Income Tax - Reconciliation of U.S. Statutory Income Tax Rate to Effective Income Tax Rate (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]
Federal income tax expense at statutory rate	$ 23,037	$ 18,854	$ 15,440
State income tax, net of federal income tax benefit	2,371	1,365	1,238
Non-deductible business expenses	1,110	1,087	918
Qualified manufacturing activities		(717)	(840)
Research and development credit			(177)
Other, net	200	285	(23)
Income tax expense benefit	$ 26,718	$ 20,874	$ 16,556