Shareholders' Equity Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018
Earnings Per Share [Abstract]
Net income	$ 24,042	$ 143,993	$ 141,625
Average Shares Outstanding:
Weighted-average common shares outstanding for basic computation	38,658	38,670	38,752
Dilutive effect of potential common shares	341	490	529
Weighted-average common shares outstanding for dilutive computation	38,999	39,160	39,281
Net income per share — basic	$ 0.62	$ 3.72	$ 3.65
Net income per share — diluted	$ 0.62	$ 3.68	$ 3.61