Subsequent Event - Additional Information (Details) - EBP 001		12 Months Ended
Jan. 01, 2026	Dec. 31, 2025	Dec. 31, 2024
EBP, Subsequent Event [Line Items]
Company matching contribution		50.00%	50.00%
Participant's contributions, percentage		9.00%	9.00%
Participants vested percentage		100.00%
Subsequent Event
EBP, Subsequent Event [Line Items]
Company matching contribution	75.00%
Participant's contributions, percentage	6.00%

Employee benefit plan participants vested percentage.

No definition available.

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Namespace Prefix:	umbf_
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Period Type:	duration

- 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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 855
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483399/855-10-50-2

Reference 2: http://www.xbrl.org/2003/role/recommendedDisclosureRef
-Topic 855
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483399/855-10-50-3

+ Details

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Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of employer matching contribution on eligible participant contribution to employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 962
-SubTopic 325
-Name Accounting Standards Codification
-Section 55
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478873/962-325-55-17

+ Details

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Namespace Prefix:	us-gaap-ebp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of participant compensation eligible for employer matching contribution for participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

+ References

+ Details

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Data Type:	dtr-types:percentItemType
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- Details

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- Details

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