Related Parties (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
Related Party Transaction [Line Items]
Subordinated Borrowings	$ 6,799		$ 6,799		$ 16,550
Other Assets [Member]
Related Party Transaction [Line Items]
Due from Related Parties, Noncurrent	12,803		12,803		$ 17,862
Investment Management [Member] | Private Equity Fund [Member]
Related Party Transaction [Line Items]
Revenue from Related Parties	$ (14)	$ 1,433	$ (96)	$ 10,182
Investment Banking [Member] | Director [Member]
Related Party Transaction [Line Items]
Revenue from Related Parties		$ 11,981		$ 13,282