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.

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
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- Definition

Amount of revenue from servicing real estate mortgages, credit cards, and other financial assets held by others. Includes premiums received in lieu of regular servicing fees.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.13 (d))
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

+ Details

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Balance Type:	credit
Period Type:	duration

- Definition

Gain/Loss on fair value changes of MSRs due to changes in valuation assumptions and derivatives used to economically hedge MSRs.

+ References

No definition available.

+ Details

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- Definition

Residential mortgage loans serviced for others including subserviced mortgages with no corresponding mortgage servicing rights asset.

+ References

No definition available.

+ Details

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Namespace Prefix:	usb_
Data Type:	xbrli:monetaryItemType
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Period Type:	instant

- Details

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Period Type:

Mortgage Servicing Rights - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Servicing Assets at Fair Value [Line Items]
Residential mortgage loans serviced for others including subserviced mortgages with no corresponding MSRs asset	$ 232,600		$ 232,600		$ 234,700
Gain (Loss) on fair value changes of MSRs due to changes in valuation assumptions and derivatives used to economically hedge MSRs	1		44	$ 17
Loan servicing and ancillary fees	$ 182	$ 183	$ 557	$ 561
Maximum [Member]
Servicing Assets at Fair Value [Line Items]
Gain (Loss) on fair value changes of MSRs due to changes in valuation assumptions and derivatives used to economically hedge MSRs		$ (1)