FAIR VALUES OF FINANCIAL INSTRUMENTS - Fair Value Option Loans Held-for-Sale (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Fair Value
Total loans	$ 498,054		$ 498,054		$ 379,155
Nonaccrual loans	43,194		43,194		19,576
Loans past due 90 days or more and still accruing	0		0		0
Unpaid Principal Balance
Total loans	479,880		479,880		368,039
Nonaccrual loans	43,551		43,551		19,955
Loans past due 90 days or more and still accruing	0		0		0
Difference
Total loans	18,174		18,174		11,116
Nonaccrual loans	(357)		(357)		(379)
Loans past due 90 days or more and still accruing	0		0		$ 0
Net gains from fair value changes	$ 15,686	$ 12,692	$ 16,856	$ 12,593