Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Principles (Details)

v3.19.3
Summary of Significant Accounting Principles (Details) - USD ($)
$ in Millions
Jan. 01, 2020
Sep. 30, 2019
Jan. 01, 2019
Jan. 01, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]        
Cumulative effect of new accounting principle     $ 165 $ 25
Right-of-use asset   $ 9,800    
Lease liability   $ 10,130    
Accounting Standards Update 2016-02        
New Accounting Pronouncements or Change in Accounting Principle [Line Items]        
Right-of-use asset     9,700  
Lease liability     9,700  
Retained Earnings        
New Accounting Pronouncements or Change in Accounting Principle [Line Items]        
Cumulative effect of new accounting principle     165 $ (32)
Retained Earnings | Accounting Standards Update 2016-02        
New Accounting Pronouncements or Change in Accounting Principle [Line Items]        
Cumulative effect of new accounting principle     $ 165  
Scenario, Forecast | Accounting Standards Update 2016-13        
New Accounting Pronouncements or Change in Accounting Principle [Line Items]        
Loans and leases receivable, percentage increase in allowance 30.00%      
Previously Reported | Scenario, Forecast | Accounting Standards Update 2016-13        
New Accounting Pronouncements or Change in Accounting Principle [Line Items]        
Loans and leases receivable, percentage increase in allowance 20.00%