Income Tax - Reconciliation of U.S. Statutory Income Tax Rate to Effective Income Tax Rate (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Federal income tax expense at statutory rate	$ 37,949	$ 33,064	$ 23,037
State income tax, net of federal income tax benefit	3,715	2,867	2,371
Non-deductible business expenses	2,414	1,485	1,110
Qualified manufacturing activities	(466)	(1,720)
Other, net	(57)	(169)	200
Income tax expense benefit	$ 43,555	$ 35,527	$ 26,718