Acquisitions (Details) - USD ($) $ / shares in Units, $ in Thousands			12 Months Ended
	Apr. 17, 2015	Feb. 20, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Revenue			$ 646,086	$ 635,742	$ 745,994
Common stock issued for the acquisition of Paramount Gold and Silver Corp. (in shares)			32,667,327
Stock Issued During Period, Value, Acquisitions (in dollars per share)			$ 5.78
Assets acquired:
Receivables			$ 110,760	129,609
Ore on leach pads			67,329	48,204
Property, Plant and Equipment, Net			195,999	227,911
Mining properties, net			589,219	501,192
Business Acquisition, Pro Forma Information [Abstract]
Net income (loss)			(367,183)	(1,186,874)	(650,563)
Paramount Gold and Silver Corp. [Member]
Business Acquisition [Line Items]
Common shares issued	$ 188,817
Cash	8,530
Transaction advisory fees and other acquisition costs	4,020
Total purchase price	201,367
Assets acquired:
Cash and cash equivalents	118
Other current assets	1,685
Property, plant, and equipment, net	215
Mining properties, net	305,175
Assets	307,193
Liabilities:
Accounts payable and accrued liabilities	2,737
Deferred income taxes	103,089
Liabilities	105,826
Net assets acquired	$ 201,367
Wharf Gold Mine [Member]
Business Acquisition [Line Items]
Cash		$ 99,400
Transaction advisory fees and other acquisition costs			2,100
Assets acquired:
Other current assets		2,924
Cash		982
Receivables		3,061
Inventory		2,147
Ore on leach pads		12,710
Property, Plant and Equipment, Net		30,055
Mining properties, net		77,424
Other non-current assets		3,966
Assets		133,269
Liabilities:
Accounts payable and accrued liabilities		5,938
Deferred income taxes		5,915
Reclamation		18,270
Other non-current liabilities		3,750
Liabilities		33,873
Net assets acquired		$ 99,396
Business Acquisition, Pro Forma Information [Abstract]
Revenue			664,086	729,742	823,994
Income (loss) before income and mining taxes			(393,498)	(1,587,128)	(786,679)
Net income (loss)			$ (367,235)	$ (1,158,874)	$ (628,563)