Fair Value of Financial Instruments (Fair value assets and liabilities measured on recurring basis transfer in out) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Level 3 Unobservable Input Reconciliation
Beginning Fair Value	$ 2,051	$ 2,983	$ 3,578
Items Included in Net Income	501	(1,434)	(28)
Gains (Losses) in OCI and other	262	446	447
Sales, Issuances, Maturities, Settlements, Calls, Net	349	(56)	(36)
Transfers In or Out of Level 3, Net	(888)	112	(978)
Ending Fair Value	2,275	2,051	2,983
Corporate bonds [Member]
Level 3 Unobservable Input Reconciliation
Beginning Fair Value	1,888	1,816	2,070
Items Included in Net Income	(27)	2	(42)
Gains (Losses) in OCI and other	34	42	56
Sales, Issuances, Maturities, Settlements, Calls, Net	266	(138)	(218)
Transfers In or Out of Level 3, Net	(656)	166	(50)
Ending Fair Value	1,505	1,888	1,816
U.S. government bonds [Member]
Level 3 Unobservable Input Reconciliation
Beginning Fair Value	1	2	3
Items Included in Net Income	0	0	0
Gains (Losses) in OCI and other	0	0	0
Sales, Issuances, Maturities, Settlements, Calls, Net	0	(1)	(4)
Transfers In or Out of Level 3, Net	0	0	3
Ending Fair Value	1	1	2
Foreign government bonds [Member]
Level 3 Unobservable Input Reconciliation
Beginning Fair Value	97	113	92
Items Included in Net Income	0	0	0
Gains (Losses) in OCI and other	0	4	8
Sales, Issuances, Maturities, Settlements, Calls, Net	(5)	(3)	(4)
Transfers In or Out of Level 3, Net	(46)	(17)	17
Ending Fair Value	46	97	113
RMBS [Member]
Level 3 Unobservable Input Reconciliation
Beginning Fair Value	158	119	136
Items Included in Net Income	(3)	(3)	(5)
Gains (Losses) in OCI and other	3	7	9
Sales, Issuances, Maturities, Settlements, Calls, Net	(8)	35	(17)
Transfers In or Out of Level 3, Net	(147)	0	(4)
Ending Fair Value	3	158	119
CLNs [Member]
Level 3 Unobservable Input Reconciliation
Beginning Fair Value			322
Items Included in Net Income			0
Gains (Losses) in OCI and other			278
Sales, Issuances, Maturities, Settlements, Calls, Net			0
Transfers In or Out of Level 3, Net			(600)
Ending Fair Value			0
State and municipal bonds [Member]
Level 3 Unobservable Input Reconciliation
Beginning Fair Value	0
Items Included in Net Income	0
Gains (Losses) in OCI and other	0
Sales, Issuances, Maturities, Settlements, Calls, Net	32
Transfers In or Out of Level 3, Net	0
Ending Fair Value	32
Hybrid and redeemable preferred securities
Level 3 Unobservable Input Reconciliation
Beginning Fair Value	100	119	156
Items Included in Net Income	(1)	(1)	3
Gains (Losses) in OCI and other	24	(6)	(26)
Sales, Issuances, Maturities, Settlements, Calls, Net	0	(9)	(14)
Transfers In or Out of Level 3, Net	(5)	(3)	0
Ending Fair Value	118	100	119
Equity securities [Member]
Level 3 Unobservable Input Reconciliation
Beginning Fair Value	56	92	88
Items Included in Net Income	(8)	8	0
Gains (Losses) in OCI and other	13	(12)	8
Sales, Issuances, Maturities, Settlements, Calls, Net	26	1	(4)
Transfers In or Out of Level 3, Net	0	(33)	0
Ending Fair Value	87	56	92
Trading securities [Member]
Level 3 Unobservable Input Reconciliation
Beginning Fair Value	68	76	91
Items Included in Net Income	3	1	3
Gains (Losses) in OCI and other	4	3	(10)
Sales, Issuances, Maturities, Settlements, Calls, Net	(2)	(8)	(7)
Transfers In or Out of Level 3, Net	(17)	(4)	(1)
Ending Fair Value	56	68	76
Derivative investments [Member]
Level 3 Unobservable Input Reconciliation
Beginning Fair Value	2,470	1,495	1,368
Items Included in Net Income	(790)	495	(151)
Gains (Losses) in OCI and other	158	363	7
Sales, Issuances, Maturities, Settlements, Calls, Net	188	117	271
Transfers In or Out of Level 3, Net	0	0
Ending Fair Value	2,026	2,470	1,495
Indexed Annuity Contracts [Member]
Level 3 Unobservable Input Reconciliation
Beginning Fair Value	(399)	(497)	(419)
Items Included in Net Income	(136)	5	(81)
Gains (Losses) in OCI and other	0	0	0
Sales, Issuances, Maturities, Settlements, Calls, Net	(197)	93	3
Transfers In or Out of Level 3, Net	0	0	0
Ending Fair Value	(732)	(399)	(497)
Guaranteed Living Benefits Embedded Derivative Reserves [Member]
Level 3 Unobservable Input Reconciliation
Beginning Fair Value	(2,217)	(408)	(676)
Items Included in Net Income	1,308	(1,809)	268
Gains (Losses) in OCI and other	0	0	0
Sales, Issuances, Maturities, Settlements, Calls, Net	0	0	0
Transfers In or Out of Level 3, Net	0	0	0
Ending Fair Value	(909)	(2,217)	(408)
Variable Interest Entities Liabilities - Derivative Instruments [Member]
Level 3 Unobservable Input Reconciliation
Beginning Fair Value	(291)	(209)	0
Items Included in Net Income	163	(82)	16
Gains (Losses) in OCI and other	0	0	0
Sales, Issuances, Maturities, Settlements, Calls, Net	0	0	0
Transfers In or Out of Level 3, Net	0	0	(225)
Ending Fair Value	(128)	(291)	(209)
Credit default swaps [Member]
Level 3 Unobservable Input Reconciliation
Beginning Fair Value	(16)	(16)	(65)
Items Included in Net Income	5	(7)	7
Gains (Losses) in OCI and other	0	0	0
Sales, Issuances, Maturities, Settlements, Calls, Net	0	7	42
Transfers In or Out of Level 3, Net	0	0	0
Ending Fair Value	(11)	(16)	(16)
U.S. pension plan assets [Member]
Level 3 Unobservable Input Reconciliation
Ending Fair Value			40
CDOs [Member]
Level 3 Unobservable Input Reconciliation
Beginning Fair Value	102	172	153
Items Included in Net Income	(2)	19	1
Gains (Losses) in OCI and other	8	(17)	30
Sales, Issuances, Maturities, Settlements, Calls, Net	61	(72)	(12)
Transfers In or Out of Level 3, Net	(15)	0	0
Ending Fair Value	154	102	172
CMBS [Member]
Level 3 Unobservable Input Reconciliation
Beginning Fair Value	34	109	259
Items Included in Net Income	(11)	(62)	(47)
Gains (Losses) in OCI and other	18	62	87
Sales, Issuances, Maturities, Settlements, Calls, Net	(12)	(78)	(72)
Transfers In or Out of Level 3, Net	(2)	3	(118)
Ending Fair Value	27	34	109
Pension and Postretirement Benefit Assets [Member]
Level 3 Unobservable Input Reconciliation
Beginning Fair Value			3
Items Included in Net Income		2	0
Gains (Losses) in OCI and other		(3)	3
Sales, Issuances, Maturities, Settlements, Calls, Net		(39)	34
Transfers In or Out of Level 3, Net		0	0
Ending Fair Value		$ 0