Deferred Income Taxes Included in Other Assets in the Consolidated Balance Sheets (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Schedule Of Deferred Income Tax Assets And Liabilities [Abstract]
Allowance for loan & lease losses	$ 463	$ 554
Deferred compensation	113	109
Reserves	96	101
Reserve for unfunded commitments	47	57
State net operating losses	18	22
Other	189	180
Total deferred tax assets	926	1,023
Lease financing	896	865
Investments in joint ventures and partnership interests	329	381
MSRs	237	254
Other comprehensive income	231	44
Qualifying Hedges And Free Standing Derivatives	105	97
Bank premises and equipment	103	114
State deferred taxes	81	76
Other	148	130
Total deferred tax liabilities	2,130	1,961
Total net deferred tax liabilities	$ (1,204)	$ (938)