LOANS AND ALLOWANCE FOR CREDIT LOSSES - Troubled Debt Restructurings Additional Information (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($) loan	Sep. 30, 2019 loan	Sep. 30, 2020 USD ($) loan	Sep. 30, 2019 loan	Dec. 31, 2019 USD ($)
Receivables [Abstract]
Commitments to lend to customers with outstanding loans classified as TDRs	$ 157		$ 157		$ 135
Accruing TDRs	5,400		5,400		6,600
Nonaccruing TDRs	$ 20,000		$ 20,000		$ 15,200
Number of loans modified that had payments default during the period | loan	0	0	1	0