Inventories (Tables)

12 Months Ended

Dec. 31, 2017

Statement [Line Items]

Disclosure of detailed information about inventories [Table Text Block]

		Dec. 31, 2017		Dec. 31, 2016
Current
Stockpile	$	13,468	$	9,368
Work in progress 1		14,552		9,100
Finished goods		71,906		54,583
Materials and supplies		41,756		39,413
		141,682		112,464
Non-current
Materials and supplies		5,809		4,537
	$	147,491		117,001