Derivatives - Derivative Balance Sheet Classification (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	$ 12,129	$ 13,706
Fair Value	(61)	(66)
Asset Derivatives	33	40
Liability Derivatives	(94)	(106)
Fixed maturities, available-for-sale
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	269	244
Fair Value	0	0
Asset Derivatives	0	0
Liability Derivatives	0	0
Other investments
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	9,585	1,277
Fair Value	23	12
Asset Derivatives	25	13
Liability Derivatives	(2)	(1)
Other liabilities
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	2,275	12,185
Fair Value	(84)	(78)
Asset Derivatives	8	27
Liability Derivatives	(92)	(105)
Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	2,626	2,310
Fair Value	(13)	(1)
Asset Derivatives	3	4
Liability Derivatives	(16)	(5)
Designated as Hedging Instrument \| Interest rate swaps
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	2,340	2,040
Fair Value	0	0
Asset Derivatives	0	1
Liability Derivatives	0	(1)
Designated as Hedging Instrument \| Foreign currency swaps
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	286	270
Fair Value	(13)	(1)
Asset Derivatives	3	3
Liability Derivatives	(16)	(4)
Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	9,503	11,396
Fair Value	(48)	(65)
Asset Derivatives	30	36
Liability Derivatives	(78)	(101)
Not Designated as Hedging Instrument \| Interest rate swaps
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	7,600
Not Designated as Hedging Instrument \| Interest rate swaps and futures
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	8,335	9,338
Fair Value	(69)	(59)
Asset Derivatives	4	3
Liability Derivatives	(73)	(62)
Not Designated as Hedging Instrument \| Foreign currency swaps and forwards
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	269	464
Fair Value	0	(1)
Asset Derivatives	0	0
Liability Derivatives	0	(1)
Not Designated as Hedging Instrument \| Credit derivatives that purchase credit protection
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	6	124
Fair Value	0	(3)
Asset Derivatives	0	0
Liability Derivatives	0	(3)
Not Designated as Hedging Instrument \| Credit derivatives that assume credit risk
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	675	500
Fair Value	21	13
Asset Derivatives	21	13
Liability Derivatives	0	0
Not Designated as Hedging Instrument \| Credit derivatives in offsetting positions
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	218	29
Fair Value	0	0
Asset Derivatives	5	5
Liability Derivatives	(5)	(5)
Not Designated as Hedging Instrument \| Equity index swaps and options
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	0	941
Fair Value	0	(15)
Asset Derivatives	0	15
Liability Derivatives	$ 0	$ (30)

Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

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Fair value of the assets less the liabilities of a derivative or group of derivatives.

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Nominal or face amount used to calculate payment on derivative.

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