XML 47 R36.htm IDEA: XBRL DOCUMENT
v3.24.1.1.u2

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 | Mar. 31, 2024 | Jun. 30, 2023
--- | --- | ---
Debt Securities, Available-for-sale [Line Items] |  |
Total AFS securities, Amortized Cost | $ 458,069 | $ 445,616
Gross Unrealized Gains | 2,539 | 1,494
Gross Unrealized Losses | (26,919) | (29,556)
Allowance for Credit Losses | 0 | 0
Estimated Fair Value | 433,689 | 417,554
Obligations of states and political subdivisions |  |
Debt Securities, Available-for-sale [Line Items] |  |
Total AFS securities, Amortized Cost | 30,008 | 45,285
Gross Unrealized Gains | 25 | 20
Gross Unrealized Losses | (1,925) | (2,737)
Allowance for Credit Losses | 0 | 0
Estimated Fair Value | 28,108 | 42,568
Corporate Obligations |  |
Debt Securities, Available-for-sale [Line Items] |  |
Total AFS securities, Amortized Cost | 35,826 | 35,700
Gross Unrealized Gains | 126 | 19
Gross Unrealized Losses | (2,139) | (3,181)
Allowance for Credit Losses | 0 | 0
Estimated Fair Value | 33,813 | 32,538
Asset backed securities |  |
Debt Securities, Available-for-sale [Line Items] |  |
Total AFS securities, Amortized Cost | 63,561 | 67,897
Gross Unrealized Gains | 1,514 | 1,274
Gross Unrealized Losses | (280) | (545)
Allowance for Credit Losses | 0 |
Estimated Fair Value | 64,795 | 68,626
Other securities |  |
Debt Securities, Available-for-sale [Line Items] |  |
Total AFS securities, Amortized Cost | 5,657 | 3,587
Gross Unrealized Gains | 21 | 39
Gross Unrealized Losses | (70) | (56)
Allowance for Credit Losses | 0 | 0
Estimated Fair Value | 5,608 | 3,570
Debt and Equity Securities |  |
Debt Securities, Available-for-sale [Line Items] |  |
Total AFS securities, Amortized Cost | 135,052 | 152,469
Gross Unrealized Gains | 1,686 | 1,352
Gross Unrealized Losses | (4,414) | (6,519)
Allowance for Credit Losses | 0 | 0
Estimated Fair Value | 132,324 | 147,302
Residential MBS issued by governmental sponsored enterprises (GSEs) |  |
Debt Securities, Available-for-sale [Line Items] |  |
Total AFS securities, Amortized Cost | 107,807 | 97,612
Gross Unrealized Gains | 645 | 122
Gross Unrealized Losses | (7,471) | (7,610)
Allowance for Credit Losses | 0 | 0
Estimated Fair Value | 100,981 | 90,124
Commercial MBS issued by GSEs |  |
Debt Securities, Available-for-sale [Line Items] |  |
Total AFS securities, Amortized Cost | 65,311 | 60,333
Gross Unrealized Gains | 150 | 11
Gross Unrealized Losses | (6,404) | (6,959)
Allowance for Credit Losses | 0 | 0
Estimated Fair Value | 59,057 | 53,385
CMOs issued by GSEs |  |
Debt Securities, Available-for-sale [Line Items] |  |
Total AFS securities, Amortized Cost | 149,899 | 135,202
Gross Unrealized Gains | 58 | 9
Gross Unrealized Losses | (8,630) | (8,468)
Allowance for Credit Losses | 0 | 0
Estimated Fair Value | 141,327 | 126,743
Total MBS and CMOs |  |
Debt Securities, Available-for-sale [Line Items] |  |
Total AFS securities, Amortized Cost | 323,017 | 293,147
Gross Unrealized Gains | 853 | 142
Gross Unrealized Losses | (22,505) | (23,037)
Allowance for Credit Losses | 0 | 0
Estimated Fair Value | $ 301,365 | $ 270,252

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=smbc_DebtAndEquitySecuritiesMember
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=smbc_CollateralizedMortgageObligationsIssuedByGovernmentalSponsoredEnterprisesMember
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: |