Income Taxes - Narrative (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Taxes [Line Items]
Tax Act, one-time net tax benefits	$ 70,100
Tax Act, benefits associated with re-measurement of deferred tax assets and liabilities	85,300
Tax Act, transition tax expense on post-1986 earnings and profits of certain foreign subsidiaries	15,200
Tax Act, benefit associated with entity restructuring and recapitalization	26,700
Tax Act, expense associated with acceleration of certain deductions	8,500
Valuation allowance for deferred income tax assets	19,328	$ 14,991	$ 16,100
Change in total valuation allowance	4,300	(1,100)	3,100
Tax effect of state and foreign net operating loss carryforwards	62,925	37,362
2018	200
2019	100
2020	1,900
2021	100
2022	200
Thereafter	65,400
Valuation allowance foreign and state net operating loss carryforwards	17,800
Reduction due to expiration of certain federal and state statutes of limitations	8,252	23,448	282
Interest and penalties expense (income) in the provision for income taxes	(200)	$ (3,200)	$ 2,400
Gross Amount Before Balance Sheet Presentation Netting
Income Taxes [Line Items]
Tax effect of state and foreign net operating loss carryforwards	$ 67,900