Earnings Per Share - Components of Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Earnings Per Share [Abstract]
Net income attributable to U.S. Bancorp	$ 1,386	$ 1,431
Preferred dividends	(61)	(60)
Impact of the purchase of noncontrolling interests	9
Earnings allocated to participating stock awards	(5)	(6)
Net income applicable to U.S. Bancorp common shareholders	$ 1,329	$ 1,365
Average common shares outstanding	1,737	1,781
Net effect of the exercise and assumed purchase of stock awards	6	8
Average diluted common shares outstanding	1,743	1,789
Earnings per common share	$ 0.77	$ 0.77
Diluted earnings per common share	$ 0.76	$ 0.76