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, 2019	Jun. 30, 2018	Jun. 30, 2017
Unaudited consolidated quarterly statements of operations data
Net revenues	$ 176,963	$ 174,636	$ 159,089	$ 144,056	$ 152,867	$ 116,336	$ 117,912	$ 106,069	$ 654,744	$ 493,184	$ 408,588
Gross margin	79,839	73,847	70,887	61,583	68,258	52,766	54,160	50,674	286,156	225,858	191,543
Income from operations	20,851	22,062	19,861	13,810	18,888	6,838	10,888	10,371	76,584	46,985	37,403
Income before income taxes	12,587	19,466	16,866	10,608	16,628	5,905	10,468	9,572	59,527	42,573	31,068
Income tax provision (benefit)	(217)	5,357	4,483	3,129	6,527	2,209	1,335	(8,381)	12,752	1,690	6,193
Net income	$ 12,804	$ 14,109	$ 12,383	$ 7,479	$ 10,101	$ 3,696	$ 9,133	$ 17,953	$ 46,775	$ 40,883	$ 24,875
Earnings Per Share [Abstract]
Basic net income per share (in dollars per share)	$ 0.26	$ 0.30	$ 0.26	$ 0.16	$ 0.22	$ 0.08	$ 0.20	$ 0.39	$ 0.98	$ 0.88	$ 0.59
Diluted net income per share (in dollars per share)	$ 0.25	$ 0.29	$ 0.26	$ 0.16	$ 0.21	$ 0.08	$ 0.19	$ 0.38	$ 0.96	$ 0.86	$ 0.58
Cost of revenues									$ 368,588	$ 267,326	$ 217,045