Fair Value (Unobservable Input Reconciliation) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Consolidated Securitization Entities
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at January 1,	$ (11)	$ (13)
Total realized/unrealized gains (losses) included in net income (loss)	(1)	0
Total realized/unrealized gains (losses) included in AOCI	0	0
Purchases	0	0
Sales	0	0
Issuances	0	0
Settlements	0	1
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Balance at March 31,	(12)	(12)
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	(1)	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	50	(64)
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance at January 1,	(411)	(300)
Total realized/unrealized gains (losses) included in net income (loss)	67	(68)
Total realized/unrealized gains (losses) included in AOCI	9	15
Purchases	8	0
Sales	0	0
Issuances	(1)	0
Settlements	(10)	8
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Balance at March 31,	(338)	(345)
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	50	(64)
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	(1,114)	47
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance at January 1,	(544)	430
Total realized/unrealized gains (losses) included in net income (loss)	(1,111)	51
Total realized/unrealized gains (losses) included in AOCI	(75)	(2)
Purchases	0	0
Sales	0	0
Issuances	0	0
Settlements	(209)	(201)
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Balance at March 31,	(1,939)	278
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	(1,114)	47
Residential mortgage loans — FVO
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at January 1,	314	308
Total realized/unrealized gains (losses) included in net income (loss)	10	22
Total realized/unrealized gains (losses) included in AOCI	0	0
Purchases	80	60
Sales	(5)	(49)
Issuances	0	0
Settlements	(7)	(12)
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Balance at March 31,	392	329
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	10	22
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	22
Corporate fixed maturity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at January 1,	12,796	13,432
Total realized/unrealized gains (losses) included in net income (loss)	(33)	(2)
Total realized/unrealized gains (losses) included in AOCI	510	(75)
Purchases	668	609
Sales	(272)	(242)
Issuances	0	0
Settlements	0	0
Transfers into Level 3	461	221
Transfers out of Level 3	(1,338)	(214)
Balance at March 31,	12,792	13,729
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	(31)	6
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	(31)	6
U.S. government and agency
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at January 1,	0	0
Total realized/unrealized gains (losses) included in net income (loss)	0	0
Total realized/unrealized gains (losses) included in AOCI	11	0
Purchases	0	0
Sales	0	0
Issuances	0	0
Settlements	0	0
Transfers into Level 3	200	0
Transfers out of Level 3	0	0
Balance at March 31,	211	0
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	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
Foreign government
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at January 1,	856	1,311
Total realized/unrealized gains (losses) included in net income (loss)	8	(18)
Total realized/unrealized gains (losses) included in AOCI	(22)	23
Purchases	19	43
Sales	(17)	(53)
Issuances	0	0
Settlements	0	0
Transfers into Level 3	47	215
Transfers out of Level 3	(179)	(137)
Balance at March 31,	712	1,384
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	8	3
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	8	3
Structured
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at January 1,	7,116	7,392
Total realized/unrealized gains (losses) included in net income (loss)	31	8
Total realized/unrealized gains (losses) included in AOCI	(46)	(30)
Purchases	937	1,450
Sales	(373)	(571)
Issuances	0	0
Settlements	0	0
Transfers into Level 3	11	8
Transfers out of Level 3	(1,024)	(615)
Balance at March 31,	6,652	7,642
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	30	13
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	30	13
State and political subdivision
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at January 1,	46	0
Total realized/unrealized gains (losses) included in net income (loss)	0	0
Total realized/unrealized gains (losses) included in AOCI	0	0
Purchases	0	0
Sales	0	0
Issuances	0	0
Settlements	0	0
Transfers into Level 3	0	2
Transfers out of Level 3	(10)	0
Balance at March 31,	36	2
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	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
Equity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at January 1,	432	345
Total realized/unrealized gains (losses) included in net income (loss)	(26)	(1)
Total realized/unrealized gains (losses) included in AOCI	43	(2)
Purchases	5	9
Sales	(1)	(5)
Issuances	0	0
Settlements	0	0
Transfers into Level 3	464	1
Transfers out of Level 3	(248)	(9)
Balance at March 31,	669	338
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	(26)	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	(26)	0
FVO And Trading Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at January 1,	270	567
Total realized/unrealized gains (losses) included in net income (loss)	8	(18)
Total realized/unrealized gains (losses) included in AOCI	0	0
Purchases	19	113
Sales	(11)	(152)
Issuances	0	0
Settlements	0	0
Transfers into Level 3	25	39
Transfers out of Level 3	(62)	(28)
Balance at March 31,	249	521
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	8	(16)
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	8	(16)
Short-term Investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at January 1,	291	336
Total realized/unrealized gains (losses) included in net income (loss)	1	1
Total realized/unrealized gains (losses) included in AOCI	2	(1)
Purchases	108	1,332
Sales	(248)	(25)
Issuances	0	0
Settlements	0	0
Transfers into Level 3	18	0
Transfers out of Level 3	(2)	(285)
Balance at March 31,	170	1,358
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	1	1
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	1
Separate Accounts
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at January 1,	1,704	1,922
Total realized/unrealized gains (losses) included in net income (loss)	32	36
Total realized/unrealized gains (losses) included in AOCI	0	0
Purchases	55	231
Sales	(201)	(127)
Issuances	0	0
Settlements	0	(1)
Transfers into Level 3	0	1
Transfers out of Level 3	(124)	(6)
Balance at March 31,	1,466	2,056
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	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