Segments (Results of Operations and Average Assets by Segment) (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020		Mar. 31, 2019		Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information
Net interest income		$ 1,229		$ 1,082
Provision for credit losses		640		90
Net interest income after provision for credit losses		589		992
Noninterest Income:
Service charges on deposits		148		131	[1]
Wealth and asset management revenue		134		112	[1]
Commercial banking revenue		124		103	[1]
Mortgage banking net revenue		120		56	[1]
Card and processing revenue		86		79	[1]
Leasing business net revenue		73		32	[1]
Other noninterest income		7	[2]	569	[1],[3]
Securities gains (losses), net		(24)		16	[1]
Securities gains, non - qualifying hedges on MSRs		3		3	[1]
Total noninterest income		671		1,101	[1]
Noninterest expense:
Compensation and benefits		647		610	[1]
Net occupancy expense		82	[4]	75	[1]
Technology and communications		93		83	[1]
Equipment Expense		32		30	[1]
Card and processing expense		31		31	[1]
Leasing business expense		35		19	[1]
Marketing expense		31		36	[1]
Other noninterest expense		249		213	[1]
Total noninterest expense		1,200		1,097	[1]
Income (Loss) Before Income Taxes		60		996
Applicable income tax expense (benefit)		14		221
Net income		46		775
Total goodwill		4,261		4,321		$ 4,252	$ 2,478
Total assets		185,391		167,853
Inter segment Elimination
Segment Reporting Information
Net interest income		0		0
Provision for credit losses		0		0
Net interest income after provision for credit losses		0		0
Noninterest Income:
Service charges on deposits		0		0	[1]
Wealth and asset management revenue	[5]	(40)		(33)	[1]
Commercial banking revenue		0		0	[1]
Mortgage banking net revenue		0		0	[1]
Card and processing revenue		0		0	[1]
Leasing business net revenue		0		0	[1]
Other noninterest income		0	[2]	0	[1],[3]
Securities gains (losses), net		0		0	[1]
Securities gains, non - qualifying hedges on MSRs		0		0	[1]
Total noninterest income		(40)		(33)	[1]
Noninterest expense:
Compensation and benefits		0		0	[1]
Net occupancy expense		0	[4]	0	[1]
Technology and communications		0		0	[1]
Equipment Expense		0		0	[1]
Card and processing expense		0		0	[1]
Leasing business expense		0		0	[1]
Marketing expense		0		0	[1]
Other noninterest expense		(40)		(33)	[1]
Total noninterest expense		(40)		(33)	[1]
Income (Loss) Before Income Taxes		0		0
Applicable income tax expense (benefit)		0		0
Net income		0		0
Total goodwill		0		0
Total assets		0		0
Commercial Banking
Segment Reporting Information
Net interest income		507		509
Provision for credit losses		45		20
Net interest income after provision for credit losses		462		489
Noninterest Income:
Service charges on deposits		84		66	[1]
Wealth and asset management revenue		1		1	[1]
Commercial banking revenue		124		103	[1]
Mortgage banking net revenue		0		0	[1]
Card and processing revenue		16		15	[1]
Leasing business net revenue		73	[6]	32	[1]
Other noninterest income		(11)	[2]	10	[1],[3]
Securities gains (losses), net		0		0	[1]
Securities gains, non - qualifying hedges on MSRs		0		0	[1]
Total noninterest income		287		227	[1]
Noninterest expense:
Compensation and benefits		150		109	[1]
Net occupancy expense		7	[4]	7	[1]
Technology and communications		3		2	[1]
Equipment Expense		7		6	[1]
Card and processing expense		2		2	[1]
Leasing business expense		35		19	[1]
Marketing expense		2		1	[1]
Other noninterest expense		274		210	[1]
Total noninterest expense		480		356	[1]
Income (Loss) Before Income Taxes		269		360
Applicable income tax expense (benefit)		45		66
Net income		224		294
Total goodwill		1,961		630
Total assets		84,576		74,377
Branch Banking
Segment Reporting Information
Net interest income		505		584
Provision for credit losses		62		52
Net interest income after provision for credit losses		443		532
Noninterest Income:
Service charges on deposits		65		64	[1]
Wealth and asset management revenue		44		36	[1]
Commercial banking revenue		1		1	[1]
Mortgage banking net revenue		2		1	[1]
Card and processing revenue		67		63	[1]
Leasing business net revenue		0		0	[1]
Other noninterest income		19	[2]	18	[1],[3]
Securities gains (losses), net		0		0	[1]
Securities gains, non - qualifying hedges on MSRs		0		0	[1]
Total noninterest income		198		183	[1]
Noninterest expense:
Compensation and benefits		168		143	[1]
Net occupancy expense		44	[4]	43	[1]
Technology and communications		1		1	[1]
Equipment Expense		11		12	[1]
Card and processing expense		30		29	[1]
Leasing business expense		0		0	[1]
Marketing expense		13		14	[1]
Other noninterest expense		221		198	[1]
Total noninterest expense		488		440	[1]
Income (Loss) Before Income Taxes		153		275
Applicable income tax expense (benefit)		32		58
Net income		121		217
Total goodwill		2,047		1,655
Total assets		70,283		69,599
Consumer Lending
Segment Reporting Information
Net interest income		89		63
