Income Taxes - Provision for Income Taxes from Continuing Operations (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current:
Federal	$ 18,307	$ 13,939	$ 7,616
State	3,472	2,989	1,369
Current Income Tax Expense (Benefit), Total	21,779	16,928	8,985
Deferred:
Federal	(338)	(1,255)	(676)
State	(267)	(260)	298
Deferred Income Tax Expense (Benefit), Total	(605)	(1,515)	(378)
Total tax expense	$ 21,174	$ 15,413	$ 8,607