INCOME TAXES - Components of provision for income taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current provision:
Federal	$ 7,263	$ 5,056	$ 4,275
State	261	300	143
Deferred (benefit) provision:
Federal	(507)	1,256	(762)
State	(355)	53	(43)
Total income tax provision	$ 6,662	$ 6,665	$ 3,613