Investments (Details) (USD $) In Millions	Sep. 30, 2011	Dec. 31, 2010
Schedule of Available for Sale Securities
Amortized cost	$ 73,935	$ 78,786
Gross unrealized gains	4,266	3,257
Gross unrealized losses	(1,807)	(2,431)
Fair value	76,394	79,612
U.S. government and agencies
Schedule of Available for Sale Securities
Amortized cost	4,009	8,320
Gross unrealized gains	337	327
Gross unrealized losses		(51)
Fair value	4,346	8,596
Municipal
Schedule of Available for Sale Securities
Amortized cost	14,445	16,201
Gross unrealized gains	816	379
Gross unrealized losses	(262)	(646)
Fair value	14,999	15,934
Corporate
Schedule of Available for Sale Securities
Amortized cost	42,335	36,260
Gross unrealized gains	2,644	1,816
Gross unrealized losses	(450)	(421)
Fair value	44,529	37,655
Foreign government
Schedule of Available for Sale Securities
Amortized cost	1,941	2,821
Gross unrealized gains	197	347
Gross unrealized losses	(5)	(10)
Fair value	2,133	3,158
Residential mortgage-backed securities ("RMBS")
Schedule of Available for Sale Securities
Amortized cost	5,027	8,509
Gross unrealized gains	146	216
Gross unrealized losses	(541)	(732)
Fair value	4,632	7,993
Commercial mortgage-backed securities ("CMBS")
Schedule of Available for Sale Securities
Amortized cost	2,045	2,213
Gross unrealized gains	37	58
Gross unrealized losses	(258)	(277)
Fair value	1,824	1,994
Asset-backed securities ("ABS")
Schedule of Available for Sale Securities
Amortized cost	4,110	4,425
Gross unrealized gains	87	113
Gross unrealized losses	(291)	(294)
Fair value	3,906	4,244
Redeemable preferred stock
Schedule of Available for Sale Securities
Amortized cost	23	37
Gross unrealized gains	2	1
Fair value	$ 25	$ 38

For an unclassified balance sheet, total of debt securities categorized neither as held-to-maturity nor trading.

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+ Details