Note 13 - Guarantor Subsidiaries (Details) - Condensed Consolidating Statements of Operations (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Condensed Income Statements, Captions [Line Items]
Revenues	$ 135,507	$ 106,629	$ 378,796	$ 268,409
Cost of sales	(86,680)	(66,937)	(235,460)	(163,770)
Depreciation, depletion, amortization	(26,804)	(19,006)	(80,342)	(53,224)
General and administrative	(7,884)	(7,720)	(23,984)	(22,141)
Exploration and pre-development	(6,188)	(9,241)	(14,333)	(31,258)
Gain/(loss) on derivative contracts	(411)	(4,564)	(2,560)	23,516
Aurizon acquisition costs		(768)		(26,368)
Other (expense) income	(3,684)	(9,393)	(22,260)	(19,308)
Income (loss) before income taxes	3,856	(11,000)	(143)	(24,144)
(Provision) benefit from income taxes	(180)	2,542	1,062	1,922
Net income (loss)	3,676	(8,458)	919	(22,222)
Changes in comprehensive income (loss)	2,276	2,489	1,438	(2,286)
Comprehensive income (loss)	5,952	(5,969)	2,357	(24,508)
Preferred stock dividends	(138)	(138)	(414)	(414)
Income (loss) applicable to common stockholders	3,538	(8,596)	505	(22,636)
Consolidation, Eliminations [Member]
Condensed Income Statements, Captions [Line Items]
Equity in earnings (loss) of subsidiaries	(96,349)	(82,896)	(32,864)	(68,198)
Other (expense) income	68,017	87,701	(11,398)	87,701
Income (loss) before income taxes	(28,332)	4,805	(44,262)	19,503
(Provision) benefit from income taxes	(68,017)	(86,014)	11,398	(87,701)
Net income (loss)	(96,349)	(81,209)	(32,864)	(68,198)
Changes in comprehensive income (loss)	(2,307)	6,157	(2,752)	6,157
Comprehensive income (loss)	(98,656)	(75,052)	(35,616)	(62,041)
Income (loss) applicable to common stockholders	(96,349)	(81,209)	(32,864)	(68,198)
Parent Company [Member]
Condensed Income Statements, Captions [Line Items]
Revenues	1,444	(2,447)	(2,029)	338
General and administrative	(4,048)	(3,550)	(13,207)	(11,015)
Exploration and pre-development	(4)	(42)	(56)	(459)
Gain/(loss) on derivative contracts	(411)	(4,564)	(2,560)	23,516
Aurizon acquisition costs		(268)		(14,416)
Equity in earnings (loss) of subsidiaries	96,349	82,896	32,864	68,198
Other (expense) income	(89,654)	(80,483)	(14,093)	(88,384)
Income (loss) before income taxes	3,676	(8,458)	919	(22,222)
Net income (loss)	3,676	(8,458)	919	(22,222)
Changes in comprehensive income (loss)	2,276	2,489	1,438	(2,286)
Comprehensive income (loss)	5,952	(5,969)	2,357	(24,508)
Preferred stock dividends	(138)	(138)	(414)	(414)
Income (loss) applicable to common stockholders	3,538	(8,596)	505	(22,636)
Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Revenues	94,202	81,687	260,577	230,562
Cost of sales	(57,995)	(45,342)	(151,145)	(133,944)
Depreciation, depletion, amortization	(17,205)	(15,736)	(53,706)	(46,630)
General and administrative	(3,590)	(3,636)	(9,819)	(10,183)
Exploration and pre-development	(3,085)	(6,551)	(5,826)	(23,299)
Other (expense) income	3,503	(811)	4,781	1,132
Income (loss) before income taxes	15,830	9,611	44,862	17,638
(Provision) benefit from income taxes	(2,878)	(3,795)	(10,486)	(9,049)
Net income (loss)	12,952	5,816	34,376	8,589
Changes in comprehensive income (loss)	78	(5,078)	303	(1,248)
Comprehensive income (loss)	13,030	738	34,679	7,341
Income (loss) applicable to common stockholders	12,952	5,816	34,376	8,589
Non-Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Revenues	39,861	27,389	120,248	37,509
Cost of sales	(28,685)	(21,595)	(84,315)	(29,826)
Depreciation, depletion, amortization	(9,599)	(3,270)	(26,636)	(6,594)
General and administrative	(246)	(534)	(958)	(943)
Exploration and pre-development	(3,099)	(2,648)	(8,451)	(7,500)
Aurizon acquisition costs		(500)		(11,952)
Other (expense) income	14,450	(15,800)	(1,550)	(19,757)
Income (loss) before income taxes	12,682	(16,958)	(1,662)	(39,063)
(Provision) benefit from income taxes	70,715	92,351	150	98,672
Net income (loss)	83,397	75,393	(1,512)	59,609
Changes in comprehensive income (loss)	2,229	(1,079)	2,449	(4,909)
Comprehensive income (loss)	85,626	74,314	937	54,700
Income (loss) applicable to common stockholders	$ 83,397	$ 75,393	$ (1,512)	$ 59,609