Capital Stock (Details) shares in Thousands, $ in Thousands	12 Months Ended
	Jun. 30, 2017 USD ($) classesofstock shares	Jun. 30, 2016 USD ($) shares	Jun. 30, 2015 USD ($) shares	May 31, 2014 USD ($)
Class of Stock [Line Items]
Number of classes of common stock outstanding | classesofstock	2
Authorized dollar amount of shares to be repurchased				$ 100,000
Remaining authorized repurchase amount	$ 68,000
Repurchases: Number of shares | shares	941	651	925
Repurchases: Cost at market value	$ 53,399	$ 31,080	$ 46,764
Shares tendered for the exercise of price of options (in shares) | shares	600	400	700
Cost of shares tendered for the exercise price of options	$ 37,500	$ 18,000	$ 35,600
Class B stock [Member]
Class of Stock [Line Items]
Common stock voting rights	10 votes per share
Common stock [Member]
Class of Stock [Line Items]
Common stock voting rights	one vote per share