Consolidated Statements of Changes in Equity - USD ($) $ in Thousands	Common Shares	Exchangeable Shares	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Earnings	Noncontrolling Interests	Total
Balance at Jun. 30, 2013	$ 642	$ 29,365	$ 2,142,173	$ (4,572)	$ 181,279	$ 21,749	$ 2,370,636
Balance (in shares) at Jun. 30, 2013	64,184,036	667,229
Issuance of common stock for:
Exchange of exchangeable shares	$ 3	$ (12,647)	12,644
Exchange of exchangeable shares (in shares)	287,372	(287,372)
Non-controlling interest assignment			(11,463)			(2,250)	(13,713)
Stock-based compensation and related share issuances	$ 1		4,296				4,297
Stock-based compensation and related share issuances (in shares)	106,993
Net (loss) income					62,641	831	63,472
Other comprehensive income (loss)				4,412			4,412
Distribution to non-controlling interests						(2,498)	(2,498)
Dividends declared					(54,049)		(54,049)
Balance at Jun. 30, 2014	$ 646	$ 16,718	2,147,650	(160)	189,871	17,832	2,372,557
Balance (in shares) at Jun. 30, 2014	64,578,401	379,857
Issuance of common stock for:
Exchange of exchangeable shares	$ 3	$ (16,718)	16,715
Exchange of exchangeable shares (in shares)	379,857	(379,857)
Peak Gold joint venture						45,700	45,700
Stock-based compensation and related share issuances	$ 1		6,278				6,279
Stock-based compensation and related share issuances (in shares)	75,289
Net (loss) income					51,965	713	52,678
Other comprehensive income (loss)				(3,132)			(3,132)
Distribution to non-controlling interests						(1,440)	(1,440)
Dividends declared					(56,715)		(56,715)
Balance at Jun. 30, 2015	$ 650		2,170,643	(3,292)	185,121	62,805	2,415,927
Balance (in shares) at Jun. 30, 2015	65,033,547
Issuance of common stock for:
Stock-based compensation and related share issuances	$ 1		9,138				9,139
Stock-based compensation and related share issuances (in shares)	60,403
Net (loss) income					(77,149)	(5,289)	(82,438)
Other comprehensive income (loss)				$ 3,292			3,292
Distribution to non-controlling interests						(647)	(647)
Dividends declared					(59,388)		(59,388)
Balance at Jun. 30, 2016	$ 651		$ 2,179,781		$ 48,584	$ 56,869	$ 2,285,885
Balance (in shares) at Jun. 30, 2016	65,093,950