Income Taxes Reconciliation of Effective Tax Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount	$ 36,199	$ 69,348	$ 44,826
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount	2,372	1,794	963
Valuation Allowance, Deferred Tax Asset, Change in Amount	(1,300)
EffectiveIncomeTaxRateReconciliationTaxCutsandJobsActof2017TransitionTax	1,174	61,690	0
Effective Income Tax Rate Reconciliation, Tax Cuts and Jobs Act of 2017, Change in tax rate, Percent	(652)	11,177	0
Effective Income Tax Rate Reconciliation, Tax Credit, Other, Amount	0	(33,837)	0
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-based Compensation Cost, Amount	(974)	(5,263)	1,117
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-based Compensation Cost, Amount	13,064	0	0
Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Amount	(19,162)	(47,482)	(31,651)
Effective Income Tax Reconciliation, Uncertain Tax Position Reserves, net	(3,088)	4,948	1,636
Effective Income Tax Rate Reconciliation, Unremitted Earnings, Amount	2,564	0	0
Effective Income Tax Rate Reconciliation, Other Adjustments, Amount	3,574	373	(1,268)
Income Tax Expense (Benefit)	25,227	62,090	11,128
Effective Income Tax Rate Reconciliation, Tax Credit, Amount	$ (9,844)	$ (658)	$ (4,495)