Fair Value of Financial Instruments - Nonrecurring Level 3 Fair value measurements (Details)	Sep. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)
Fair Value Assets and Liabilities measured on Recurring and Nonrecurring basis valuation techniques
Other real estate owned, net	$ 2,288,255	$ 2,288,255
Non-recurring
Fair Value Assets and Liabilities measured on Recurring and Nonrecurring basis valuation techniques
Impaired loans with a valuation allowance, net	257,270	248,930
Other real estate owned, net	2,288,255	2,288,255
Level 3 | Non-recurring
Fair Value Assets and Liabilities measured on Recurring and Nonrecurring basis valuation techniques
Impaired loans with a valuation allowance, net	257,270	248,930
Other real estate owned, net	2,288,255	2,288,255
Market price or appraised value | Management discount on appraised values | Level 3 | Non-recurring
Fair Value Assets and Liabilities measured on Recurring and Nonrecurring basis valuation techniques
Impaired loans with a valuation allowance, net	257,270	248,930
Other real estate owned, net	$ 2,288,255	$ 2,288,255
Market price or appraised value | Management discount on appraised values | Minimum | Level 3 | Non-recurring
Fair Value Assets and Liabilities measured on Recurring and Nonrecurring basis valuation techniques
Impaired loans with a valuation allowance, net, measurement input	0.05	0.05
Other real estate owned, net, measurement input	0.05	0.05
Market price or appraised value | Management discount on appraised values | Maximum | Level 3 | Non-recurring
Fair Value Assets and Liabilities measured on Recurring and Nonrecurring basis valuation techniques
Impaired loans with a valuation allowance, net, measurement input	0.15	0.15
Other real estate owned, net, measurement input	0.15	0.15