FAIR VALUE - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Additional provision for loan losses	$ 500	$ 1,500	$ 4,500	$ 5,000	$ 600	$ 1,000	$ 3,500	$ 600	$ 11,500	$ 5,700	$ 1,800
Assets measured at fair value on non-recurring basis
Outstanding balance of impaired loans with an allowance recorded					11,657					11,657	2,721
Valuation allowance on impaired loans					4,676					4,676	$ 189
Loans held for sale	52,800				12,600				52,800	12,600
Other Real Estate	0								0
Real estate owned additional provision									0	0
Non-recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Additional provision for loan losses									2,600
Assets measured at fair value on non-recurring basis
Outstanding balance of impaired loans with an allowance recorded	9,600				11,700				9,600	11,700
Valuation allowance on impaired loans	6,700				4,700				6,700	4,700
Carrying Amount
Assets measured at fair value on non-recurring basis
Loans held for sale	52,785				12,643				52,785	12,643
Carrying Amount | Non-recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying amount of impaired loans					6,981					6,981
Individually evaluated commercial and industrial loans	2,940								2,940
Assets measured at fair value on non-recurring basis
Valuation allowance on impaired loans	2,900				0				2,900	0
Loans held for sale	$ 52,785				$ 12,643				$ 52,785	$ 12,643