Segments (Results of Operations and Average Assets by Segment) (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018		Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2016
Segment Reporting Information
Net interest income		$ 4,140				$ 3,798		$ 3,615
Provision for (benefit from) loan and lease losses		237				261	[1]	343	[1]
Net interest income after provision for loan and lease losses		3,903				3,537		3,272
Noninterest Income:
Service charges on deposits		549				554		558
Wealth and asset management revenue		444				419		404
Corporate banking revenue		438				353		432
Card and processing revenue		329				313		319
Mortgage banking net revenue		212				224		285
Other noninterest income		887	[2]			1,357	[3]	688	[4]
Securities gains (losses), net		(54)				2		10
Securities gains (losses), net - non-qualifying hedges on mortgage servcing rights		(15)				2		0
Total noninterest income		2,790				3,224		2,696
Noninterest expense:
Salaries, wages and incentives		1,783				1,633		1,612
Employee benefits		332				356		339
Net occupancy expense		292				295		299
Technology and communications		285				245		234
Equipment expense		123				117		118
Card and processing expense		123				129		132
Other noninterest expense	[1]	990				1,007		1,026
Total noninterest expense		3,928				3,782		3,760
Income (Loss) Before Income Taxes		2,765				2,979		2,208
Applicable income tax expense (benefit)		572				799		665
Net income (loss)		2,193		$ 2,193		2,180	[1]	1,543	[1]	$ 1,543
Total goodwill		2,478		2,478		2,445		2,416		2,416
Total Assets		146,069		146,069		142,081		142,080		142,080
Intersegment Elimination
Segment Reporting Information
Net interest income		0				0		0
Provision for (benefit from) loan and lease losses		0				0		0
Net interest income after provision for loan and lease losses		0				0		0
Noninterest Income:
Service charges on deposits		0				0		0
Wealth and asset management revenue	[5]	(138)				(132)		(131)
Corporate banking revenue		0				0		0
Card and processing revenue		0				0		0
Mortgage banking net revenue		0				0		0
Other noninterest income		0				0		0
Securities gains (losses), net		0				0		0
Securities gains (losses), net - non-qualifying hedges on mortgage servcing rights		0				0
Total noninterest income		(138)				(132)		(131)
Noninterest expense:
Salaries, wages and incentives		0				0		0
Employee benefits		0				0		0
Net occupancy expense		0				0		0
Technology and communications		0				0		0
Equipment expense		0				0		0
Card and processing expense		0				0		0
Other noninterest expense		(138)				(132)		(131)
Total noninterest expense		(138)				(132)		(131)
Income (Loss) Before Income Taxes		0				0		0
Applicable income tax expense (benefit)		0				0		0
Net income (loss)		0				0		0
Total goodwill		0		0		0		0		0
Total Assets		0		0		0		0		0
Commercial Banking
Segment Reporting Information
Net interest income		1,713				1,652		1,814
Provision for (benefit from) loan and lease losses		(26)				38		76
Net interest income after provision for loan and lease losses		1,739				1,614		1,738
Noninterest Income:
Service charges on deposits		273				287		292
Wealth and asset management revenue		3				3		4
Corporate banking revenue		432				348	[6]	430	[7]
Card and processing revenue		58				57		62
Mortgage banking net revenue		0				0		0
Other noninterest income		151	[2]			143	[3]	119	[4]
Securities gains (losses), net		0				0		0
Securities gains (losses), net - non-qualifying hedges on mortgage servcing rights		0				0
Total noninterest income		917				838	[6]	907
Noninterest expense:
Salaries, wages and incentives		300				252		254
Employee benefits		44				42		42
Net occupancy expense		26				26		26
Technology and communications		7				9		13
Equipment expense		23				18		16
Card and processing expense		4				3		4
Other noninterest expense		859				884		873
Total noninterest expense		1,263				1,234		1,228
Income (Loss) Before Income Taxes		1,393				1,218		1,417
Applicable income tax expense (benefit)		254				391		403
Net income (loss)		1,139				827		1,014
Total goodwill		630		630		613		613		613
Total Assets		61,630		61,630		58,456		57,995		57,995
Branch Banking
Segment Reporting Information
Net interest income		2,034				1,782		1,669
Provision for (benefit from) loan and lease losses		171				153		138
Net interest income after provision for loan and lease losses		1,863				1,629		1,531
Noninterest Income:
Service charges on deposits		275				265		265
Wealth and asset management revenue		150				141		140
Corporate banking revenue		5				5		5
Card and processing revenue		266				251		253
Mortgage banking net revenue		5				6		7
Other noninterest income		53	[2]			88	[3]	85	[4]
Securities gains (losses), net		0				0		0
Securities gains (losses), net - non-qualifying hedges on mortgage servcing rights		0				0
Total noninterest income		754				756	[3]	755	[4]
Noninterest expense:
Salaries, wages and incentives		438				425		419
Employee benefits		98				101		101
Net occupancy expense		175				176		178
Technology and communications		5				4		3
Equipment expense		50				52		56
Card and processing expense		121				127		128
Other noninterest expense		841				796		798
Total noninterest expense		1,728				1,681		1,683
Income (Loss) Before Income Taxes		889				704		603
