DERIVATIVES - Non-Designated Hedges (Details) - Interest rate swaps - Non-Designated Hedges - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Derivatives
Notional amounts	$ 199,641	$ 147,967
Weighted average pay rates (as a percent)	4.40%	3.96%
Weighted average receive rates (as a percent)	4.40%	3.96%
Weighted average maturity	12 years 5 months 27 days	12 years 4 months 13 days
Fair value of combined interest rate swaps	$ 0	$ 0