XML 75 R59.htm IDEA: XBRL DOCUMENT
v3.25.2

Available for Sale Securities - Amortized cost, gross unrealized gains, gross unrealized losses, ACL, and approximate fair value of securities available for sale (Details) - USD ($) $ in Thousands | Jun. 30, 2025 | Jun. 30, 2024
--- | --- | ---
Debt Securities, Available-for-Sale [Line Items] |  |
Total AFS securities, Amortized Cost | $ 475,395 | $ 450,243
Gross Unrealized Gains | 3,128 | 2,680
Gross Unrealized Losses | (17,679) | (25,020)
Allowance for Credit Losses | 0 | 0
Estimated Fair Value | 460,844 | 427,903
Obligations of states and political subdivisions |  |
Debt Securities, Available-for-Sale [Line Items] |  |
Total AFS securities, Amortized Cost | 26,030 | 29,960
Gross Unrealized Gains | 5 | 4
Gross Unrealized Losses | (1,772) | (2,211)
Allowance for Credit Losses | 0 | 0
Estimated Fair Value | 24,263 | 27,753
Corporate obligations |  |
Debt Securities, Available-for-Sale [Line Items] |  |
Total AFS securities, Amortized Cost | 31,199 | 32,998
Gross Unrealized Gains | 75 | 60
Gross Unrealized Losses | (632) | (1,781)
Allowance for Credit Losses | 0 | 0
Estimated Fair Value | 30,642 | 31,277
Asset backed securities |  |
Debt Securities, Available-for-Sale [Line Items] |  |
Total AFS securities, Amortized Cost | 42,059 | 57,403
Gross Unrealized Gains | 567 | 1,525
Gross Unrealized Losses | (145) | (249)
Allowance for Credit Losses | 0 | 0
Estimated Fair Value | 42,481 | 58,679
Other securities |  |
Debt Securities, Available-for-Sale [Line Items] |  |
Total AFS securities, Amortized Cost | 4,007 | 5,387
Gross Unrealized Gains | 10 | 20
Gross Unrealized Losses | (53) | (74)
Allowance for Credit Losses | 0 | 0
Estimated Fair Value | 3,964 | 5,333
Debt securities |  |
Debt Securities, Available-for-Sale [Line Items] |  |
Total AFS securities, Amortized Cost | 103,295 | 125,748
Gross Unrealized Gains | 657 | 1,609
Gross Unrealized Losses | (2,602) | (4,315)
Allowance for Credit Losses | 0 | 0
Estimated Fair Value | 101,350 | 123,042
Residential MBS issued by governmental sponsored enterprises (GSEs) |  |
Debt Securities, Available-for-Sale [Line Items] |  |
Total AFS securities, Amortized Cost | 138,377 | 110,918
Gross Unrealized Gains | 1,623 | 692
Gross Unrealized Losses | (5,005) | (6,855)
Allowance for Credit Losses | 0 | 0
Estimated Fair Value | 134,995 | 104,755
Commercial MBS issued by GSEs |  |
Debt Securities, Available-for-Sale [Line Items] |  |
Total AFS securities, Amortized Cost | 96,377 | 65,195
Gross Unrealized Gains | 446 | 297
Gross Unrealized Losses | (4,821) | (5,746)
Allowance for Credit Losses | 0 | 0
Estimated Fair Value | 92,002 | 59,746
CMOs issued by GSEs |  |
Debt Securities, Available-for-Sale [Line Items] |  |
Total AFS securities, Amortized Cost | 137,346 | 148,382
Gross Unrealized Gains | 402 | 82
Gross Unrealized Losses | (5,251) | (8,104)
Allowance for Credit Losses | 0 | 0
Estimated Fair Value | 132,497 | 140,360
MBS and CMOs |  |
Debt Securities, Available-for-Sale [Line Items] |  |
Total AFS securities, Amortized Cost | 372,100 | 324,495
Gross Unrealized Gains | 2,471 | 1,071
Gross Unrealized Losses | (15,077) | (20,705)
Allowance for Credit Losses | 0 | 0
Estimated Fair Value | $ 359,494 | $ 304,861

X
- Definition Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2 + Details
Name: | us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2 + Details
Name: | us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount excluding accrued interest, of allowance for credit loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479130/326-30-45-1 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amortized cost excluding accrued interest, before allowance for credit loss, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479130/326-30-45-1 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount excluding accrued interest, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479130/326-30-45-1 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (aa) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (aaa) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-3 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-3 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-3 Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-3 Reference 12: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-3 + Details
Name: | us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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

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

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

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

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

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

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

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

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