Income Taxes - Summary of Reconciliation Between Income Taxes and Effective Income Tax Provision (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Provision at federal statutory rate	$ 26,222	$ 30,087	$ 28,430
State income taxes, net	2,418	2,229	2,426
Nondeductible business expenses	462	696	589
Tax credits	(1,278)	(1,532)	(1,434)
Other, net	(929)	(533)	(774)
Total income tax provision	$ 26,895	$ 30,947	$ 29,237