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		12 Months Ended
		Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Beginning balance		$ 861		$ 804		$ 380
Included in earnings		(73)		(107)		130
Purchases		158		234		(3)
Sale and exercise of warrant						(334)
Settlements		(19)		(86)		(131)
Transfers into Level 3		64	[1]	16	[2]	18	[3]
Ending balance		991		861		804
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		(57)	[4]	(191)	[5]	(45)	[6]
Residential Mortgage
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Beginning balance		137		143		167
Included in earnings		(3)		1		(2)
Purchases		0		0		0
Sale and exercise of warrant						0
Settlements		(19)		(23)		(40)
Transfers into Level 3		64	[1]	16	[2]	18	[3]
Ending balance		179		137		143
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		(3)	[4]	1	[5]	(2)	[6]
Mortgage Servicing Rights
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Beginning balance	[7]	858		744
Included in earnings		(83)		(122)	[7]
Purchases		163		236	[7]
Settlements		0		0	[7]
Transfers into Level 3		0		0	[7]
Ending balance		938		858	[7]	744	[7]
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		(4)		(122)	[7]
Interest Rate Contract
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Beginning balance		3	[8]	8	[9]	12
Included in earnings		72	[8]	94	[9]	115	[10]
Purchases		(5)	[8]	(2)	[9]	(3)	[10]
Sale and exercise of warrant						0
Settlements		(71)	[8]	(97)	[9]	(116)	[10]
Transfers into Level 3		0	[1]	0		0
Ending balance		(1)	[8]	3	[8]	8	[9]
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		9	[4],[8]	10	[5],[9]	13	[6],[10]
Equity Contract
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Beginning balance		(137)	[9]	(91)	[10]	201
Included in earnings		(59)	[8]	(80)	[9]	17	[10]
Purchases		0		0		0
Sale and exercise of warrant	[10]					(334)
Settlements		71	[8]	34	[9]	25	[10]
Transfers into Level 3		0		0		0
Ending balance		(125)	[8]	(137)	[9]	(91)	[10]
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		$ (59)	[4],[8]	$ (80)	[5],[9]	$ (56)	[6],[10]

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

[2] Includes certain residential mortgage loans held for sale that were transferred to held for investment.

[3] Includes certain residential mortgage loans held for sale that were transferred to held for investment.

[4] Includes interest income and expense.

[5] Includes interest income and expense.

[6] Includes interest income and expense.

[7] 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 December 31, 2017 and were m easured under the amortization method at December 31, 2016.

[8] Net interest rate derivatives include derivative assets and liabilities of $ 7 and $ 8 , respectively, as of December 31, 2018 .

[9] Net interest rate derivatives include derivative assets and liabilities of $ 8 and $ 5 , respect ively, as of December 31, 2017 .

[10] Net interest rate derivatives include derivative assets and liabilities of $ 13 and $ 5 , respectively, as of December 31, 2016 . Net equity derivatives include derivative assets and liabilities of $ 0 and $ 9 1 , respectively, as of December 31, 2016 .