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, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Earnings Per Share [Abstract]
Net income attributable to U.S. Bancorp	$ 1,500	$ 1,522	$ 2,973	$ 2,908
Preferred dividends	(64)	(79)	(133)	(140)
Impact of preferred stock redemption			(10)
Impact of the purchase of noncontrolling interests				9
Earnings allocated to participating stock awards	(6)	(8)	(13)	(13)
Net income applicable to U.S. Bancorp common shareholders	$ 1,430	$ 1,435	$ 2,817	$ 2,764
Average common shares outstanding	1,684	1,725	1,689	1,731
Net effect of the exercise and assumed purchase of stock awards	6	6	6	6
Average diluted common shares outstanding	1,690	1,731	1,695	1,737
Earnings per common share	$ 0.85	$ 0.83	$ 1.67	$ 1.60
Diluted earnings per common share	$ 0.85	$ 0.83	$ 1.66	$ 1.59