Quarterly report pursuant to Section 13 or 15(d)

Accumulated Other Comprehensive Income (Loss) - Change in Accumulated OCI (Details)

v3.10.0.1
Accumulated Other Comprehensive Income (Loss) - Change in Accumulated OCI (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2018
Sep. 30, 2017
Sep. 30, 2018
Sep. 30, 2017
Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]          
Beginning Balance     $ 267,146 $ 266,195  
Accounting change rated to certain tax effects     0    
Cumulative adjustment for adoption of hedge accounting standard         $ 25
Net change $ (1,503) $ 437 (6,541) 1,120  
Ending Balance 262,158 271,969 262,158 271,969  
Accumulated Other Comprehensive Income (Loss)          
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]          
Beginning Balance     (7,082) (7,288)  
Accounting change rated to certain tax effects     (1,270)    
Cumulative adjustment for adoption of hedge accounting standard         57
Net change     (6,541) 1,120  
Ending Balance (14,836) (6,168) (14,836) (6,168)  
Debt and Equity Securities          
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]          
Beginning Balance     (1,206) (1,267)  
Accounting change rated to certain tax effects     (393)    
Cumulative adjustment for adoption of hedge accounting standard         0
Net change     (6,166) 931  
Ending Balance (7,765) (336) (7,765) (336)  
Debit Valuation Adjustments          
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]          
Beginning Balance     (1,060) (767)  
Accounting change rated to certain tax effects     (220)    
Cumulative adjustment for adoption of hedge accounting standard         0
Net change     183 (149)  
Ending Balance (1,097) (916) (1,097) (916)  
Derivatives          
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]          
Beginning Balance     (831) (895)  
Accounting change rated to certain tax effects     (189)    
Cumulative adjustment for adoption of hedge accounting standard         57
Net change     (346) 156  
Ending Balance (1,309) (739) (1,309) (739)  
Employee Benefit Plans          
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]          
Beginning Balance     (3,192) (3,480)  
Accounting change rated to certain tax effects     (707)    
Cumulative adjustment for adoption of hedge accounting standard         0
Net change     91 80  
Ending Balance (3,808) (3,400) (3,808) (3,400)  
Foreign currency          
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]          
Beginning Balance     (793) (879)  
Accounting change rated to certain tax effects     239    
Cumulative adjustment for adoption of hedge accounting standard         $ 0
Net change     (303) 102  
Ending Balance $ (857) $ (777) $ (857) $ (777)