FAIR VALUE OF ASSETS AND LIABILITIES - Fair Value of Financial Instruments (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Assets
Accrued investment income	$ 55	$ 52
Fair Value | Fair Value, Inputs, Level 1, Level 2, and Level 3
Assets
Accrued investment income	55	52
Mortgage and other loans	11	11
Liabilities:
Repurchase agreements	403	311
Cash collateral for loaned securities		106
Fair Value | Level 1
Assets
Accrued investment income	0	0
Mortgage and other loans	0	0
Liabilities:
Repurchase agreements	0	0
Cash collateral for loaned securities		0
Fair Value | Level 2
Assets
Accrued investment income	55	52
Mortgage and other loans	0	0
Liabilities:
Repurchase agreements	403	311
Cash collateral for loaned securities		106
Fair Value | Level 3
Assets
Accrued investment income	0	0
Mortgage and other loans	11	11
Liabilities:
Repurchase agreements	0	0
Cash collateral for loaned securities		0
Carrying Amount
Assets
Accrued investment income	55	52
Mortgage and other loans	11	11
Liabilities:
Repurchase agreements	$ 403	311
Cash collateral for loaned securities		$ 106