FAIR VALUE - Assets and Liabilities Measured on Nonrecurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Assets and Liabilities Measured on Nonrecurring Basis [Abstract]
Individually assessed loans		$ 25,063
Other real estate owned		883
Mortgage servicing rights		682
Contingent consideration	$ 2,900
Valuation allowance	1,834	3,874
Mortgage Servicing Rights [Member]
Assets and Liabilities Measured on Nonrecurring Basis [Abstract]
Valuation allowance	0	200
Significant Unobservable Inputs, Level 3 [Member]
Assets and Liabilities Measured on Nonrecurring Basis [Abstract]
Individually assessed loans	18,794
Other real estate owned	891
Mortgage servicing rights	794
Non-recurring [Member]
Assets and Liabilities Measured on Nonrecurring Basis [Abstract]
Individually assessed loans	18,794	25,063
Other real estate owned	891	883
Mortgage servicing rights	794	682
Contingent consideration	2,900	0
Total	23,379	26,628
Non-recurring [Member] | Quoted Prices in Active Markets For Identical Assets, Level 1 [Member]
Assets and Liabilities Measured on Nonrecurring Basis [Abstract]
Individually assessed loans	0	0
Other real estate owned	0	0
Mortgage servicing rights	0	0
Contingent consideration	0	0
Total	0	0
Non-recurring [Member] | Significant Observable Inputs, Level 2 [Member]
Assets and Liabilities Measured on Nonrecurring Basis [Abstract]
Individually assessed loans	0	0
Other real estate owned	0	0
Mortgage servicing rights	0	0
Contingent consideration	0	0
Total	0	0
Non-recurring [Member] | Significant Unobservable Inputs, Level 3 [Member]
Assets and Liabilities Measured on Nonrecurring Basis [Abstract]
Individually assessed loans	18,794	25,063
Other real estate owned	891	883
Mortgage servicing rights	794	682
Contingent consideration	2,900	0
Total	$ 23,379	$ 26,628