Income Taxes - Summary of Income Tax Provision from Continuing Operations Resulted in Effective Tax Rates (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income tax expense at federal statutory rate									$ 30,487	$ 44,731	$ 36,885
State income taxes, net of federal benefit									781	6,075	1,587
Benefit from lower foreign tax rates									(8,500)	(7,827)	(5,973)
Valuation allowance on foreign tax credits and net operating loss carryforward									253	254	2,326
Other expenses not deductible for tax purposes									2,466	3,082	2,719
Adjustment to reserve for uncertain tax positions									456	(3,547)	658
Impact of 2017 U.S. tax reform — deferred tax									(63,525)	0	0
Impact of 2017 U.S. tax reform — transition tax									18,655	0	0
Other adjustments, net									(1,930)	(485)	1,131
Income tax provision	$ (38,458)	$ 9,197	$ 527	$ 7,877	$ (1,832)	$ 10,292	$ 15,437	$ 18,386	$ (20,857)	$ 42,283	$ 39,333