Income Taxes - Reconciliation of Differences between Income Tax Provision and Income Tax Determined by Applying US Federal Statutory Rate (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Effective Income Tax Rate Reconciliation, Amount [Abstract]
U.S. Federal statutory taxes	$ 35,990	$ 26,876	$ 23,432
State and local taxes, net of U.S. Federal benefit	3,747	2,806	2,856
Permanent items	396	1,308	249
Excess tax benefits from vesting or settlement of stock compensation awards	(1,749)
Domestic production activities deduction	(2,740)	(2,262)	(1,117)
Federal credits	(488)	(328)	(214)
Other	(173)	289	221
Total income tax provision	$ 34,983	$ 28,689	$ 25,427