XML 86 R70.htm IDEA: XBRL DOCUMENT
v3.25.2

Loans and Allowance for Credit Losses - Allowance for off-balance credit exposure (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Jun. 30, 2025 | Jun. 30, 2024 | Jun. 30, 2023
Allowance for off-balance sheet credit exposure: |  |  |
Balance, beginning of period | $ 3,263 | $ 6,288 | $ 3,358
Provision (benefit) charged to expense | 676 | (3,025) | 2,930
Balance, end of period | 3,939 | 3,263 | 6,288
Commercial and industrial |  |  |
Allowance for off-balance sheet credit exposure: |  |  |
Balance, beginning of period | 782 | 730 | 420
Provision (benefit) charged to expense | 292 | 52 | 310
Balance, end of period | 1,074 | 782 | 730
Agriculture production |  |  |
Allowance for off-balance sheet credit exposure: |  |  |
Balance, beginning of period | 37 | 107 | 218
Provision (benefit) charged to expense | (37) | (70) | (111)
Balance, end of period |  | 37 | 107
Consumer |  |  |
Allowance for off-balance sheet credit exposure: |  |  |
Balance, beginning of period | 12 | 16 | 2
Provision (benefit) charged to expense | (12) | (4) | 14
Balance, end of period |  | 12 | 16
All other loans |  |  |
Allowance for off-balance sheet credit exposure: |  |  |
Balance, beginning of period |  | 10 |
Provision (benefit) charged to expense | 8 | (10) | 10
Balance, end of period | 8 |  | 10
Secured by real estate | 1-4 residential real estate |  |  |
Allowance for off-balance sheet credit exposure: |  |  |
Balance, beginning of period | 140 | 126 | 107
Provision (benefit) charged to expense | 62 | 14 | 19
Balance, end of period | 202 | 140 | 126
Secured by real estate | Commercial Real Estate | Non-owner occupied |  |  |
Allowance for off-balance sheet credit exposure: |  |  |
Balance, beginning of period | 153 | 154 | 202
Provision (benefit) charged to expense | (19) | (1) | (48)
Balance, end of period | 134 | 153 | 154
Secured by real estate | Commercial Real Estate | Owner occupied |  |  |
Allowance for off-balance sheet credit exposure: |  |  |
Balance, beginning of period | 136 | 182 | 78
Provision (benefit) charged to expense | 25 | (46) | 104
Balance, end of period | 161 | 136 | 182
Secured by real estate | Multi-family real estate |  |  |
Allowance for off-balance sheet credit exposure: |  |  |
Balance, beginning of period | 31 | 16 | 15
Provision (benefit) charged to expense | (31) | 15 | 1
Balance, end of period |  | 31 | 16
Secured by real estate | Construction and land development |  |  |
Allowance for off-balance sheet credit exposure: |  |  |
Balance, beginning of period | 1,912 | 4,897 | 2,243
Provision (benefit) charged to expense | 367 | (2,985) | 2,654
Balance, end of period | 2,279 | 1,912 | 4,897
Secured by real estate | Agriculture real estate |  |  |
Allowance for off-balance sheet credit exposure: |  |  |
Balance, beginning of period | 60 | 50 | 73
Provision (benefit) charged to expense | 21 | 10 | (23)
Balance, end of period | $ 81 | $ 60 | $ 50

X
- Definition Amount of expected credit loss for credit exposure on off-balance-sheet commitment, including but not limited to, loan commitment, standby letter of credit, financial guarantee not accounted for as insurance. Excludes off-balance sheet credit exposure accounted for as insurance and instrument accounted for under derivatives and hedging. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479344/326-20-45-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 460 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482454/460-10-45-1 + Details
Name: | us-gaap_OffBalanceSheetCreditLossLiability
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of expense (reversal of expense) for expected credit loss for off-balance sheet credit exposure. Excludes off-balance sheet credit exposure accounted for as insurance and instrument accounted for under derivatives and hedging. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-13 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 220 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 22 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147476148/220-40-50-22 + Details
Name: | us-gaap_OffBalanceSheetCreditLossLiabilityCreditLossExpenseReversal
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
Name: | us-gaap_OffBalanceSheetCreditLossLiabilityRollforward
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=smbc_CommercialAndIndustrialPortfolioMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=smbc_AgricultureProductionPortfolioMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=srt_OtherPropertyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CollateralAxis=us-gaap_RealEstateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=srt_SingleFamilyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialRealEstatePortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ClassOfFinancingReceivableTypeOfBorrowerAxis=us-gaap_CommercialBorrowerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ClassOfFinancingReceivableTypeOfBorrowerAxis=us-gaap_ConsumerBorrowerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=srt_MultifamilyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=smbc_ConstructionPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=smbc_AgricultureRealEstatePortfolioMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |