Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Income tax expense	$ (43,666)	$ (40,124)	$ (133,092)	$ (173,399)
Effective tax rate	27.00%	31.00%	26.00%	34.00%
Federal statutory rate			21.00%	35.00%
Undistributed Earnings of Foreign Subsidiaries	$ (5,600)	$ (5,500)	$ 600	$ 1,200
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount	3,400	2,400	9,500	8,400
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount		8,400	15,800	900
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount			8,300
Effective Income Tax Rate Reconciliation, Other Reconciling Items, Amount		600		(2,000)
Effective Income Tax Rate Reconciliation, Deduction, Qualified Production Activity, Amount		$ 2,800		$ 13,100
Deferred Tax Assets, Tax Credit Carryforwards, Foreign	15,600		15,600
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount			(15,600)
Second component of tax deductible goodwill, net of tax	$ 1,000		$ 1,000