FAIR VALUE OF ASSETS AND LIABILITIES - Fair Value of Financial Instruments (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Assets
Accrued investment income	$ 53	$ 52
Fair Value | Fair Value, Inputs, Level 1, Level 2, and Level 3
Assets
Accrued investment income	53	52
Mortgage and other loans	11	11
Liabilities:
Repurchase agreements	301	311
Cash collateral for loaned securities	164	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	0
Fair Value | Level 2
Assets
Accrued investment income	53	52
Mortgage and other loans	0	0
Liabilities:
Repurchase agreements	301	311
Cash collateral for loaned securities	164	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	0
Carrying Amount
Assets
Accrued investment income	53	52
Mortgage and other loans	11	11
Liabilities:
Repurchase agreements	301	311
Cash collateral for loaned securities	$ 164	$ 106