Share Capital, Option Plans and Share-Based Payments - Schedule of Share-Based Payments (Details) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 27,594	$ 30,507	$ 25,978
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	9,828	12,196	13,202
Restricted Stock Units (RSUs) | Long Term Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	6,602	6,452	5,086
Restricted Stock Units (RSUs) | Other plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	936	2,804	1,573
Performance Stock Units (PSUs) | Long Term Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	3,553	3,624	2,688
Deferred Share Units (directors)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	2,921	2,849	2,764
Employee Share Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 3,754	$ 2,582	$ 665