XML 122 R106.htm IDEA: XBRL DOCUMENT
v3.20.2

Commitments and Credit Risk - Standby Letters of Credit: Letters of Credit (Details) - USD ($) $ in Millions | Jun. 30, 2020 | Jun. 30, 2019
--- | --- | ---
Commitments and Credit Risk |  |
Letters of Credit Outstanding, Amount | $ 3.2 | $ 2.6

X
- References No definition available. + Details
Name: | smbc_CommitmentsAndCreditRiskDisclosureAbstract
Namespace Prefix: | smbc_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The total amount of the contingent obligation under letters of credit outstanding as of the reporting date. + References No definition available. + Details
Name: | us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant