CREDIT FACILITIES - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 27, 2023	Dec. 13, 2023	Aug. 18, 2023	Dec. 30, 2022	Nov. 21, 2022	Nov. 03, 2021	Aug. 27, 2021	May 05, 2021	Feb. 23, 2021
Line of Credit Facility [Line Items]
Line of credit facility, commitment	$ 1,700,000,000
Uncommitted amount available	240,000,000
Extension period for availability				2 years
Borrowings from FHLB	$ 819,000,000	$ 519,000,000
Federal Home Loan Bank Membership
Line of Credit Facility [Line Items]
Maximum percentage of admitted assets allowed for borrowing base	10.00%
Admitted assets for FHLB	$ 26,300,000,000
Maximum amount available under FHLB	2,600,000,000
Interest expense	$ 30,000,000	4,000,000
Amount of borrowed funds required to be used to acquire additional membership stock, percentage	4.50%
Federal Home Loan Bank Membership | Asset Pledged as Collateral
Line of Credit Facility [Line Items]
Qualifying collateral pledged	$ 1,100,000,000
Bermuda Re Wells Fargo Bilateral Letter of Credit Facility
Line of Credit Facility [Line Items]
Line of credit facility, commitment	500,000,000	500,000,000								$ 500,000,000	$ 50,000,000
Bermuda Re Citibank Letter of Credit Facility - Uncommitted
Line of Credit Facility [Line Items]
Uncommitted amount available	140,000,000
Bermuda Re Citibank Letter of Credit Facility One
Line of Credit Facility [Line Items]
Line of credit facility, commitment	230,000,000	230,000,000
Bermuda Re Bayerische Landesbank Bilateral Secured Credit Facility
Line of Credit Facility [Line Items]
Line of credit facility, commitment	200,000,000	200,000,000							$ 200,000,000
Bermuda Re Bayerische Landesbank Bilateral Unsecured Letter of Credit Facility
Line of Credit Facility [Line Items]
Line of credit facility, commitment	150,000,000	150,000,000				$ 150,000,000
Bermuda Re Lloyd’s Bank Letter of Credit Facility
Line of Credit Facility [Line Items]
Line of credit facility, commitment	250,000,000	250,000,000
Bermuda Re Lloyd's Bank Credit Facility-Committed
Line of Credit Facility [Line Items]
Line of credit facility, commitment	250,000,000	50,000,000	$ 15,000,000		$ 250,000,000
Bermuda Re Barclays Credit Facility
Line of Credit Facility [Line Items]
Line of credit facility, commitment	200,000,000	200,000,000						$ 200,000,000
Bermuda Re Nordea Bank Letter of Credit Facility
Line of Credit Facility [Line Items]
Line of credit facility, commitment	300,000,000	300,000,000					$ 300,000,000
Nordea Bank Letter of Credit Facility - Committed
Line of Credit Facility [Line Items]
Line of credit facility, commitment	200,000,000	200,000,000					200,000,000
Nordea Bank Letter of Credit Facility - Uncommitted
Line of Credit Facility [Line Items]
Line of credit facility, commitment	$ 100,000,000	$ 100,000,000					$ 100,000,000