PREMISES AND EQUIPMENT - Lease Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2019
Property, Plant and Equipment [Abstract]
Lease liabilities			$ 14.8
Right-of-use assets			$ 13.5
Finance lease, weighted average remaining lease term			2 years 8 months 12 days
Finance lease, weighted average discount rate			2.80%
Operating lease lease, weighted average remaining lease term			11 years 9 months 18 days
Operating lease, weighted average discount rate			3.54%
Rent expense	$ 2.0	$ 2.0
Leases not yet commenced, lease liabilities			$ 2.4
Leases not yet commenced, right of use assets			$ 4.1