Quarterly report pursuant to Section 13 or 15(d)

Accumulated Other Comprehensive Income (Loss) - Changes in OCI Components Before- and After-tax (Details)

v3.8.0.1
Accumulated Other Comprehensive Income (Loss) - Changes in OCI Components Before- and After-tax (Details) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
After-tax    
Comprehensive income $ 2,935 $ 5,309
Total other comprehensive income (loss)    
Before-tax    
Net change (5,407) (193)
Tax effect    
Net change 1,424 165
After-tax    
Comprehensive income (3,983) (28)
Available-for-sale securities | Debt and Equity Securities    
Before-tax    
Net increase (decrease) in fair value (5,323) (124)
Net realized (gains) losses reclassified into earnings (2) (45)
Net change (5,325) (169)
Tax effect    
Net increase (decrease) in fair value 1,360 53
Net realized (gains) losses reclassified into earnings 2 17
Net change 1,362 70
After-tax    
Other comprehensive income (loss) before reclassification, net of tax (3,963) (71)
Net realized (gains) losses reclassified into earnings 0 (28)
Comprehensive income (3,963) (99)
Debit Valuation Adjustments    
Before-tax    
Net increase (decrease) in fair value 342 9
Net realized (gains) losses reclassified into earnings 17 6
Net change 359 15
Tax effect    
Net increase (decrease) in fair value (82) (4)
Net realized (gains) losses reclassified into earnings (4) (2)
Net change (86) (6)
After-tax    
Other comprehensive income (loss) before reclassification, net of tax 260 5
Net realized (gains) losses reclassified into earnings 13 4
Comprehensive income 273 9
Derivatives    
Before-tax    
Net increase (decrease) in fair value (424) (9)
Net realized (gains) losses reclassified into earnings 23 70
Net change (401) 61
Tax effect    
Net increase (decrease) in fair value 131 3
Net realized (gains) losses reclassified into earnings (5) (26)
Net change 126 (23)
After-tax    
Other comprehensive income (loss) before reclassification, net of tax (293) (6)
Net realized (gains) losses reclassified into earnings 18 44
Comprehensive income (275) 38
Derivatives | Net interest income    
Before-tax    
Net realized (gains) losses reclassified into earnings 50 112
Tax effect    
Net realized (gains) losses reclassified into earnings (12) (42)
After-tax    
Net realized (gains) losses reclassified into earnings 38 70
Derivatives | Personnel expense    
Before-tax    
Net realized (gains) losses reclassified into earnings (27) (42)
Tax effect    
Net realized (gains) losses reclassified into earnings 7 16
After-tax    
Net realized (gains) losses reclassified into earnings (20) (26)
Employee Benefit Plans    
Before-tax    
Net realized (gains) losses reclassified into earnings 41 43
Settlements, curtailments and other 0 0
Net change 41 43
Tax effect    
Net realized (gains) losses reclassified into earnings (11) (16)
Settlements, curtailments and other 0 0
Net change (11) (16)
After-tax    
Net realized (gains) losses reclassified into earnings 30 27
Settlements, curtailments and other 0 0
Comprehensive income 30 27
Prior service cost    
Before-tax    
Net realized (gains) losses reclassified into earnings (1) 1
Tax effect    
Net realized (gains) losses reclassified into earnings 0 0
After-tax    
Net realized (gains) losses reclassified into earnings (1) 1
Net actuarial losses    
Before-tax    
Net realized (gains) losses reclassified into earnings 42 42
Tax effect    
Net realized (gains) losses reclassified into earnings (11) (16)
After-tax    
Net realized (gains) losses reclassified into earnings 31 26
Foreign currency    
Before-tax    
Net increase (decrease) in fair value (82) (131)
Net realized (gains) losses reclassified into earnings 1 (12)
Net change (81) (143)
Tax effect    
Net increase (decrease) in fair value 34 108
Net realized (gains) losses reclassified into earnings (1) 32
Net change 33 140
After-tax    
Other comprehensive income (loss) before reclassification, net of tax (48) (23)
Net realized (gains) losses reclassified into earnings 0 20
Comprehensive income $ (48) $ (3)