Fair Value, Option, Gains and Losses (Details) (USD $) In Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Mortgages held for sale [Member] | Mortgage banking noninterest income [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Gains on changes in fair value	$ 2,252	$ 1,986	$ 4,109	$ 5,217
Mortgages held for sale [Member] | Other noninterest income [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Gains on changes in fair value	0	0	0	0
Loans held for sale [Member] | Mortgage banking noninterest income [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Gains on changes in fair value	0	0	0	0
Loans held for sale [Member] | Other noninterest income [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Gains on changes in fair value	(2)	11	19	28
Loans [Member] | Mortgage banking noninterest income [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Gains on changes in fair value	0	16	13	68
Loans [Member] | Other noninterest income [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Gains on changes in fair value	0	0	0	0
Long-term debt [Member] | Mortgage banking noninterest income [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Gains on changes in fair value	0	(15)	(11)	(60)
Long-term debt [Member] | Other noninterest income [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Gains on changes in fair value	0	0	0	0
Other interests held [Member] | Mortgage banking noninterest income [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Gains on changes in fair value	0	0	0	0
Other interests held [Member] | Other noninterest income [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Gains on changes in fair value	$ (49)	$ 22	$ (25)	$ (24)