Debt (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Sep. 30, 2014 3.25% Convertible Senior Notes due March 2028 [Member]	Dec. 31, 2013 3.25% Convertible Senior Notes due March 2028 [Member]	Sep. 30, 2014 Senior Notes due 2021 [Member]	Mar. 12, 2014 Senior Notes due 2021 [Member]	Dec. 31, 2013 Senior Notes due 2021 [Member]	Jan. 29, 2013 Senior Notes due 2021 [Member]	Sep. 30, 2014 Palmarejo gold production royalty [Member]	Sep. 30, 2014 Capital Lease Obligations [Member]	Dec. 31, 2013 Capital Lease Obligations [Member]	Sep. 30, 2014 Palmarejo gold production royalty [Member] oz	Sep. 30, 2014 Maximum [Member] Palmarejo gold production royalty [Member] oz	Sep. 30, 2014 Convertible Senior Notes Due March 2028 [Member]	Dec. 31, 2013 Convertible Senior Notes Due March 2028 [Member]	Feb. 12, 2013 Convertible Senior Notes Due March 2028 [Member]	Sep. 30, 2014 Senior Notes due Two Thousand Twenty One [Member]	Dec. 31, 2013 Senior Notes due Two Thousand Twenty One [Member]	Sep. 30, 2014 Capital Lease Obligations [Member]	Dec. 31, 2013 Capital Lease Obligations [Member]
Debt Instrument [Line Items]
Debt Instrument, Convertible, Carrying Amount of Equity Component						$ 10,900,000
Debt Instrument, Interest Rate, Effective Percentage												30.50%
Royalty Guarantees, Commitments, Ounces of Gold															302,584	400,000
Minimum Obligation Paid in Monthly Payments															4,167
Annual Inflation Compounding Adjustment															1.00%
Percentage of Actual Gold Production	50.00%
Long term debt and capital lease obligations
Current	11,733,000		11,733,000		2,505,000													0	48,700,000	0	0	6,399,000	2,505,000
Debt Instrument, Face Amount						0	5,334,000	450,000,000	150,000,000		300,000,000						5,334,000
Non-current	457,744,000		457,744,000		306,130,000			440,075,000		300,000,000			17,669,000	796,000
Interest expenses incurred for various debt instruments
Interest Paid on Senior Notes due 2021	8,809,000	5,906,000	24,132,000	15,947,000
Interest Paid on Convertible Notes due 2028	43,000	43,000	130,000	423,000
Line of Credit Facility, Commitment Fee Amount	0	176,000	179,000	434,000
Write off revolver costs, interest expense	0		3,035,000	0
Interest Paid on Capital Leases	334,000	89,000	726,000	355,000
Interest Expense	0	18,000	0	287,000
Accretion of Franco Nevada royalty obligation	2,545,000	4,023,000	8,639,000	12,192,000
Amortization of debt issuance costs	415,000	540,000	1,333,000	1,604,000
Accretion of debt discount	(107,000)	0	(252,000)	576,000
Capitalized interest	(423,000)	(1,133,000)	(942,000)	(1,494,000)
Total interest expense, net of capitalized interest	$ 11,616,000	$ 9,662,000	$ 36,980,000	$ 30,324,000