SEGMENT AND RELATED INFORMATION: (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 segment	Sep. 30, 2012	Dec. 31, 2012
SEGMENT AND RELATED INFORMATION:
Number of reportable segments			3
Financial information relating to segments
Net sales outside of segments	$ 1,384,500,000	$ 1,552,400,000	$ 4,417,700,000	$ 5,018,200,000
Cost of sales (exclusive of depreciation, amortization and depletion)	666,037,000	670,861,000	2,105,014,000	2,060,664,000
Selling, general and administrative	24,107,000	23,758,000	76,933,000	74,551,000
Depreciation, amortization and depletion	101,489,000	81,283,000	285,577,000	236,655,000
Exploration	11,983,000	12,470,000	33,958,000	33,795,000
Legal fees related to SCC shareholder derivative lawsuit		316,233,000		316,233,000
Operating income	580,891,000	447,774,000	1,916,250,000	2,296,293,000
Interest, net	(43,700,000)	(25,800,000)	(137,300,000)	(107,000,000)
Other income (expense)	1,724,000	3,527,000	19,507,000	29,086,000
Income taxes	(195,190,000)	(219,802,000)	(596,942,000)	(848,544,000)
Equity earnings of affiliate	1,865,000	13,565,000	15,169,000	38,239,000
Non-controlling interest	(1,344,000)	(1,395,000)	(4,353,000)	(5,316,000)
Net income attributable to SCC	344,221,000	217,866,000	1,212,350,000	1,402,843,000
Capital expenditures	488,200,000	258,200,000	1,190,500,000	665,900,000
Property, net	6,032,088,000	4,856,200,000	6,032,088,000	4,856,200,000	5,156,731,000
Total assets	10,935,671,000	10,841,800,000	10,935,671,000	10,841,800,000	10,383,749,000
Mexican Open-pit
Financial information relating to segments
Net sales outside of segments	641,000,000	784,700,000	2,227,700,000	2,483,300,000
Cost of sales (exclusive of depreciation, amortization and depletion)	265,400,000	294,500,000	982,900,000	926,200,000
Selling, general and administrative	8,200,000	8,400,000	26,100,000	25,500,000
Depreciation, amortization and depletion	46,200,000	36,900,000	129,600,000	106,200,000
Exploration	700,000	1,000,000	2,400,000	4,200,000
Operating income	320,500,000	443,900,000	1,086,700,000	1,421,200,000
Capital expenditures	335,000,000	133,700,000	881,000,000	537,000,000
Property, net	3,266,500,000	2,244,600,000	3,266,500,000	2,244,600,000
Total assets	5,474,700,000	4,082,300,000	5,474,700,000	4,082,300,000
Mexican IMMSA Unit
Financial information relating to segments
Net sales outside of segments	88,200,000	86,600,000	268,100,000	281,300,000
Intersegment sales	18,200,000	22,300,000	75,600,000	98,100,000
Cost of sales (exclusive of depreciation, amortization and depletion)	74,200,000	60,700,000	235,700,000	206,000,000
Selling, general and administrative	3,500,000	3,600,000	11,200,000	10,800,000
Depreciation, amortization and depletion	7,600,000	6,300,000	21,400,000	18,900,000
Exploration	6,700,000	8,300,000	19,400,000	21,200,000
Operating income	14,400,000	30,000,000	56,000,000	122,500,000
Capital expenditures	13,100,000	12,400,000	44,500,000	40,500,000
Property, net	372,500,000	341,200,000	372,500,000	341,200,000
Total assets	882,000,000	807,500,000	882,000,000	807,500,000
Peruvian Operations
Financial information relating to segments
Net sales outside of segments	655,300,000	681,100,000	1,921,900,000	2,253,600,000
Cost of sales (exclusive of depreciation, amortization and depletion)	340,900,000	341,400,000	976,500,000	1,033,300,000
Selling, general and administrative	11,700,000	11,000,000	37,000,000	35,600,000
Depreciation, amortization and depletion	43,600,000	40,100,000	127,200,000	118,100,000
Exploration	4,600,000	3,200,000	12,200,000	8,400,000
Operating income	254,500,000	285,400,000	769,000,000	1,058,200,000
Capital expenditures	122,100,000	70,100,000	225,300,000	158,200,000
Property, net	2,330,500,000	2,146,800,000	2,330,500,000	2,146,800,000
Total assets	3,527,800,000	3,184,300,000	3,527,800,000	3,184,300,000
Corporate, other and eliminations
Financial information relating to segments
Intersegment sales	(18,200,000)	(22,300,000)	(75,600,000)	(98,100,000)
Cost of sales (exclusive of depreciation, amortization and depletion)	(14,500,000)	(25,700,000)	(90,100,000)	(104,800,000)
Selling, general and administrative	700,000	700,000	2,600,000	2,700,000
Depreciation, amortization and depletion	4,100,000	(2,000,000)	7,400,000	(6,600,000)
Legal fees related to SCC shareholder derivative lawsuit		316,200,000		316,200,000
Operating income	(8,500,000)	(311,500,000)	4,500,000	(305,600,000)
Capital expenditures	18,000,000	42,000,000	39,700,000	(69,800,000)
Property, net	62,600,000	123,600,000	62,600,000	123,600,000
Total assets	$ 1,051,200,000	$ 2,767,700,000	$ 1,051,200,000	$ 2,767,700,000