Defined Benefit Pension Plan - Funded status (Details) - USD ($)	12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Change in projected benefit obligation
Projected benefit obligation at beginning of year	$ 12,363,236	$ 10,601,032
Interest cost	335,720	371,932
Benefits paid	(418,160)	(297,103)
Actuarial (gain) loss	269,252	(1,687,375)
Projected benefit obligation at end of year	12,011,544	12,363,236
Change in plan assets
Fair value of plan assets at beginning of year	9,268,753	9,770,170
Actual return on assets	3,257,972	(204,314)
Employer contributions	0	0
Benefits paid	(418,160)	(297,103)
Fair value of plan assets at end of year	12,108,565	9,268,753
Funded status at end of year	$ 97,021	$ (3,094,483)