Accounting Changes - Additional Information (Detail) - USD ($) $ in Billions	Jan. 01, 2020	Dec. 31, 2019
Increase in lease assets related to adoption of accounting guidance		$ 1.3
Increase in lease related liabilities related to adoption of accounting guidance		$ 1.3
Accounting Standards Update 2016-13 [Member] \| Forecast [Member] \| Retained Earnings [Member]
Increase in allowance for credit losses	$ 1.5

New accounting pronouncement or change in accounitng principle effect of adoption on lease related liabilities.

No definition available.

Name:	usb_NewAccountingPronouncementOrChangeInAccountingPrincipleEffectOfAdoptionOnLeaseRelatedLiabilities
Namespace Prefix:	usb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant