FAIR VALUE - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Provision for Loan and Lease Losses	$ 200	$ 1,900	$ 1,400	$ 3,650
Assets measured at fair value on non-recurring basis
Outstanding balance of impaired loans with an allowance recorded	0		0		$ 1,708
Valuation allowance on impaired loans	0		0		1,708
Other real estate	$ 175		$ 175
Non-recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Provision for Loan and Lease Losses					$ 1,700