Fair Value of Assets and Liabilities (Details 3) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended	6 Months Ended	3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended	6 Months Ended			3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended	6 Months Ended				3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012 Fixed income securities	Jun. 30, 2011 Fixed income securities	Jun. 30, 2012 Fixed income securities	Jun. 30, 2011 Fixed income securities	Jun. 30, 2012 U.S. government and agencies	Jun. 30, 2012 U.S. government and agencies	Jun. 30, 2012 Municipal	Jun. 30, 2011 Municipal	Jun. 30, 2012 Municipal	Jun. 30, 2011 Municipal	Jun. 30, 2012 Corporate	Jun. 30, 2011 Corporate	Jun. 30, 2012 Corporate	Jun. 30, 2011 Corporate	Jun. 30, 2011 Residential mortgage-backed securities ("RMBS")	Jun. 30, 2012 Residential mortgage-backed securities ("RMBS")	Jun. 30, 2011 Residential mortgage-backed securities ("RMBS")	Mar. 31, 2012 Residential mortgage-backed securities ("RMBS")	Jun. 30, 2012 Commercial mortgage-backed securities ("CMBS")	Jun. 30, 2011 Commercial mortgage-backed securities ("CMBS")	Jun. 30, 2012 Commercial mortgage-backed securities ("CMBS")	Jun. 30, 2011 Commercial mortgage-backed securities ("CMBS")	Jun. 30, 2012 Asset-backed securities ("ABS")	Jun. 30, 2011 Asset-backed securities ("ABS")	Jun. 30, 2012 Asset-backed securities ("ABS")	Jun. 30, 2011 Asset-backed securities ("ABS")	Jun. 30, 2012 Redeemable preferred stock	Jun. 30, 2012 Redeemable preferred stock	Jun. 30, 2011 Redeemable preferred stock	Mar. 31, 2011 Redeemable preferred stock	Dec. 31, 2010 Redeemable preferred stock	Jun. 30, 2012 Equity securities	Jun. 30, 2011 Equity securities	Jun. 30, 2012 Equity securities	Jun. 30, 2011 Equity securities	Jun. 30, 2012 Free-standing derivatives, net	Jun. 30, 2011 Free-standing derivatives, net	Jun. 30, 2012 Free-standing derivatives, net	Jun. 30, 2011 Free-standing derivatives, net	Jun. 30, 2012 Other assets	Mar. 31, 2012 Other assets	Dec. 31, 2011 Other assets	Jun. 30, 2011 Other assets	Mar. 31, 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	$ 3,126	$ 8,357	$ 3,095	$ 9,102	$ 3,082	$ 8,384	$ 3,146	$ 9,059			$ 1,267	$ 1,864	$ 1,332	$ 2,016	$ 1,461	$ 2,035	$ 1,405	$ 1,908	$ 1,398	$ 51	$ 1,794	$ 4	$ 50	$ 995	$ 60	$ 923	$ 299	$ 2,091	$ 297	$ 2,417	$ 1	$ 1	$ 1	$ 1	$ 1	$ 113	$ 43	$ 43	$ 63	$ (70)	$ (71)	$ (95)	$ (21)	$ 1	$ 1	$ 1	$ 1	$ 1	$ 1
Total realized and unrealized gains (losses) included in net income, recurring Level 3 assets	5	(29)	37	(107)	12	(26)	27	(63)			(4)	(13)	(6)	(24)	1	23	6	35	(26)		(87)		(1)	(21)	(2)	(42)	16	11	29	55						(4)		(4)	(10)	(3)	(3)	14	(34)
Total realized and unrealized gains (losses) included in OCI on Statement of Financial Position	12	70	66	336	6	70	60	336			10	45	17	66	(5)	8	23	18	1		106		2	4	8	118	(1)	12	12	28						6		6
Purchases	211	272	418	524	116	253	250	457				3	42	13	55	35	131	131					2	2	2	10	58	213	74	303	1	1				92		162		3	19	6	67
Sales	(169)	(819)	(332)	(1,441)	(154)	(818)	(317)	(1,440)			(100)	(321)	(205)	(455)	(41)	(347)	(99)	(378)	(60)		(378)		(1)	(41)	(1)	(66)	(11)	(49)	(11)	(163)	(1)	(1)				(15)	(1)	(15)	(1)
Settlements	(28)	(161)	(77)	(373)	(27)	(160)	(81)	(305)			(9)	(2)	(10)	(3)	(7)	(4)	(40)	(12)	(51)		(128)			(1)	(15)	(2)	(11)	(102)	(16)	(160)										(1)	(1)	4	(68)
Transfers into Level 3	88	97	144	248	88	97	144	248	8	8					80	87	136	182						10		66
Transfers out of Level 3	(61)	(226)	(167)	(728)	(61)	(226)	(167)	(718)			(20)	(22)	(26)	(59)	(20)	(117)	(38)	(164)	(68)	(47)	(113)		(5)	(10)	(5)	(69)	(16)	(9)	(51)	(313)									(10)
Balance at end of period	3,184	7,561	3,184	7,561	3,062	7,574	3,062	7,574	8	8	1,144	1,554	1,144	1,554	1,524	1,720	1,524	1,720	1,194	4	1,194	4	47	938	47	938	334	2,167	334	2,167	1	1	1	1	1	192	42	192	42	(71)	(56)	(71)	(56)	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	21	(63)	28	(133)
Effect to net income included in realized capital gains and losses	(3)	(38)	23	(123)
Effect to net income included in investment income	9	9	15	16
Effect to net income included in interest credited to contract holder funds	32	(26)	(24)	(63)
Effect to net income included in life and annuity contract benefits	(17)	(8)	14	37
Free-standing derivatives, assets	1	22	1	22
Free-standing derivatives, liabilities	$ 72	$ 78	$ 72	$ 78