Income Taxes - A Reconciliation of the Provision for income taxes from continuing operations (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Expected provision at federal statutory rate									$ 13,446	$ 9,116	$ (2,282)
State income taxes, net									1,714	709	(705)
Change in valuation allowance									(2,385)	(7,618)	2,222
Domestic production activity deduction									(1,002)	0	0
Other									454	58	51
Total	$ 3,527	$ 1,042	$ 4,599	$ 3,059	$ 3,267	$ (1,169)	$ 86	$ 81	$ 12,227	$ 2,265	$ (714)
Effective tax rate									31.80%	8.70%	10.90%