Earnings Per Share - Components of Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended
		Mar. 31, 2021		Mar. 31, 2020
Earnings Per Share [Abstract]
Net income attributable to U.S. Bancorp		$ 2,280		$ 1,171
Preferred dividends		(90)	[1]	(78)	[2]
Impact of preferred stock call	[3]	(5)
Earnings allocated to participating stock awards		(10)		(5)
Net income applicable to U.S. Bancorp common shareholders		$ 2,175		$ 1,088
Average common shares outstanding		1,502		1,518
Net effect of the exercise and assumed purchase of stock awards		1		1
Average diluted common shares outstanding		1,503		1,519
Earnings per common share		$ 1.45		$ 0.72
Diluted earnings per common share		$ 1.45		$ 0.72

[1] Reflects dividends declared per share on the Company’s Series A, Series B, Series F, Series I, Series J, Series K, Series L and Series M Non-Cumulative Perpetual Preferred Stock of $875.00, $218.75, $406.25, $232.953, $662.50, $343.75, $234.375, and $202.778 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 $884.722, $221.18, $406.25, $321.88, $662.50 and $343.75, respectively.

[3] Represents stock issuance costs originally recorded in preferred stock upon issuance of the Company’s Series I Preferred Stock that were reclassified to retained earnings on the date the Company announced its intent to redeem the outstanding shares.