Applicable income tax expense (benefit)		187				249		213
Net income (loss)		702				455		390
Total goodwill		1,655		1,655		1,655		1,655		1,655
Total Assets		61,040		61,040		57,931		55,979		55,979
Consumer Lending
Segment Reporting Information
Net interest income		237				240		248
Provision for (benefit from) loan and lease losses		42				40		44
Net interest income after provision for loan and lease losses		195				200		204
Noninterest Income:
Service charges on deposits		0				0		0
Wealth and asset management revenue		0				0		0
Corporate banking revenue		0				0		0
Card and processing revenue		0				0		0
Mortgage banking net revenue		206				217		277
Other noninterest income		14	[2]			18	[3]	26	[4]
Securities gains (losses), net		0				0		0
Securities gains (losses), net - non-qualifying hedges on mortgage servcing rights		(15)				2
Total noninterest income		205				237		303
Noninterest expense:
Salaries, wages and incentives		156				152		158
Employee benefits		36				37		37
Net occupancy expense		10				10		10
Technology and communications		5				2		1
Equipment expense		0				0		0
Card and processing expense		0				0		0
Other noninterest expense		195				210		224
Total noninterest expense		402				411		430
Income (Loss) Before Income Taxes		(2)				26		77
Applicable income tax expense (benefit)		(1)				9		27
Net income (loss)		(1)				17		50
Total goodwill		0		0		0		0		0
Total Assets		22,044		22,044		22,218		22,041		22,041
Wealth and Asset Management
Segment Reporting Information
Net interest income		182				154		168
Provision for (benefit from) loan and lease losses		12				6		1
Net interest income after provision for loan and lease losses		170				148		167
Noninterest Income:
Service charges on deposits		1				1		2
Wealth and asset management revenue		429				407		391
Corporate banking revenue		2				1		0
Card and processing revenue		5				5		4
Mortgage banking net revenue		1				1		1
Other noninterest income		18	[2]			4	[3]	1	[4]
Securities gains (losses), net		0				0		0
Securities gains (losses), net - non-qualifying hedges on mortgage servcing rights		0				0
Total noninterest income		456				419		399
Noninterest expense:
Salaries, wages and incentives		173				154		142
Employee benefits		29				27		26
Net occupancy expense		12				11		10
Technology and communications		1				0		0
Equipment expense		1				0		0
Card and processing expense		0				0		0
Other noninterest expense		288				276		254
Total noninterest expense		504				468		432
Income (Loss) Before Income Taxes		122				99		134
Applicable income tax expense (benefit)		25				34		48
Net income (loss)		97				65		86
Total goodwill		193		193		177		148		148
Total Assets		10,337		10,337		9,494		9,494		9,494
General Corporate and Other
Segment Reporting Information
Net interest income		(26)				(30)		(284)
Provision for (benefit from) loan and lease losses		38				24		84
Net interest income after provision for loan and lease losses		(64)				(54)		(368)
Noninterest Income:
Service charges on deposits		0				1		(1)
Wealth and asset management revenue		0				0		0
Corporate banking revenue		(1)				(1)		(3)
Card and processing revenue		0				0		0
Mortgage banking net revenue		0				0		0
Other noninterest income		651	[2]			1,104	[3]	457	[4]
Securities gains (losses), net		(54)				2		10
Securities gains (losses), net - non-qualifying hedges on mortgage servcing rights		0				0
Total noninterest income		596				1,106		463
Noninterest expense:
Salaries, wages and incentives		716				650		639
Employee benefits		125				149		133
Net occupancy expense		69				72		75
Technology and communications		267				230		217
Equipment expense		49				47		46
Card and processing expense		(2)				(1)		0
Other noninterest expense		(1,055)				(1,027)		(992)
Total noninterest expense		169				120		118
Income (Loss) Before Income Taxes		363				932		(23)
Applicable income tax expense (benefit)		107				116		(26)
Net income (loss)		256				816		3
Total goodwill		0		0		0		0		0
Total Assets		$ (8,982)	[8]	$ (8,982)	[8]	$ (6,018)	[9]	$ (3,429)	[10]	$ (3,429)	[10]

[1] Effective in the fourth quarter of 2018, Fifth Third retrospectively applied a change in its accounting policy for investments in affordable housing projects that qualify for LIHTC in accordance with ASU 2014-01. Refer to Note 1 for additional information.

[2] Includes impairment charges of $ 45 for branches and land. For more information refer to Note 7 and Note 26 .

[3] Includes impairment charges of $ 7 for branches and land. For more information refer to Note 7 and Note 26 .

[4] Includes impairment charges of $ 32 for branches and land. For more information refer to Note 7 .

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

[6] Includes impairment charges of $ 52 for operating lease equipment. For more information refer to Note 26 .

[7] Includes impairment charges of $ 20 for operating lease equipment.

[8] Includes bank premises and equipment of $ 42 classified as held for sale. For more information refer to Note 7 .

[9] Includes bank premises and equipment of $ 27 classified as held for sale. For more information refer to Note 7 .

[10] Includes bank premises and equipment of $ 39 classified as held for sale .