Reclassifications Out of Accumulated Other Comprehensive Income (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Reclassifications Out Of Accumulated Other Comprehensive Income
Income Before Income Taxes	$ 591		$ 603
Applicable income tax expense	179		173
Net income	422		430
Net Unrealized Gains On Available For Sale Securities | Net Losses Included In Net Income
Reclassifications Out Of Accumulated Other Comprehensive Income
Reclassification adjustment for net gains included in net income	(7)
Income Before Income Taxes	(7)
Applicable income tax expense	2
Net income	(5)
Net Unrealized Gains On Cash Flow Hedge Activities
Reclassifications Out Of Accumulated Other Comprehensive Income
Income Before Income Taxes	21
Applicable income tax expense	(7)
Net income	14
Net Unrealized Gains On Cash Flow Hedge Activities | Interest Rate Contracts Related To C&I Loans
Reclassifications Out Of Accumulated Other Comprehensive Income
Reclassification adjustment for net gains on cash flow hedge derivatives included in net income	22
Net Unrealized Gains On Cash Flow Hedge Activities | Interest Rate Contracts Related To Long-Term Debt
Reclassifications Out Of Accumulated Other Comprehensive Income
Reclassification adjustment for net gains on cash flow hedge derivatives included in net income	(1)
Amortization Of Defined Benefit Pension Items | Net Actuarial Loss
Reclassifications Out Of Accumulated Other Comprehensive Income
Net periodic pension cost	(3)	[1]
Income Before Income Taxes	(3)
Applicable income tax expense	1
Net income	(2)
Total Reclassifications For The Period
Reclassifications Out Of Accumulated Other Comprehensive Income
Net income	$ 7

[1] This AOCI component is included in the computation of net periodic benefit cost. Refer to Note 20 in the Bancorp’s Annual Report on Form 10-K for the year ended December 31, 2012 for information on the computation of net periodic benefit cost.