Write-Downs (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Entity Location [Line Items]
Write-downs	$ 1,472,721	$ 772,993	$ 5,825
Property, Plant and Equipment, Other Types [Member]
Entity Location [Line Items]
Write-downs	242,877	151,092	0
Other Mining Properties [Member]
Entity Location [Line Items]
Write-downs	1,229,844	621,901	5,825
Martha [Member] | Other Mining Properties [Member]
Entity Location [Line Items]
Write-downs	0	205	5,825
Couer Capital (El Gallo) [Member] | Other Mining Properties [Member]
Entity Location [Line Items]
Write-downs	6,202	0	0
Joaquin Project - Argentina [Member] | Other Mining Properties [Member]
Entity Location [Line Items]
Write-downs	83,429	0	0
La Preciosa [Member]
Entity Location [Line Items]
Write-downs	372,500
La Preciosa [Member] | Property, Plant and Equipment, Other Types [Member]
Entity Location [Line Items]
Write-downs	1,055	0	0
La Preciosa [Member] | Other Mining Properties [Member]
Entity Location [Line Items]
Write-downs	371,411	0	0
Kensington [Member]
Entity Location [Line Items]
Write-downs		130,700
Kensington [Member] | Property, Plant and Equipment, Other Types [Member]
Entity Location [Line Items]
Write-downs	40,161	48,357	0
Kensington [Member] | Other Mining Properties [Member]
Entity Location [Line Items]
Write-downs	67,671	82,337	0
San Bartolome [Member] | Property, Plant and Equipment, Other Types [Member]
Entity Location [Line Items]
Write-downs	86,426	0	0
San Bartolome [Member] | Other Mining Properties [Member]
Entity Location [Line Items]
Write-downs	32,328	0	0
Palmarejo [Member]
Entity Location [Line Items]
Write-downs	784,000	642,100
Palmarejo [Member] | Property, Plant and Equipment, Other Types [Member]
Entity Location [Line Items]
Write-downs	115,235	102,735	0
Palmarejo [Member] | Other Mining Properties [Member]
Entity Location [Line Items]
Write-downs	$ 668,803	$ 539,359	$ 0