Debt (Details Textual) (USD $)	0 Months Ended	3 Months Ended		9 Months Ended																	9 Months Ended	0 Months Ended
	May 27, 2014	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Sep. 30, 2014 Convertible Senior Notes Due March 2028 [Member]	Dec. 31, 2013 Convertible Senior Notes Due March 2028 [Member]	Sep. 30, 2014 Senior Notes due Two Thousand Twenty One [Member]	Mar. 12, 2014 Senior Notes due Two Thousand Twenty One [Member]	Dec. 31, 2013 Senior Notes due Two Thousand Twenty One [Member]	Jan. 29, 2013 Senior Notes due Two Thousand Twenty One [Member]	Sep. 30, 2014 Banco Bisa Line of Credit [Member]	Sep. 30, 2014 Banco de Credito Line of Credit [Member]	Sep. 30, 2014 Palmarejo gold production royalty [Member]	Sep. 30, 2014 Palmarejo gold production royalty [Member] oz	Sep. 30, 2014 Palmarejo gold production royalty [Member] Maximum [Member] oz	Sep. 30, 2014 3.25% Convertible Senior Notes due March 2028 [Member]	Dec. 31, 2013 3.25% Convertible Senior Notes due March 2028 [Member]	Feb. 12, 2013 3.25% Convertible Senior Notes due March 2028 [Member]	Sep. 30, 2014 Palmarejo [Member]	Oct. 02, 2014 Subsequent Event [Member]
Debt and capital lease obligations (Textual) [Abstract]
Debt Instrument, Repurchase Amount									$ 12,600,000
Long-term Debt									437,400,000
Interest rate on notes							3.25%	3.25%	7.875%		7.875%	7.875%						3.25%
Debt Instrument, Face Amount							0	5,334,000	450,000,000	150,000,000		300,000,000						5,334,000
Debt		11,733,000		11,733,000		2,505,000													0	48,700,000
Debt Instrument, Repurchased Face Amount																		43,300,000
Interest Expense, Debt		0	18,000	0	287,000
Accretion of debt discount		(107,000)	0	(252,000)	576,000
Effective interest rate on the notes															30.50%
Borrowing under term facility		100,000,000		100,000,000									7,000,000	4,000,000
Line of credit facility, increase, additional borrowings		50,000,000
Write off revolver costs, interest expense		0		3,035,000	0
Line of credit facility, commitment fee amount		0	176,000	179,000	434,000
Line of Credit Facility, Interest Rate at Period End													2.75%	3.00%
Line of Credit Facility, Amount Outstanding		0		0
Loss on termination of revolving credit facility		0	0	3,035,000	0
Royalty Guarantees, Commitments, Ounces of Gold																302,584	400,000
Percentage of Actual Gold Production		50.00%
Further Payment Made on Number of Additional Ounces of Gold																97,416
Termination payment																						2,000,000.0
Production to be sold, percent																						50.00%
Sale of production, price per ounce of gold																						800
Aggregate deposit to be received																						22,000,000.0
Payments to Acquire Royalty Interests in Mining Properties	2,200,000	11,351,000	12,619,000	38,379,000	43,548,000
Expected Royalty Duration																					1.7
Additional Long term debt and capital lease obligations(Textual) [Abstract]
Implicit Interest Rate		30.00%
Accretion of Royalty Obligation		2,545,000	4,023,000	8,639,000	12,192,000
Remaining Minimum Obligation Under Royalty Agreements		38,100,000		38,100,000		51,200,000
Expensed Interest		11,616,000	9,662,000	36,980,000	30,324,000
Capitalized interest		(423,000)	(1,133,000)	(942,000)	(1,494,000)
Debt Instrument, Convertible, Carrying Amount of Equity Component							$ 10,900,000