LONG-TERM SUBORDINATED NOTES - Schedule of Outstanding Fixed to Floating Rate Long-Term Subordinated Notes (Details) - USD ($)	Sep. 30, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Consolidated Balance Sheet Amount	$ 218,000,000	$ 218,000,000
Subordinated Notes 6.60% | Long Term Subordinated Debt
Debt Instrument [Line Items]
Original Principal Amount	400,000,000
Consolidated Balance Sheet Amount	218,000,000	218,000,000
Fair Value	$ 197,000,000	$ 187,000,000