Loans - Other Consumer Loans, by Delinquency, Geography and Risk (Details 7) (USD $) In Millions, unless otherwise specified	Sep. 30, 2011	Dec. 31, 2010	Sep. 30, 2010
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	$ 692,944	$ 685,498	$ 687,049
Other Consumer [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	78,423	80,490
Percentage Of Loans Thirty Plus Days Past Due To Total Retained Loans	1.56%	1.75%
Other Consumer [Member] | Current and less than 30 days past due and still accruing [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	76,208	78,016
Other Consumer [Member] | Noncriticized [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	16,939	16,154
Other Consumer [Member] | Criticized Performing [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	954	1,247
Other Consumer [Member] | Criticized Nonaccrual [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	557	586
Other Consumer [Member] | California [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	6,799	6,488
Other Consumer [Member] | New York [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	7,780	8,057
Other Consumer [Member] | Florida [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	2,762	2,865
Other Consumer [Member] | Illinois [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	4,609	4,868
Other Consumer [Member] | Texas [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	8,128	8,328
Other Consumer [Member] | New Jersey [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	2,710	2,766
Other Consumer [Member] | Arizona [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	2,996	3,104
Other Consumer [Member] | Washington [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	1,143	1,110
Other Consumer [Member] | Ohio [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	5,141	5,618
Other Consumer [Member] | Michigan [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	4,294	4,564
Other Consumer [Member] | All Other States [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	32,061	32,722
Other Consumer [Member] | 30-119 days past due [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	1,572	1,725
Other Consumer [Member] | Days Past Due, 120 or More [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	643	749
Other Consumer [Member] | Past Due And Still Accruing 90 Days Or More Member
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	567	625
Other Consumer [Member] | Nonaccrual [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	938	1,040
Current and less than 30 days past due and still accruing [Member] | Consumer Loans Auto Financing Receivable [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	46,188	47,778
Past Due And Still Accruing 90 Days Or More Member | Consumer Loans Auto Financing Receivable [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	0	0
Nonaccrual [Member] | Consumer Loans Auto Financing Receivable [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	114	141
Noncriticized [Member] | Consumer Loans Auto Financing Receivable [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	5,537	5,803
Criticized Performing [Member] | Consumer Loans Auto Financing Receivable [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	174	265
Criticized Nonaccrual [Member] | Consumer Loans Auto Financing Receivable [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	1	12
Consumer Loans Auto Financing Receivable [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	46,659	48,367
Percentage Of Loans Thirty Plus Days Past Due To Total Retained Loans	1.01%	1.22%
Consumer Loans Auto Financing Receivable [Member] | California [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	4,335	4,307
Consumer Loans Auto Financing Receivable [Member] | New York [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	3,579	3,875
Consumer Loans Auto Financing Receivable [Member] | Florida [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	1,826	1,923
Consumer Loans Auto Financing Receivable [Member] | Illinois [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	2,398	2,608
Consumer Loans Auto Financing Receivable [Member] | Texas [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	4,397	4,505
Consumer Loans Auto Financing Receivable [Member] | New Jersey [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	1,819	1,842
Consumer Loans Auto Financing Receivable [Member] | Arizona [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	1,497	1,499
Consumer Loans Auto Financing Receivable [Member] | Washington [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	737	716
Consumer Loans Auto Financing Receivable [Member] | Ohio [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	2,674	2,961
Consumer Loans Auto Financing Receivable [Member] | Michigan [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	2,272	2,434
Consumer Loans Auto Financing Receivable [Member] | All Other States [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	21,125	21,697
Consumer Loans Auto Financing Receivable [Member] | 30-119 days past due [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	465	579
Consumer Loans Auto Financing Receivable [Member] | Days Past Due, 120 or More [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	6	10
Current and less than 30 days past due and still accruing [Member] | Consumer business banking
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	16,798	16,240
Past Due And Still Accruing 90 Days Or More Member | Consumer business banking
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	0	0
Nonaccrual [Member] | Consumer business banking
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	756	832
Noncriticized [Member] | Consumer business banking
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	11,402	10,351
Criticized Performing [Member] | Consumer business banking
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	780	982
Criticized Nonaccrual [Member] | Consumer business banking
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	556	574
Consumer business banking
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	17,272	16,812
Percentage Of Loans Thirty Plus Days Past Due To Total Retained Loans	2.74%	3.40%
Consumer business banking | California [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	1,211	851
Consumer business banking | New York [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	2,745	2,877
Consumer business banking | Florida [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	269	220
Consumer business banking | Illinois [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	1,340	1,320
Consumer business banking | Texas [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	2,635	2,550
Consumer business banking | New Jersey [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	419	422
Consumer business banking | Arizona [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	1,171	1,218
Consumer business banking | Washington [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	151	115
Consumer business banking | Ohio [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	1,555	1,647
Consumer business banking | Michigan [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	1,369	1,401
Consumer business banking | All Other States [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	4,407	4,191
Consumer business banking | 30-119 days past due [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	303	351
Consumer business banking | Days Past Due, 120 or More [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	171	221
Current and less than 30 days past due and still accruing [Member] | Student And Other Loans [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	13,222	13,998
Past Due And Still Accruing 90 Days Or More Member | Student And Other Loans [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	567	625
Nonaccrual [Member] | Student And Other Loans [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	68	67
Student And Other Loans [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	14,492	15,311
Percentage Of Loans Thirty Plus Days Past Due To Total Retained Loans	1.90%	1.61%
Student And Other Loans [Member] | California [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	1,253	1,330
Student And Other Loans [Member] | New York [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	1,456	1,305
Student And Other Loans [Member] | Florida [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	667	722
Student And Other Loans [Member] | Illinois [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	871	940
Student And Other Loans [Member] | Texas [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	1,096	1,273
Student And Other Loans [Member] | New Jersey [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	472	502
Student And Other Loans [Member] | Arizona [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	328	387
Student And Other Loans [Member] | Washington [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	255	279
Student And Other Loans [Member] | Ohio [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	912	1,010
Student And Other Loans [Member] | Michigan [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	653	729
Student And Other Loans [Member] | All Other States [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	6,529	6,834
Student And Other Loans [Member] | 30-119 days past due [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	804	795
Student And Other Loans [Member] | Days Past Due, 120 or More [Member]
Schedule of Loan Credit Quality, by Portfolio Segment and Class, by Geography, Delinquency, Risk Rating [Line Items]
Retained loans	$ 466	$ 518