Earnings Per Share - Components of Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2020		Jun. 30, 2019		Jun. 30, 2020		Jun. 30, 2019
Earnings Per Share [Abstract]
Net income attributable to U.S. Bancorp	$ 689		$ 1,821		$ 1,860		$ 3,520
Preferred dividends	(72)	[1]	(72)	[2]	(150)	[3]	(151)	[4]
Earnings allocated to participating stock awards	(3)		(8)		(8)		(15)
Net income applicable to U.S. Bancorp common shareholders	$ 614		$ 1,741		$ 1,702		$ 3,354
Average common shares outstanding	1,506		1,590		1,512		1,596
Net effect of the exercise and assumed purchase of stock awards	1		2		1		3
Average diluted common shares outstanding	1,507		1,592		1,513		1,599
Earnings per common share	$ 0.41		$ 1.09		$ 1.13		$ 2.10
Diluted earnings per common share	$ 0.41		$ 1.09		$ 1.12		$ 2.10

[1] Reflects dividends declared per share on the Company’s Series A, Series B, Series F, Series H, Series I and Series K Non-Cumulative Perpetual Preferred Stock of $884.722, $221.18, $406.25, $321.88, $640.625 and $343.75, respectively.

[2] Reflects dividends declared per share on the Company’s Series A, Series B, Series F, Series H, Series I and Series K Non-Cumulative Perpetual Preferred Stock of $914.234, $221.18, $406.25, $321.88, $640.625 and $343.75, 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 $1,769.444, $442.36, $812.50, $643.76, $640.625, $662.50 and $687.50, 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 $1,866.062, $439.93, $812.50, $643.76, $640.625, $662.50 and $687.50, respectively.