Fair Value Measurements (Reconciliation of Assets and Liabilities Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs) (Level 3) (Detail) - USD ($) $ in Millions		3 Months Ended				9 Months Ended
		Sep. 30, 2017		Sep. 30, 2016		Sep. 30, 2017		Sep. 30, 2016
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Beginning Balance		$ 902		$ 412		$ 804		$ 380
Included in earnings		(53)		28		(94)		133
Purchases/originations		32		(1)		206		(2)
Settlements		(25)		(42)		(67)		(120)
Transfers Into Level 3	[1]	4		3		11		9
Ending Balance		860		400		860		400
The amount of total gains or losses for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held	[2]	(68)		19		(157)		40
Residential Mortgage
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Beginning Balance		142		154		143		167
Included in earnings		0		0		2		3
Purchases/originations		0		0		0		0
Settlements		(6)		(8)		(16)		(30)
Transfers Into Level 3	[1]	4		3		11		9
Ending Balance		140		149		140		149
The amount of total gains or losses for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held	[2]	0		0		2		3
Mortgage servicing rights
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Beginning Balance		849				744
Included in earnings		(34)				(104)
Purchases/originations		33				(208)
Settlements		0				0
Transfers Into Level 3		0	[1]			0
Ending Balance		848				848
The amount of total gains or losses for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held		(34)	[2]			104
Interest Rate Contract
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Beginning Balance		9	[3]	30	[4],[5]	8	[3]	12	[4],[5]
Included in earnings		28	[3]	42	[4],[5]	77	[3]	127	[4]
Purchases/originations		(1)	[3]	(1)	[4],[5]	(2)	[3]	(2)	[4]
Settlements		(28)	[3]	(42)	[4],[5]	(75)	[3]	(108)	[4]
Transfers Into Level 3	[1]	0	[3]	0	[4],[5]	0	[3]	0	[4]
Ending Balance		8	[3]	29	[4],[5]	8	[3]	29	[4],[5]
The amount of total gains or losses for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held	[2]	13	[3]	33	[4],[5]	14	[3]	34	[4]
Equity Contract
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Beginning Balance		(98)		228	[4],[5]	(91)		201	[4],[5]
Included in earnings		(47)		(14)	[4],[5]	(69)		3	[4]
Purchases/originations		0		0	[4],[5]	0		0	[4]
Settlements		9		8	[4],[5]	24		18	[4]
Transfers Into Level 3	[1]	0		0	[4],[5]	0		0	[4]
Ending Balance		(136)		222	[4],[5]	(136)		222	[4],[5]
The amount of total gains or losses for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held	[2]	$ (47)		$ (14)	[4],[5]	$ (69)		$ 3	[4]

[1] Includes certain residential mortgage loans originated as held for sale that were transferred to held for invest ment.

[2] Includes interest income and expense . Effective January 1, 2017, the Bancorp has elected the fair value measurement method for all existing classes of its residential mortgage servicing rights. The servic ing r ights were measured at fair value at September 30 , 2017 and were measured under the amortization method at December 31, 2016 .

[3] Net interest rate derivatives include derivative assets and liabilities of $ 13 and $ 5 , respectively , as of September 30, 2017 .

[4] Net interest rate derivatives include derivative assets and liabilities of $33 and $4 , respectively, as of September 30, 2016 . Net equity derivatives include derivativ e assets and liabilities of $325 and $103 , respectively, as of September 30, 2016 .

[5] Net interest rate derivatives include derivative assets and liabilities of $ 33 and $ 4 , respectively, as of September 30, 2016 . Net equity derivatives include derivative assets and liabilities of $ 325 and $ 103 , respectively, as of September 30, 2016 .