Long-Term Investments (Equity-Method Investments) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Schedule of Equity Method Investments [Line Items]
Investments accounted for under the equity method	$ 14,026		$ 14,026		$ 17,721
Proceeds from long-term equity method investment			847	$ 834
Equity in losses from investments	303	$ 1,526	2,823	$ 2,108
Indian Creek Investors LP (“Indian Creek”)
Schedule of Equity Method Investments [Line Items]
Investments accounted for under the equity method	$ 2,871		$ 2,871		5,248
Equity-method ownership percentage	20.04%		20.04%
Boyar Value Fund (“Boyar”)
Schedule of Equity Method Investments [Line Items]
Investments accounted for under the equity method	$ 8,475		$ 8,475		7,816
Equity-method ownership percentage	32.43%		32.43%
Quoted market value	$ 8,475		$ 8,475
Ladenburg Thalmann Financial Services Inc. (“LTS”)
Schedule of Equity Method Investments [Line Items]
Investments accounted for under the equity method	$ 2,680		$ 2,680		4,657
Equity-method ownership percentage	7.75%		7.75%
Quoted market value	$ 43,751		$ 43,751
Castle Brands, Inc. (“Castle”)
Schedule of Equity Method Investments [Line Items]
Investments accounted for under the equity method	$ 0		$ 0		$ 0
Equity-method ownership percentage	7.88%		7.88%
Quoted market value	$ 16,979		$ 16,979