SECURITIES SOLD UNDER AGREEMENTS TO REPURCHASE - Summary of Securities Sold Under Repurchase Agreements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Assets Sold under Agreements to Repurchase [Line Items]
Securities sold under agreements to repurchase	$ 11,641	$ 20,635
Weighted Average
Assets Sold under Agreements to Repurchase [Line Items]
Securities sold under agreements to repurchase	$ 12,115	$ 14,043	$ 15,692
Average interest rate during the year	0.68%	0.61%	0.15%
Weighted average interest rate at year-end	0.35%	0.81%	0.14%
Maximum
Assets Sold under Agreements to Repurchase [Line Items]
Securities sold under agreements to repurchase	$ 15,998	$ 23,626	$ 23,270