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		6 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Earnings Per Share [Abstract]
Net income	$ 38,078	$ 37,010	$ 72,833	$ 72,011
Weighted average shares outstanding (in shares)	72,342	76,905	72,683	77,977
Dilutive impact from:
Share-based payment awards (in shares)	694	413	650	379
Dilutive weighted average shares outstanding (in shares)	73,036	77,318	73,333	78,356
Income per share
Basic (in dollars per share)	$ 0.53	$ 0.48	$ 1.00	$ 0.92
Dilutive (in dollars per share)	$ 0.52	$ 0.48	$ 0.99	$ 0.92