Guarantees and Contingent Liabilities - Additional Information (Detail) - USD ($) shares in Millions, $ in Millions	3 Months Ended
Mar. 31, 2016	Dec. 31, 2015
Guarantees And Contingent Liabilities (Textual) [Abstract]
Liability related to remaining Visa Litigation, carrying amount	$ 19
Merchant Processing [Member]
Guarantees And Contingent Liabilities (Textual) [Abstract]
Value of airline tickets purchased to deliver at future date	9,500
Company held collateral in escrow deposits, letters of credit and indemnities from financial institutions and liens on various assets	396
Asset Sales [Member]
Guarantees And Contingent Liabilities (Textual) [Abstract]
Representation and warranty reserve	30	$ 30
Unresolved representation and warranty claims from GSEs	$ 6	$ 12
Visa Class B Shares [Member]
Guarantees And Contingent Liabilities (Textual) [Abstract]
Number of shares sold	0.5
Remaining shares held by the Company	5.9

Carrying amount of estimated litigation liability for known or estimated probable loss from litigation, which may include attorneys' fees and other litigation costs, which is expected to be paid after one year or beyond the normal operating cycle, if longer.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.25)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14326-108349

+ Details

Name:	us-gaap_LitigationReserveNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Total of allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24092-122690

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 09
-Article 12

+ Details

Name:	us-gaap_ValuationAllowancesAndReservesBalance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Company held collateral in escrow deposits, letters of credit and indemnities from financial institutions, and liens on various assets.

+ References

No definition available.

+ Details

Name:	usb_CollateralInEscrowDepositsLettersOfCreditAndIndemnitiesFromFinancialInstitutionsAndLiensOnVariousAssets
Namespace Prefix:	usb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Guarantees and contingent liabilities.

+ References

No definition available.

+ Details

Name:	usb_GuaranteesAndContingentLiabilitiesTextualAbstract
Namespace Prefix:	usb_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Number Of Shares Sold

+ References

No definition available.

+ Details

Name:	usb_NumberOfSharesSold
Namespace Prefix:	usb_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Remaining shares held by the company.

+ References

No definition available.

+ Details

Name:	usb_RemainingSharesHeldByTheCompany
Namespace Prefix:	usb_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Unresolved representation and warranty claims from GSEs.

+ References

No definition available.

+ Details

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

- Definition

Value of airline tickets purchased to deliver at a future date.

+ References

No definition available.

+ Details

Name:	usb_ValueOfAirlineTicketsPurchasedToDeliverAtFutureDate
Namespace Prefix:	usb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=usb_MerchantProcessingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=usb_AssetsSalesArrangementsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=usb_VisaClassBSharesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: