DERIVATIVE INSTRUMENTS - Schedule of Interest Rate Fair Value Hedges Hedged Items (Details) - USD ($) $ in Millions		Dec. 31, 2018	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional Amount of Derivatives		$ 38,355	$ 25,751
Fair value hedges
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional Amount of Derivatives		11,656	15,310
Interest rate swaptions | Fair value hedges
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional Amount of Derivatives		500	$ 0
Fixed maturity securities | Interest rate swaptions
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Carrying Amount of Hedged Assets/ (Liabilities)	[1]	6,593
Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of Hedged Assets/ (Liabilities)		$ 294

[1] The balance includes $294 million of hedging adjustment on discontinued hedging relationships.