Consolidated Statements of Cash Flows - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)		$ (1,319)	$ 55,352	$ (367,183)
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent		12,244	(32,917)	79,372
Adjustments:
Amortization		146,549	116,528	125,953
Accretion		9,980	9,142	13,332
Deferred income taxes		(13,888)	(54,184)	(38,496)
Loss on Extinguishment of Debt		9,342	21,365	(15,916)
Fair value adjustments, net		864	11,581	(5,202)
Stock-based compensation		10,541	9,715	9,272
Gain on sale of the Joaquin project		(21,138)	0	0
Write-downs		0	4,446	246,625
Foreign exchange and other		(7,974)	356	18,983
Changes in operating assets and liabilities:
Receivables		18,895	(2,783)	(5,022)
Prepaid expenses and other current assets		(2,015)	(4,420)	5,702
Inventories		23,517	(34,610)	15,578
Accounts payable and accrued liabilities		11,562	(3,110)	4,414
CASH PROVIDED BY OPERATING ACTIVITIES		197,160	96,461	87,412
Cash Provided by (Used in) Operating Activities, Discontinued Operations		11,296	29,356	26,130
Net Cash Provided by (Used in) Operating Activities		208,456	125,817	113,542
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures		(136,734)	(94,382)	(88,973)
Payments to Acquire Businesses, Net of Cash Acquired		(156,248)	(1,417)	(110,846)
Proceeds from the sale of assets		16,705	16,296	607
Purchase of short term investments and equity securities		(15,058)	(178)	(1,880)
Sales and maturities of short-term investments		11,321	7,077	605
Other		(217)	(4,208)	(4,586)
Net Cash Provided by (Used in) Investing Activities, Continuing Operations		(280,231)	(76,812)	(205,073)
Cash Provided by (Used in) Investing Activities, Discontinued Operations		(1,392)	(6,631)	(6,220)
CASH USED IN INVESTING ACTIVITIES		(281,623)	(83,443)	(211,293)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from Issuance of Common Stock		0	269,556	0
Proceeds from Issuance of Unsecured Debt		342,620	0	150,000
Payments on long-term debt, capital leases, and associated costs		(203,045)	(318,153)	(70,603)
Gold production royalty payments		0	(27,155)	(39,235)
Other		(3,746)	172	(542)
Net Cash Provided by (Used in) Financing Activities, Continuing Operations		135,829	(75,580)	39,620
Cash Provided by (Used in) Financing Activities, Discontinued Operations		(84)	(4,648)	(10,612)
Net Cash Provided by (Used in) Financing Activities		135,745	(80,228)	29,008
Effect of exchange rate changes on cash and cash equivalents		203	(678)	(1,404)
INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS		62,781	(38,532)	(70,147)
Cash and cash equivalents at beginning of period		118,312	158,420	240,119
Cash and cash equivalents at end of period		192,032	118,312	158,420
Net Cash Provided by (Used in) Discontinued Operations	[1]	(10,939)	1,576	11,552
CashAndCashEquivalentsPeriodIncreaseDecreaseExcludingNetCashProvidedByUsedInDiscontinuedOperationsAssetsHeldForSale		73,720	(40,108)	(81,699)
Net subsidiary payments to parent company		$ 20,759	$ 16,501
Net parent company payments to subsidiary				$ 2,254

[1] Less net cash provided by (used in) discontinued operations includes the following cash transactions: net subsidiary payments to parent company of $20,759, $16,501 during the years ended December 31, 2017, 2016, respectively, and net parent company payments to subsidiary of $2,254 during the year ended December 31, 2015.