Stockholders' Equity and Regulatory Capital (Details) $ in Thousands	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)
Southern Bank \| Total Capital (to Risk-Weighted Assets)
Capital	$ 271,137	$ 247,199
Capital to Risk Weighted Assets	12.88	12.81
Capital Required for Capital Adequacy	$ 168,355	$ 154,364
Capital Required for Capital Adequacy to Risk Weighted Assets	8.00	8.00
Capital Required to be Well Capitalized	$ 210,444	$ 192,954
Capital Required to be Well Capitalized to Risk Weighted Assets	10.00	10.00
Southern Bank \| Tier I Capital (to Risk-Weighted Assets)
Capital	$ 244,822	$ 225,985
Capital to Risk Weighted Assets	11.63	11.71
Capital Required for Capital Adequacy	$ 126,266	$ 115,773
Capital Required for Capital Adequacy to Risk Weighted Assets	6.00	6.00
Capital Required to be Well Capitalized	$ 168,355	$ 154,364
Capital Required to be Well Capitalized to Risk Weighted Assets	8.00	8.00
Southern Bank \| Tier I Capital (to Average Assets)
Capital	$ 244,822	$ 225,985
Capital to Risk Weighted Assets	9.66	10.38
Capital Required for Capital Adequacy	$ 101,370	$ 87,077
Capital Required for Capital Adequacy to Risk Weighted Assets	4.00	4.00
Capital Required to be Well Capitalized	$ 126,713	$ 108,846
Capital Required to be Well Capitalized to Risk Weighted Assets	5.00	5.00
Southern Bank \| Common Equity Tier I Capital (to Risk-Weighted Assets)
Capital	$ 244,822	$ 225,985
Capital to Risk Weighted Assets	11.63	11.71
Capital Required for Capital Adequacy	$ 94,700	$ 86,829
Capital Required for Capital Adequacy to Risk Weighted Assets	4.50	4.50
Capital Required to be Well Capitalized	$ 136,789	$ 125,420
Capital Required to be Well Capitalized to Risk Weighted Assets	6.50	6.50
Consolidated \| Total Capital (to Risk-Weighted Assets)
Capital	$ 278,924	$ 256,982
Capital to Risk Weighted Assets	13.17	13.22
Capital Required for Capital Adequacy	$ 169,473	$ 155,536
Capital Required for Capital Adequacy to Risk Weighted Assets	8.00	8.00
Consolidated \| Tier I Capital (to Risk-Weighted Assets)
Capital	$ 252,609	$ 235,768
Capital to Risk Weighted Assets	11.92	12.13
Capital Required for Capital Adequacy	$ 127,105	$ 116,652
Capital Required for Capital Adequacy to Risk Weighted Assets	6.00	6.00
Consolidated \| Tier I Capital (to Average Assets)
Capital	$ 252,609	$ 235,768
Capital to Risk Weighted Assets	9.95	10.81
Capital Required for Capital Adequacy	$ 101,528	$ 87,231
Capital Required for Capital Adequacy to Risk Weighted Assets	4.00	4.00
Consolidated \| Common Equity Tier I Capital (to Risk-Weighted Assets)
Capital	$ 237,467	$ 220,725
Capital to Risk Weighted Assets	11.21	11.35
Capital Required for Capital Adequacy	$ 95,328	$ 87,489
Capital Required for Capital Adequacy to Risk Weighted Assets	4.50	4.50

Amount of total capital as defined by regulatory framework.

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