FAIR VALUE - Assets and liabilities measured on a non-recurring basis (Details)		3 Months Ended		6 Months Ended	9 Months Ended		12 Months Ended
	Jun. 30, 2023 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Jun. 30, 2023 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)
Assets and Liabilities Measured on Nonrecurring Basis
Valuation allowance		$ 470,000			$ 470,000		$ 0
Contingent consideration					1,450,000		0
Acquisition-related contingent consideration adjustment		$ 80,000	$ 0		1,080,000	$ 400,000
Payment of contingent consideration					$ 1,214,000	$ 0
FBD
Assets and Liabilities Measured on Nonrecurring Basis
Contingent consideration, measurement input		0.0691			0.0691
Acquisition-related contingent consideration adjustment	$ 100,000
Fair value contingent consideration adjustment	1,000,000.0
FBD | Probability of achievement
Assets and Liabilities Measured on Nonrecurring Basis
Contingent consideration, measurement input		0.378			0.378
TGA
Assets and Liabilities Measured on Nonrecurring Basis
Acquisition-related contingent consideration adjustment				$ 1,100,000	$ 100,000
Fair value contingent consideration adjustment	$ 2,800,000
Payment of contingent consideration					2,400,000
Fair value of the remaining contingent consideration liability		$ 500,000			$ 500,000
TGA | Probability of achievement
Assets and Liabilities Measured on Nonrecurring Basis
Contingent consideration, measurement input		0.861			0.861
Minimum | FBD
Assets and Liabilities Measured on Nonrecurring Basis
Contingent consideration					$ 0
Minimum | TGA
Assets and Liabilities Measured on Nonrecurring Basis
Contingent consideration					$ 0
Contingent consideration, measurement input		0.0673			0.0673
Maximum | FBD
Assets and Liabilities Measured on Nonrecurring Basis
Contingent consideration					$ 2,700,000
Maximum | TGA
Assets and Liabilities Measured on Nonrecurring Basis
Contingent consideration					$ 3,400,000
Contingent consideration, measurement input		0.0694			0.0694
Mortgage servicing rights
Assets and Liabilities Measured on Nonrecurring Basis
Valuation allowance		$ 1,200,000			$ 1,200,000		700,000
Non-recurring
Assets and Liabilities Measured on Nonrecurring Basis
Individually assessed loans		3,014,000			3,014,000		0
Other real estate owned		578,000			578,000		503,000
Mortgage servicing rights		309,000			309,000		1,169,000
Contingent consideration		(2,950,000)			(2,950,000)		(2,800,000)
Total		951,000			951,000		(1,128,000)
Non-recurring | Level 1
Assets and Liabilities Measured on Nonrecurring Basis
Individually assessed loans		0			0		0
Other real estate owned		0			0		0
Mortgage servicing rights		0			0		0
Contingent consideration		0			0		0
Total		0			0		0
Non-recurring | Level 2
Assets and Liabilities Measured on Nonrecurring Basis
Individually assessed loans		0			0		0
Other real estate owned		0			0		0
Mortgage servicing rights		0			0		0
Contingent consideration		0			0		0
Total		0			0		0
Non-recurring | Level 3
Assets and Liabilities Measured on Nonrecurring Basis
Individually assessed loans		3,014,000			3,014,000		0
Other real estate owned		578,000			578,000		503,000
Mortgage servicing rights		309,000			309,000		1,169,000
Contingent consideration		(2,950,000)			(2,950,000)		(2,800,000)
Total		$ 951,000			$ 951,000		$ (1,128,000)