Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ (235,400)	$ 88,100	$ (240,800)	$ 136,500
Other comprehensive income, net of tax:
Foreign currency translation adjustments	10,500	2,900	(14,600)	(800)
Unrealized loss on derivative instruments	(2,100)	(4,000)	(12,400)	(6,500)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	0	100	100	(500)
Comprehensive income (loss)	(227,000)	87,200	(267,700)	128,800
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest	0	100	0	100
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	$ (227,000)	$ 87,100	$ (267,700)	$ 128,700