INVESTMENT OPERATIONS - Schedule of Fair Value of Trading Securities (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Debt and Equity Securities, FV-NI [Line Items]
Fixed maturity securities	$ 2,833	$ 2,958
Residential mortgage-backed securities
Debt and Equity Securities, FV-NI [Line Items]
Fixed maturity securities	181	209
Commercial mortgage-backed securities
Debt and Equity Securities, FV-NI [Line Items]
Fixed maturity securities	213	214
Other asset-backed securities
Debt and Equity Securities, FV-NI [Line Items]
Fixed maturity securities	175	163
U.S. government-related securities
Debt and Equity Securities, FV-NI [Line Items]
Fixed maturity securities	35	91
Other government-related securities
Debt and Equity Securities, FV-NI [Line Items]
Fixed maturity securities	32	30
States, municipals, and political subdivisions
Debt and Equity Securities, FV-NI [Line Items]
Fixed maturity securities	282	282
Corporate securities
Debt and Equity Securities, FV-NI [Line Items]
Fixed maturity securities	1,772	1,860
Redeemable preferred stocks
Debt and Equity Securities, FV-NI [Line Items]
Fixed maturity securities	11	13
Fixed maturities
Debt and Equity Securities, FV-NI [Line Items]
Fixed maturity securities	2,701	2,862
Equity securities
Debt and Equity Securities, FV-NI [Line Items]
Fixed maturity securities	23	20
Short-term investments
Debt and Equity Securities, FV-NI [Line Items]
Fixed maturity securities	$ 109	$ 76