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, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Earnings Per Share [Abstract]
Net income attributable to U.S. Bancorp	$ 1,522	$ 1,483	$ 2,908	$ 2,914
Preferred dividends	(79)	(60)	(140)	(120)
Impact of the purchase of noncontrolling interests			9
Earnings allocated to participating stock awards	(8)	(6)	(13)	(12)
Net income applicable to U.S. Bancorp common shareholders	$ 1,435	$ 1,417	$ 2,764	$ 2,782
Average common shares outstanding	1,725	1,771	1,731	1,776
Net effect of the exercise and assumed purchase of stock awards	6	8	6	8
Average diluted common shares outstanding	1,731	1,779	1,737	1,784
Earnings per common share	$ 0.83	$ 0.80	$ 1.60	$ 1.57
Diluted earnings per common share	$ 0.83	$ 0.80	$ 1.59	$ 1.56