Mining Properties (Details) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Mining Properties
Operational mining properties:	$ 631,432	$ 622,361
Accumulated depletion	(176,159)	(149,211)
Operational mining properties, net	455,273	473,150
Mineral interest	1,727,863	1,727,863
Accumulated depletion	(122,538)	(78,939)
Mineral interest, net	1,605,325	1,648,924
Non-producing and developmental properties(B)	142	142
Total mining properties	2,060,740	2,122,216
Palmarejo [Member]
Mining Properties
Operational mining properties:	131,261	128,734
Accumulated depletion	(37,054)	(22,655)
Operational mining properties, net	94,207	106,079
Mineral interest	1,657,188	1,657,188
Accumulated depletion	(109,222)	(68,026)
Mineral interest, net	1,547,966	1,589,162
Non-producing and developmental properties(B)	0	0
Total mining properties	1,642,173	1,695,241
Rochester [Member]
Mining Properties
Operational mining properties:	103,441	99,720
Accumulated depletion	(97,435)	(97,435)
Operational mining properties, net	6,006	2,285
Mineral interest	0	0
Accumulated depletion	0	0
Mineral interest, net	0	0
Non-producing and developmental properties(B)	0	0
Total mining properties	6,006	2,285
San Bartolome [Member]
Mining Properties
Operational mining properties:	66,710	66,655
Accumulated depletion	(12,331)	(10,031)
Operational mining properties, net	54,379	56,624
Mineral interest	26,642	26,642
Accumulated depletion	(4,946)	(4,027)
Mineral interest, net	21,696	22,615
Non-producing and developmental properties(B)	0	0
Total mining properties	76,075	79,239
Martha [Member]
Mining Properties
Operational mining properties:	10,714	10,096
Accumulated depletion	(9,996)	(9,998)
Operational mining properties, net	718	98
Mineral interest	0	0
Accumulated depletion	0	0
Mineral interest, net	0	0
Non-producing and developmental properties(B)	0	0
Total mining properties	718	98
Endeavor [Member]
Mining Properties
Operational mining properties:	0	0
Accumulated depletion	0	0
Operational mining properties, net	0	0
Mineral interest	44,033	44,033
Accumulated depletion	(8,370)	(6,886)
Mineral interest, net	35,663	37,147
Non-producing and developmental properties(B)	0	0
Total mining properties	35,663	37,147
Kensington [Member]
Mining Properties
Operational mining properties:	319,306	317,156
Accumulated depletion	(19,343)	(9,092)
Operational mining properties, net	299,963	308,064
Mineral interest	0	0
Accumulated depletion	0	0
Mineral interest, net	0	0
Non-producing and developmental properties(B)	0	0
Total mining properties	299,963	308,064
Other Mining Properties [Member]
Mining Properties
Operational mining properties:	0	0
Accumulated depletion	0	0
Operational mining properties, net	0	0
Mineral interest	0	0
Accumulated depletion	0	0
Mineral interest, net	0	0
Non-producing and developmental properties(B)	142	142
Total mining properties	$ 142	$ 142