Net Income Per Share - Calculations of Basic and Diluted Net Income per Share and Basic and Dilutive Weighted Average Shares Outstanding (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended						9 Months Ended
	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Mar. 31, 2020	Mar. 31, 2019
Net income	$ 43,521	$ 38,275	$ 46,284	$ 61,587	$ 59,217	$ 38,066	$ 128,080	$ 158,869
Weighted average shares outstanding (in shares)	67,806			69,423			68,122	70,286
Dilutive impact from:
Employee equity awards (in shares)	676			737			784	856
Dilutive weighted average shares outstanding (in shares)	68,482			70,160			68,906	71,142
Income per share
Basic (in dollars per share)	$ 0.64			$ 0.89			$ 1.88	$ 2.26
Dilutive (in dollars per share)	$ 0.64			$ 0.88			$ 1.86	$ 2.23