SECURITIES (Narrative) (Details)	3 Months Ended
	Sep. 30, 2022 USD ($)	Jun. 30, 2022 USD ($) bankLocation	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Debt securities, held-to-maturity, transferred from available-for-sale, book value	$ 934,500,000
OCI, debt securities, held-to-maturity, transferred from available-for-sale, unrealized gain (loss), after tax	186,300,000
Accrued interest receivable			$ 33,000,000	$ 29,400,000
Debt securities, held-to-maturity, unrealized loss				0
Debt securities, held-to-maturity, sold | bankLocation		2
Debt securities, held-to-maturity, sale		$ 2,200,000
Gain (loss) on sale of investments		$ 100,000
FHLB stock			12,300,000	22,600,000
Held to maturity securities, fair value			0	0
Obligations of states and political subdivisions
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Held to maturity securities, fair value			0	0
Municipal Bonds
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Debt securities, held-to-maturity, transferred from available-for-sale, fair value	$ 748,300,000
Collateral Pledged
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Securities pledged as collateral			$ 1,490,000,000	$ 1,660,000,000