Commitments and Contingencies (Details Textual) (USD $)	12 Months Ended				12 Months Ended			12 Months Ended
	Dec. 31, 2011 oz Agreement	Dec. 31, 2010 oz	Dec. 31, 2009	Jan. 21, 2009	Dec. 31, 2011 Rochester [Member] Employee	Dec. 31, 2010 Rochester [Member]	Jul. 07, 1995 Echo Bay [Member] oz	Dec. 31, 2011 Kensington [Member]	Jul. 07, 1995 Kensington [Member]	Jul. 07, 1995 Coeur Alaska Inc [Member]
Commitments and Contingencies (Textual) [Abstract]
Employment for mining and crushing operation					200
Total benefit expected under termination plan					$ 4,500,000
Acquisition of ownership interest							50.00%		100.00%
Volume related to net smelter return royalty of future gold production							1,000,000
Purchase price and construction and development expenses										32,500,000
Minimum royalty range for gold price per ounce								1.00%
Gold price per ounce for minimum royalty range								400
Maximum royalty range for gold price per ounce					5.00%			2.50%
Gold price per ounce for maximum royalty range					23.02			475
Royalty expenses					2,200,000	200,000
Additional Commitment And Contingencies (Textual) [Abstract]
Accrued obligations for postemployment benefits		$ 7,400,000	$ 4,900,000
Number of labor agreements in South America	2
Percentage of labor force covered by collective bargaining agreements		14.40%
Royalty to be capped in terms of ounces of production	1,000,000
Purchased royalty				50.00%
Royalty agreement minimum obligation for the period	400,000	400,000
Royalty agreement minimum obligation for per month	4,167 ounces per month	4,167 ounces per month
Royalty agreement period	8 years	8 years