Fair Value Disclosures (Notional or Contractual Amounts and Fair Values of Off-Balance Sheet Financial Instruments) (Details) (USD $) In Millions	Jun. 30, 2011	Dec. 31, 2010
Residential mortgage loans sold with recourse	$ 1,464	$ 1,624
Commitments to fund affordable housing investments	296	334
Notional/Contract Amount [Member]
Commitments to extend, originate or purchase credit	38,703	36,917
Residential mortgage loans sold with recourse	1,464	1,624
Other loans sold with recourse	4,535	4,352
Letters of credit and financial guarantees written	6,387	7,291
Commitments to fund affordable housing investments	296	334
Fair Value [Member]
Commitments to extend, originate or purchase credit	68	65
Residential mortgage loans sold with recourse	7	6
Other loans sold with recourse	21	19
Letters of credit and financial guarantees written	42	41
Commitments to fund affordable housing investments	$ 280	$ 316