Nature of Business and Summary of Significant Accounting Policies - Net Income per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2019
Nature of Business and Summary of Significant Accounting Policies
Basic EPS	$ 14,901	$ 8,520	$ 12,223
Diluted EPS	$ 14,901	$ 8,520	$ 12,223
Weighted average
Basic (in shares)	18,348,000	18,444,000	18,574,000
Stock Options	56,000	49,000	50,000
Diluted (in shares)	18,404,000	18,493,000	18,624,000
Effect of Dilutive Securities:
Basic (in dollars per share)	$ 0.81	$ 0.46	$ 0.66
Diluted (in dollars per share)	$ 0.81	$ 0.46	$ 0.66
Excluded from diluted EPS	20,000	38,819	2,957