Income Taxes (Net operating loss carryforwards) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Loss Carryforwards and other details [Abstract]
Undistributed earnings of foreign subsidiaries	$ 1,100,000
U.S. Federal
Loss Carryforwards and other details [Abstract]
Operating loss carryforwards	220,445	$ 292,715
Tax credit carryforward	12,600
U.S. State
Loss Carryforwards and other details [Abstract]
Operating loss carryforwards	121,095	138,218
Foreign
Loss Carryforwards and other details [Abstract]
Operating loss carryforwards	2,967	$ 3,378
Repatriation of earnings estimated tax impact	$ 80,500