Fair Value Measurements (Details 1) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Assets:
Total assets	$ 5,718
Liabilities:
Total liabilities	17,740	$ 15,058
Royalty obligation embedded derivative [Member]
Liabilities:
Derivative fair value of derivative liability		4,957
Rochester Royalty Obligation [Member]
Liabilities:
Derivative fair value of derivative liability		9,593
Other Derivative Instrument [Member]
Assets:
Fair value of derivative asset	57
Liabilities:
Derivative fair value of derivative liability		508
Gold Put Purchase and Call Sold Options Net [Member]
Assets:
Fair value of derivative asset	131
Liabilities:
Derivative fair value of derivative liability	36
Equity Securities [Member]
Assets:
Equity securities	5,530	2,766
Fair Value, Inputs, Level 1 [Member]
Assets:
Total assets	5,523
Liabilities:
Total liabilities	0	0
Fair Value, Inputs, Level 1 [Member] | Royalty obligation embedded derivative [Member]
Liabilities:
Derivative fair value of derivative liability		0
Fair Value, Inputs, Level 1 [Member] | Rochester Royalty Obligation [Member]
Liabilities:
Derivative fair value of derivative liability		0
Fair Value, Inputs, Level 1 [Member] | Other Derivative Instrument [Member]
Assets:
Fair value of derivative asset	0
Liabilities:
Derivative fair value of derivative liability		0
Fair Value, Inputs, Level 1 [Member] | Gold Put Purchase and Call Sold Options Net [Member]
Assets:
Fair value of derivative asset	0
Liabilities:
Derivative fair value of derivative liability	0
Fair Value, Inputs, Level 1 [Member] | Equity Securities [Member]
Assets:
Equity securities	5,523	2,756
Fair Value, Inputs, Level 2 [Member]
Assets:
Total assets	188
Liabilities:
Total liabilities	36	508
Fair Value, Inputs, Level 2 [Member] | Royalty obligation embedded derivative [Member]
Liabilities:
Derivative fair value of derivative liability		0
Fair Value, Inputs, Level 2 [Member] | Rochester Royalty Obligation [Member]
Liabilities:
Derivative fair value of derivative liability		0
Fair Value, Inputs, Level 2 [Member] | Other Derivative Instrument [Member]
Assets:
Fair value of derivative asset	57
Liabilities:
Derivative fair value of derivative liability		508
Fair Value, Inputs, Level 2 [Member] | Gold Put Purchase and Call Sold Options Net [Member]
Assets:
Fair value of derivative asset	131
Fair Value, Inputs, Level 2 [Member] | Equity Securities [Member]
Assets:
Equity securities	0	0
Fair Value, Inputs, Level 3 [Member]
Assets:
Total assets	7
Liabilities:
Total liabilities	17,704	14,550
Fair Value, Inputs, Level 3 [Member] | Royalty obligation embedded derivative [Member]
Liabilities:
Derivative fair value of derivative liability		4,957
Fair Value, Inputs, Level 3 [Member] | Rochester Royalty Obligation [Member]
Liabilities:
Derivative fair value of derivative liability		9,593
Fair Value, Inputs, Level 3 [Member] | Other Derivative Instrument [Member]
Assets:
Fair value of derivative asset	0
Liabilities:
Derivative fair value of derivative liability		0
Fair Value, Inputs, Level 3 [Member] | Gold Put Purchase and Call Sold Options Net [Member]
Assets:
Fair value of derivative asset	0
Liabilities:
Derivative fair value of derivative liability	0
Fair Value, Inputs, Level 3 [Member] | Equity Securities [Member]
Assets:
Equity securities	7	$ 10
Palmarejo Royalty Obligation [Member] | Royalty obligation embedded derivative [Member]
Liabilities:
Derivative fair value of derivative liability	6,827
Palmarejo Royalty Obligation [Member] | Fair Value, Inputs, Level 1 [Member] | Royalty obligation embedded derivative [Member]
Liabilities:
Derivative fair value of derivative liability	0
Palmarejo Royalty Obligation [Member] | Fair Value, Inputs, Level 2 [Member] | Royalty obligation embedded derivative [Member]
Liabilities:
Derivative fair value of derivative liability	0
Palmarejo Royalty Obligation [Member] | Fair Value, Inputs, Level 3 [Member] | Royalty obligation embedded derivative [Member]
Liabilities:
Derivative fair value of derivative liability	6,827
Rochester Royalty Obligation [Member] | Royalty Obligation [Member]
Liabilities:
Derivative fair value of derivative liability	10,877
Rochester Royalty Obligation [Member] | Fair Value, Inputs, Level 1 [Member] | Royalty Obligation [Member]
Liabilities:
Derivative fair value of derivative liability	0
Rochester Royalty Obligation [Member] | Fair Value, Inputs, Level 2 [Member] | Royalty Obligation [Member]
Liabilities:
Derivative fair value of derivative liability	0
Rochester Royalty Obligation [Member] | Fair Value, Inputs, Level 3 [Member] | Royalty Obligation [Member]
Liabilities:
Derivative fair value of derivative liability	$ 10,877