Goodwill and Intangibles (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill impairment	$ 0	$ 0	$ 0	$ 0
Concept (Cowen Prime)
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill, Acquired During Period			9,300,000
Finite-lived Intangible Assets Acquired			$ 8,500,000
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life			7 years 8 months 12 days
Amortization of Intangible Assets	$ 0		$ 100,000
Minimum | Concept (Cowen Prime)
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life			1 year
Maximum | Concept (Cowen Prime)
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life			9 years