Reclassifications Out of Accumulated Other Comprehensive Income (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013		Jun. 30, 2012
Reclassifications Out Of Accumulated Other Comprehensive Income
Income Before Income Taxes	$ 841	$ 565	$ 1,432		$ 1,168
Applicable income tax expense	250	180	429		352
Net income	591	385	1,013		815
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 losses (gains) included in net income			(58)	[1]
Income Before Income Taxes			(58)	[1]
Applicable income tax expense			20	[1]
Net income			(38)	[1]
Net Unrealized Gains On Cash Flow Hedge Activities
Reclassifications Out Of Accumulated Other Comprehensive Income
Income Before Income Taxes			31	[1]
Applicable income tax expense			(11)	[1]
Net income			20	[1]
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			32	[1]
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)	[1]
Amortization Of Defined Benefit Pension Items | Net Actuarial Loss
Reclassifications Out Of Accumulated Other Comprehensive Income
Net periodic pension cost			(6)	[1],[2]
Income Before Income Taxes			(6)	[1]
Applicable income tax expense			2	[1]
Net income			(4)	[1]
Total Reclassifications For The Period
Reclassifications Out Of Accumulated Other Comprehensive Income
Net income			$ (22)	[1]

[1] Amounts in parentheses indicate reductions to net income

[2] 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.