Investments (Details 16) (USD $) In Millions, unless otherwise specified	Sep. 30, 2011	Dec. 31, 2010
Continuous Gross Unrealized Loss and OTTI Loss for Fixed Maturity and Equity Securities Available-for-Sale
Total number of securities in an unrealized loss position less than 12 months	4,414	5,609
Total number of securities in an unrealized loss position equal to or greater than 12 months	1,340	1,704
Fixed maturity securities [Member]
Continuous Gross Unrealized Loss and OTTI Loss for Fixed Maturity and Equity Securities Available-for-Sale
Less than 12 months Estimated Fair Value	$ 65,713	$ 104,579
Less than 12 Months Gross Unrealized Loss	2,379	2,501
Equal to or Greater than 12 Months Estimated Fair Value	14,847	24,679
Equal to or Greater than 12 Months Gross Unrealized Loss	2,871	4,079
Total Estimated Fair Value	80,560	129,258
Total Gross Unrealized Loss	5,250	6,580
U.S. corporate securities [Member]
Continuous Gross Unrealized Loss and OTTI Loss for Fixed Maturity and Equity Securities Available-for-Sale
Less than 12 months Estimated Fair Value	18,303	22,954
Less than 12 Months Gross Unrealized Loss	597	447
Equal to or Greater than 12 Months Estimated Fair Value	4,981	8,319
Equal to or Greater than 12 Months Gross Unrealized Loss	879	1,155
Total Estimated Fair Value	23,284	31,273
Total Gross Unrealized Loss	1,476	1,602
Foreign corporate securities [Member]
Continuous Gross Unrealized Loss and OTTI Loss for Fixed Maturity and Equity Securities Available-for-Sale
Less than 12 months Estimated Fair Value	16,560	22,415
Less than 12 Months Gross Unrealized Loss	846	410
Equal to or Greater than 12 Months Estimated Fair Value	1,480	3,976
Equal to or Greater than 12 Months Gross Unrealized Loss	261	515
Total Estimated Fair Value	18,040	26,391
Total Gross Unrealized Loss	1,107	925
Foreign government debt securities [Member]
Continuous Gross Unrealized Loss and OTTI Loss for Fixed Maturity and Equity Securities Available-for-Sale
Less than 12 months Estimated Fair Value	8,092	26,659
Less than 12 Months Gross Unrealized Loss	208	585
Equal to or Greater than 12 Months Estimated Fair Value	158	189
Equal to or Greater than 12 Months Gross Unrealized Loss	12	17
Total Estimated Fair Value	8,250	26,848
Total Gross Unrealized Loss	220	602
RMBS [Member]
Continuous Gross Unrealized Loss and OTTI Loss for Fixed Maturity and Equity Securities Available-for-Sale
Less than 12 months Estimated Fair Value	3,761	7,588
Less than 12 Months Gross Unrealized Loss	324	212
Equal to or Greater than 12 Months Estimated Fair Value	4,501	6,700
Equal to or Greater than 12 Months Gross Unrealized Loss	965	1,175
Total Estimated Fair Value	8,262	14,288
Total Gross Unrealized Loss	1,289	1,387
U.S. Treasury, agency and government guaranteed securities [Member]
Continuous Gross Unrealized Loss and OTTI Loss for Fixed Maturity and Equity Securities Available-for-Sale
Less than 12 months Estimated Fair Value	8,937	13,401
Less than 12 Months Gross Unrealized Loss	9	530
Equal to or Greater than 12 Months Estimated Fair Value	39	118
Equal to or Greater than 12 Months Gross Unrealized Loss	2	29
Total Estimated Fair Value	8,976	13,519
Total Gross Unrealized Loss	11	559
CMBS [Member]
Continuous Gross Unrealized Loss and OTTI Loss for Fixed Maturity and Equity Securities Available-for-Sale
Less than 12 months Estimated Fair Value	4,974	3,787
Less than 12 Months Gross Unrealized Loss	200	29
Equal to or Greater than 12 Months Estimated Fair Value	620	1,363
Equal to or Greater than 12 Months Gross Unrealized Loss	109	249
Total Estimated Fair Value	5,594	5,150
Total Gross Unrealized Loss	309	278
ABS [Member]
Continuous Gross Unrealized Loss and OTTI Loss for Fixed Maturity and Equity Securities Available-for-Sale
Less than 12 months Estimated Fair Value	4,670	2,713
Less than 12 Months Gross Unrealized Loss	189	42
Equal to or Greater than 12 Months Estimated Fair Value	2,087	3,026
Equal to or Greater than 12 Months Gross Unrealized Loss	480	667
Total Estimated Fair Value	6,757	5,739
Total Gross Unrealized Loss	669	709
State and political subdivision securities [Member]
Continuous Gross Unrealized Loss and OTTI Loss for Fixed Maturity and Equity Securities Available-for-Sale
Less than 12 months Estimated Fair Value	416	5,061
Less than 12 Months Gross Unrealized Loss	6	246
Equal to or Greater than 12 Months Estimated Fair Value	981	988
Equal to or Greater than 12 Months Gross Unrealized Loss	163	272
Total Estimated Fair Value	1,397	6,049
Total Gross Unrealized Loss	169	518
Other fixed maturity securities [Member]
Continuous Gross Unrealized Loss and OTTI Loss for Fixed Maturity and Equity Securities Available-for-Sale
Less than 12 months Estimated Fair Value	0	1
Less than 12 Months Gross Unrealized Loss	0	0
Equal to or Greater than 12 Months Estimated Fair Value	0	0
Equal to or Greater than 12 Months Gross Unrealized Loss	0	0
Total Estimated Fair Value	0	1
Total Gross Unrealized Loss	0	0
Equity Securities [Member]
Continuous Gross Unrealized Loss and OTTI Loss for Fixed Maturity and Equity Securities Available-for-Sale
Less than 12 months Estimated Fair Value	643	280
Less than 12 Months Gross Unrealized Loss	71	21
Equal to or Greater than 12 Months Estimated Fair Value	409	825
Equal to or Greater than 12 Months Gross Unrealized Loss	157	220
Total Estimated Fair Value	1,052	1,105
Total Gross Unrealized Loss	228	241
Common stock
Continuous Gross Unrealized Loss and OTTI Loss for Fixed Maturity and Equity Securities Available-for-Sale
Less than 12 months Estimated Fair Value	416	89
Less than 12 Months Gross Unrealized Loss	41	12
Equal to or Greater than 12 Months Estimated Fair Value	23	1
Equal to or Greater than 12 Months Gross Unrealized Loss	1	0
Total Estimated Fair Value	439	90
Total Gross Unrealized Loss	42	12
Non-redeemable preferred stock [Member]
Continuous Gross Unrealized Loss and OTTI Loss for Fixed Maturity and Equity Securities Available-for-Sale
Less than 12 months Estimated Fair Value	227	191
Less than 12 Months Gross Unrealized Loss	30	9
Equal to or Greater than 12 Months Estimated Fair Value	386	824
Equal to or Greater than 12 Months Gross Unrealized Loss	156	220
Total Estimated Fair Value	613	1,015
Total Gross Unrealized Loss	$ 186	$ 229

Disclosure regarding factors used to determine that the impairment of securities not categorized as either held-to-maturity securities or trading securities (hence equal to available for sale securities) where cost exceeds fair value is not an other than temporary impairment. This item contains disclosure of the number of investment positions in the available-for-sale investments determined to be temporarily impaired for equal to or greater than twelve months.

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