Share Capital, Option Plans and Share-Based Payments - Schedule of Weighted-Average Fair Value Of Options And Weighted-Average Assumptions Used (Details) - $ / shares	3 Months Ended		6 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Weighted-average fair value of options granted (in dollars per share)	$ 7.49	$ 6.58	$ 7.46	$ 6.54
Weighted-average assumptions used:
Expected volatility	26.64%	28.53%	27.11%	29.29%
Risk–free interest rate	1.95%	1.22%	1.81%	1.06%
Expected dividend yield	1.48%	1.43%	1.45%	1.45%
Expected life (in years)	4 years 6 months 30 days	4 years 4 months 2 days	4 years 5 months 1 day	4 years 3 months 29 days
Forfeiture rate (based on historical rates)	6.00%	5.00%	6.00%	5.00%
Average exercised share price (in dollars per share)	$ 34.48	$ 30.37	$ 34.49	$ 29.83