Annual report pursuant to Section 13 and 15(d)

Securities - Gains and Losses on Sales of AFS Debt Securities (Details)

v3.8.0.1
Securities - Gains and Losses on Sales of AFS Debt Securities (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Available-for-sale Securities, Gross Realized Gain (Loss) [Abstract]      
Net gains on sales of AFS debt securities $ 255 $ 490 $ 1,138
Debt securities      
Available-for-sale Securities, Gross Realized Gain (Loss) [Abstract]      
Gross gains 352 520 1,174
Gross losses (97) (30) (36)
Net gains on sales of AFS debt securities 255 490 1,138
Income tax expense attributable to realized net gains on sales of AFS debt securities $ 97 $ 186 $ 432