Income Taxes Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Taxes [Line Items]
Effective income tax rate reconciliation, at federal statutory income tax rate, percent		35.00%	35.00%	35.00%
Net income tax benefit		$ 13,894
Income tax benefit from lower foreign tax rates		25,374
Tax Cuts and Jobs Act
Income Taxes [Line Items]
Deferred income tax benefit from change in tax rate		116,200
Tax Cuts and Jobs Act - Provisional
Income Taxes [Line Items]
Net income tax benefit		13,894
Deferred tax asset reversal, foreign income tax credits		70,200
Current income tax expense, mandatory tax on undistributed earnings		32,100
Income tax benefit from lower foreign tax rates		$ 25,374
Forecast
Income Taxes [Line Items]
Effective income tax rate reconciliation, at federal statutory income tax rate, percent	21.00%