Business Changes and Developments Intangible Assets Associated With Acquisitions (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 62,764	$ 103,279
Intangible Assets, accumulated amortization	21,754	33,735
Investment Banking [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	56,020	53,255
Intangible Assets, accumulated amortization	18,088	4,254
Investment Management [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	6,744	50,024
Intangible Assets, accumulated amortization	3,666	29,481
Client Related [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	56,830	93,630
Intangible Assets, accumulated amortization	20,592	31,116
Client Related [Member] | Investment Banking [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	50,700	47,800
Intangible Assets, accumulated amortization	17,201	4,006
Client Related [Member] | Investment Management [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	6,130	45,830
Intangible Assets, accumulated amortization	3,391	27,110
Non Compete Non Solicit Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	169	2,084
Intangible Assets, accumulated amortization	108	1,830
Non Compete Non Solicit Agreements [Member] | Investment Banking [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	0	135
Intangible Assets, accumulated amortization	0	121
Non Compete Non Solicit Agreements [Member] | Investment Management [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	169	1,949
Intangible Assets, accumulated amortization	108	1,709
Other Intangible Assets Associated With Acquisition [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	5,765	7,565
Intangible Assets, accumulated amortization	1,054	789
Other Intangible Assets Associated With Acquisition [Member] | Investment Banking [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	5,320	5,320
Intangible Assets, accumulated amortization	887	127
Other Intangible Assets Associated With Acquisition [Member] | Investment Management [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	445	2,245
Intangible Assets, accumulated amortization	$ 167	$ 662