Income Taxes - Summary of Provision (Benefit) for Income Taxes from Continuing Operations (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current:
Federal	$ 5,080	$ 6,442	$ 5,833
State	89	2,030	921
Current income tax expense	5,169	8,472	6,754
Deferred:
Federal	6,310	85	1,854
State	(2,271)	(1,770)	1,044
Deferred income taxes	4,039	(1,685)	2,898
Total provision	$ 9,208	$ 6,787	$ 9,652