418	36,257
Gemini Capital Management, LLC [Member] | Gemini Capital Management, LLC [Member] | Management fee [Member]
Investment Advisory Services [Abstract]
Revenue from related parties	76,776	76,548	88,904
Affiliated funds [Member] | G B L [Member] | Advisory fees [Member]
Investment Advisory Services [Abstract]
Revenue from related parties	900,000	1,000,000	1,400,000
Affiliated funds [Member] | G.distributors, LLC [Member] | Advisory and distribution fees [Member]
Investment Advisory Services [Abstract]
Revenue from related parties	37,200,000	30,200,000
Affiliated funds [Member] | G.distributors, LLC [Member] | Distribution fees [Member]
Investment Advisory Services [Abstract]
Revenue from related parties	$ 12,000	$ 13,000	$ 15,000