Income Taxes Narrative (Details) - USD ($) $ in Thousands	12 Months Ended			60 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2022	Dec. 30, 2017	Dec. 31, 2014
Effective Income Tax Rate Reconciliation, Percent	55.20%	58.60%	59.60%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	35.00%
Deferred Tax Assets, Valuation Allowance	$ 285,784	$ 249,560	$ 235,339			$ 257,728
Deferred Tax Assets, Tax Credit Carryforwards, Alternative Minimum Tax	3,300
Deferred Tax Assets, Tax Credit Carryforwards, Foreign	49,300
Deferred Tax Assets, Tax Credit Carryforwards, General Business	3,700
Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Percent				25.00%
Deferred Tax Assets, Net of Valuation Allowance	77,115	116,833			$ 10,000
Undistributed Earnings of Foreign Subsidiaries and Foreign Corporate Joint Ventures [Member]
Undistributed Earnings of Foreign Subsidiaries	$ 5,200	$ 4,900
Tax Cuts and Jobs Act [Domain]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%
Tax Adjustments, Settlements, and Unusual Provisions	$ 30,400