Interim Financial Results (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018
Summary of selected quarterly financial information
Revenue, net	$ 59,368	$ 56,077	$ 61,242	$ 56,228	$ 56,170	$ 56,012	$ 58,167	$ 55,609	$ 232,915	$ 225,958	$ 203,204
Gross profit	49,919	46,982	51,012	47,038	46,460	46,742	48,373	46,410	194,951	187,985	168,356
Net income	$ 3,824	$ 1,661	$ 4,303	$ 1,761	$ 3,907	$ 1,782	$ 829	$ 911	$ 11,549	$ 7,429	$ 5,761
Per common share:
Income per share, basic (dollars per share)	$ 0.27	$ 0.12	$ 0.31	$ 0.13	$ 0.27	$ 0.13	$ 0.06	$ 0.07	$ 0.82	$ 0.53	$ 0.41
Income per share, diluted (dollars per share)	$ 0.26	$ 0.11	$ 0.30	$ 0.12	$ 0.26	$ 0.12	$ 0.06	$ 0.06	$ 0.79	$ 0.50	$ 0.41