Write-Downs Narrative (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Impaired Long-Lived Assets Held and Used [Line Items]
Write-downs	$ 1,472,721,000	$ 772,993,000	$ 5,825,000
Write-downs, net of tax	1,021,800,000	593,200,000
Palmarejo [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Write-downs	784,000,000	642,100,000
Write-downs, net of tax	504,500,000	462,300,000
La Preciosa [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Write-downs	372,500,000
Write-downs, net of tax	$ 244,900,000