FAIR VALUE - Carrying Amounts and Estimated Fair Values of Other Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Financial assets:
Fair Value	$ 1,083,330	$ 1,034,795
Carrying Value
Financial assets:
Net loans	8,919,165	8,748,335
Fair Value	1,090,235	1,079,695
Financial liabilities:
Deposits	13,110,672	13,012,308
Overnight borrowings	58,400	768,400
Securities sold under agreement to repurchase, short-term	304,607	346,652
Other Federal Home Loan Bank borrowings	17,284	19,474
Subordinated notes payable	0	3,249
Fair Value
Financial assets:
Net loans	8,765,403	8,696,185
Fair Value	1,083,330	1,034,795
Financial liabilities:
Deposits	13,080,256	12,981,487
Overnight borrowings	58,400	768,400
Securities sold under agreement to repurchase, short-term	304,607	346,652
Other Federal Home Loan Bank borrowings	17,131	19,377
Subordinated notes payable	$ 0	$ 3,249