Related Party Transactions (Details 1) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Related Party Transaction [Line Items]
Accretion of the November 2016 Loan discount		$ 510	$ 0	$ 1,250	$ 0
Interest expense related to the November 2016 Loan		642	0	1,914	0
Interest expense related to Komatsu financial loans	[1],[2]	143	144	428	464
Accretion of the June 2015 Loan discount		0	621	0	1,853
Interest expense related to the June 2015 Loan		0	1,050	0	3,057
Accretion of discount and interest on loan		$ 1,295	$ 1,815	$ 3,592	$ 5,374

[1] Interest capitalization ended on March 31, 2016 because the mine went into production on April 1, 2016.

[2] Komatsu is not a related party and has only been included in the above table to reconcile the total interest expense incurred for the period to the amounts capitalized and expensed.