Stockholders' Equity and Regulatory Capital (Details) $ in Thousands	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)
Southern Bank \| Total Capital (to Risk-Weighted Assets)
Capital	$ 496,105	$ 454,699
Capital to Risk Weighted Assets	0.1268	0.1177
Capital Required for Capital Adequacy	$ 312,877	$ 308,932
Capital Required for Capital Adequacy to Risk Weighted Assets	0.0800	0.0800
Capital Required to be Well Capitalized	$ 391,097	$ 386,166
Capital Required to be Well Capitalized to Risk Weighted Assets	0.1000	0.1000
Southern Bank \| Tier I Capital (to Risk-Weighted Assets)
Capital	$ 447,192	$ 407,764
Capital to Risk Weighted Assets	0.1143	0.1056
Capital Required for Capital Adequacy	$ 234,658	$ 231,699
Capital Required for Capital Adequacy to Risk Weighted Assets	0.0600	0.0600
Capital Required to be Well Capitalized	$ 312,877	$ 308,932
Capital Required to be Well Capitalized to Risk Weighted Assets	0.0800	0.0800
Southern Bank \| Tier I Capital (to Average Assets)
Capital	$ 447,192	$ 407,764
Capital to Risk Weighted Assets	0.0979	0.0954
Capital Required for Capital Adequacy	$ 182,723	$ 170,942
Capital Required for Capital Adequacy to Risk Weighted Assets	0.0400	0.0400
Capital Required to be Well Capitalized	$ 228,403	$ 213,677
Capital Required to be Well Capitalized to Risk Weighted Assets	0.0500	0.0500
Southern Bank \| Common Equity Tier I Capital (to Risk-Weighted Assets)
Capital	$ 447,192	$ 407,764
Capital to Risk Weighted Assets	0.1143	0.1056
Capital Required for Capital Adequacy	$ 175,993	$ 173,774
Capital Required for Capital Adequacy to Risk Weighted Assets	0.0450	0.0450
Capital Required to be Well Capitalized	$ 254,213	$ 251,008
Capital Required to be Well Capitalized to Risk Weighted Assets	0.0650	0.0650
Consolidated \| Total Capital (to Risk-Weighted Assets)
Capital	$ 524,023	$ 481,236
Capital to Risk Weighted Assets	0.1323	0.1252
Capital Required for Capital Adequacy	$ 316,979	$ 307,528
Capital Required for Capital Adequacy to Risk Weighted Assets	0.0800	0.0800
Consolidated \| Tier I Capital (to Risk-Weighted Assets)
Capital	$ 467,027	$ 426,644
Capital to Risk Weighted Assets	0.1179	0.1110
Capital Required for Capital Adequacy	$ 237,734	$ 230,646
Capital Required for Capital Adequacy to Risk Weighted Assets	0.0600	0.0600
Consolidated \| Tier I Capital (to Average Assets)
Capital	$ 467,027	$ 426,644
Capital to Risk Weighted Assets	0.1019	0.0995
Capital Required for Capital Adequacy	$ 183,262	$ 171,470
Capital Required for Capital Adequacy to Risk Weighted Assets	0.0400	0.0400
Consolidated \| Common Equity Tier I Capital (to Risk-Weighted Assets)
Capital	$ 451,474	$ 411,196
Capital to Risk Weighted Assets	0.1139	0.1070
Capital Required for Capital Adequacy	$ 178,300	$ 172,985
Capital Required for Capital Adequacy to Risk Weighted Assets	0.0450	0.0450

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Amount of minimum total risk-based capital required for capital adequacy as defined by regulatory framework.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 505
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477270/942-505-50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477270/942-505-50-1B

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