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, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Earnings Per Share [Abstract]
Net income	$ 37,835	$ 35,834	$ 110,668	$ 107,845
Weighted average shares outstanding (in shares)	71,828	75,676	72,402	77,221
Dilutive impact from:
Share-based payment awards (in shares)	835	506	734	431
Dilutive weighted average shares outstanding (in shares)	72,663	76,182	73,136	77,652
Income per share
Basic (in dollars per share)	$ 0.53	$ 0.47	$ 1.53	$ 1.40
Dilutive (in dollars per share)	$ 0.52	$ 0.47	$ 1.51	$ 1.39