Accumulated Other Comprehensive Income (Loss) - Schedule of Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance, Value	$ 1,596,610	$ 1,641,240	$ 1,580,664
Other comprehensive income (loss), net of tax:	(7,496)	(24,942)	35,197
Ending balance, Value	1,975,430	1,596,610	1,641,240
Foreign Currency Translation [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance, Value	(118,441)	(93,319)
Other comprehensive income (loss) before reclassifications, net of tax	(7,773)	(25,122)
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	0	0
Other comprehensive income (loss), net of tax:	(7,773)	(25,122)
Ending balance, Value	(126,214)	(118,441)	(93,319)
Unrealized Gains (Losses) on Available-For-Sale Marketable Debt Securities [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance, Value	2	(178)
Other comprehensive income (loss) before reclassifications, net of tax	277	180
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	0	0
Other comprehensive income (loss), net of tax:	277	180
Ending balance, Value	279	2	(178)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance, Value	(118,439)	(93,497)	(128,694)
Other comprehensive income (loss) before reclassifications, net of tax	(7,496)	(24,942)
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	0	0
Other comprehensive income (loss), net of tax:	(7,496)	(24,942)	35,197
Ending balance, Value	$ (125,935)	$ (118,439)	$ (93,497)