Securities Available for Sale, Other-Than-Temporary Impairment (OTTI), Included in Earnings (Details) (USD $) In Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Other-Than-Temporary Impairment Equity Securities Earnings [Abstract]
Securities available for sale	$ 189	$ 106	$ 269	$ 212
Nonmarketable equity securities	16	62	57	153
Total OTTI write-downs included in earnings	205	168	326	365
Debt Securities [Member]
Other-Than-Temporary Impairment Debt Securities Earnings [Abstract]
Debt securities	189	106	269	198
Other-Than-Temporary Impairment Equity Securities Earnings [Abstract]
Securities available for sale	189	106	269	198
US States and Political Subdivisions [Member]
Other-Than-Temporary Impairment Debt Securities Earnings [Abstract]
Debt securities	2	3	2	8
Residential [Member]
Other-Than-Temporary Impairment Debt Securities Earnings [Abstract]
Debt securities	144	37	206	76
Other-Than-Temporary Impairment Equity Securities Earnings [Abstract]
Securities available for sale	144	37	206	76
Commercial [Member]
Other-Than-Temporary Impairment Debt Securities Earnings [Abstract]
Debt securities	9	42	23	55
Corporate debt securities [Member]
Other-Than-Temporary Impairment Debt Securities Earnings [Abstract]
Debt securities	0	4	0	5
Collateralized debt obligations [Member]
Other-Than-Temporary Impairment Debt Securities Earnings [Abstract]
Debt securities	0	5	0	11
Other Debt Securities [Member]
Other-Than-Temporary Impairment Debt Securities Earnings [Abstract]
Debt securities	34	15	38	43
Equity Securities [Member]
Other-Than-Temporary Impairment Equity Securities Earnings [Abstract]
Equity securities	0	0	0	14
Perpetual preferred securities [Member]
Other-Than-Temporary Impairment Equity Securities Earnings [Abstract]
Equity securities	$ 0	$ 0	$ 0	$ 14