Interim Financial Results (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2019
Summary of selected quarterly financial information
Revenue, net	$ 54,777	$ 51,570	$ 59,007	$ 54,827	$ 59,368	$ 56,077	$ 61,242	$ 56,228	$ 220,181	$ 232,915	$ 225,958
Gross profit	44,995	42,752	48,818	45,429	49,919	46,982	51,012	47,038	181,994	194,951	187,985
Net income	$ 4,907	$ 1,724	$ 3,812	$ 2,451	$ 3,824	$ 1,661	$ 4,303	$ 1,761	$ 12,894	$ 11,549	$ 7,429
Per common share:
Income per share, basic (dollars per share)	$ 0.36	$ 0.12	$ 0.27	$ 0.17	$ 0.27	$ 0.12	$ 0.31	$ 0.13	$ 0.92	$ 0.82	$ 0.53
Income per share, diluted (dollars per share)	$ 0.35	$ 0.12	$ 0.26	$ 0.17	$ 0.26	$ 0.11	$ 0.30	$ 0.12	$ 0.90	$ 0.79	$ 0.50