Derivatives Derivatives (Effects on the Consolidated Statement of Operations and Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Discontinuation of Cash Flow Hedge Due to Forecasted Transaction Probable of Not Occurring, Net	$ 13	$ 2	$ 45	$ 51
Derivative, Gain (Loss) on Derivative, Net	(549)	732	2,213	630
Net Investment Income	2,774	2,749	7,423	8,188
Net investment gains (losses)	30	88	(96)	100
Net other expenses	1,360	1,297	3,738	3,680
Net policyholder benefits and claims	(5,979)	(7,016)	(17,081)	(18,443)
Interest credited to policyholder account balances	(538)	(668)	(1,720)	(1,993)
Nonperformance Risk [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net derivatives gains (losses)	(12)	20	53	9
Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	0	0	0	0
Net Investment Income	11	5	26	14
Net investment gains (losses)	47	(2)	144	(15)
Net other expenses	0	0	0	0
Net policyholder benefits and claims	0	0	0	0
Interest credited to policyholder account balances	0	0	0	0
Other Comprehensive Income (Loss), before Tax	(1,062)	1,025	1,936	1,575
Fair Value Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	0	0	0	0
Net Investment Income	(3)	6	0	5
Net investment gains (losses)	0	0	0	0
Net other expenses	0	0	0	0
Net policyholder benefits and claims	(15)	(14)	(24)	(16)
Interest credited to policyholder account balances	0	(1)	0	(1)
Fixed Maturities [Member] | Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Hedged Asset, Discontinued Fair Value Hedge, Cumulative Increase (Decrease)	(1)		(1)		$ (1)
Interest rate contracts | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	0	0	0	0
Net Investment Income	9	5	24	16
Net investment gains (losses)	10	0	58	(1)
Net other expenses	0	0	0	0
Net policyholder benefits and claims	0	0	0	0
Interest credited to policyholder account balances	0	0	0	0
Other Comprehensive Income (Loss), before Tax	(19)	(5)	(82)	(15)
Currency Swap [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	0	0	0	0
Net Investment Income	2	0	2	(2)
Net investment gains (losses)	406	(344)	221	(263)
Net other expenses	0	0	0	0
Net policyholder benefits and claims	0	0	0	0
Interest credited to policyholder account balances	0	0	0	0
Other Comprehensive Income (Loss), before Tax	(408)	344	(223)	265
Foreign Currency Gain (Loss) [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	0	0	0	0
Net Investment Income	0	0	0	0
Net investment gains (losses)	(369)	342	(135)	249
Net other expenses	0	0	0	0
Net policyholder benefits and claims	0	0	0	0
Interest credited to policyholder account balances	0	0	0	0
Other Comprehensive Income (Loss), before Tax	0	0	0	0
Derivative [Member] | Currency Swap [Member] | Fair Value Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	0	0	0	0
Net Investment Income	(49)	36	15	16
Net investment gains (losses)	0	0	0	0
Net other expenses	0	0	0	0
Net policyholder benefits and claims	0	0	0	0
Interest credited to policyholder account balances	0	0	0	0
Derivative [Member] | Interest Rate Swap [Member] | Fair Value Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	0	0	0	0
Net Investment Income	0	(1)	(11)	(5)
Net investment gains (losses)	0	0	0	0
Net other expenses	0	0	0	0
Net policyholder benefits and claims	(154)	(223)	(589)	(555)
Interest credited to policyholder account balances	0	(1)	0	(1)
Fixed maturity securities AFS | Currency Swap [Member] | Fair Value Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	0	0	0	0
Net Investment Income	45	(29)	(13)	(11)
Net investment gains (losses)	0	0	0	0
Net other expenses	0	0	0	0
Net policyholder benefits and claims	0	0	0	0
Interest credited to policyholder account balances	0	0	0	0
Fixed maturity securities AFS | Interest Rate Swap [Member] | Fair Value Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	0	0	0	0
Net Investment Income	1	0	9	5
Net investment gains (losses)	0	0	0	0
Net other expenses	0	0	0	0
Net policyholder benefits and claims	(139)	(237)	(613)	(571)
Interest credited to policyholder account balances	0	0	0	0
Accumulated Other Comprehensive Income (Loss) | Credit forwards [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Other Comprehensive Income (Loss), before Tax	0	0	0	0
Accumulated Other Comprehensive Income (Loss) | Currency Swap [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Other Comprehensive Income (Loss), before Tax	(432)	165	552	211
Accumulated Other Comprehensive Income (Loss) | Interest Rate Swap [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Other Comprehensive Income (Loss), before Tax	(203)	521	1,689	1,114
Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	(1,014)	1,091	2,683	1,273
Net Investment Income	(6)	(2)	(12)	(4)
Net investment gains (losses)	0	0	0	0
Net other expenses	0	0	0	0
Net policyholder benefits and claims	(88)	(3)	(35)	(92)
Interest credited to policyholder account balances	0	0	0	0
Equity Market Risk [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	(376)	(22)	(78)	(651)
Net Investment Income	(6)	0	(6)	0
Net investment gains (losses)	0	0	0	0
Net other expenses	0	0	0	0
Net policyholder benefits and claims	(88)	(3)	(35)	(92)
Interest credited to policyholder account balances	0	0	0	0
Foreign Currency Gain (Loss) [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	109	(32)	(31)	(101)
Net Investment Income	0	0	0	0
Net investment gains (losses)	0	0	0	0
Net other expenses	0	0	0	0
Net policyholder benefits and claims	0	0	0	0
Interest credited to policyholder account balances	0	0	0	0
Interest Rate Risk [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	(461)	977	2,876	1,725
Net Investment Income	0	(2)	(6)	(4)
Net investment gains (losses)	0	0	0	0
Net other expenses	0	0	0	0
Net policyholder benefits and claims	0	0	0	0
Interest credited to policyholder account balances	0	0	0	0
Foreign Exchange [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	(278)	175	11	191
Net Investment Income	0	0	0	0
Net investment gains (losses)	0	0	0	0
Net other expenses	0	0	0	0
Net policyholder benefits and claims	0	0	0	0
Interest credited to policyholder account balances	0	0	0	0
Credit Default Swap, Buying Protection [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	(5)	(4)	21	(16)
Net Investment Income	0	0	0	0
Net investment gains (losses)	0	0	0	0
Net other expenses	0	0	0	0
Net policyholder benefits and claims	0	0	0	0
Interest credited to policyholder account balances	0	0	0	0
Credit Default Swap, Selling Protection [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	(3)	(3)	(116)	125
Net Investment Income	0	0	0	0
Net investment gains (losses)	0	0	0	0
Net other expenses	0	0	0	0
Net policyholder benefits and claims	0	0	0	0
Interest credited to policyholder account balances	0	0	0	0
Net Embedded Derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	270	(424)	(889)	(847)
Net policyholder benefits and claims	0	0	0	0
Nonoperating Income (Expense) [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Gain (Loss) on Derivative, Net	195	65	419	204
Net Investment Income	56	70	212	204
Net investment gains (losses)	0	0	0	0
Net other expenses	0	0	0	0
Net policyholder benefits and claims	(51)	(35)	(132)	(98)
Interest credited to policyholder account balances	(36)	(42)	(118)	(110)
Other Comprehensive Income (Loss), before Tax	0	0	0	0
Effects of Derivatives on Consolidated Statements of Operations and Comprehensive Income (Loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net Investment Income	58	79	226	219
Net investment gains (losses)	47	(2)	144	(15)
Net other expenses	0	0	0	0
Net policyholder benefits and claims	52	(18)	(73)	10
Interest credited to policyholder account balances	36	41	118	109
Other Comprehensive Income (Loss), before Tax	$ (1,062)	$ 1,025	$ 1,936	$ 1,575