Changes in Accumulated Other Comprehensive (Loss) Income (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	$ 2,207,018	$ 1,480,158	$ 1,522,354
Other comprehensive income (loss)	(39,464)	52,370	(5,814)
Balance	2,562,444	2,207,018	1,480,158
Foreign Currency Translation Reclassification Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	25,389	(23,514)
Other comprehensive loss before reclassifications, net of tax	(36,207)	48,903
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	0	0
Other comprehensive income (loss)	(36,207)	48,903
Balance	(10,818)	25,389	(23,514)
Unrealized Gains (Losses) on Marketable Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	6,954	3,480
Other comprehensive loss before reclassifications, net of tax	(2,255)	5,839
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	(995)	(2,365)
Other comprehensive income (loss)	(3,250)	3,474
Balance	3,704	6,954	3,480
Amortization of Prior Service Credit
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	1,173	1,180
Other comprehensive loss before reclassifications, net of tax	0	0
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	(7)	(7)	(148)
Other comprehensive income (loss)	(7)	(7)
Balance	1,166	1,173	1,180
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	33,516	(18,854)	(13,040)
Other comprehensive loss before reclassifications, net of tax	(38,462)	54,742
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	(1,002)	(2,372)	(838)
Other comprehensive income (loss)	(39,464)	52,370	(5,814)
Balance	$ (5,948)	$ 33,516	$ (18,854)