COMMITMENTS AND CONTINGENCIES: (Details 2) (USD $) In Millions, unless otherwise specified	9 Months Ended			1 Months Ended	0 Months Ended	3 Months Ended	9 Months Ended	12 Months Ended			0 Months Ended	1 Months Ended	9 Months Ended		1 Months Ended
	Sep. 30, 2013 Tia Maria ha	Sep. 30, 2013 Virgen Maria ha	Sep. 30, 2013 Garcia Ataucuri litigation workers plaintiff	Jul. 31, 2012 Minera Krypton Mining Rehabilitation workers	Dec. 25, 2012 Peruvian operations	Mar. 31, 2013 Peruvian operations	Sep. 30, 2013 Peruvian operations item	Dec. 31, 1992 Peruvian operations	Dec. 31, 1978 Peruvian operations	Dec. 31, 1971 Peruvian operations	Sep. 26, 2013 Peruvian operations Toquepala	Apr. 30, 1996 Peruvian operations Garcia Ataucuri and Others against SCC's Peruvian Branch person	Sep. 30, 2013 Peruvian operations Garcia Ataucuri and Others against SCC's Peruvian Branch solesdeoro	Sep. 30, 2013 Peruvian operations Garcia Ataucuri and Others against SCC's Peruvian Branch laborshares	Aug. 31, 2009 Peruvian operations Exploraciones de Concesiones Metalicas S.A.C. ("Excomet")
Litigation matter
Number of former employees who filed the complaint												900
Statutory participation of mine workers in pre-tax profit (as a percent)								8.00%		10.00%
Statutory participation of mine workers in pre-tax profit paid in cash (as a percent)								100.00%	4.00%	40.00%
Statutory participation of mine workers in pre-tax profit received as equity interest of enterprise (as a percent)										60.00%
Percentage of pre-tax profits delivered as "labor shares"									5.50%
Damages sought by the plaintiff													3,876,380,679.65	38,763,806.80
Face value of one labor share													100.00	100.00
Labor shares issued by the Branch													100.00%	100.00%
Plaintiffs do not represent the percent of SCC's eligible employees													100.00%	100.00%
Soles de oro equivalent to today's one nuevo sol													1,000,000,000	1,000,000,000
Number of plaintiffs involved in lawsuits filed			800
Number of former Branch workers			216
Number of former Branch workers			37
Area of mining concession (in hectares)	32,989.64	943.72
Percentage of mining concession		2.90%
Purchase price of shares paid to former stockholders															$ 2
Percentage of labor unionized							66.00%
Total number of workers							4,469
Number of labor unions							7
Number of labor unions represent majority of workers							3
Number of labor unions at each production area represent majority of workers							1
Total number of workers at the three major unions							2,244
Number of labor unions other than majority workers unions							4
Term of collective bargaining agreement						3 years
Percentage of annual salary increase as per collective bargaining agreement in year 2013						6.50%
Percentage of annual salary increase as per collective bargaining agreement in year 2014						5.00%
Percentage of annual salary increase as per collective bargaining agreement in year 2015						5.00%
Percentage of workers of the major union											45.00%
Period of illegal work stoppage					2 days						1 day
Number of workers hired				130