Stock Incentive Plans - Long term incentive plans (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Performance period (in years)	3 years
Long Term Incentive Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
LTIP three-year plan	. 16, 2014	. 15, 2013	. 14, 2012
Number of shares issued	227,707	175,291	185,063
Average share value on date of issuance (in USD per share)	$ 157.07	$ 113.91	$ 119.06
Total value	$ 35,766	$ 19,967	$ 22,034