Income Taxes - Reconciliation of Differences between Income Tax Provision (Benefit) and Income Tax Determined by Applying US Federal Statutory Rate (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Effective Income Tax Rate Reconciliation, Amount [Abstract]
U.S. Federal statutory taxes	$ 26,876	$ 23,432	$ 8,417
State and local taxes, net of U.S. Federal benefit	2,806	2,856	1,061
Permanent items	1,308	249	225
Domestic production activities deduction	(2,262)	(1,117)
Federal credits	(328)	(214)	(566)
Other	172	(43)	244
Increase (decrease) in valuation allowance	117	264	(19,930)
Total income tax provision (benefit)	$ 28,689	$ 25,427	$ (10,549)