v2.4.0.8
Loans and Allowance for Credit Losses, Allowance for Credit Losses by Category (Details) (USD $)
In Millions, unless otherwise specified
 3 Months Ended 6 Months Ended
Jun. 30, 2013
Jun. 30, 2012
Jun. 30, 2013
Jun. 30, 2012
Financing Receivable, Allowance for Credit Losses [Roll Forward]        
Allowance for credit losses, beginning balance $ 17,193 $ 19,129 $ 17,477 $ 19,668
Provision for credit losses 652 1,800 1,871 3,795
Interest income on certain impaired loans (73) (82) (146) (169)
Loan charge-offs (1,669) (2,689) (3,530) (5,569)
Loan recoveries 517 489 959 974
Net loan charge-offs (1,152) (2,200) (2,571) (4,595)
Allowances related to business combinations/other (2) (1) (13) (53)
Allowance for credit losses, ending balance 16,618 18,646 16,618 18,646
Commercial Portfolio Segment [Member]
        
Financing Receivable, Allowance for Credit Losses [Roll Forward]        
Allowance for credit losses, beginning balance 5,786 6,130 5,714 6,358
Provision for credit losses 172 410 364 598
Interest income on certain impaired loans (16) (23) (35) (54)
Loan charge-offs (272) (556) (532) (1,114)
Loan recoveries 228 198 398 371
Net loan charge-offs (44) (358) (134) (743)
Allowances related to business combinations/other (2) 0 (13) 0
Allowance for credit losses, ending balance 5,896 6,159 5,896 6,159
Consumer Portfolio Segment [Member]
        
Financing Receivable, Allowance for Credit Losses [Roll Forward]        
Allowance for credit losses, beginning balance 11,407 12,999 11,763 13,310
Provision for credit losses 480 1,390 1,507 3,197
Interest income on certain impaired loans (57) (59) (111) (115)
Loan charge-offs (1,397) (2,133) (2,998) (4,455)
Loan recoveries 289 291 561 603
Net loan charge-offs (1,108) (1,842) (2,437) (3,852)
Allowances related to business combinations/other 0 (1) 0 (53)
Allowance for credit losses, ending balance $ 10,722 $ 12,487 $ 10,722 $ 12,487