Fair Value (Unobservable Input Reconciliation) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Consolidated Securitization Entities
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	$ (12)	$ (12)	$ (11)	$ (13)
Total realized/unrealized gains (losses) included in net income (loss)	0	0	0	0
Total realized/unrealized gains (losses) included in AOCI	0	0	0	0
Purchases	0	0	0	0
Sales	0	0	0	0
Issuances	0	0	0	0
Settlements	0	1	(1)	2
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Balance, end of period	(12)	(11)	(12)	(11)
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	0	0	0	0
Net Derivatives
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	(103)	(103)	90	(141)
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance, beginning of period	(132)	(372)	(411)	(300)
Total realized/unrealized gains (losses) included in net income (loss)	(116)	(97)	110	(163)
Total realized/unrealized gains (losses) included in AOCI	(7)	7	36	3
Purchases	0	0	12	4
Sales	0	0	0	0
Issuances	(1)	(1)	(1)	(1)
Settlements	(33)	24	(33)	18
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	(2)	0
Balance, end of period	(289)	(439)	(289)	(439)
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	(103)	(103)	90	(141)
Net Embedded Derivatives
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	750	(1,743)	(4,884)	(973)
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance, beginning of period	(6,804)	841	(544)	430
Total realized/unrealized gains (losses) included in net income (loss)	765	(1,753)	(4,851)	(964)
Total realized/unrealized gains (losses) included in AOCI	(27)	(38)	(237)	(19)
Purchases	0	0	0	0
Sales	0	0	0	0
Issuances	0	0	0	0
Settlements	(239)	(216)	(673)	(613)
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Balance, end of period	(6,305)	(1,166)	(6,305)	(1,166)
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	750	(1,743)	(4,884)	(973)
Residential mortgage loans — FVO
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	449	345	314	308
Total realized/unrealized gains (losses) included in net income (loss)	10	(2)	22	18
Total realized/unrealized gains (losses) included in AOCI	0	0	0	0
Purchases	42	18	187	114
Sales	(5)	(37)	(12)	(100)
Issuances	0	0	0	0
Settlements	(15)	(9)	(30)	(25)
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Balance, end of period	481	315	481	315
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	10	(2)	22	18
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	10	(2)	22	18
Trading Liabilities
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	0	(4)	0	0
Total realized/unrealized gains (losses) included in net income (loss)	0	0	0	0
Total realized/unrealized gains (losses) included in AOCI	0	0	0	0
Purchases	0	(2)	0	(2)
Sales	0	0	0	0
Issuances	0	0	0	0
Settlements	0	0	0	0
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	4	0	0
Balance, end of period	0	(2)	0	(2)
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	0	0	0	0
Corporate fixed maturity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	13,710	13,520	12,796	13,432
Total realized/unrealized gains (losses) included in net income (loss)	15	25	(4)	62
Total realized/unrealized gains (losses) included in AOCI	98	(296)	1,027	(759)
Purchases	680	955	1,893	1,884
Sales	(595)	(351)	(1,034)	(964)
Issuances	0	0	0	0
Settlements	0	0	0	0
Transfers into Level 3	424	699	711	844
Transfers out of Level 3	(473)	(1,850)	(1,530)	(1,797)
Balance, end of period	13,859	12,702	13,859	12,702
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	1	10	2	21
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	1	10	2	21
U.S. government and agency
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	323	55	0	0
Total realized/unrealized gains (losses) included in net income (loss)	0	0	0	0
Total realized/unrealized gains (losses) included in AOCI	(1)	0	17	(1)
Purchases	99	0	111	0
Sales	0	(1)	0	(1)
Issuances	0	0	0	0
Settlements	0	0	0	0
Transfers into Level 3	0	18	200	19
Transfers out of Level 3	(104)	(55)	(11)	0
Balance, end of period	317	17	317	17
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	0	0	0	0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	0	0	0	0
