Loans - Summary of Consumer Loans excluding Credit Card (Details 5) (USD $) In Millions	Sep. 30, 2011	Dec. 31, 2010	Sep. 30, 2010
Consumer loans by class, excluding the credit card loan portfolio segment
Retained loans	$ 692,944	$ 685,498	$ 687,049
Consumer Loan Excluding Credit Card
Consumer loans by class, excluding the credit card loan portfolio segment
Retained loans	310,104	327,464
Residential real estate, excluding PCI [Member]
Consumer loans by class, excluding the credit card loan portfolio segment
Retained loans	164,553	174,211
Home Equity - Senior Lien [Member]
Consumer loans by class, excluding the credit card loan portfolio segment
Retained loans	22,364	24,376
Home Equity - Junior Lien [Member]
Consumer loans by class, excluding the credit card loan portfolio segment
Retained loans	57,914	64,009
Prime Mortgages, including option ARMs [Member]
Consumer loans by class, excluding the credit card loan portfolio segment
Retained loans	74,230	74,539
Subprime Mortgage [Member]
Consumer loans by class, excluding the credit card loan portfolio segment
Retained loans	10,045	11,287
Total other consumer [Member]
Consumer loans by class, excluding the credit card loan portfolio segment
Retained loans	78,423	80,490
Auto [Member]
Consumer loans by class, excluding the credit card loan portfolio segment
Retained loans	46,659	48,367
Consumer business banking
Consumer loans by class, excluding the credit card loan portfolio segment
Retained loans	17,272	16,812
Student And Other Loans [Member]
Consumer loans by class, excluding the credit card loan portfolio segment
Retained loans	14,492	15,311
PCI Home Equity [Member]
Consumer loans by class, excluding the credit card loan portfolio segment
Retained loans	23,105	24,459
PCI Prime Mortgage [Member]
Consumer loans by class, excluding the credit card loan portfolio segment
Retained loans	15,626	17,322
PCI Subprime Mortgage [Member]
Consumer loans by class, excluding the credit card loan portfolio segment
Retained loans	5,072	5,398
PCI Option ARMs [Member]
Consumer loans by class, excluding the credit card loan portfolio segment
Retained loans	$ 23,325	$ 25,584