Variable Interest Entities (Details) (USD $)	6 Months Ended	12 Months Ended
	Jun. 30, 2011	Dec. 31, 2010
Variable Interest Entities
Investment securities related to state and political subdivisions	$ 2,830,000,000	$ 2,850,000,000
Variable interest entity, other short-term borrowings	2,420,000,000	2,500,000,000
Weighted-average life of trusts, years	7.5	7.7
Total standby bond purchase agreement committed to trusts	2,470,000,000
Asset-backed securities, fair value	6,060,000,000	6,110,000,000
Receivable loans Purchased	1,680,000,000	2,200,000,000
Commercial paper	0	1,920,000,000
Aggregate notional value of CDOs	1,000,000,000	1,000,000,000
Carrying value of the underlying collateral	$ 292,000,000	$ 323,000,000