DERIVATIVES (Details) - Interest rate swaps - Derivative designated as a cash flow hedge - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Derivatives
Notional amounts	$ 290,000	$ 175,000
Weighted average pay rates (as a percent)	1.78%	1.61%
Weighted average receive rates (as a percent)	1.33%	0.95%
Weighted average maturity	2 years 10 months 21 days	2 years 11 months 23 days