Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Tax Contingency [Line Items]
Effective tax rate	21.90%	33.00%
Income tax expense (benefit)	$ 10,415	$ 13,747
Decrease in effective tax rate due to increase in domestic production activities deduction	11.10%
Statutory tax rate, percentage	21.00%
Excess tax benefits from stock based awards	$ 1,700	$ 1,000
Valuation allowance	$ 2,800
Earliest Tax Year [Member] | Federal Tax Jurisdiction [Member]
Income Tax Contingency [Line Items]
Tax years subject to examination	2014
Latest Tax Year [Member] | Federal Tax Jurisdiction [Member]
Income Tax Contingency [Line Items]
Tax years subject to examination	2017