Note 14 - Guarantor Subsidiaries (Details) - Condensed Consolidating Statements of Operations - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Condensed Income Statements, Captions [Line Items]
Revenues	$ 104,197	$ 117,502	$ 223,289	$ 243,289
Cost of sales	(67,567)	(71,039)	(141,532)	(148,780)
Depreciation, depletion, amortization	(27,166)	(27,735)	(52,420)	(53,538)
General and administrative	(8,296)	(8,159)	(17,016)	(16,100)
Gain/(loss) on derivative contracts	(887)	(11,601)	4,905	(2,149)
Acquisition costs	(2,147)		(2,147)
Income (loss) before income taxes	(26,799)	(19,424)	(12,808)	(4,000)
(Provision) benefit from income taxes	132	5,025	(1,307)	1,242
Net income (loss)	(26,667)	(14,399)	(14,115)	(2,758)
Comprehensive income (loss)	(27,822)	(16,587)	(13,334)	(3,596)
Preferred stock dividends	(138)	(138)	(276)	(276)
Income (loss) applicable to common stockholders	(26,805)	(14,537)	(14,391)	(3,034)
Consolidation, Eliminations [Member]
Condensed Income Statements, Captions [Line Items]
Equity in earnings (loss) of subsidiaries	738	81,189	(39,304)	63,486
Other (expense) income	19,895	(76,112)	16,439	(79,415)
Income (loss) before income taxes	20,633	5,077	(22,865)	(15,929)
(Provision) benefit from income taxes	(19,895)	76,112	(16,439)	79,415
Net income (loss)	738	81,189	(39,304)	63,486
Changes in comprehensive income (loss)	1,081	928	(776)	(445)
Comprehensive income (loss)	1,819	82,117	(40,080)	63,041
Income (loss) applicable to common stockholders	738	81,189	(39,304)	63,486
Consolidated [Member]
Condensed Income Statements, Captions [Line Items]
Revenues	104,197	117,502	223,289	243,289
Cost of sales	(67,567)	(71,039)	(141,532)	(148,780)
Depreciation, depletion, amortization	(27,166)	(27,735)	(52,420)	(53,538)
General and administrative	(8,296)	(8,159)	(17,016)	(16,100)
Exploration and pre-development	(6,210)	(3,577)	(11,346)	(8,146)
Gain/(loss) on derivative contracts	(887)	(11,601)	4,905	(2,149)
Acquisition costs	(2,147)		(2,147)
Other (expense) income	(18,723)	(14,815)	(16,541)	(18,576)
Income (loss) before income taxes	(26,799)	(19,424)	(12,808)	(4,000)
(Provision) benefit from income taxes	132	5,025	(1,307)	1,242
Net income (loss)	(26,667)	(14,399)	(14,115)	(2,758)
Changes in comprehensive income (loss)	(1,156)	(2,188)	780	(838)
Comprehensive income (loss)	(27,823)	(16,587)	(13,335)	(3,596)
Preferred stock dividends	(138)	(138)	(276)	(276)
Income (loss) applicable to common stockholders	(26,805)	(14,537)	(14,391)	(3,034)
Parent Company [Member]
Condensed Income Statements, Captions [Line Items]
Revenues	1,081	(3,454)	1,393	(3,473)
General and administrative	(4,373)	(4,529)	(8,815)	(9,159)
Exploration and pre-development	(122)	(8)	(339)	(52)
Gain/(loss) on derivative contracts	(887)	(11,601)	4,905	(2,149)
Acquisition costs	(2,055)		(2,055)
Equity in earnings (loss) of subsidiaries	(738)	(81,189)	39,304	(63,486)
Other (expense) income	(19,573)	86,382	(48,508)	75,561
Income (loss) before income taxes	(26,667)	(14,399)	(14,115)	(2,758)
Net income (loss)	(26,667)	(14,399)	(14,115)	(2,758)
Changes in comprehensive income (loss)	(1,156)	(2,188)	780	(838)
Comprehensive income (loss)	(27,823)	(16,587)	(13,335)	(3,596)
Preferred stock dividends	(138)	(138)	(276)	(276)
Income (loss) applicable to common stockholders	(26,805)	(14,537)	(14,391)	(3,034)
Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Revenues	67,531	82,665	154,465	166,375
Cost of sales	(41,512)	(43,217)	(92,949)	(93,150)
Depreciation, depletion, amortization	(16,452)	(19,280)	(33,063)	(36,501)
General and administrative	(3,392)	(3,221)	(7,285)	(6,229)
Exploration and pre-development	(1,445)	(1,784)	(2,579)	(2,742)
Acquisition costs	(92)		(92)
Other (expense) income	3,499	870	7,066	1,278
Income (loss) before income taxes	8,137	16,033	25,563	29,031
(Provision) benefit from income taxes	(1,956)	(4,722)	(6,902)	(7,608)
Net income (loss)	6,181	11,311	18,661	21,423
Changes in comprehensive income (loss)	183	168	(11)	225
Comprehensive income (loss)	6,364	11,479	18,650	21,648
Income (loss) applicable to common stockholders	6,181	11,311	18,661	21,423
Non-Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Revenues	35,585	38,291	67,431	80,387
Cost of sales	(26,055)	(27,822)	(48,583)	(55,630)
Depreciation, depletion, amortization	(10,714)	(8,455)	(19,357)	(17,037)
General and administrative	(531)	(409)	(916)	(712)
Exploration and pre-development	(4,643)	(1,785)	(8,428)	(5,352)
Other (expense) income	(22,544)	(25,955)	8,462	(16,000)
Income (loss) before income taxes	(28,902)	(26,135)	(1,391)	(14,344)
(Provision) benefit from income taxes	21,983	(66,365)	22,034	(70,565)
Net income (loss)	(6,919)	(92,500)	20,643	(84,909)
Changes in comprehensive income (loss)	(1,264)	(1,096)	787	220
Comprehensive income (loss)	(8,183)	(93,596)	21,430	(84,689)
Income (loss) applicable to common stockholders	$ (6,919)	$ (92,500)	$ 20,643	$ (84,909)