v2.4.0.6
Loans And The Allowance For Credit Losses (Analysis Of The Allowance For Credit Losses By Portfolio 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
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]        
Allowance for loan losses at beginning of period $ 2,530 $ 3,186 $ 2,745 $ 3,185
Allowance allocated to purchased loans   84   84
Provision for loan losses 26 398 143 880
Charge-offs (315) (579) (691) (1,091)
Recoveries 50 31 94 62
Net loan losses (265) (548) (597) (1,029)
Allowance for loan losses 2,291 3,120 2,291 3,120
Reserve for unfunded credit commitments 91 78 78 71
Provision (credit) for unfunded credit commitments   6 13 13
Reserve for unfunded credit commitments 91 84 91 84
Allowance for credit losses 2,382 3,204 2,382 3,204
Individually evaluated for impairment 210 295 210 295
Collectively evaluated for impairment 2,172 2,909 2,172 2,909
Allowance for credit losses 2,382 3,204 2,382 3,204
Individually evaluated for impairment 911 1,606 911 1,606
Collectively evaluated for impairment 75,291 79,570 75,291 79,570
Total loans evaluated for impairment 76,202 81,176 76,202 81,176
Commercial [Member]
        
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]        
Allowance for loan losses at beginning of period 982 1,138 1,030 1,055
Allowance allocated to purchased loans   10   10
Provision for loan losses (16) 72 45 297
Charge-offs (107) (107) (232) (258)
Recoveries 25 14 41 23
Net loan losses (82) (93) (191) (235)
Allowance for loan losses 884 1,127 884 1,127
Reserve for unfunded credit commitments 44 37 30 32
Provision (credit) for unfunded credit commitments 17 (5) 31  
Reserve for unfunded credit commitments 61 32 61 32
Allowance for credit losses 945 1,159 945 1,159
Individually evaluated for impairment 93 128 93 128
Collectively evaluated for impairment 852 1,031 852 1,031
Allowance for credit losses 945 1,159 945 1,159
Individually evaluated for impairment 428 599 428 599
Collectively evaluated for impairment 36,449 35,219 36,449 35,219
Total loans evaluated for impairment 36,877 35,818 36,877 35,818
Investor Real Estate [Member]
        
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]        
Allowance for loan losses at beginning of period 898 1,285 991 1,370
Provision for loan losses (80) 171 (90) 260
Charge-offs (62) (306) (157) (487)
Recoveries 10 3 22 10
Net loan losses (52) (303) (135) (477)
Allowance for loan losses 766 1,153 766 1,153
Reserve for unfunded credit commitments 26 17 26 16
Provision (credit) for unfunded credit commitments   11   12
Reserve for unfunded credit commitments 26 28 26 28
Allowance for credit losses 792 1,181 792 1,181
Individually evaluated for impairment 117 163 117 163
Collectively evaluated for impairment 675 1,018 675 1,018
Allowance for credit losses 792 1,181 792 1,181
Individually evaluated for impairment 483 989 483 989
Collectively evaluated for impairment 8,964 12,442 8,964 12,442
Total loans evaluated for impairment 9,447 13,431 9,447 13,431
Consumer [Member]
        
Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items]        
Allowance for loan losses at beginning of period 650 763 724 760
Allowance allocated to purchased loans   74   74
Provision for loan losses 122 155 188 323
Charge-offs (146) (166) (302) (346)
Recoveries 15 14 31 29
Net loan losses (131) (152) (271) (317)
Allowance for loan losses 641 840 641 840
Reserve for unfunded credit commitments 21 24 22 23
Provision (credit) for unfunded credit commitments (17)   (18) 1
Reserve for unfunded credit commitments 4 24 4 24
Allowance for credit losses 645 864 645 864
Individually evaluated for impairment   4   4
Collectively evaluated for impairment 645 860 645 860
Allowance for credit losses 645 864 645 864
Individually evaluated for impairment   18   18
Collectively evaluated for impairment 29,878 31,909 29,878 31,909
Total loans evaluated for impairment $ 29,878 $ 31,927 $ 29,878 $ 31,927