Capital Stock (Details) - USD ($)					1 Months Ended			12 Months Ended
	Nov. 12, 2013	Sep. 22, 2010	Nov. 11, 2009	Sep. 16, 2009	Nov. 30, 2013	Sep. 30, 2006	Jun. 30, 2004	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2014	Nov. 30, 2001
Stock-based compensation disclosure
Aggregate number of common shares reserved for future issuance								15,500,000
Proceeds from stock options exercised								$ 5,161,000	$ 4,429,000	$ 9,136,000
Stock options
Stock-based compensation disclosure
Options exercised (in shares)								555,000
Exercise price (in dollars per share)								$ 3.19
Exercise price (in dollars per share)								$ 17.00
Deferred share units
Stock-based compensation disclosure
Compensation expense								$ 380,000	389,000	433,000
2006 Plan
Stock-based compensation disclosure
Compensation expense								$ 21,900,000	15,300,000	15,600,000
2006 Plan | Stock options
Stock-based compensation disclosure
Options exercised (in shares)								555,000
Proceeds from stock options exercised								$ 5,161,000	$ 4,429,000	$ 9,136,000
Exercisable at the end of the period (in shares)								6,453,000	5,380,000	4,637,000
Weighted-Average Exercise Price (in dollars per share)								$ 12.63	$ 11.89	$ 9.79
Stock options granted to directors (in shares)								3,340,000
2001 Director Plan
Stock-based compensation disclosure
Aggregate number of common shares reserved for future issuance											50,000
2001 Director Plan | Deferred share units
Stock-based compensation disclosure
Compensation expense								$ (72,000)	$ 16,000	$ (30,000)
Stock units outstanding (in shares)								6,000	6,000	6,000
Stock units issued (in shares)								0	0	0
2004 Director Plan | Deferred share units
Stock-based compensation disclosure
Monthly vesting rights (as a percent)							8.30%
Vesting period						3 years
Compensation Policy for Non-Employee Directors | Stock options
Stock-based compensation disclosure
Grant date fair value		$ 30,000
Stock options granted to directors (in shares)								80,000	80,000	80,000
Compensation Policy for Non-Employee Directors | Deferred share units
Stock-based compensation disclosure
Compensation expense								$ 380,000	$ 389,000	$ 433,000
Stock units issued (in shares)					43,615			41,000	31,000	28,000
Vesting period	1 year			1 year
Common stock issued when a director ceases to be a member (in shares)			1
Stock units previously granted (in shares)								12,000	15,000	19,000
Non-employee directors-initial grant | Deferred share units
Stock-based compensation disclosure
Vesting period			3 years
Grant date fair value			$ 65,000
Non-employee directors-first anniversary | Deferred share units
Stock-based compensation disclosure
Grant date fair value			$ 30,000
Non-employee directors-after year one | Deferred share units
Stock-based compensation disclosure
Vesting period			1 year
Grant date fair value			$ 30,000