Consolidated Statements of Changes in Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Deficit Cumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss) Cumulative Effect, Period of Adoption, Adjustment	JDS Silver [Member]	JDS Silver [Member] Common Stock	JDS Silver [Member] Additional Paid-In Capital
Balances, in shares at Dec. 31, 2017			185,638
Balances at Dec. 31, 2017	$ 814,977	$ 0	$ 1,856	$ 3,357,345	$ (2,546,743)	$ 2,604	$ 2,519	$ (2,604)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
NET INCOME (LOSS)	(48,405)				(48,405)
Other comprehensive income (loss)	26						26
Stock Issued During Period, Shares, Acquisitions			16,390
Stock Issued During Period, Value, Acquisitions	82,668		$ 163	82,505
Common stock issued under stock-based compensation plans, net (in shares)			1,282
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	3,246		$ 14	3,232
Balances at Dec. 31, 2018	852,512		$ 2,033	3,443,082	(2,592,544)		(59)
Balances, in shares at Dec. 31, 2018			203,310
Increase (Decrease) in Stockholders' Equity [Roll Forward]
NET INCOME (LOSS)	(341,203)				(341,203)
Other comprehensive income (loss)	(77)						(77)
Stock Issued During Period, Shares, Acquisitions										953
Stock Issued During Period, Value, Acquisitions									$ 5,973	$ 8	$ 5,965
Common stock issued for the extinguishment of Senior Notes (in shares)			4,453
Stock Issued During Period, Value, Extinguishment of Debt	21,291		$ 45	21,246
Common stock issued under "at the market" stock offering (in shares)			30,850
Stock Issued During Period, Value, New Issues	122,832		$ 309	122,523
Common stock issued under stock-based compensation plans, net (in shares)			1,963
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	5,676		$ 20	5,656
Balances at Dec. 31, 2019	667,004		$ 2,415	3,598,472	(2,933,747)		(136)
Balances, in shares at Dec. 31, 2019			241,529
Increase (Decrease) in Stockholders' Equity [Roll Forward]
NET INCOME (LOSS)	25,627				25,627
Other comprehensive income (loss)	(11,000)						(11,000)
Stock Issued During Period, Shares, Acquisitions										878
Stock Issued During Period, Value, Acquisitions									$ 5,295	$ 9	$ 5,286
Common stock issued under stock-based compensation plans, net (in shares)			1,345
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	6,553		$ 14	6,539
Balances at Dec. 31, 2020	$ 693,479		$ 2,438	$ 3,610,297	$ (2,908,120)		$ (11,136)
Balances, in shares at Dec. 31, 2020			243,752