SEGMENTED INFORMATION (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Operating Segment Reporting
Gold and silver sales	$ 14,613	$ 16,160	$ 35,803	$ 39,042
Production costs applicable to sales	(5,763)	(7,288)	(14,830)	(17,742)
Mine development costs	(1,316)	(163)	(2,014)	(337)
Exploration costs	(1,689)	(3,080)	(3,429)	(5,422)
General and administrative expenses	(2,600)	(3,277)	(5,368)	(6,485)
Impairment of mineral property interests and property and equipment		(28,542)		(28,542)
Income (loss) on investment in Minera Santa Cruz S.A. (net of amortization)	4,133	(2,652)	9,096	(2,323)
Gain (loss) on sale of assets			(541)
Operating (loss) income	6,729	(29,677)	17,099	(24,509)
Income taxes recovery (note 9)	856	12,321	2,723	13,484
Investment in Minera Santa Cruz S.A.	170,807	174,147	170,807	174,147	$ 167,107
Mineral property interests	243,051	258,625	243,051	258,625	237,245
Total assets	493,104	506,615	493,104	506,615	$ 475,085
Argentina
Operating Segment Reporting
Exploration costs	(193)	(659)	(503)	(922)
General and administrative expenses	(146)	(173)	(185)	(320)
Income (loss) on investment in Minera Santa Cruz S.A. (net of amortization)	4,133	(2,652)	9,096	(2,323)
Operating (loss) income	3,667	(3,634)	8,144	(3,853)
Investment in Minera Santa Cruz S.A.	170,807	174,147	170,807	174,147
Mineral property interests	191,490	202,889	191,490	202,889
Total assets	369,615	379,987	369,615	379,987
Mexico
Operating Segment Reporting
Gold and silver sales	14,613	16,160	35,803	39,042
Production costs applicable to sales	(5,763)	(7,288)	(14,830)	(17,742)
Mine development costs	(619)	(163)	(697)	(337)
Exploration costs	(860)	(1,275)	(1,645)	(2,874)
General and administrative expenses	(770)	(1,141)	(1,489)	(2,014)
Operating (loss) income	5,869	5,863	15,365	14,210
Mineral property interests	14,763	10,051	14,763	10,051
Total assets	65,023	67,946	65,023	67,946
United States
Operating Segment Reporting
Mine development costs	(697)		(1,317)
Exploration costs	(599)	(1,065)	(1,187)	(1,454)
General and administrative expenses	(52)	(49)	(107)	(108)
Impairment of mineral property interests and property and equipment		(28,542)		(28,542)
Operating (loss) income	(1,571)	(29,846)	(3,098)	(30,527)
Mineral property interests	36,798	45,685	36,798	45,685
Total assets	37,642	46,435	37,642	46,435
Corporate & Other
Operating Segment Reporting
Exploration costs	(37)	(81)	(94)	(172)
General and administrative expenses	(1,632)	(1,914)	(3,587)	(4,043)
Operating (loss) income	(1,236)	(2,060)	(3,312)	(4,339)
Total assets	$ 20,824	$ 12,247	$ 20,824	$ 12,247