Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended			12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2017
Investments, Owned, Federal Income Tax Note [Line Items]
Effective Income Tax Rate Reconciliation, Repatriation of Foreign Earnings, Amount		$ 3,300
Income Tax Expense (Benefit)	$ (27,613)		$ (40,857)
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%			35.00%
Undistributed Earnings of Foreign Subsidiaries		20,900		$ 20,900
Document Period End Date	Mar. 31, 2018
Tax Cuts and Jobs Act 2017 [Member]
Investments, Owned, Federal Income Tax Note [Line Items]
Deferred Tax Liabilities, Deferred Expense		124,200		$ 124,200
Income Tax Expense (Benefit)		$ 120,900