INCOME TAXES - Components of Net Deferred Tax Liability (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Components of net deferred tax liability
Investment securities	$ 191,953	$ 0
Allowance for loan losses	15,346	12,435
Employee benefits	5,775	7,708
Operating lease liabilities	7,552	7,955
Other, net	4,385	1,250
Deferred tax asset	225,011	29,348
Investment securities	0	7,227
Goodwill and intangibles	39,454	41,917
Operating lease right-of-use assets	7,303	7,693
Loan origination costs	9,731	8,993
Depreciation	96	535
Mortgage servicing rights	640	278
Pension	18,154	22,950
Deferred tax liability	75,378	89,593
Net deferred tax (liability)		$ (60,245)
Net deferred tax asset	$ 149,633