Fair Value Measurements (Details 4) (USD $)	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010
ASSETS
Trading account assets	$ 769,000,000		$ 985,000,000		$ 1,014,000,000
Securities available for sale	18,680,000,000		21,933,000,000		19,773,000,000
Held-to-maturity securities	19,000,000		17,000,000		19,000,000
Other investments	1,195,000,000		1,358,000,000		1,415,000,000
Loans, net of allowance	46,610,000,000		48,503,000,000		51,115,000,000
Loans held for sale	381,000,000	426,000,000	467,000,000	637,000,000	699,000,000	556,000,000
Derivative assets	900,000,000		1,006,000,000		1,153,000,000
LIABILITIES
Long-term debt	10,997,000,000		10,592,000,000		10,451,000,000
Derivative liabilities	991,000,000		1,142,000,000		1,321,000,000
Carrying Amount [Member]
ASSETS
Cash and short-term investments	5,416,000,000		1,622,000,000
Trading account assets	769,000,000		985,000,000
Securities available for sale	18,680,000,000		21,933,000,000
Held-to-maturity securities	19,000,000		17,000,000
Other investments	1,195,000,000		1,358,000,000
Loans, net of allowance	46,610,000,000		48,503,000,000
Loans held for sale	381,000,000		467,000,000
Mortgage servicing assets	180,000,000		196,000,000
Derivative assets	900,000,000		1,006,000,000
LIABILITIES
Deposits with no stated maturity	47,568,000,000		45,598,000,000
Time deposits	12,842,000,000		15,012,000,000
Short-term borrowings	2,179,000,000		3,196,000,000
Long-term debt	10,997,000,000		10,592,000,000
Derivative liabilities	991,000,000		1,142,000,000
Carrying Amount [Member] | Discontinued Operation or Asset Disposal [Member]
ASSETS
Loans, net of allowance	3,100,000,000		3,200,000,000
Loans held for sale	0		15,000,000
Fair Value [Member]
ASSETS
Cash and short-term investments	5,416,000,000		1,622,000,000
Trading account assets	769,000,000		985,000,000
Securities available for sale	18,680,000,000		21,933,000,000
Held-to-maturity securities	19,000,000		17,000,000
Other investments	1,195,000,000		1,358,000,000
Loans, net of allowance	45,759,000,000		46,140,000,000
Loans held for sale	381,000,000		467,000,000
Mortgage servicing assets	247,000,000		284,000,000
Derivative assets	900,000,000		1,006,000,000
LIABILITIES
Deposits with no stated maturity	47,568,000,000		45,598,000,000
Time deposits	13,253,000,000		15,502,000,000
Short-term borrowings	2,179,000,000		3,196,000,000
Long-term debt	11,321,000,000		10,611,000,000
Derivative liabilities	991,000,000		1,142,000,000
Fair Value By Balance Sheet Grouping (Textuals)
Loans in the trusts	3,100,000,000		3,100,000,000
Securities issued by the education lending securitization trust	2,900,000,000		3,000,000,000
Fair Value [Member] | Discontinued Operation or Asset Disposal [Member]
ASSETS
Loans, net of allowance	2,800,000,000		2,800,000,000
Residential Real Estate Mortgage Loans [Member]
ASSETS
Loans, net of allowance	$ 1,800,000,000		$ 1,800,000,000