Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Tax [Line Items]
Effective tax rate	29.20%	36.70%	26.50%	36.70%
Accounting Standards Update (“ASU”) 2016-09 [Member]
Income Tax [Line Items]
Excess tax benefit from option exercises recognized as a reduction to income tax expense	$ 16,464		$ 36,364
Excess tax benefit recognized		$ 2,394		$ 8,678