Schedule of Mineral Property, Plant and Equipment (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014
Property, Plant And Equipment Schedule Of Mineral Property, Plant And Equipment 1	$ 18,322
Property, Plant And Equipment Schedule Of Mineral Property, Plant And Equipment 2	18,322
Property, Plant And Equipment Schedule Of Mineral Property, Plant And Equipment 3	14,009
Property, Plant And Equipment Schedule Of Mineral Property, Plant And Equipment 4	13,931
Property, Plant And Equipment Schedule Of Mineral Property, Plant And Equipment 5	6,103
Property, Plant And Equipment Schedule Of Mineral Property, Plant And Equipment 6	808
Property, Plant And Equipment Schedule Of Mineral Property, Plant And Equipment 7	5,613
Property, Plant And Equipment Schedule Of Mineral Property, Plant And Equipment 8	5,613
Property, Plant And Equipment Schedule Of Mineral Property, Plant And Equipment 9	44,047
Property, Plant And Equipment Schedule Of Mineral Property, Plant And Equipment 10	38,674
Property, Plant And Equipment Schedule Of Mineral Property, Plant And Equipment 11	34,976
Property, Plant And Equipment Schedule Of Mineral Property, Plant And Equipment 12	34,976
Property, Plant And Equipment Schedule Of Mineral Property, Plant And Equipment 13	4,330
Property, Plant And Equipment Schedule Of Mineral Property, Plant And Equipment 14	4,330
Property, Plant And Equipment Schedule Of Mineral Property, Plant And Equipment 15	118
Property, Plant And Equipment Schedule Of Mineral Property, Plant And Equipment 16	118
Property, Plant And Equipment Schedule Of Mineral Property, Plant And Equipment 17	83,471
Property, Plant And Equipment Schedule Of Mineral Property, Plant And Equipment 18	78,098
Property, Plant And Equipment Schedule Of Mineral Property, Plant And Equipment 19	(7,332)
Property, Plant And Equipment Schedule Of Mineral Property, Plant And Equipment 20	(7,332)
Property, Plant And Equipment Schedule Of Mineral Property, Plant And Equipment 21	(3,861)
Property, Plant And Equipment Schedule Of Mineral Property, Plant And Equipment 22	(3,861)
Property, Plant And Equipment Schedule Of Mineral Property, Plant And Equipment 23	(1,630)
Property, Plant And Equipment Schedule Of Mineral Property, Plant And Equipment 24	(1,630)
Property, Plant And Equipment Schedule Of Mineral Property, Plant And Equipment 25	(12,823)
Property, Plant And Equipment Schedule Of Mineral Property, Plant And Equipment 26	(12,823)
Property, Plant And Equipment Schedule Of Mineral Property, Plant And Equipment 27	(170)
Property, Plant And Equipment Schedule Of Mineral Property, Plant And Equipment 28	(167)
Property, Plant And Equipment Schedule Of Mineral Property, Plant And Equipment 29	(12,993)
Property, Plant And Equipment Schedule Of Mineral Property, Plant And Equipment 30	(12,990)
Property, Plant And Equipment Schedule Of Mineral Property, Plant And Equipment 31	70,478
Property, Plant And Equipment Schedule Of Mineral Property, Plant And Equipment 32	$ 65,108