Commitments And Contingencies (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Loss Contingencies [Line Items]
Rent expense	$ 1,305	$ 1,660	$ 2,619
Sublease income	731	784	304
Income Tax Examination, Estimate of Possible Loss			4,683
Principal Transactions and Other Income	$ 78	$ 7,979	(6,668)
Guarantee Obligations [Member]
Loss Contingencies [Line Items]
Guarantee liability				$ 1,084
Principal Transactions and Other Income			$ 1,084