Income Taxes - Reconciliation of Income Tax Expense With Expected Amounts Based Upon Statutory Federal Tax Rates (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Expected federal income tax at statutory rate	$ 66,790	$ 53,431	$ 64,656
State income taxes before valuation allowance, net of federal tax effect	(1,563)	605	(1,376)
Effect of foreign source income	(1,362)	2,359	(27,581)
Tax contingencies	1,785	468	2,816
Valuation allowance	2,051	527	3,195
U.S. federal research credit	(6,514)	(2,263)	(4,881)
Equity compensation	(1,411)	(3,826)	(2,321)
Transition Tax Due To 2017 Tax Act	0	89	72,993
Remeasurement of Deferred Tax Assets Due To 2017 Tax Act	0	619	(10,248)
Incremental Taxes on Unremitted Foreign Earnings Release Due To 2017 Tax Act	0	0	3,968
Foreign derived intangible income	(7,851)	(4,846)	0
Legal entity restructuring foreign tax credit	0	(25,080)	0
Legal entity restructuring dividends received deduction	9,398	(9,398)	0
Other items, net	1,866	992	(1,556)
Income tax expense	$ 63,189	$ 13,677	$ 99,665