Condensed Consolidated Statement Of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 63,401	$ 68,347	$ 205,410	$ 109,747
Other comprehensive (loss) income:
Net foreign currency translation adjustment	(1,793)	3,399	(3,875)	(102)
Actuarial gain on pension plans	0	0	933	6,299
Unrealized gain on fair value of derivative instruments	0	0	0	1,642
Total comprehensive income	$ 61,608	$ 71,746	$ 202,468	$ 117,586