INCOME TAX - Income tax expense - (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income tax expense
Currently payable	$ 4,726	$ 4,578	$ 3,616
Deferred	5,697	5,950	1,589
Change in valuation allowance	(190)	(2,749)	114
Total income tax expense	$ 10,233	$ 7,779	$ 5,319