Earnings Per Share - Components of Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2019		Sep. 30, 2018		Sep. 30, 2019		Sep. 30, 2018
Earnings Per Share [Abstract]
Net income attributable to U.S. Bancorp	$ 1,908		$ 1,815		$ 5,428		$ 5,240
Preferred dividends	(79)	[1]	(76)	[2]	(230)	[3]	(210)	[4]
Earnings allocated to participating stock awards	(8)		(7)		(23)		(23)
Net income applicable to U.S. Bancorp common shareholders	$ 1,821		$ 1,732		$ 5,175		$ 5,007
Average common shares outstanding	1,575		1,629		1,589		1,641
Net effect of the exercise and assumed purchase of stock awards	3		4		3		4
Average diluted common shares outstanding	1,578		1,633		1,592		1,645
Earnings per common share	$ 1.16		$ 1.06		$ 3.26		$ 3.05
Diluted earnings per common share	$ 1.15		$ 1.06		$ 3.25		$ 3.04

[1] Reflects dividends declared per share on the Company’s Series A, Series B, Series F, Series H, Series J and Series K Non-Cumulative Perpetual Preferred Stock of $894.444, $223.61, $406.25, $321.88, $662.50 and $343.75, respectively.

[2] Reflects dividends declared per share on the Company’s Series A, Series B, Series F, Series H, Series J and Series K Non-Cumulative Perpetual Preferred Stock of $894.444, $223.61, $406.25, $321.88, $662.50 and $232.99, respectively.

[3] Reflects dividends declared per share on the Company’s Series A, Series B, Series F, Series H, Series I, Series J and Series K Non-Cumulative Perpetual Preferred Stock of $2,760.506, $663.54, $1,218.75, $965.64, $640.625, $1,325.00 and $1,031.25, respectively.

[4] Reflects dividends declared per share on the Company’s Series A, Series B, Series F, Series H, Series I, Series J and Series K Non-Cumulative Perpetual Preferred Stock of $2,654.166, $663.54, $1,218.75, $965.64, $640.625, $1,325.00 and $232.99, respectively.