Fair Values of Assets and Liabilities - Losses Recognized Related to Nonrecurring Fair Value Measurements of Individual Assets or Portfolios (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2013	Mar. 31, 2012
Fair Value Assets Measured On Nonrecurring Basis Losses Recognized [Abstract]
Loans	$ 21	$ 18
Other assets	$ 39	$ 47

Losses recognized fair value assets measured on nonrecurring basis loans receivable.

No definition available.

Name:	usb_LossesRecognizedFairValueAssetsMeasuredOnNonrecurringBasisLoansReceivable
Namespace Prefix:	usb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration