GOODWILL, CORE DEPOSIT PREMIUM AND OTHER INTANGIBLE ASSETS (Carrying amount of intangible assets (including accumulated amortization) (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 101,185	$ 114,885
Accumulated Amortization	79,534	81,891
Net Carrying Amount	21,651	32,994
Core deposit intangibles
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	101,185	101,185
Accumulated Amortization	79,534	76,031
Net Carrying Amount	21,651	25,154
Mortgage Servicing Rights
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	0	13,700
Accumulated Amortization	0	5,860
Net Carrying Amount	$ 0	$ 7,840