FAIR VALUES OF FINANCIAL INSTRUMENTS - Fair Value Option Loans Held-for-Sale (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Fair Value
Total loans	$ 416,974	$ 379,155
Nonaccrual loans	54,151	19,576
Loans past due 90 days or more and still accruing	0	0
Unpaid Principal Balance
Total loans	407,889	368,039
Nonaccrual loans	54,824	19,955
Loans past due 90 days or more and still accruing	0	0
Difference
Total loans	9,085	11,116
Nonaccrual loans	(673)	(379)
Loans past due 90 days or more and still accruing	0	0
Net gains from fair value changes	$ 7,365	$ 11,326	$ 10,875