Segment Reporting (Details 1) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013		Dec. 31, 2012	Mar. 31, 2012		Dec. 31, 2011
Assets
Cash and cash equivalents	$ 331,311		$ 125,440	$ 151,883		$ 175,012
Short term investments	1,498		999
Other assets	127,209		120,906
TOTAL ASSETS	3,423,682		3,221,401
Palmarejo [Member]
Assets
TOTAL ASSETS	1,900,071	[1]		2,008,004	[1]
Reportable Segment [Member]
Assets
Total assets for reportable segments	2,963,664		2,974,056
TOTAL ASSETS	2,963,664	[1]		2,965,093	[1]
San Bartolome [Member]
Assets
TOTAL ASSETS	303,761	[1]		285,276	[1]
Kensington [Member]
Assets
TOTAL ASSETS	498,762	[1]		504,082	[1]
Rochester [Member]
Assets
TOTAL ASSETS	114,381	[1]		90,072	[1]
Martha [Member]
Assets
TOTAL ASSETS	8,304	[1]		24,183	[1]
Endeavor [Member]
Assets
TOTAL ASSETS	93,770	[1]		36,372	[1]
Other Mining Properties [Member]
Assets
TOTAL ASSETS	13,561	[1]		17,104	[1]
Joaquin [Member]
Assets
TOTAL ASSETS	$ 31,054	[1]		$ 0	[1]

[1] Segment assets consist of receivables, prepaids, inventories, property, plant and equipment, and mining properties