Provision for credit losses		13		13
Net interest income after provision for credit losses		76		50
Noninterest Income:
Service charges on deposits		0		0	[1]
Wealth and asset management revenue		0		0	[1]
Commercial banking revenue		0		0	[1]
Mortgage banking net revenue		117		55	[1]
Card and processing revenue		0		0	[1]
Leasing business net revenue		0		0	[1]
Other noninterest income		4	[2]	3	[1],[3]
Securities gains (losses), net		0		0	[1]
Securities gains, non - qualifying hedges on MSRs		3		3	[1]
Total noninterest income		124		61	[1]
Noninterest expense:
Compensation and benefits		51		45	[1]
Net occupancy expense		2	[4]	2	[1]
Technology and communications		2		2	[1]
Equipment Expense		0		0	[1]
Card and processing expense		0		0	[1]
Leasing business expense		0		0	[1]
Marketing expense		1		1	[1]
Other noninterest expense		66		51	[1]
Total noninterest expense		122		101	[1]
Income (Loss) Before Income Taxes		78		10
Applicable income tax expense (benefit)		17		2
Net income		61		8
Total goodwill		0		0
Total assets		27,132		24,662
Wealth and Asset Management
Segment Reporting Information
Net interest income		37		49
Provision for credit losses		1		0
Net interest income after provision for credit losses		36		49
Noninterest Income:
Service charges on deposits		0		0	[1]
Wealth and asset management revenue		129		108	[1]
Commercial banking revenue		0		0	[1]
Mortgage banking net revenue		1		0	[1]
Card and processing revenue		0		1	[1]
Leasing business net revenue		0		0	[1]
Other noninterest income		5	[2]	5	[1],[3]
Securities gains (losses), net		0		0	[1]
Securities gains, non - qualifying hedges on MSRs		0		0	[1]
Total noninterest income		135		114	[1]
Noninterest expense:
Compensation and benefits		61		56	[1]
Net occupancy expense		3	[4]	3	[1]
Technology and communications		0		0	[1]
Equipment Expense		0		0	[1]
Card and processing expense		0		0	[1]
Leasing business expense		0		0	[1]
Marketing expense		1		1	[1]
Other noninterest expense		78		70	[1]
Total noninterest expense		143		130	[1]
Income (Loss) Before Income Taxes		28		33
Applicable income tax expense (benefit)		6		7
Net income		22		26
Total goodwill		253		193
Total assets		11,653		9,916
General Corporate and Other
Segment Reporting Information
Net interest income		91		(123)
Provision for credit losses		519		5
Net interest income after provision for credit losses		(428)		(128)
Noninterest Income:
Service charges on deposits		(1)		1	[1]
Wealth and asset management revenue		0		0	[1]
Commercial banking revenue		(1)		(1)	[1]
Mortgage banking net revenue		0		0	[1]
Card and processing revenue		3		0	[1]
Leasing business net revenue		0		0	[1]
Other noninterest income		(10)	[2]	533	[1],[3]
Securities gains (losses), net		(24)		16	[1]
Securities gains, non - qualifying hedges on MSRs		0		0	[1]
Total noninterest income		(33)		549	[1]
Noninterest expense:
Compensation and benefits		217		257	[1]
Net occupancy expense		26	[4]	20	[1]
Technology and communications		87		78	[1]
Equipment Expense		14		12	[1]
Card and processing expense		(1)		0	[1]
Leasing business expense		0		0	[1]
Marketing expense		14		19	[1]
Other noninterest expense		(350)		(283)	[1]
Total noninterest expense		7		103	[1]
Income (Loss) Before Income Taxes		(468)		318
Applicable income tax expense (benefit)		(86)		88
Net income		(382)		230
Total goodwill		0		(1,843)	[7]
Total assets		$ (8,253)	[8]	$ (10,701)	[9]

[1] During the first quarter of 2020, certain noninterest income and noninterest expense line items were reclassified to better align disclosures to business activities. These reclassifications were retrospectively applied to all prior periods presented. Total noninterest income and noninterest expense did not change as a result of these reclassifications.

[2] Includes impairment charges of $3 for branches and land. For more information refer to Note 8 and Note 23.

[3] Includes impairment charges of $20 for branches and land. For more information refer to Note 8.

[4] Includes impairment losses and termination charges of $2 for ROU assets related to certain operating leases. For more information refer to Note 10.

[5] Revenue sharing agreements between wealth and asset management and branch banking are eliminated in the Condensed Consolidated Statements of Income.

[6] Includes impairment charges of $3 for operating lease equipment. For more information refer to Note 9 and Note 23.

[7] Due to the timing of the MB Financial, Inc. acquisition, the Bancorp was in the process of completing its analysis of the allocation of the goodwill across its four business segments, therefore goodwill was presented as part of General Corporate and Other as of March 31, 2019.

[8] Includes bank premises and equipment of $36 classified as held for sale. For more information refer to Note 8.

[9] Includes bank premises and equipment of $78 classified as held for sale. For more information refer to Note 8.