Note 5 - Income Taxes (Tables)

12 Months Ended

Dec. 31, 2017

Notes Tables

Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]

	2017			2016			2015
Current:
Domestic	$	22,171		$	(10,702	)	$	3,892
Foreign		(22,526	)		(13,713	)		(5,376	)
Total current income tax provision		(355	)		(24,415	)		(1,484	)
Deferred:
Domestic		(30,766	)		7,480			(75,456	)
Foreign		11,242			(10,493	)		20,630
Total deferred income tax provision		(19,524	)		(3,013	)		(54,826	)
Total income tax provision	$	(19,879	)	$	(27,428	)	$	(56,310	)

Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block]

	2017			2016		2015
Domestic	$	(7,920	)	$	41,014	$	(65,895	)
Foreign		4,280			55,961		35,237
Total	$	(3,640	)	$	96,975	$	(30,658	)

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

	2017					2016					2015
Computed “statutory” benefit (provision)	$	1,274		35	%	$	(33,941	)	35	%	$	10,731		35	%
Percentage depletion		5,174		142			8,114		(8	)		2,432		8
Change in valuation allowance		24,464		672			11,336		(12	)		(84,951	)	(277	)
Federal rate change		(37,546	)	(1,031	)		—		—			—		—
State taxes, net of federal taxes		1,112		30			(565	)	1			(3,639	)	(12	)
Foreign currency remeasurement of monetary assets and liabilities		(10,357	)	(284	)		(4,598	)	5			28,184		92
Rate differential on foreign earnings		(1,438	)	(39	)		(6,853	)	7			(4,746	)	(15	)
Compensation		(661	)	(18	)		(1,517	)	1			(1,014	)	(3	)
Foreign withholding taxes		(278	)	(8	)		—		—			—		—
Expiration of U.S. foreign tax credits		(2,300	)	(63	)		—		—			—		—
Other		677		18			596		(1	)		(3,307	)	(12	)
Total provision	$	(19,879	)	(546	)%	$	(27,428	)	28	%	$	(56,310	)	(184	)%

Schedule of Deferred Tax Assets and Liabilities [Table Text Block]

	December 31,
	2017			2016
Deferred tax assets:
Accrued reclamation costs	$	21,812		$	30,188
Deferred exploration		17,426			26,785
Foreign net operating losses		1,003			1,058
Domestic net operating losses		130,186			82,359
AMT credit carryforwards		584			20,405
Pension and benefit obligation		12,584			18,115
Foreign exchange loss		18,112			34,977
Foreign tax credit carryforward		4,983			7,283
Miscellaneous		25,411			30,166
Total deferred tax assets		232,101			251,336
Valuation allowance		(78,684	)		(99,602	)
Total deferred tax assets		153,417			151,734
Deferred tax liabilities:
Miscellaneous		(4,978	)		(3,046	)
Properties, plants and equipment		(268,476	)		(235,700	)
Total deferred tax liabilities		(273,454	)		(238,746	)
Net deferred tax liability	$	(120,037	)	$	(87,012	)

Summary of Positions for which Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Table Text Block]

	2017			2016			2015
Balance at beginning of year	$	(99,602	)	$	(115,806	)	$	(32,094	)
Increase related to non-utilization of net operating loss carryforwards and non-recognition of deferred tax assets due to uncertainty of recovery		(14,964	)		(2,868	)		(92,393	)
Decrease related to utilization and expiration of deferred tax assets, other		35,882			19,072			8,681
Balance at end of year	$	(78,684	)	$	(99,602	)	$	(115,806	)