Share Capital, Option Plans and Share-Based Payments - Additional Information (Details) - USD ($)	12 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2017
Cash Dividends
Dividends declared per common share (in dollars per share)	$ 0.6300	$ 0.5478	$ 0.4770
Payments of dividends	$ 168,859,000	$ 145,613,000	$ 120,581,000
Share Capital
Preference shares issued (in shares)	0
Treasury Stock
Purchase of treasury stock (in shares)	726,059	0	244,240
Purchase of treasury stock	$ 26,499,000	$ 0	$ 8,198,000
Issuance of treasury stock (in shares)	613,524	411,276	409,922

Aggregate dividends declared during the period for each share of common stock outstanding.

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The cash outflow to reacquire common stock during the period.

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