Mineral Properties - Awak Mas (Details) - PT Masmindo Dwi Area - Awak Mas - USD ($) $ in Thousands		3 Months Ended
	Nov. 01, 2019	Mar. 31, 2020
First 1,250,000 Ounces Produced
Property, Plant and Equipment [Line Items]
NSR Royalty Cancellation, Percentage	1.00%
Remaining NSR Royalty Cancellation, Percentage	1.00%
Next 1,250,000 Ounces Produced
Property, Plant and Equipment [Line Items]
NSR Royalty Cancellation, Percentage	1.25%
Remaining NSR Royalty Cancellation, Percentage	1.25%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-04-20 | First 1,250,000 Ounces Produced
Property, Plant and Equipment [Line Items]
NSR Cancellation Proceeds	$ 2,400
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-05-08 | First 1,250,000 Ounces Produced
Property, Plant and Equipment [Line Items]
NSR Cancellation Proceeds		$ 2,400
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-04-30
Property, Plant and Equipment [Line Items]
NSR Cancellation Proceeds	$ 2,500