Property, Plant and Equipment (Summary of Original Cost of Property, Plant and Equipment) (Details) - USD ($) |
Jun. 30, 2020 |
Jun. 30, 2019 |
|---|---|---|
| Property, plant and equipment, gross | $ 15,714,983 | $ 15,962,555 |
| Accumulated depreciation | (12,248,205) | (12,137,144) |
| Property, plant and equipment, net | 3,466,778 | 3,825,411 |
| Land [Member] | ||
| Property, plant and equipment, gross | 45,000 | 45,000 |
| Building and improvements [Member] | ||
| Property, plant and equipment, gross | 4,387,113 | 4,591,429 |
| Machinery and equipment [Member] | ||
| Property, plant and equipment, gross | 11,118,670 | 11,156,006 |
| Furniture and fixtures [Member] | ||
| Property, plant and equipment, gross | $ 164,200 | $ 170,120 |