Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Taxes [Line Items]
Effective Income Tax Rate			19.25%	20.00%	35.00%
Tax Cuts and Jobs Act of 2017 (the "Act"), income tax benefit	$ (22,500)
Tax Cuts and Jobs Act of 2017 (the "Act"), provisional amount related to the remeasurement of certain deferred tax assets and liabilities	22,300
Tax Cuts and Jobs Act of 2017 (the "Act"), one-time transition tax on the mandatory deemed repatriation of foreign earnings	200
Tax Cuts and Jobs Act of 2017 (the "Act"), cumulative foreign earnings	32,400		$ 32,400
Deferred tax liability	333,044		333,044	$ 458,256
Income tax examination, Increase (decrease) in liability from prior year	(29,600)		(29,600)	(28,400)
Unrecognized tax benefits net of offsetting assets	148,600		148,600	108,700
Liability related to uncertain tax position inclusive interest and penalties	178,200		178,200	137,200
Net acquired uncertain tax position			37,900
Anticipated payment of tax liabilities related to interest and penalty accrual	4,000		4,000	$ 9,200
Unrecognized tax benefits arising from U.S. Federal and state tax			$ 15,600
Scenario Forecast
Income Taxes [Line Items]
Effective Income Tax Rate		21.00%
UNITED KINGDOM
Income Taxes [Line Items]
Statutory foreign income tax expense (benefit)			19.25%	20.00%
ISRAEL
Income Taxes [Line Items]
Earnings exempted associated with foreign subsidiary	18,600		$ 18,600
Foreign Subsidiaries
Income Taxes [Line Items]
Deferred tax liability	$ 2,700		$ 2,700