Investments (Sales or Disposals and Impairments of Fixed Maturity and Equity Securities) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Components of Sales or Disposals of Fixed Maturity and Equity Securities
Proceeds	$ 22,341	$ 15,863	$ 41,977	$ 35,382
Gross investment gains	333	248	841	583
Gross investment losses	(149)	(154)	(294)	(490)
Total OTTI losses recognized in earnings:
Credit-related	(39)	(68)	(81)	(141)
Other	(1)	(25)	(40)	(100)
Total OTTI losses recognized in earnings	(40)	(93)	(121)	(241)
Net investment gains (losses)	144	1	426	(148)
Fixed maturity securities [Member]
Components of Sales or Disposals of Fixed Maturity and Equity Securities
Proceeds	22,072	15,625	41,622	35,019
Gross investment gains	323	225	823	550
Gross investment losses	(144)	(152)	(275)	(484)
Total OTTI losses recognized in earnings:
Credit-related	(39)	(68)	(81)	(141)
Other	0	(23)	(18)	(83)
Total OTTI losses recognized in earnings	(39)	(91)	(99)	(224)
Net investment gains (losses)	140	(18)	449	(158)
Equity Securities [Member]
Components of Sales or Disposals of Fixed Maturity and Equity Securities
Proceeds	269	238	355	363
Gross investment gains	10	23	18	33
Gross investment losses	(5)	(2)	(19)	(6)
Total OTTI losses recognized in earnings:
Credit-related	0	0	0	0
Other	(1)	(2)	(22)	(17)
Total OTTI losses recognized in earnings	(1)	(2)	(22)	(17)
Net investment gains (losses)	$ 4	$ 19	$ (23)	$ 10