Derivatives (Derivatives Pertaining to Hedged Items) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivative Gains (Losses) Recognized for Hedged Items	$ (5)	$ (27)	$ (12)	$ (27)
Amount of Gains (Losses) Deferred in AOCI	(139)	73	414	39
Derivatives Not Designated or Not Qualifying as Hedging Instruments:
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivative Gains (Losses) Recognized for Hedged Items	(2)	(4)	(9)	(4)
Amount of Gains (Losses) Deferred in AOCI	0	0	0	0
Cash flow hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivative Gains (Losses) Recognized for Hedged Items	(3)	(23)	(3)	(23)
Amount of Gains (Losses) Deferred in AOCI	(139)	73	414	39
Net Derivative Gains (Losses) Recognized for Derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	(2,645)	135	4,109	(1,175)
Net Derivative Gains (Losses) Recognized for Derivatives | Derivatives Not Designated or Not Qualifying as Hedging Instruments:
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	(2,649)	112	4,104	(1,223)
Net Derivative Gains (Losses) Recognized for Derivatives | Cash flow hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	4	23	5	48
Net Investment Income
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	9	8	21	17
Net Investment Income | Derivatives Not Designated or Not Qualifying as Hedging Instruments:
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	0	0	0	0
Net Investment Income | Cash flow hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	9	8	21	17
Interest rate derivatives | Derivatives Not Designated or Not Qualifying as Hedging Instruments:
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivative Gains (Losses) Recognized for Hedged Items	0	0	0	0
Amount of Gains (Losses) Deferred in AOCI	0	0	0	0
Interest rate derivatives | Cash flow hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivative Gains (Losses) Recognized for Hedged Items	0	0	0	0
Amount of Gains (Losses) Deferred in AOCI	(4)	0	93	0
Interest rate derivatives | Net Derivative Gains (Losses) Recognized for Derivatives | Derivatives Not Designated or Not Qualifying as Hedging Instruments:
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	(165)	917	4,756	1,249
Interest rate derivatives | Net Derivative Gains (Losses) Recognized for Derivatives | Cash flow hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	0	6	1	28
Interest rate derivatives | Net Investment Income | Derivatives Not Designated or Not Qualifying as Hedging Instruments:
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	0	0	0	0
Interest rate derivatives | Net Investment Income | Cash flow hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	0	0	1	1
Foreign currency exchange rate derivatives | Derivatives Not Designated or Not Qualifying as Hedging Instruments:
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivative Gains (Losses) Recognized for Hedged Items	(2)	(4)	(9)	(4)
Amount of Gains (Losses) Deferred in AOCI	0	0	0	0
Foreign currency exchange rate derivatives | Cash flow hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivative Gains (Losses) Recognized for Hedged Items	(3)	(23)	(3)	(23)
Amount of Gains (Losses) Deferred in AOCI	(135)	73	321	39
Foreign currency exchange rate derivatives | Net Derivative Gains (Losses) Recognized for Derivatives | Derivatives Not Designated or Not Qualifying as Hedging Instruments:
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	(27)	30	105	22
Foreign currency exchange rate derivatives | Net Derivative Gains (Losses) Recognized for Derivatives | Cash flow hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	4	17	4	20
Foreign currency exchange rate derivatives | Net Investment Income | Derivatives Not Designated or Not Qualifying as Hedging Instruments:
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	0	0	0	0
Foreign currency exchange rate derivatives | Net Investment Income | Cash flow hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	9	8	20	16
Credit derivatives | Derivatives Not Designated or Not Qualifying as Hedging Instruments:
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivative Gains (Losses) Recognized for Hedged Items	0	0	0	0
Amount of Gains (Losses) Deferred in AOCI	0	0	0	0
Credit derivatives | Net Derivative Gains (Losses) Recognized for Derivatives | Derivatives Not Designated or Not Qualifying as Hedging Instruments:
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	29	11	(2)	29
Credit derivatives | Net Investment Income | Derivatives Not Designated or Not Qualifying as Hedging Instruments:
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	0	0	0	0
Equity derivatives | Derivatives Not Designated or Not Qualifying as Hedging Instruments:
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivative Gains (Losses) Recognized for Hedged Items	0	0	0	0
Amount of Gains (Losses) Deferred in AOCI	0	0	0	0
Equity derivatives | Net Derivative Gains (Losses) Recognized for Derivatives | Derivatives Not Designated or Not Qualifying as Hedging Instruments:
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	(1,606)	(344)	358	(1,790)
Equity derivatives | Net Investment Income | Derivatives Not Designated or Not Qualifying as Hedging Instruments:
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	0	0	0	0
Embedded derivatives | Derivatives Not Designated or Not Qualifying as Hedging Instruments:
Derivative Instruments, Gain (Loss) [Line Items]
Net Derivative Gains (Losses) Recognized for Hedged Items	0	0	0	0
Amount of Gains (Losses) Deferred in AOCI	0	0	0	0
Embedded derivatives | Net Derivative Gains (Losses) Recognized for Derivatives | Derivatives Not Designated or Not Qualifying as Hedging Instruments:
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	(880)	(502)	(1,113)	(733)
Embedded derivatives | Net Investment Income | Derivatives Not Designated or Not Qualifying as Hedging Instruments:
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	$ 0	$ 0	$ 0	$ 0