Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Principles (Details)

v3.10.0.1
Summary of Significant Accounting Principles (Details) - USD ($)
$ in Billions
 9 Months Ended
Sep. 30, 2018
Jan. 01, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]    
Revenue, performance obligation timing Substantially all card fees are recognized at the transaction date, except for certain time-based fees such as annual fees, which are recognized over 12 months. Other Revenue Measurement and Recognition Policies The Corporation did not disclose the value of any open performance obligations at September 30, 2018, as its contracts with customers generally have a fixed term that is less than one year, an open term with a cancellation period that is less than one year, or provisions that allow the Corporation to recognize revenue at the amount it has the right to invoice.  
Minimum    
New Accounting Pronouncements or Change in Accounting Principle [Line Items]    
Fee percentage of assets under management 0.50%  
Minimum | Accounting Standards Update 2016-02 | Forecast    
New Accounting Pronouncements or Change in Accounting Principle [Line Items]    
Right-of-use asset   $ 9
Lease liability   9
Maximum    
New Accounting Pronouncements or Change in Accounting Principle [Line Items]    
Fee percentage of assets under management 1.50%  
Maximum | Accounting Standards Update 2016-02 | Forecast    
New Accounting Pronouncements or Change in Accounting Principle [Line Items]    
Right-of-use asset   11
Lease liability   $ 11