SHAREHOLDERS' EQUITY (Details) $ in Thousands							3 Months Ended		9 Months Ended		12 Months Ended
	Aug. 29, 2016 $ / shares	Feb. 12, 2016 USD ($) $ / shares	Oct. 01, 2015 USD ($) shares	Aug. 17, 2015 $ / shares	Jun. 18, 2015 $ / shares	Mar. 11, 2015 USD ($) item shares	Sep. 30, 2016 $ / shares shares	Sep. 30, 2015 shares	Sep. 30, 2016 USD ($) $ / shares shares	Sep. 30, 2015 USD ($) $ / shares shares	Dec. 31, 2015 USD ($) shares
Exchangeable shares converted into common stock								4,000,000	24,200,000		4,300,000
Exchangeable, shares outstanding							0	24,200,000	0	24,200,000	24,213,000
Common stock issued							299,453,000	0	299,453,000	0	274,421,000
Weighted average exercise price of stock options (in dollars per share) | $ / shares									$ 2.56
Exercise of stock options | $									$ 3,500
Proceeds from exercise of stock options (note 8) | $									$ 3,500
Number of mining contractors with which the entity has entered into an agreement | item						1
Semi-annual return of capital payable (in dollars per share) | $ / shares		0.005					0.005		0.005	0.010
Return of capital distribution paid | $		$ 1,500							$ 2,986	$ 1,502
Fair Value of common stock at issuance | $						$ 400
Share repurchase program | $									$ 582		$ 1,800
Number of shares authorized to be repurchased			15,000,000
Period of time over which common stock can be repurchased			12 months
Authorized maximum to be spent on repurchases | $			$ 15,000
Share repurchase program (in shares)									557,991		1,896,442
Settlement agreement regarding outstanding litigation
Number of mining contractors with which the entity has entered into an agreement | item						1
Common Stock
Shares of common stock issued upon exercise of stock options									1,377,000
Exercise of stock options | $									$ 3,500
Shares issued for settlement of accounts payable (in shares)						430,295
Shares issued for settlement of accounts payable (note 8) (in shares)										430,000
Annual return of capital declared (in dollars per share) | $ / shares					$ 0.01
Semi-annual return of capital payable (in dollars per share) | $ / shares	0.005			0.005
Share repurchase program | $									$ 582
Share repurchase program (in shares)									558,000