Derivative Financial Instruments - Net Realized Gains (Losses) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Derivatives, Fair Value [Line Items]
Net Investment Income	$ 505	$ 413	$ 1,329	$ 1,235
Other net realized capital gains (losses)	(73)	7	(163)	2
Derivative, Gain (Loss) on Derivative, Net	37	(50)	(14)	(220)
Interest rate contracts | Other Comprehensive Income (Loss) | Designated as Hedging Instrument | Cash flow hedges
Derivatives, Fair Value [Line Items]
Derivative, Gain (Loss) on Derivative, Net	(1)	0	1	2
Interest rate contracts | Investment Income | Designated as Hedging Instrument | Cash flow hedges
Derivatives, Fair Value [Line Items]
Derivative, Gain (Loss) on Derivative, Net	0	0	0	0
Interest rate contracts | Other Net Realized Capital Gains (Losses) | Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Gain (Loss) on Derivative, Net	10	10	55	(76)
Foreign exchange contracts | Other Comprehensive Income (Loss) | Designated as Hedging Instrument | Cash flow hedges
Derivatives, Fair Value [Line Items]
Derivative, Gain (Loss) on Derivative, Net	(35)	28	26	36
Foreign exchange contracts | Investment Income | Designated as Hedging Instrument | Cash flow hedges
Derivatives, Fair Value [Line Items]
Derivative, Gain (Loss) on Derivative, Net	0	2	5	7
Net realized gains (losses) on derivatives	3	2	8	7
Foreign exchange contracts | Other Net Realized Capital Gains (Losses) | Designated as Hedging Instrument | Cash flow hedges
Derivatives, Fair Value [Line Items]
Net realized gains (losses) on derivatives	(3)	0	(3)	0
Foreign exchange contracts | Other Net Realized Capital Gains (Losses) | Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Gain (Loss) on Derivative, Net	(2)	2	2	4
Equity contract | Other Net Realized Capital Gains (Losses) | Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Gain (Loss) on Derivative, Net	0	0	0	1
Fixed maturities | Other Net Realized Capital Gains (Losses)
Derivatives, Fair Value [Line Items]
Derivative, Gain (Loss) on Derivative, Net	(2)	2	2	4
Product | Other Net Realized Capital Gains (Losses)
Derivatives, Fair Value [Line Items]
Derivative, Gain (Loss) on Derivative, Net	24	(36)	(89)	(49)
Reinsurance agreements | Interest Credited and Other Benefits to Contract Owners
Derivatives, Fair Value [Line Items]
Derivative, Gain (Loss) on Derivative, Net	0	(29)	23	(106)
Managed Custody Guarantees | Gain (Loss) on Investments
Derivatives, Fair Value [Line Items]
Derivative, Gain (Loss) on Derivative, Net	7	0	(10)	0
Credit contracts | Other Net Realized Capital Gains (Losses) | Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Gain (Loss) on Derivative, Net	$ 0	$ 1	$ 3	$ 2