Earnings Per Share - Components of Earnings per Share (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Earnings Per Share [Abstract]
Net income attributable to U.S. Bancorp	$ 1,484	$ 1,415	$ 2,912	$ 2,753
Preferred dividends	(64)	(64)	(128)	(110)
Impact of preferred stock redemption (a)	(8)		(8)
Earnings allocated to participating stock awards	(7)	(6)	(13)	(13)
Net income applicable to U.S. Bancorp common shareholders	$ 1,405	$ 1,345	$ 2,763	$ 2,630
Average common shares outstanding	1,843	1,888	1,851	1,895
Net effect of the exercise and assumed purchase of stock awards	10	10	9	9
Average diluted common shares outstanding	1,853	1,898	1,860	1,904
Earnings per common share	$ 0.76	$ 0.71	$ 1.49	$ 1.39
Diluted earnings per common share	$ 0.76	$ 0.71	$ 1.49	$ 1.38