XML 61 R54.htm IDEA: XBRL DOCUMENT
v3.25.3

Securities - Schedule of Amortized Cost Basis by Credit Rating of Held to Maturity Investment (Detail) - USD ($) $ in Thousands | Sep. 30, 2025 | Dec. 31, 2024
--- | --- | ---
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Held to maturity securities | $ 5,654,232 | $ 5,378,912
Competitive [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Held to maturity securities | 1,378,720 | 1,093,659
Utilities [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Held to maturity securities | 1,663,555 | 1,645,788
State and political subdivisions [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Held to maturity securities | 3,042,275 | 2,739,447
Credit Rating, AAA [Member] | Competitive [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Held to maturity securities | 48,372 |
Credit Rating, AAA [Member] | Utilities [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Held to maturity securities | 774,751 | 759,798
Credit Rating, AAA [Member] | State and political subdivisions [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Held to maturity securities | 823,123 | 759,798
Credit Rating, AA [Member] | Competitive [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Held to maturity securities | 51,835 |
Credit Rating, AA [Member] | Utilities [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Held to maturity securities | 754,910 | 761,706
Credit Rating, AA [Member] | State and political subdivisions [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Held to maturity securities | 806,745 | 761,706
Credit Rating, A [Member] | Competitive [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Held to maturity securities | 401,250 | 424,690
Credit Rating, A [Member] | Utilities [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Held to maturity securities | 110,326 | 99,127
Credit Rating, A [Member] | State and political subdivisions [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Held to maturity securities | 511,576 | 523,817
Credit Rating, BBB [Member] | Competitive [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Held to maturity securities | 797,970 | 610,351
Credit Rating, BBB [Member] | Utilities [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Held to maturity securities | 22,895 | 24,509
Credit Rating, BBB [Member] | State and political subdivisions [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Held to maturity securities | 820,865 | 634,860
Credit Rating, BB [Member] | Competitive [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Held to maturity securities | 41,021 | 36,628
Credit Rating, BB [Member] | Utilities [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Held to maturity securities | 673 | 648
Credit Rating, BB [Member] | State and political subdivisions [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Held to maturity securities | 41,694 | 37,276
Credit Rating, B [Member] | Competitive [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Held to maturity securities | 23,551 |
Credit Rating, B [Member] | State and political subdivisions [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Held to maturity securities | 23,551 |
Credit Rating, CCC-C [Member] | Competitive [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Held to maturity securities | 14,721 | 21,990
Credit Rating, CCC-C [Member] | State and political subdivisions [Member] |  |
Debt Securities Held To Maturity Credit Quality Indicator [Line Items] |  |
Held to maturity securities | $ 14,721 | $ 21,990

X
- 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/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-5 + Details
Name: | us-gaap_DebtSecuritiesHeldToMaturityCreditQualityIndicatorLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount, before allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479344/326-20-45-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 825 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 1A -Publisher FASB -URI https://asc.fasb.org/1943274/2147482736/825-10-45-1A Reference 3: http://fasb.org/us-gaap/role/ref/otherTransitionRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 7A -Publisher FASB -URI https://asc.fasb.org/1943274/2147481962/310-10-50-7A Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-5 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 14 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-14 + Details
Name: | us-gaap_HeldToMaturitySecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=umbf_USStatesAndPoliticalSubdivisionsCompetitiveMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=umbf_USStatesAndPoliticalSubdivisionsUtilitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_USStatesAndPoliticalSubdivisionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CreditRatingMoodysAxis=srt_MoodysA3RatingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CreditRatingMoodysAxis=srt_MoodysA2RatingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CreditRatingMoodysAxis=srt_MoodysA1RatingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CreditRatingMoodysAxis=srt_MoodysB3RatingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CreditRatingMoodysAxis=srt_MoodysB2RatingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CreditRatingMoodysAxis=srt_MoodysB1RatingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CreditRatingMoodysAxis=srt_MoodysCRatingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |