v2.4.0.6
Loans And The Allowance For Credit Losses (Interest Income on Loans Modified in Troubled Debt Restructuring) (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
Financing Receivable, Recorded Investment [Line Items]        
Average Balance $ 4,873 $ 4,396 $ 4,987 $ 4,469
Interest Income Recognized 36 21 70 39
Commercial And Industrial [Member]
        
Financing Receivable, Recorded Investment [Line Items]        
Average Balance 669 452 699 444
Interest Income Recognized 4   8  
Commercial Real Estate Mortgage - Owner Occupied [Member]
        
Financing Receivable, Recorded Investment [Line Items]        
Average Balance 756 690 771 697
Interest Income Recognized 2 1 5 2
Commercial Real Estate Construction - Owner Occupied [Member]
        
Financing Receivable, Recorded Investment [Line Items]        
Average Balance 26 30 27 31
Total Commercial [Member]
        
Financing Receivable, Recorded Investment [Line Items]        
Average Balance 1,451 1,172 1,497 1,172
Interest Income Recognized 6 1 13 2
Commercial Investor Real Estate Mortgage [Member]
        
Financing Receivable, Recorded Investment [Line Items]        
Average Balance 1,560 1,234 1,598 1,301
Interest Income Recognized 11 3 21 5
Commercial Investor Real Estate Construction [Member]
        
Financing Receivable, Recorded Investment [Line Items]        
Average Balance 220 442 257 469
Interest Income Recognized 2   4  
Total Investor Real Estate [Member]
        
Financing Receivable, Recorded Investment [Line Items]        
Average Balance 1,780 1,676 1,855 1,770
Interest Income Recognized 13 3 25 5
Residential First Mortgage [Member]
        
Financing Receivable, Recorded Investment [Line Items]        
Average Balance 1,147 1,083 1,139 1,072
Interest Income Recognized 9 11 19 20
Home Equity [Member]
        
Financing Receivable, Recorded Investment [Line Items]        
Average Balance 444 401 443 390
Interest Income Recognized 6 5 11 10
Indirect [Member]
        
Financing Receivable, Recorded Investment [Line Items]        
Average Balance 2 2 2 2
Other Consumer [Member]
        
Financing Receivable, Recorded Investment [Line Items]        
Average Balance 49 62 51 63
Interest Income Recognized 2 1 2 2
Total Consumer [Member]
        
Financing Receivable, Recorded Investment [Line Items]        
Average Balance 1,642 1,548 1,635 1,527
Interest Income Recognized $ 17 $ 17 $ 32 $ 32