INVESTMENT OPERATIONS - Schedule of Fair Value of Trading Securities (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Debt and Equity Securities, FV-NI [Line Items]
Fixed maturity securities	$ 2,916	$ 2,958
Residential mortgage-backed securities
Debt and Equity Securities, FV-NI [Line Items]
Fixed maturity securities	161	209
Commercial mortgage-backed securities
Debt and Equity Securities, FV-NI [Line Items]
Fixed maturity securities	220	214
Other asset-backed securities
Debt and Equity Securities, FV-NI [Line Items]
Fixed maturity securities	180	163
U.S. government-related securities
Debt and Equity Securities, FV-NI [Line Items]
Fixed maturity securities	34	91
Other government-related securities
Debt and Equity Securities, FV-NI [Line Items]
Fixed maturity securities	56	30
States, municipals, and political subdivisions
Debt and Equity Securities, FV-NI [Line Items]
Fixed maturity securities	288	282
Corporate securities
Debt and Equity Securities, FV-NI [Line Items]
Fixed maturity securities	1,846	1,860
Redeemable preferred stocks
Debt and Equity Securities, FV-NI [Line Items]
Fixed maturity securities	8	13
Fixed maturities
Debt and Equity Securities, FV-NI [Line Items]
Fixed maturity securities	2,793	2,862
Equity securities
Debt and Equity Securities, FV-NI [Line Items]
Fixed maturity securities	15	20
Short-term investments
Debt and Equity Securities, FV-NI [Line Items]
Fixed maturity securities	$ 108	$ 76