Share Capital, Option Plans and Share-Based Payments - RSU's, DSU's and ESPP (Details) - USD ($) $ in Millions	3 Months Ended
Sep. 30, 2018	Sep. 30, 2017
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares)	0	2,968
Award vesting period	3 years
Stock issued	$ 0.1	$ 0.2
Stock issued (in shares)	2,968	8,332
Deferred Stock Units (DSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares)	3,158	3,203
Employee Share Purchase Plan (ESPP)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards purchase price discount	15.00%
Common shares eligible for issuance (in shares)	176,074	192,369
Cash received from employee stock purchase plan	$ 5.7	$ 5.7

Cash collected to be used to purchase Common Stock in future periods

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Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Total number of shares issued during the period, including shares forfeited, as a result of Restricted Stock Awards.

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Aggregate value of stock related to Restricted Stock Awards issued during the period.

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