Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating Loss Carryforwards [Line Items]
NOLs to offset federal minimum taxable income	$ 575,300
Valuation allowance	97,177	$ 110,404
Undistributed earnings of foreign subsidiaries	205,000
Deferred tax liability not recorded on earnings of foreign subsidiaries permanently invested abroad	59,000
Increase (decrease) in valuation allowance	13,227	$ 22,203	$ (12,287)
Expected decrease in unrecognized tax benefit related to uncertain tax position over next 12 months	4,300
Subsidiary [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	2,100,000
Consolidated Tax Group [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	1,600,000
Jefferies [Member]
Operating Loss Carryforwards [Line Items]
Increase (decrease) in valuation allowance			$ 11,100
Foreign Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	74,400
Valuation allowance	$ 7,200