Condensed Consolidated Statement Of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 67,889	$ 13,186	$ 142,009	$ 41,400
Other comprehensive (loss) income:
Net foreign currency translation adjustment	1,507	1,239	(2,082)	(3,501)
Actuarial gain on pension plans	933	6,299	933	6,299
Unrealized gain on fair value of derivative instruments	0	442	0	1,642
Total comprehensive income	$ 70,329	$ 21,166	$ 140,860	$ 45,840