Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 88,388	$ 95,529	$ 224,929	$ 243,783
Other comprehensive income, net of tax:
Foreign currency translation adjustments	(12,385)	1,804	(13,189)	(12,099)
Unrealized gain (loss) on derivative instruments	(449)	(2,111)	(6,948)	2,998
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	63	66	(481)	196
Comprehensive income	75,617	95,288	204,411	234,878
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest	0	0	100	0
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	$ 75,617	$ 95,288	$ 204,311	$ 234,878