Fair Value Measurements (Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis) (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair Value Measurements		$ 435	$ 1,161
Fair Value Measured On Nonrecurring Basis Gains Losses		(75)	(128)
Commercial Loans Held-for-Sale | Commercial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair Value Measurements		1	5
Fair Value Measured On Nonrecurring Basis Gains Losses		(19)	(2)
Commercial and Industrial Loans | Commercial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair Value Measurements		318	347
Fair Value Measured On Nonrecurring Basis Gains Losses		(26)	(47)
Commercial Mortgage Loans | Commercial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair Value Measurements		25	85
Fair Value Measured On Nonrecurring Basis Gains Losses		(2)	6
Commercial Construction Loans | Commercial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair Value Measurements			0
Fair Value Measured On Nonrecurring Basis Gains Losses			2
Commercial Leases | Commercial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair Value Measurements		2
Fair Value Measured On Nonrecurring Basis Gains Losses		(1)
Servicing Rights
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair Value Measurements	[1]		685
Fair Value Measured On Nonrecurring Basis Gains Losses	[1]		(85)
Other Real Estate Owned
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair Value Measurements		19	27
Fair Value Measured On Nonrecurring Basis Gains Losses		(4)	(3)
Bank premises and equipment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair Value Measurements		15	12
Fair Value Measured On Nonrecurring Basis Gains Losses		(3)	1
Operating lease equipment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair Value Measurements		55
Fair Value Measured On Nonrecurring Basis Gains Losses		(20)
Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair Value Measurements		435	1,161
Fair Value, Inputs, Level 3 | Commercial Loans Held-for-Sale | Commercial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair Value Measurements		1	5
Fair Value, Inputs, Level 3 | Commercial and Industrial Loans | Commercial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair Value Measurements		318	347
Fair Value, Inputs, Level 3 | Commercial Mortgage Loans | Commercial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair Value Measurements		25	85
Fair Value, Inputs, Level 3 | Commercial Construction Loans | Commercial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair Value Measurements			0
Fair Value, Inputs, Level 3 | Commercial Leases | Commercial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair Value Measurements		2
Fair Value, Inputs, Level 3 | Servicing Rights
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair Value Measurements	[1]		685
Fair Value, Inputs, Level 3 | Other Real Estate Owned
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair Value Measurements		19	27
Fair Value, Inputs, Level 3 | Bank premises and equipment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair Value Measurements		15	$ 12
Fair Value, Inputs, Level 3 | Operating lease equipment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair Value Measurements		$ 55

[1] Effective January 1, 2017, the Bancorp has elected the fair value measurement method for all existing classes of its residential mortgage servicing rights. The servicing rights were measured at fair value at March 31, 2017 and were measured under the amortization method at December 31, 2016.