Income Taxes Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Deferred Tax Assets, Operating Loss Carryforwards	$ 48,294	$ 78,650
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits	59,697	39,992
Deferred Tax Assets, Goodwill and Intangible Assets	0	1,042
Deferred Tax Assets, Investments	0	5,776
Deferred Tax Assets, Tax Credit Carryforwards, Foreign	9,036	4,419
Deferred Tax Assets, Acquired Lease Liability	2,098	3,473
Deferred Tax Assets, Other	2,444	2,696
Deferred Tax Assets, Gross	121,569	136,048
Deferred Tax Assets, Valuation Allowance	9,135	2,103
Deferred Tax Assets, Net of Valuation Allowance	112,434	133,945
Deferred Tax Liabilities, Unrealized Gains on Trading Securities	13,092	7,523
Deferred Tax Liabilities, Other	4,643	6,402
Deferred Tax Liabilities, Intangible Assets	1,642	3,697
Deferred Tax Liabilities, Gross	19,377	17,622
Deferred Income Tax Expense (Benefit)	18,965	41,170	$ (22,594)
Preferred stock dividends declared	6,792	6,792	$ 6,792
Deferred tax assets/(liabilities), net	$ 93,057	$ 116,323