Commitments and Contingencies - Liability for future environmental expenditures (Details) - USD ($)	12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Commitments and Contingencies
Beginning Balance	$ 1,037,000
Charges to income	1,100,000	$ 1,119,155
Remedial and investigatory spending	60,280	82,155
Ending Balance	976,720	1,037,000
Current, included in Other Liabilities	976,720	514,000
Long-term environmental	0	523,000
Total liability	$ 976,720	$ 1,037,000