Accounting Changes - Additional Information (Detail) - Accounting Standards Update 2016-13 [Member] $ in Billions	Jan. 01, 2020 USD ($)
Increase in allowance for credit losses due to new accounting standard	$ 1.5
Decrease in retained earnings due to new accounting standard	$ 1.1

Financing receivable allowance for credit losses increase due to new accounting standard.

No definition available.

Name:	usb_FinancingReceivableAllowanceForCreditLossesIncreaseDueToNewAccountingStandard
Namespace Prefix:	usb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration