Fair Value (Recurring Fair Value Measurements) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	$ 184,574	$ 169,564
Short-term investments	2,352	1,883
Mortgage Loans on Real Estate, Commercial and Consumer, Net	66,102	65,549
Derivative assets	11,175	8,080
Separate account assets	124,892	117,867
Liabilities [Abstract]
Derivative liabilities	1,694	2,102
Embedded derivatives within liability host contracts	2,348	1,325
Separate account liabilities	124,892	117,867
Residential mortgage loans - FVO
Assets [Abstract]
Mortgage Loans on Real Estate, Commercial and Consumer, Net	176	188
Recurring
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	184,574	169,564
Short-term investments	2,352	1,883
Other investments	1,138	1,251
Derivative assets	11,175	8,080
Separate account assets	124,892	117,867
Total assets	324,307	298,833
Liabilities [Abstract]
Derivative liabilities	1,694	2,102
Embedded derivatives within liability host contracts	2,348	1,325
Total liabilities	4,078	3,449
Recurring \| Interest rate contracts
Assets [Abstract]
Derivative assets	8,231	5,770
Liabilities [Abstract]
Derivative liabilities	103	358
Recurring \| Foreign currency exchange rate contracts
Assets [Abstract]
Derivative assets	2,146	1,642
Liabilities [Abstract]
Derivative liabilities	1,308	1,225
Recurring \| Credit contracts
Assets [Abstract]
Derivative assets	127	204
Liabilities [Abstract]
Derivative liabilities	6	12
Recurring \| Equity market contracts
Assets [Abstract]
Derivative assets	671	464
Liabilities [Abstract]
Derivative liabilities	277	507
Recurring \| Derivative Liabilities Within Separate Accounts
Liabilities [Abstract]
Separate account liabilities	36	22
Recurring \| Residential mortgage loans - FVO
Assets [Abstract]
Mortgage Loans on Real Estate, Commercial and Consumer, Net	176	188
Recurring \| U.S. corporate
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	59,334	58,459
Recurring \| U.S. government and agency
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	34,937	29,248
Recurring \| Foreign corporate
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	30,607	30,301
Recurring \| RMBS
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	26,278	22,773
Recurring \| ABS
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	12,522	10,201
Recurring \| Municipals
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	8,974	7,856
Recurring \| CMBS
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	6,788	5,720
Recurring \| Foreign government
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	5,134	5,006
Recurring \| Level 1
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	15,242	11,487
Short-term investments	2,048	1,077
Other investments	302	396
Derivative assets	1	0
Separate account assets	26,384	22,753
Total assets	43,977	35,713
Liabilities [Abstract]
Derivative liabilities	13	5
Embedded derivatives within liability host contracts	0	0
Total liabilities	31	6
Recurring \| Level 1 \| Interest rate contracts
Assets [Abstract]
Derivative assets	0	0
Liabilities [Abstract]
Derivative liabilities	0	0
Recurring \| Level 1 \| Foreign currency exchange rate contracts
Assets [Abstract]
Derivative assets	0	0
Liabilities [Abstract]
Derivative liabilities	0	0
Recurring \| Level 1 \| Credit contracts
Assets [Abstract]
Derivative assets	0	0
Liabilities [Abstract]
Derivative liabilities	0	0
Recurring \| Level 1 \| Equity market contracts
Assets [Abstract]
Derivative assets	1	0
Liabilities [Abstract]
Derivative liabilities	13	5
Recurring \| Level 1 \| Derivative Liabilities Within Separate Accounts
Liabilities [Abstract]
Separate account liabilities	18	1
Recurring \| Level 1 \| Residential mortgage loans - FVO
Assets [Abstract]
Mortgage Loans on Real Estate, Commercial and Consumer, Net	0	0
Recurring \| Level 1 \| U.S. corporate
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	0	0
Recurring \| Level 1 \| U.S. government and agency
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	14,763	11,484
Recurring \| Level 1 \| Foreign corporate
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	0	0
Recurring \| Level 1 \| RMBS
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	479	3
Recurring \| Level 1 \| ABS
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	0	0
Recurring \| Level 1 \| Municipals
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	0	0
Recurring \| Level 1 \| CMBS
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	0	0
Recurring \| Level 1 \| Foreign government
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	0	0
Recurring \| Level 2
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	151,110	145,283
Short-term investments	304	789
Other investments	314	56
Derivative assets	10,361	7,943
Separate account assets	97,553	94,192
Total assets	259,642	248,263
Liabilities [Abstract]
Derivative liabilities	1,659	1,888
Embedded derivatives within liability host contracts	0	0
Total liabilities	1,669	1,902
Recurring \| Level 2 \| Interest rate contracts
Assets [Abstract]
Derivative assets	7,468	5,690
Liabilities [Abstract]
Derivative liabilities	95	167
Recurring \| Level 2 \| Foreign currency exchange rate contracts
Assets [Abstract]
Derivative assets	2,143	1,642
Liabilities [Abstract]
Derivative liabilities	1,308	1,225
Recurring \| Level 2 \| Credit contracts
Assets [Abstract]
Derivative assets	110	172
Liabilities [Abstract]
Derivative liabilities	5	11
Recurring \| Level 2 \| Equity market contracts
Assets [Abstract]
Derivative assets	640	439
Liabilities [Abstract]
Derivative liabilities	251	485
Recurring \| Level 2 \| Derivative Liabilities Within Separate Accounts
Liabilities [Abstract]
Separate account liabilities	10	14
Recurring \| Level 2 \| Residential mortgage loans - FVO
Assets [Abstract]
Mortgage Loans on Real Estate, Commercial and Consumer, Net	0	0
Recurring \| Level 2 \| U.S. corporate
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	53,028	53,975
Recurring \| Level 2 \| U.S. government and agency
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	20,174	17,764
Recurring \| Level 2 \| Foreign corporate
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	23,033	25,403
Recurring \| Level 2 \| RMBS
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	22,683	20,158
Recurring \| Level 2 \| ABS
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	11,604	9,459
Recurring \| Level 2 \| Municipals
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	8,971	7,849
Recurring \| Level 2 \| CMBS
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	6,490	5,679
Recurring \| Level 2 \| Foreign government
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	5,127	4,996
Recurring \| Level 3
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	18,222	12,794
Short-term investments	0	17
Other investments	522	799
Derivative assets	813	137
Separate account assets	955	922
Total assets	20,688	14,857
Liabilities [Abstract]
Derivative liabilities	22	209
Embedded derivatives within liability host contracts	2,348	1,325
Total liabilities	2,378	1,541
Recurring \| Level 3 \| Interest rate contracts
Assets [Abstract]
Derivative assets	763	80
Liabilities [Abstract]
Derivative liabilities	8	191
Recurring \| Level 3 \| Foreign currency exchange rate contracts
Assets [Abstract]
Derivative assets	3	0
Liabilities [Abstract]
Derivative liabilities	0	0
Recurring \| Level 3 \| Credit contracts
Assets [Abstract]
Derivative assets	17	32
Liabilities [Abstract]
Derivative liabilities	1	1
Recurring \| Level 3 \| Equity market contracts
Assets [Abstract]
Derivative assets	30	25
Liabilities [Abstract]
Derivative liabilities	13	17
Recurring \| Level 3 \| Derivative Liabilities Within Separate Accounts
Liabilities [Abstract]
Separate account liabilities	8	7
Recurring \| Level 3 \| Residential mortgage loans - FVO
Assets [Abstract]
Mortgage Loans on Real Estate, Commercial and Consumer, Net	176	188
Recurring \| Level 3 \| U.S. corporate
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	6,306	4,484
Recurring \| Level 3 \| U.S. government and agency
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	0	0
Recurring \| Level 3 \| Foreign corporate
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	7,574	4,898
Recurring \| Level 3 \| RMBS
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	3,116	2,612
Recurring \| Level 3 \| ABS
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	918	742
Recurring \| Level 3 \| Municipals
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	3	7
Recurring \| Level 3 \| CMBS
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	298	41
Recurring \| Level 3 \| Foreign government
Assets [Abstract]
Estimated Fair Value of Fixed Maturity Securities AFS	7	10
Other limited partnership interests \| Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	$ 71	$ 90

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