v2.4.0.6
Business Segment Information (Schedule Of Financial Information By Reportable Segment) (Detail) (USD $)
In Millions, unless otherwise specified
 3 Months Ended 6 Months Ended
Jun. 30, 2012
Jun. 30, 2011
Jun. 30, 2012
Jun. 30, 2011
Segment Reporting Information [Line Items]        
Provision for loan losses $ 26 $ 398 $ 143 $ 880
Non-interest income 507 543 1,031 1,123
Non-interest expense 249 385 562 719
Income tax expense (126) 34 (208) 63
Banking/Treasury [Member]
        
Segment Reporting Information [Line Items]        
Net interest income 828 848 1,645 1,695
Provision for loan losses 26 398 143 880
Non-interest income 420 452 861 944
Non-interest expense 778 889 1,626 1,757
Income tax expense 112 (29) 184 (71)
Net income 332 42 553 73
Average assets 117,729 123,429 118,355 123,695
Insurance [Member]
        
Segment Reporting Information [Line Items]        
Net interest income 1   1 1
Non-interest income 35 33 69 70
Non-interest expense 25 23 50 49
Income tax expense 4 3 7 8
Net income 7 7 13 14
Average assets 553 520 549 521
Investment Banking/Brokerage/Trust Continuing Operations [Member]
        
Segment Reporting Information [Line Items]        
Net interest income 9 8 19 15
Non-interest income 52 58 101 109
Non-interest expense 39 44 79 82
Income tax expense 10 (8) 17  
Net income 12 30 24 42
Average assets 4,144 3,489 4,187 3,495
Investment Banking/Brokerage/Trust Discontinued Operations [Member]
        
Segment Reporting Information [Line Items]        
Net interest income   8 7 16
Non-interest income 15 238 255 501
Non-interest expense 11 242 323 477
Income tax expense   (26) (25) (9)
Net income 4 30 (36) 49
Average assets 49 3,240 1,413 3,233
Total Company [Member]
        
Segment Reporting Information [Line Items]        
Net interest income 838 864 1,672 1,727
Provision for loan losses 26 398 143 880
Non-interest income 522 781 1,286 1,624
Non-interest expense 853 1,198 2,078 2,365
Income tax expense 126 (60) 183 (72)
Net income 355 109 554 178
Average assets $ 122,475 $ 130,678 $ 124,504 $ 130,944