Supplementary Information (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016
Unaudited consolidated quarterly statements of operations data
Net revenues	$ 152,867	$ 116,336	$ 117,912	$ 106,069	$ 115,608	$ 107,317	$ 98,014	$ 87,649	$ 493,184	$ 408,588	$ 270,154
Gross margin	68,258	52,766	54,160	50,674	53,927	50,783	47,389	39,444	225,858	191,543	127,619
Income from operations	18,888	6,838	10,888	10,371	13,008	11,695	8,958	3,742	46,985	37,403	23,973
Income before income taxes	16,628	5,905	10,468	9,572	11,307	10,218	6,983	2,560	42,573	31,068	25,286
Income tax (benefit) provision	6,527	2,209	1,335	(8,381)	2,503	3,170	1,779	(1,259)	1,690	6,193	5,544
Net income	$ 10,101	$ 3,696	$ 9,133	$ 17,953	$ 8,804	$ 7,048	$ 5,204	$ 3,819	$ 40,883	$ 24,875	$ 19,742
Earnings Per Share [Abstract]
Basic net income per share (in dollars per share)	$ 0.22	$ 0.08	$ 0.20	$ 0.39	$ 0.19	$ 0.16	$ 0.13	$ 0.10	$ 0.88	$ 0.59	$ 0.58
Diluted net income per share (in dollars per share)	$ 0.21	$ 0.08	$ 0.19	$ 0.38	$ 0.19	$ 0.16	$ 0.13	$ 0.10	$ 0.86	$ 0.58	$ 0.56
Cost of revenues									$ 267,326	$ 217,045	$ 142,535