SEGMENT AND RELATED INFORMATION: (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($) segment	Jun. 30, 2014 USD ($)	Dec. 31, 2014 USD ($)
SEGMENT AND RELATED INFORMATION:
Number of reportable segments | segment			3
Financial information relating to segments
Net sales	$ 1,382,900	$ 1,487,400	$ 2,657,700	$ 2,841,800
Cost of sales (exclusive of depreciation, amortization and depletion)	706,868	726,589	1,386,690	1,368,483
Selling, general and administrative	24,963	25,397	49,832	49,895
Depreciation, amortization and depletion	125,302	116,091	242,265	226,544
Exploration	12,111	22,068	22,399	36,679
Environmental reclamation	10,532		16,460
Operating income	503,147	597,267	940,084	1,160,194
Interest, net	(51,100)	(33,200)	(74,200)	(69,300)
Other income (expense)	(1,605)	(5,779)	(5,369)	(9,985)
Income taxes	(157,042)	(225,769)	(286,235)	(429,931)
Equity earnings of affiliate	2,655	5,861	5,415	11,899
Non-controlling interest	(1,299)	(1,129)	(2,556)	(2,337)
Net income attributable to SCC	294,714	337,253	577,144	660,642
Capital expenditure	284,900	360,100	507,700	697,000
Property, net	7,691,669	6,933,700	7,691,669	6,933,700	$ 7,436,430
Total assets	13,348,619	11,507,900	13,348,619	11,507,900	$ 11,526,742
Corporate, other and eliminations
Financial information relating to segments
Net sales	(15,500)	(22,500)	(34,400)	(46,900)
Cost of sales (exclusive of depreciation, amortization and depletion)	(9,000)	(15,600)	(19,800)	(10,700)
Selling, general and administrative	1,900	1,200	5,200	2,100
Depreciation, amortization and depletion	(400)	5,000	1,800	5,800
Exploration	4,600	8,100	9,100	14,900
Operating income	(11,700)	(21,200)	(30,700)	(59,000)
Capital expenditure	6,600	1,000	7,900	3,400
Property, net	68,000	131,300	68,000	131,300
Total assets	1,798,700	1,203,200	1,798,700	1,203,200
Mexican Open-Pit | Operating segment
Financial information relating to segments
Net sales	733,600	772,100	1,397,800	1,420,300
Cost of sales (exclusive of depreciation, amortization and depletion)	299,600	312,100	596,400	541,600
Selling, general and administrative	11,600	9,100	20,900	17,800
Depreciation, amortization and depletion	60,400	54,900	114,500	109,500
Exploration	1,000	800	1,800	1,700
Environmental reclamation	10,500		16,500
Operating income	350,500	395,200	647,700	749,700
Capital expenditure	202,200	252,300	363,900	520,000
Property, net	4,662,500	3,918,800	4,662,500	3,918,800
Total assets	7,066,200	5,976,800	7,066,200	5,976,800
Mexican IMMSA Unit | Operating segment
Financial information relating to segments
Net sales	87,000	87,700	177,400	183,600
Cost of sales (exclusive of depreciation, amortization and depletion)	77,600	83,000	167,500	167,400
Selling, general and administrative	1,500	3,900	3,400	7,600
Depreciation, amortization and depletion	7,900	7,800	15,600	15,600
Exploration	2,900	7,400	5,200	12,400
Operating income	12,600	8,100	20,100	27,500
Capital expenditure	8,800	9,200	15,400	18,200
Property, net	392,100	379,800	392,100	379,800
Total assets	837,100	896,600	837,100	896,600
Mexican IMMSA Unit | Intersegment sales
Financial information relating to segments
Net sales	15,500	22,500	34,400	46,900
Peruvian Operations | Operating segment
Financial information relating to segments
Net sales	562,300	627,600	1,082,500	1,237,900
Cost of sales (exclusive of depreciation, amortization and depletion)	339,600	347,100	642,600	670,200
Selling, general and administrative	10,000	11,200	20,300	22,400
Depreciation, amortization and depletion	57,400	48,400	110,300	95,600
Exploration	3,600	5,800	6,300	7,700
Operating income	151,700	215,100	303,000	442,000
Capital expenditure	67,300	97,600	120,500	155,400
Property, net	2,569,100	2,503,800	2,569,100	2,503,800
Total assets	$ 3,646,600	$ 3,431,300	$ 3,646,600	$ 3,431,300