DERIVATIVE INSTRUMENTS - Schedule of Interest Rate Fair Value Hedges Hedged Items (Details) - USD ($) $ in Millions		Mar. 31, 2019	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional Amount of Derivatives		$ 39,051	$ 38,355
Fair value hedges
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional Amount of Derivatives		13,079	11,656
Interest rate swaptions | Fair value hedges
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional Amount of Derivatives		1,500	500
Fixed maturity securities | Interest rate swaptions
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Carrying Amount of Hedged Assets/ (Liabilities)	[1]	5,285	6,593
Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of Hedged Assets/(Liabilities)		$ 276	$ 294

[1] The balance includes hedging adjustment on discontinued hedging relationships of $276 in 2019 and $294 in 2018.