v3.3.0.814
Legal Matters Legal Matters - Accrued Litigation (Details)
$ in Millions
1 Months Ended 12 Months Ended
Dec. 31, 2010
financial_institution
Sep. 30, 2015
USD ($)
Sep. 30, 2014
USD ($)
Loss Contingency Accrual [Roll Forward]      
Accrued Litigation, Beginning of Period   $ 1,456 $ 5
Accrued Litigation, End of Period   1,024 1,456
Unsettled      
Loss Contingency Accrual [Roll Forward]      
Provision for unsettled legal matters   14 453
Settled Litigation      
Loss Contingency Accrual [Roll Forward]      
Payments on unsettled and settled matters   (446) (58)
Covered Litigation      
Loss Contingency Accrual [Roll Forward]      
Accrued Litigation, Beginning of Period   1,449 0
Accrued Litigation, End of Period   1,023 1,449
Covered Litigation | Settled Litigation      
Loss Contingency Accrual [Roll Forward]      
Payments on unsettled and settled matters   (426) (57)
Canadian Competition Proceedings      
Loss Contingencies [Line Items]      
Number of Financial Institutions | financial_institution 10    
Interchange Multidistrict Litigation      
Loss Contingency Accrual [Roll Forward]      
Provision for unsettled legal matters   0 1,056
Interchange Multidistrict Litigation | Covered Litigation      
Loss Contingency Accrual [Roll Forward]      
Provision for unsettled legal matters   $ 0 $ 1,056