XML 93 R82.htm IDEA: XBRL DOCUMENT
v3.25.0.1

Derivative Financial Instruments - Additional Information (Details) | 3 Months Ended | 6 Months Ended |  |
--- | --- | --- | --- | ---
Dec. 31, 2024 USD ($) | Dec. 31, 2023 USD ($) | Dec. 31, 2024 USD ($) | Dec. 31, 2023 USD ($) | Sep. 30, 2024 USD ($) DerivativeInstrument | Jun. 30, 2024 USD ($) DerivativeInstrument
1-4 Family interest rate swaps |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |
Notional Amount | $ 50,000,000 |  | $ 50,000,000 |  |  | $ 40,000,000
Interest Income | $ 83,000 | $ 0 | $ 261,000 | $ 0 |  |
1-4 Family interest rate swaps (1) |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |
Notional Amount |  |  |  |  | $ 10,000,000 |
Number of derivative instruments executed | DerivativeInstrument |  |  |  |  | 1 |
1-4 Family interest rate swaps (2) |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |
Notional Amount |  |  |  |  |  | $ 20,000,000
Number of derivative instruments executed | DerivativeInstrument |  |  |  |  |  | 2

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 815 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480237/815-40-50-5 + Details
Name: | us-gaap_DerivativeLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Nominal or face amount used to calculate payment on derivative. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1B -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-1B Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1A -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-1A + Details
Name: | us-gaap_DerivativeNotionalAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

X
- Definition The number of derivative instruments of a particular group held by the entity. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478795/946-210-50-6 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section 55 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147477439/946-210-55-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 5 -Subparagraph (SX 210.12-13(Column A)(Footnote 3)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-5 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 5 -Subparagraph (SX 210.12-13(Column C)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-5 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 5A -Subparagraph (SX 210.12-13A(Column B)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-5A Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1B -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-1B Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-1A + Details
Name: | us-gaap_DerivativeNumberOfInstrumentsHeld
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of increase (decrease) in interest income for hedge basis adjustment from hedged layer exceeding outstanding amount of closed portfolio of financial asset or beneficial interest secured by financial instrument. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 5C -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-5C Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1CC -Publisher FASB -URI https://asc.fasb.org/1943274/2147480627/815-20-45-1CC + Details
Name: | us-gaap_InterestIncomeHedgeBasisAdjustmentPortfolioLayerMethod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateSwapMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=smbc_InterestRateSwapOneMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=smbc_InterestRateSwapTwoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |