Commitments and Contingencies - Liability for future environmental expenditures (Details) - USD ($)	3 Months Ended	12 Months Ended
	Jun. 30, 2020	Jun. 30, 2020	Jun. 30, 2020	Jun. 30, 2019
Commitments and Contingencies
Charges to income	$ 200,000	$ 1,119,155
Remedial and investigatory spending		82,155
Ending Balance	1,037,000	1,037,000
Current, included in Other Liabilities			$ 514,000
Long-term environmental			523,000	$ 0
Total	$ 1,037,000	$ 1,037,000	$ 1,037,000