Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 92,540	$ 62,041	$ 148,254	$ 59,130
Other comprehensive income, net of tax:
Foreign currency translation adjustments	(24,881)	17,020	(13,903)	30,436
Unrealized gain (loss) on derivative instruments	580	(1,397)	5,109	(1,041)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	45	0
Comprehensive income	$ 68,284	$ 77,664	$ 139,590	$ 88,525