SEGMENT AND RELATED INFORMATION: (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013 segment	Jun. 30, 2012	Dec. 31, 2012
SEGMENT AND RELATED INFORMATION:
Number of reportable segments			3
Financial information relating to segments
Net sales outside of segments	$ 1,410,200,000	$ 1,659,900,000	$ 3,033,200,000	$ 3,465,800,000
Cost of sales (exclusive of depreciation, amortization and depletion)	712,295,000	667,876,000	1,438,977,000	1,389,803,000
Selling, general and administrative	27,452,000	25,362,000	52,826,000	50,793,000
Depreciation, amortization and depletion	93,516,000	78,428,000	184,088,000	155,372,000
Exploration	11,651,000	12,600,000	21,975,000	21,325,000
Operating income	565,309,000	875,610,000	1,335,359,000	1,848,519,000
Interest, net	(46,500,000)	(40,600,000)	(93,500,000)	(81,200,000)
Other income (expense)	16,935,000	18,324,000	17,783,000	25,559,000
Income taxes	(166,806,000)	(309,973,000)	(401,752,000)	(628,742,000)
Equity earnings of affiliate	5,141,000	22,020,000	13,304,000	24,674,000
Non-controlling interest	(1,368,000)	(1,789,000)	(3,009,000)	(3,921,000)
Net income attributable to SCC	372,737,000	563,547,000	868,129,000	1,184,977,000
Capital expenditures	385,500,000	230,300,000	702,300,000	407,700,000
Property, net	5,636,382,000	4,666,200,000	5,636,382,000	4,666,200,000	5,156,731,000
Total assets	10,654,290,000	8,373,100,000	10,654,290,000	8,373,100,000	10,383,749,000
Mexican Open-pit
Financial information relating to segments
Net sales outside of segments	724,100,000	819,800,000	1,586,700,000	1,698,600,000
Cost of sales (exclusive of depreciation, amortization and depletion)	336,700,000	312,100,000	717,400,000	631,700,000
Selling, general and administrative	9,100,000	8,400,000	17,900,000	17,100,000
Depreciation, amortization and depletion	43,200,000	35,700,000	83,400,000	69,300,000
Exploration	800,000	2,500,000	1,700,000	3,200,000
Operating income	334,300,000	461,100,000	766,300,000	977,300,000
Capital expenditures	295,400,000	268,200,000	546,000,000	403,300,000
Property, net	2,965,100,000	2,049,500,000	2,965,100,000	2,049,500,000
Total assets	4,928,400,000	3,704,000,000	4,928,400,000	3,704,000,000
Mexican IMMSA Unit
Financial information relating to segments
Net sales outside of segments	90,000,000	94,100,000	179,900,000	194,700,000
Intersegment sales	25,400,000	37,900,000	57,400,000	75,800,000
Cost of sales (exclusive of depreciation, amortization and depletion)	88,500,000	69,800,000	161,600,000	145,300,000
Selling, general and administrative	3,900,000	3,600,000	7,700,000	7,200,000
Depreciation, amortization and depletion	7,100,000	6,300,000	13,800,000	12,600,000
Exploration	6,600,000	6,700,000	12,700,000	12,900,000
Operating income	9,300,000	45,600,000	41,500,000	92,500,000
Capital expenditures	13,500,000	13,700,000	31,400,000	28,100,000
Property, net	367,100,000	334,400,000	367,100,000	334,400,000
Total assets	865,700,000	770,800,000	865,700,000	770,800,000
Peruvian Operations
Financial information relating to segments
Net sales outside of segments	596,100,000	746,000,000	1,266,600,000	1,572,500,000
Cost of sales (exclusive of depreciation, amortization and depletion)	318,800,000	332,700,000	635,700,000	691,900,000
Selling, general and administrative	13,200,000	12,100,000	25,300,000	24,600,000
Depreciation, amortization and depletion	42,200,000	39,000,000	83,600,000	78,000,000
Exploration	4,300,000	3,400,000	7,600,000	5,200,000
Operating income	217,600,000	358,800,000	514,400,000	772,800,000
Capital expenditures	63,900,000	60,200,000	103,200,000	88,100,000
Property, net	2,234,700,000	2,118,800,000	2,234,700,000	2,118,800,000
Total assets	3,411,000,000	3,116,100,000	3,411,000,000	3,116,100,000
Corporate, other and eliminations
Financial information relating to segments
Intersegment sales	(25,400,000)	(37,900,000)	(57,400,000)	(75,800,000)
Cost of sales (exclusive of depreciation, amortization and depletion)	(31,700,000)	(46,700,000)	(75,700,000)	(79,100,000)
Selling, general and administrative	1,200,000	1,300,000	1,900,000	1,900,000
Depreciation, amortization and depletion	1,000,000	(2,600,000)	3,300,000	(4,500,000)
Operating income	4,100,000	10,100,000	13,100,000	5,900,000
Capital expenditures	12,700,000	(111,800,000)	21,700,000	(111,800,000)
Property, net	69,500,000	163,500,000	69,500,000	163,500,000
Total assets	$ 1,449,200,000	$ 782,200,000	$ 1,449,200,000	$ 782,200,000