v3.19.3.a.u2
Stockholders' Equity and Accumulated Other Comprehensive Income (Loss) (Reclassification From Accumulated Other Comprehensive Income) (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]      
Net interest income and other financing income $ 3,745 $ 3,735 $ 3,539
Other (927) (963) (952)
Income tax (expense) benefits (403) (387) (619)
Reclassification out of Accumulated Other Comprehensive Income [Member]      
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]      
Net income (loss) (76) (25) 28
Accumulated Net Unrealized Loss on Held To Maturity Securities [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]      
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]      
Net interest income and other financing income (7) (9) (10)
Income tax (expense) benefits 2 3 4
Net income (loss) (5) (6) (6)
Accumulated Net Unrealized Securities Available For Sale Gain (Loss) [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]      
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]      
Securities gains, net (28) 0 19
Income tax (expense) benefits 7 0 (7)
Net income (loss) (21) 0 12
Accumulated Net Gain (Loss) from Derivative Instruments Designated as Cash Flow Hedges [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]      
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]      
Net interest income and other financing income 24 (12) (86)
Income tax (expense) benefits 6 (3) (33)
Net income (loss) (18) 9 53
Accumulated Defined Benefit Pension Plans Adjustment [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]      
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]      
Other (43) (36) (48)
Income tax (expense) benefits 11 8 17
Net income (loss) $ (32) $ (28) $ (31)