Annual report pursuant to Section 13 and 15(d)

Derivatives - Derivatives Designated as Accounting Hedges - Fair Value Hedges (Details)

v3.6.0.2
Derivatives - Derivatives Designated as Accounting Hedges - Fair Value Hedges (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Effect of Fair Value Hedges on Results of Operations [Abstract]      
Derivative $ (2,219) $ (2,496) $ (82)
Hedged Item 1,321 1,597 (827)
Hedge Ineffectiveness (898) (899) (909)
Interest rate risk on long-term debt | Interest expense      
Effect of Fair Value Hedges on Results of Operations [Abstract]      
Derivative (1,488) (718) 2,144
Hedged Item 646 (77) (2,935)
Hedge Ineffectiveness (842) (795) (791)
Interest rate and foreign currency risk on long-term debt | Interest expense      
Effect of Fair Value Hedges on Results of Operations [Abstract]      
Derivative (941) (1,898) (2,212)
Hedged Item 944 1,812 2,120
Hedge Ineffectiveness 3 (86) (92)
Interest rate risk on AFS securities | Interest income      
Effect of Fair Value Hedges on Results of Operations [Abstract]      
Derivative 227 105 (35)
Hedged Item (286) (127) 3
Hedge Ineffectiveness (59) (22) (32)
Price risk on commodity inventory | Trading gain (loss)      
Effect of Fair Value Hedges on Results of Operations [Abstract]      
Derivative (17) 15 21
Hedged Item 17 (11) (15)
Hedge Ineffectiveness $ 0 $ 4 $ 6