Reclassifications Out of Accumulated Other Comprehensive Income (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Reclassifications Out Of Accumulated Other Comprehensive Income
Income Before Income Taxes	$ 606		$ 841		$ 1,044		$ 1,432
Applicable income tax expense	167		250		287		429
Net income	439		591		756		1,013
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	14	[1]	(51)	[1]	19	[1]	(58)	[1]
Income Before Income Taxes	14	[1]	(51)	[1]	19	[1]	(58)	[1]
Applicable income tax expense	(5)	[1]	18	[1]	(7)	[1]	20	[1]
Net income	9	[1]	(33)	[1]	12	[1]	(38)	[1]
Net Unrealized Gains On Cash Flow Hedge Activities
Reclassifications Out Of Accumulated Other Comprehensive Income
Income Before Income Taxes	11	[1]	10	[1]	21	[1]	31	[1]
Applicable income tax expense	(5)	[1]	(4)	[1]	(8)	[1]	(11)	[1]
Net income	6	[1]	6	[1]	13	[1]	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	11	[1]	10	[1]	21	[1]	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	(1)	[1],[2]	(3)	[1],[2]	(3)	[1],[2]	(6)	[1],[2]
Income Before Income Taxes	(1)	[1]	(3)	[1]	(3)	[1]	(6)	[1]
Applicable income tax expense			1	[1]	1	[1]	2	[1]
Net income	(1)	[1]	(2)	[1]	(2)	[1]	(4)	[1]
Total Reclassifications For The Period
Reclassifications Out Of Accumulated Other Comprehensive Income
Net income	$ 14	[1]	$ (29)	[1]	$ 23	[1]	$ (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 21 in the Bancorp’s Annual Report on Form 10-K for the year ended December 31, 2013 for information on the computation of net periodic benefit cost.