RELATED PARTY TRANSACTIONS: (Details)			3 Months Ended			1 Months Ended	3 Months Ended			12 Months Ended								3 Months Ended					3 Months Ended			3 Months Ended							3 Months Ended			3 Months Ended				3 Months Ended			3 Months Ended			3 Months Ended
	Mar. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Mar. 31, 2014 Grupo Mexico and affiliates USD ($)	Mar. 31, 2013 Grupo Mexico and affiliates USD ($)	Dec. 31, 2013 Grupo Mexico and affiliates USD ($)	May 31, 2010 MGE USD ($)	Mar. 31, 2014 MGE USD ($)	Mar. 31, 2013 MGE USD ($)	Mar. 31, 2012 MGE USD ($)	Dec. 31, 2012 MGE USD ($)	Dec. 31, 2005 MGE item	Dec. 31, 2013 MGE USD ($)	Mar. 31, 2012 MGE Controladora de Infraestructura Energetica Mexico, S. A. de C. V. USD ($)	Mar. 31, 2012 MGE Controladora de Infraestructura Energetica Mexico, S. A. de C. V. MXN	Mar. 31, 2012 MGE Minera Mexico Maximum	Mar. 31, 2014 Compania Perforadora Mexico S.A.P.I. de C.V. USD ($)	Dec. 31, 2013 Compania Perforadora Mexico S.A.P.I. de C.V. USD ($)	Mar. 31, 2014 Cia Perforadora Mexico S.A.P.I. de C.V and affiliates USD ($)	Mar. 31, 2013 Cia Perforadora Mexico S.A.P.I. de C.V and affiliates USD ($)	Mar. 31, 2014 Equity investment in affiliate USD ($)	Mar. 31, 2013 Equity investment in affiliate USD ($)	Dec. 31, 2013 Equity investment in affiliate USD ($)	Mar. 31, 2014 Mexico Proyectos y Desarrollos, S.A. de C.V. and affiliates USD ($)	Mar. 31, 2013 Mexico Proyectos y Desarrollos, S.A. de C.V. and affiliates USD ($)	Dec. 31, 2013 Mexico Proyectos y Desarrollos, S.A. de C.V. and affiliates USD ($)	Mar. 31, 2014 Mexico Proyectos y Desarrollos, S.A. de C.V. USD ($)	Mar. 31, 2013 Mexico Proyectos y Desarrollos, S.A. de C.V. USD ($)	Mar. 31, 2014 Grupo Mexico and affiliates USD ($)	Mar. 31, 2013 Grupo Mexico and affiliates USD ($)	Mar. 31, 2014 Asarco LLC ("Asarco") USD ($)	Mar. 31, 2013 Asarco LLC ("Asarco") USD ($)	Dec. 31, 2013 Asarco LLC ("Asarco") USD ($)	Mar. 31, 2014 Higher Technology S.A.C. USD ($)	Mar. 31, 2013 Higher Technology S.A.C. USD ($)	Dec. 31, 2013 Higher Technology S.A.C. USD ($)	Mar. 31, 2014 Breaker, S.A. de C.V and affiliates ("Breaker") USD ($)	Mar. 31, 2013 Breaker, S.A. de C.V and affiliates ("Breaker") USD ($)	Dec. 31, 2013 Breaker, S.A. de C.V and affiliates ("Breaker") USD ($)	Dec. 31, 2013 Sempertrans and affiliates USD ($)	Mar. 31, 2014 Mexico Transportes Aereos S.A. de C.V. ("Mextransport") USD ($)	Mar. 31, 2013 Mexico Transportes Aereos S.A. de C.V. ("Mextransport") USD ($)	Dec. 31, 2013 Mexico Transportes Aereos S.A. de C.V. ("Mextransport") USD ($)	Mar. 31, 2014 Ferrocarril Mexicano, S.A. de C.V. USD ($)	Mar. 31, 2013 Ferrocarril Mexicano, S.A. de C.V. USD ($)	Dec. 31, 2013 Ferrocarril Mexicano, S.A. de C.V. USD ($)	Mar. 31, 2014 Servicios y Fabricaciones Mecanicas S.A.C. USD ($)	Mar. 31, 2013 Servicios y Fabricaciones Mecanicas S.A.C. USD ($)	Mar. 31, 2014 Sempertrans France Belting Technology USD ($)	Mar. 31, 2013 Sempertrans France Belting Technology USD ($)	Mar. 31, 2014 Companies with relationship to SCC executive officers' families USD ($)	Mar. 31, 2013 Companies with relationship to SCC executive officers' families USD ($)
Related party transactions
Related parties receivables current:	$ 37,450,000	$ 38,062,000	$ 800,000		$ 800,000		$ 27,000,000					$ 18,800,000				$ 900,000	$ 700,000			$ 7,200,000		$ 17,200,000	$ 1,600,000		$ 600,000
Related parties receivable non-current:	161,244,000	161,244,000					161,200,000			184,000,000		161,200,000
Related parties payables:	39,488,000	28,373,000	4,100,000		3,300,000		15,500,000					14,400,000											400,000							13,900,000		6,200,000	100,000		100,000	300,000		300,000	100,000	200,000		600,000	5,000,000		3,300,000
Total purchases from related parties			121,200,000	52,100,000			48,900,000											1,200,000	600,000				47,200,000	9,300,000				3,500,000	3,500,000	15,100,000	32,900,000		300,000	300,000		900,000	800,000			600,000	600,000		5,300,000	5,800,000		300,000	100,000	300,000	100,000	1,800,000	1,300,000
Sales revenues from related parties			24,600,000	37,000,000			24,300,000	100,000										100,000	100,000							200,000	200,000				36,600,000									100,000	100,000
Number of power plants											2
Maximum amount of line of credit granted to related party						350,000,000
Interest rate (as a percent)						4.40%				5.75%										3.35%
Percentage of interest acquired													99.999%	99.999%
Value of interest acquired													150,000,000	1,928,600,000
Ownership percentage															0.001%
Loan repaid									150,000,000
Loan granted																				56,600,000
Interest earned							2,300,000													100,000	400,000
Outstanding amount																				$ 7,200,000
Ownership percentage																				44.20%
Basis of variable interest rate																				6 months Libor
Spread on variable interest rate (as a percent)																				3.00%