Guarantees and Contingent Liabilities - Summary of Other Guarantees and Contingent Liabilities (Detail) $ in Millions	Mar. 31, 2017 USD ($)
Standby Letters of Credit [Member]
Guarantor Obligations [Line Items]
Carrying Amount	$ 63
Maximum Potential Future Payments	12,010
Third Party Borrowing Arrangements [Member]
Guarantor Obligations [Line Items]
Maximum Potential Future Payments	12
Securities Lending Indemnifications [Member]
Guarantor Obligations [Line Items]
Collateral Held	4,139
Maximum Potential Future Payments	4,042
Asset Sales [Member]
Guarantor Obligations [Line Items]
Carrying Amount	130
Maximum Potential Future Payments	6,247
Merchant Processing [Member]
Guarantor Obligations [Line Items]
Collateral Held	720
Carrying Amount	59
Maximum Potential Future Payments	93,642
Tender Option Bond Program Guarantee [Member]
Guarantor Obligations [Line Items]
Collateral Held	1,521
Maximum Potential Future Payments	1,476
Minimum Revenue Guarantees [Member]
Guarantor Obligations [Line Items]
Maximum Potential Future Payments	8
Other Guarantees [Member]
Guarantor Obligations [Line Items]
Maximum Potential Future Payments	$ 1,178

The current carrying amount of the liability for the freestanding or embedded guarantor's obligations under the guarantee or each group of similar guarantees.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6851643&loc=d3e12069-110248

+ Details

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

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_GuaranteeObligationsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=6851643&loc=d3e12069-110248

+ Details

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

- Definition

Guarantee obligations collateral held.

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=us-gaap_StandbyLettersOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=usb_ThirdPartyBorrowingArrangementsMember
Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=us-gaap_IndemnificationGuaranteeMember
Namespace Prefix:
Data Type:	na
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- Details

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

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

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=usb_TenderOptionBondProgramGuaranteeMember
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Data Type:	na
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- Details

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=us-gaap_GuaranteeOfBusinessRevenueMember
Namespace Prefix:
Data Type:	na
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- Details

Name:	us-gaap_GuaranteeObligationsByNatureAxis=us-gaap_GuaranteeTypeOtherMember
Namespace Prefix:
Data Type:	na
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