Income Taxes - Income Tax Expense (Benefit), Continuing Operations (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Current:
Federal	$ 22,265	$ 15,782	$ 4,140
State	4,632	2,527	449
Deferred	1,951	250	1,046
Income tax expense (benefit)	$ 28,848	$ 18,559	$ 5,635