Note 17 - Guarantor Subsidiaries (Details) - Condensed Consolidating Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Condensed Cash Flow Statements, Captions [Line Items]
Cash flows from operating activities	$ 26,644	$ 69,016	$ 69,891
Cash flows from investing activities:
Additions to properties, plants, and equipment	(150,736)	(113,096)	(87,546)
Acquisition of Aurizon Mines Ltd.	(321,117)
Cash flows from financing activities:
Borrowings on debt	490,000
Changes in cash and cash equivalents	21,191	(75,479)	(17,143)
Effect of exchange rate changes on cash	(4,905)
Cash and cash equivalents at beginning of year	190,984	266,463	283,606
Cash and cash equivalents at end of year	212,175	190,984	266,463
Parent [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Cash flows from operating activities	(9,958)	49,295	105,740
Cash flows from investing activities:
Additions to properties, plants, and equipment	(1,535)	(618)	(2)
Acquisition of Aurizon Mines Ltd.	(498,705)
Other investing activities, net		(48,815)	(38,356)
Cash flows from financing activities:
Dividends paid to stockholders	(6,543)	(17,673)	(9,414)
Borrowings on debt	490,000
Other financing activity	20,746	52,227	(150,118)
Changes in cash and cash equivalents	(5,995)	34,416	(92,150)
Cash and cash equivalents at beginning of year	132,266	97,850	190,000
Cash and cash equivalents at end of year	126,271	132,266	97,850
Guarantor Subsidiaries [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Cash flows from operating activities	17,940	42,957	79,166
Cash flows from investing activities:
Additions to properties, plants, and equipment	(107,893)	(107,425)	(87,454)
Other investing activities, net	(11)	891	(1,659)
Cash flows from financing activities:
Payments on debt	(7,039)	(5,878)	(2,938)
Other financing activity	79,937	(41,903)	88,193
Changes in cash and cash equivalents	(17,066)	(111,358)	75,308
Cash and cash equivalents at beginning of year	57,075	168,433	93,125
Cash and cash equivalents at end of year	40,009	57,075	168,433
Non-Guarantor Subsidiaries [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Cash flows from operating activities	(20,129)	(14,296)	(12,449)
Cash flows from investing activities:
Additions to properties, plants, and equipment	(41,308)	(5,053)	(90)
Acquisition of Aurizon Mines Ltd.	177,588
Other investing activities, net	(3,633)	(5,835)	1
Cash flows from financing activities:
Payments on debt		(12)
Other financing activity	(63,361)	26,659	12,237
Changes in cash and cash equivalents	49,157	1,463	(301)
Effect of exchange rate changes on cash	(4,905)
Cash and cash equivalents at beginning of year	1,643	180	481
Cash and cash equivalents at end of year	45,895	1,643	180
Consolidation, Eliminations [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Cash flows from operating activities	38,791	(8,940)	(102,566)
Cash flows from investing activities:
Other investing activities, net		48,817	47,741
Cash flows from financing activities:
Other financing activity	(38,791)	(39,877)	54,825
Consolidated [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Cash flows from operating activities	26,644	69,016	69,891
Cash flows from investing activities:
Additions to properties, plants, and equipment	(150,736)	(113,096)	(87,546)
Acquisition of Aurizon Mines Ltd.	(321,117)
Other investing activities, net	(3,644)	(4,942)	7,727
Cash flows from financing activities:
Dividends paid to stockholders	(6,543)	(17,673)	(9,414)
Borrowings on debt	490,000
Payments on debt	(7,039)	(5,890)	(2,938)
Other financing activity	(1,469)	(2,894)	5,137
Changes in cash and cash equivalents	26,096	(75,479)	(17,143)
Effect of exchange rate changes on cash	(4,905)
Cash and cash equivalents at beginning of year	190,984	266,463	283,606
Cash and cash equivalents at end of year	$ 212,175	$ 190,984	$ 266,463