Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands			12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Schedule Of Allocation Of Income Tax Expense Benefit [Line Items]
Federal corporate tax rate			21.00%	21.00%	35.00%
Increase in income tax expense benefit			$ 1,000
Deferred tax assets and liabilities, net of valuation allowance					$ 2,400
Alternative minimum tax credit refund					2,600
Effective income tax rate reconciliation, repatriation of foreign earnings			87,100	$ 73,000
Unrecognized Tax Benefits	$ 163,980	$ 160,040	171,425	163,980	160,040	$ 151,100
Unrecognized tax benefits that might impact effective tax rate	164,000		171,400	164,000
Tax benefits	14,800	$ 9,200	(5,410)	(11,006)	(10,944)
Interest and penalties recorded			200	200	$ 300
Liability for uncertain tax positions	$ 900		1,100	$ 900
Deferred Tax Assets [Member]
Schedule Of Allocation Of Income Tax Expense Benefit [Line Items]
Unrecognized Tax Benefits			156,600
Other Noncurrent Liabilities [Member]
Schedule Of Allocation Of Income Tax Expense Benefit [Line Items]
Unrecognized Tax Benefits			14,800
BEAT [Member]
Schedule Of Allocation Of Income Tax Expense Benefit [Line Items]
Recognised provisional tax benefit			$ 3,900