Intangible Asset Amortization and Other Business Developments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	May 08, 2017
Subsequent Event [Member] | Goodwill [Member]
Business Acquisition [Line Items]
Assets Held for Sale			$ 28,500
Subsequent Event [Member] | Deferred Revenue [Member]
Business Acquisition [Line Items]
Liabilities Held for Sale			$ 400
Investment Banking [Member]
Business Acquisition [Line Items]
Amortization of Intangible Assets	$ 2,357	$ 3,215
Investment Management [Member]
Business Acquisition [Line Items]
Amortization of Intangible Assets	$ 118	$ 199