Earnings Per Share - Components of Earnings Per Share (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Earnings Per Share [Abstract]
Net income attributable to U.S. Bancorp	$ 1,471	$ 1,468	$ 4,363	$ 4,380
Preferred dividends	(60)	(61)	(181)	(189)
Impact of preferred stock redemption				(8)
Earnings allocated to participating stock awards	(6)	(7)	(19)	(20)
Net income applicable to U.S. Bancorp common shareholders	$ 1,405	$ 1,400	$ 4,163	$ 4,163
Average common shares outstanding	1,798	1,832	1,809	1,844
Net effect of the exercise and assumed purchase of stock awards	9	11	10	10
Average diluted common shares outstanding	1,807	1,843	1,819	1,854
Earnings per common share	$ 0.78	$ 0.76	$ 2.30	$ 2.26
Diluted earnings per common share	$ 0.78	$ 0.76	$ 2.29	$ 2.25