Fair Value of Assets and Liabilities (Details 3) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended				3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended							3 Months Ended	9 Months Ended			3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012 Fixed income securities	Sep. 30, 2011 Fixed income securities	Sep. 30, 2012 Fixed income securities	Sep. 30, 2011 Fixed income securities	Sep. 30, 2012 U.S. government and agencies	Jun. 30, 2012 U.S. government and agencies	Sep. 30, 2012 Municipal	Sep. 30, 2011 Municipal	Sep. 30, 2012 Municipal	Sep. 30, 2011 Municipal	Sep. 30, 2012 Corporate	Sep. 30, 2011 Corporate	Sep. 30, 2012 Corporate	Sep. 30, 2011 Corporate	Sep. 30, 2012 Residential mortgage-backed securities ("RMBS")	Sep. 30, 2011 Residential mortgage-backed securities ("RMBS")	Sep. 30, 2012 Residential mortgage-backed securities ("RMBS")	Sep. 30, 2011 Residential mortgage-backed securities ("RMBS")	Sep. 30, 2012 Commercial mortgage-backed securities ("CMBS")	Sep. 30, 2011 Commercial mortgage-backed securities ("CMBS")	Sep. 30, 2012 Commercial mortgage-backed securities ("CMBS")	Sep. 30, 2011 Commercial mortgage-backed securities ("CMBS")	Sep. 30, 2012 Asset-backed securities ("ABS")	Sep. 30, 2011 Asset-backed securities ("ABS")	Sep. 30, 2012 Asset-backed securities ("ABS")	Sep. 30, 2011 Asset-backed securities ("ABS")	Sep. 30, 2012 Redeemable preferred stock	Jun. 30, 2012 Redeemable preferred stock	Sep. 30, 2011 Redeemable preferred stock	Jun. 30, 2011 Redeemable preferred stock	Dec. 31, 2010 Redeemable preferred stock	Sep. 30, 2012 Equity securities	Sep. 30, 2012 Equity securities	Sep. 30, 2011 Equity securities	Jun. 30, 2011 Equity securities	Sep. 30, 2012 Free-standing derivatives, net	Sep. 30, 2011 Free-standing derivatives, net	Sep. 30, 2012 Free-standing derivatives, net	Sep. 30, 2011 Free-standing derivatives, net	Sep. 30, 2012 Other assets	Jun. 30, 2012 Other assets	Dec. 31, 2011 Other assets	Sep. 30, 2011 Other assets	Jun. 30, 2011 Other assets	Dec. 31, 2010 Other assets
Fair Value Assets Measured on Recurring Basis Unobservable Input Reconciliation Calculation Rollforward
Balance at beginning of period	$ 3,184	$ 7,561	$ 3,095	$ 9,102	$ 3,062	$ 7,574	$ 3,146	$ 9,059		$ 8	$ 1,144	$ 1,554	$ 1,332	$ 2,016	$ 1,524	$ 1,720	$ 1,405	$ 1,908	$ 4	$ 1,194	$ 51	$ 1,794	$ 47	$ 938	$ 60	$ 923	$ 334	$ 2,167	$ 297	$ 2,417	$ 1	$ 1	$ 1	$ 1	$ 1	$ 192	$ 43	$ 63	$ 42	$ (71)	$ (56)	$ (95)	$ (21)	$ 1	$ 1	$ 1	$ 1	$ 1	$ 1
Total gains (losses) included in: net income	4	(108)	41	(215)	(4)	(51)	23	(114)			(4)	(10)	(10)	(34)	10	(4)	16	31				(87)	(1)	(1)	(3)	(43)	(9)	(36)	20	19						(3)	(7)	(10)		11	(57)	25	(91)
Total gains (losses) included in: OCI	88	(100)	154	236	88	(100)	148	236			14	1	31	67	39	(23)	62	(5)		2		108	1	(5)	9	113	34	(75)	46	(47)							6
Transfers into Level 3	170	23	314	271	170	23	314	271	8		53		53		74	3	210	185						20		86	43		43
Transfers out of Level 3	(26)	(2,435)	(193)	(3,163)	(26)	(2,435)	(193)	(3,153)				(22)	(26)	(81)		(107)	(38)	(271)		(1,100)	(47)	(1,213)		(877)	(5)	(946)	(26)	(329)	(77)	(642)								(10)
Purchases	92	417	510	941	69	412	319	869			4		46	13	62	245	193	376					3	2	5	12		165	74	468	1					2	164			21	5	27	72
Sales	(328)	(130)	(660)	(1,571)	(320)	(130)	(637)	(1,570)			(49)	(70)	(254)	(525)	(120)	(59)	(219)	(437)				(378)			(1)	(66)	(151)	(1)	(162)	(164)	(1)					(8)	(23)	(1)
Settlements	(41)	(142)	(118)	(515)	(50)	(140)	(131)	(445)					(10)	(3)	(46)	(45)	(86)	(57)	(1)	(4)	(1)	(132)		(1)	(15)	(3)	(3)	(90)	(19)	(250)										9	(2)	13	(70)
Balance at end of period	3,143	5,086	3,143	5,086	2,989	5,153	2,989	5,153	8	8	1,162	1,453	1,162	1,453	1,543	1,730	1,543	1,730	3	92	3	92	50	76	50	76	222	1,801	222	1,801	1	1	1	1	1	183	183	42	42	(30)	(110)	(30)	(110)	1	1	1	1	1	1
Fair value assets and liabilities measured on recurring basis, gain (loss) included in earnings
Total realized and unrealized gains (losses) included in net income, recurring Level 3 assets and liabilities	164	(106)	192	(239)
Effect to net income included in realized capital gains and losses	(4)	(119)	19	(242)
Effect to net income included in investment income	7	14	22	30
Effect to net income included in interest credited to contract holder funds	143	54	119	(9)
Effect to net income included in life and annuity contract benefits	18	(55)	32	(18)
Free-standing derivatives, assets	2	1	2	1
Free-standing derivatives, liabilities	$ 32	$ 111	$ 32	$ 111