Deferred Income Taxes Included in Other Assets in the Consolidated Balance Sheets (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Schedule Of Deferred Income Tax Assets And Liabilities [Line Items]
Allowance for loan & lease losses	$ 649	$ 789
Deferred compensation	105	119
Impairment reserves	74	102
Reserves	63	70
Reserve for unfunded commitments	47	63
State net operating losses	33	63
Other	191	216
Total deferred tax assets	1,162	1,422
Lease financing	844	853
Investments in joint ventures and partnership interests	470	468
Other comprehensive income	202	253
MSRs	162	173
Bank premises and equipment	108	95
State deferred taxes	64	74
Other	155	130
Total deferred tax liabilities	2,005	2,046
Total net deferred tax (liability) asset	$ (843)	$ (624)