LOANS AND ALLOWANCE FOR CREDIT LOSSES - Troubled Debt Restructurings Additional Information (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020 USD ($) loan	Jun. 30, 2019 loan	Jun. 30, 2020 USD ($) loan	Jun. 30, 2019 loan	Dec. 31, 2019 USD ($)
Receivables [Abstract]
Commitments to lend to customers with outstanding loans classified as TDRs	$ 135		$ 135		$ 135
Accruing TDRs	5,600		5,600		6,600
Nonaccruing TDRs	$ 20,300		$ 20,300		$ 15,200
Number of loans modified that had payments default during the period | loan	1	0	1	0