Foreign government
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	376	1,336	856	1,311
Total realized/unrealized gains (losses) included in net income (loss)	2	4	9	10
Total realized/unrealized gains (losses) included in AOCI	1	(1)	(2)	1
Purchases	21	17	58	30
Sales	(7)	(17)	(36)	(39)
Issuances	0	0	0	0
Settlements	0	0	0	0
Transfers into Level 3	0	11	41	7
Transfers out of Level 3	(71)	(659)	(604)	(629)
Balance, end of period	322	691	322	691
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	2	4	9	10
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	2	4	9	10
Structured Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	6,700	7,018	7,116	7,392
Total realized/unrealized gains (losses) included in net income (loss)	34	29	101	88
Total realized/unrealized gains (losses) included in AOCI	39	(46)	28	(68)
Purchases	1,034	2,544	2,291	4,062
Sales	(512)	(418)	(1,357)	(1,304)
Issuances	0	0	0	0
Settlements	0	0	0	0
Transfers into Level 3	81	361	43	355
Transfers out of Level 3	(316)	(955)	(1,162)	(1,992)
Balance, end of period	7,060	8,533	7,060	8,533
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	33	33	96	89
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	33	33	96	89
State and political subdivision
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	53	55	46	0
Total realized/unrealized gains (losses) included in net income (loss)	0	0	1	0
Total realized/unrealized gains (losses) included in AOCI	3	1	2	0
Purchases	0	20	0	46
Sales	0	0	0	0
Issuances	0	0	0	0
Settlements	0	0	0	0
Transfers into Level 3	7	0	7	0
Transfers out of Level 3	(17)	(30)	(10)	0
Balance, end of period	46	46	46	46
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	0	0	1	0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	0	0	1	0
Equity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	682	489	432	345
Total realized/unrealized gains (losses) included in net income (loss)	5	6	(21)	7
Total realized/unrealized gains (losses) included in AOCI	(9)	(14)	43	(22)
Purchases	4	12	20	57
Sales	(20)	(13)	(25)	(34)
Issuances	0	0	0	0
Settlements	0	0	0	0
Transfers into Level 3	1	0	455	107
Transfers out of Level 3	(8)	(30)	(249)	(10)
Balance, end of period	655	450	655	450
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	(1)	0	(27)	0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	(1)	0	(27)	0
FVO And Trading Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	231	475	270	567
Total realized/unrealized gains (losses) included in net income (loss)	4	(16)	9	(27)
Total realized/unrealized gains (losses) included in AOCI	0	0	0	0
Purchases	18	91	43	130
Sales	(6)	(41)	(29)	(130)
Issuances	0	0	0	0
Settlements	0	0	0	0
Transfers into Level 3	0	80	18	82
Transfers out of Level 3	(4)	(191)	(68)	(224)
Balance, end of period	243	398	243	398
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	4	(16)	9	(25)
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	4	(16)	9	(25)
Short-term Investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	175	1,809	291	336
Total realized/unrealized gains (losses) included in net income (loss)	1	0	1	1
Total realized/unrealized gains (losses) included in AOCI	(1)	0	4	0
Purchases	664	1,296	673	1,313
Sales	(55)	(11)	(294)	(28)
Issuances	0	0	0	0
Settlements	0	0	0	0
Transfers into Level 3	0	5	1	0
Transfers out of Level 3	(111)	(1,786)	(3)	(309)
Balance, end of period	673	1,313	673	1,313
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	1	0	1	0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	1	0	1	0
Separate Accounts
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	1,627	1,925	1,704	1,922
Total realized/unrealized gains (losses) included in net income (loss)	(25)	24	7	5
Total realized/unrealized gains (losses) included in AOCI	0	0	0	0
Purchases	4	95	108	297
Sales	(155)	(93)	(233)	(232)
Issuances	30	0	27	0
Settlements	(45)	0	(58)	(2)
Transfers into Level 3	8	2	9	3
Transfers out of Level 3	(180)	(271)	(300)	(311)
Balance, end of period	1,264	1,682	1,264	1,682
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	0	0	0	0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	$ 0	$ 0	$ 0	$ 0