FAIR VALUE DISCLOSURES, Assets (Liabilities) Measured at Fair Value on Recurring and Non-Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021
Securities available for sale [Abstract]
Securities available for sale	$ 584,969		$ 701,711
Mortgage servicing rights	27,749	$ 26,658	27,474	$ 28,424	$ 27,505	$ 19,700
State and Municipal [Member]
Securities available for sale [Abstract]
Securities available for sale	160,573		225,055
Residential Mortgage-backed Securities [Member]
Securities available for sale [Abstract]
Securities available for sale	285,351		328,845
Commercial Mortgage-backed Securities [Member]
Securities available for sale [Abstract]
Securities available for sale	39,714		41,967
Collateralized Mortgage Obligations [Member]
Securities available for sale [Abstract]
Securities available for sale	71,953		75,638
Other Securities [Member]
Securities available for sale [Abstract]
Securities available for sale	10,615		11,112
Recurring [Member]
Securities available for sale [Abstract]
Asset-backed and other amortizing securities	16,763		19,094
Loans held for sale (mandatory)	14,496		10,038
Mortgage servicing rights	27,749		27,474
Asset derivatives	22,607		21,162
Liability derivatives	(117)		(128)
Recurring [Member] | State and Municipal [Member]
Securities available for sale [Abstract]
Securities available for sale	160,573		225,055
Recurring [Member] | Residential Mortgage-backed Securities [Member]
Securities available for sale [Abstract]
Securities available for sale	285,351		328,845
Recurring [Member] | Commercial Mortgage-backed Securities [Member]
Securities available for sale [Abstract]
Securities available for sale	39,714		41,967
Recurring [Member] | Collateralized Mortgage Obligations [Member]
Securities available for sale [Abstract]
Securities available for sale	71,953		75,638
Recurring [Member] | Other Securities [Member]
Securities available for sale [Abstract]
Securities available for sale	10,615		11,112
Recurring [Member] | Level 1 [Member]
Securities available for sale [Abstract]
Asset-backed and other amortizing securities	0		0
Loans held for sale (mandatory)	0		0
Mortgage servicing rights	0		0
Asset derivatives	0		0
Liability derivatives	0		0
Recurring [Member] | Level 1 [Member] | State and Municipal [Member]
Securities available for sale [Abstract]
Securities available for sale	0		0
Recurring [Member] | Level 1 [Member] | Residential Mortgage-backed Securities [Member]
Securities available for sale [Abstract]
Securities available for sale	0		0
Recurring [Member] | Level 1 [Member] | Commercial Mortgage-backed Securities [Member]
Securities available for sale [Abstract]
Securities available for sale	0		0
Recurring [Member] | Level 1 [Member] | Collateralized Mortgage Obligations [Member]
Securities available for sale [Abstract]
Securities available for sale	0		0
Recurring [Member] | Level 1 [Member] | Other Securities [Member]
Securities available for sale [Abstract]
Securities available for sale	0		0
Recurring [Member] | Level 2 [Member]
Securities available for sale [Abstract]
Asset-backed and other amortizing securities	16,763		19,094
Loans held for sale (mandatory)	14,496		10,038
Mortgage servicing rights	0		0
Asset derivatives	22,607		21,162
Liability derivatives	(117)		(128)
Recurring [Member] | Level 2 [Member] | State and Municipal [Member]
Securities available for sale [Abstract]
Securities available for sale	160,573		225,055
Recurring [Member] | Level 2 [Member] | Residential Mortgage-backed Securities [Member]
Securities available for sale [Abstract]
Securities available for sale	285,351		328,845
Recurring [Member] | Level 2 [Member] | Commercial Mortgage-backed Securities [Member]
Securities available for sale [Abstract]
Securities available for sale	39,714		41,967
Recurring [Member] | Level 2 [Member] | Collateralized Mortgage Obligations [Member]
Securities available for sale [Abstract]
Securities available for sale	71,953		75,638
Recurring [Member] | Level 2 [Member] | Other Securities [Member]
Securities available for sale [Abstract]
Securities available for sale	10,615		11,112
Recurring [Member] | Level 3 [Member]
Securities available for sale [Abstract]
Asset-backed and other amortizing securities	0		0
Loans held for sale (mandatory)	0		0
Mortgage servicing rights	27,749		27,474
Asset derivatives	0		0
Liability derivatives	0		0
Recurring [Member] | Level 3 [Member] | State and Municipal [Member]
Securities available for sale [Abstract]
Securities available for sale	0		0
Recurring [Member] | Level 3 [Member] | Residential Mortgage-backed Securities [Member]
Securities available for sale [Abstract]
Securities available for sale	0		0
Recurring [Member] | Level 3 [Member] | Commercial Mortgage-backed Securities [Member]
Securities available for sale [Abstract]
Securities available for sale	0		0
Recurring [Member] | Level 3 [Member] | Collateralized Mortgage Obligations [Member]
Securities available for sale [Abstract]
Securities available for sale	0		0
Recurring [Member] | Level 3 [Member] | Other Securities [Member]
Securities available for sale [Abstract]
Securities available for sale	0		0
Non-recurring [Member]
Assets measured at fair value on a non-recurring basis [Abstract]
Loans held for investment	1,447		4,821
Non-recurring [Member] | Level 1 [Member]
Assets measured at fair value on a non-recurring basis [Abstract]
Loans held for investment	0		0
Non-recurring [Member] | Level 2 [Member]
Assets measured at fair value on a non-recurring basis [Abstract]
Loans held for investment	0		0
Non-recurring [Member] | Level 3 [Member]
Assets measured at fair value on a non-recurring basis [Abstract]
Loans held for investment	$ 1,447		$ 4,821