EPS (Calculation of Earnings Per Share and the Reconciliation of Earnings Per Share to Earnings Per Diluted Share) (Detail) - USD ($) $ / shares in Units, $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Earnings per share:
Net income (loss) available to common shareholders		$ 2,118	$ 2,105	$ 1,472
Less: Income allocated to participating securities		23	23	15
Net income allocated to common shareholders		2,095	2,082	1,457
Earnings per diluted share:
Net income available to common shareholders		2,118	2,105	1,472
Stock-based awards		0	0	0
Net income available to common shareholders plus assumed conversions		2,118	2,105	1,472
Less: Income allocated to participating securities		23	23	15
Net income allocated to common shareholders plus assumed conversions		$ 2,095	$ 2,082	$ 1,457
Earnings per share:
Net income allocated to common shareholders		673,346,168	728,289,200	757,432,291
Effect of dilutive securities:
Stock-based awards		12,000,000	13,000,000	7,000,000
Net income allocated to common shareholders		685,488,498	740,691,433	764,495,353
Earnings per share:
Earnings per share - basic	[1]	$ 3.11	$ 2.86	$ 1.92
Earnings per diluted share:
Earnings per share - diluted	[1]	$ 3.06	$ 2.81	$ 1.91

[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.