Note 7 - Property, Plant and Equipment and Construction-In-Process (Details) - Activity in Construction and Development (USD $)			12 Months Ended									12 Months Ended						12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 Projects Under Exploration and Development [Member] Up-Front Bonus Lease Costs [Member]	Dec. 31, 2012 Projects Under Exploration and Development [Member] Up-Front Bonus Lease Costs [Member]	Dec. 31, 2011 Projects Under Exploration and Development [Member] Up-Front Bonus Lease Costs [Member]	Dec. 31, 2013 Projects Under Exploration and Development [Member] Drilling and Construction Costs [Member]	Dec. 31, 2012 Projects Under Exploration and Development [Member] Drilling and Construction Costs [Member]	Dec. 31, 2011 Projects Under Exploration and Development [Member] Drilling and Construction Costs [Member]	Dec. 31, 2012 Projects Under Exploration and Development [Member] Interest Capitalized [Member]	Dec. 31, 2011 Projects Under Exploration and Development [Member] Interest Capitalized [Member]	Dec. 31, 2013 Projects Under Exploration and Development [Member] Interest Capitalized [Member]	Dec. 31, 2013 Projects Under Exploration and Development [Member]	Dec. 31, 2012 Projects Under Exploration and Development [Member]	Dec. 31, 2011 Projects Under Exploration and Development [Member]	Dec. 31, 2013 Construction in Progress [Member] Up-Front Bonus Lease Costs [Member]	Dec. 31, 2012 Construction in Progress [Member] Up-Front Bonus Lease Costs [Member]	Dec. 31, 2010 Construction in Progress [Member] Up-Front Bonus Lease Costs [Member]	Dec. 31, 2013 Construction in Progress [Member] Drilling and Construction Costs [Member]	Dec. 31, 2012 Construction in Progress [Member] Drilling and Construction Costs [Member]	Dec. 31, 2011 Construction in Progress [Member] Drilling and Construction Costs [Member]	Dec. 31, 2013 Construction in Progress [Member] Interest Capitalized [Member]	Dec. 31, 2012 Construction in Progress [Member] Interest Capitalized [Member]	Dec. 31, 2011 Construction in Progress [Member] Interest Capitalized [Member]	Dec. 31, 2013 Construction in Progress [Member]	Dec. 31, 2012 Construction in Progress [Member]	Dec. 31, 2011 Construction in Progress [Member]
Note 7 - Property, Plant and Equipment and Construction-In-Process (Details) - Activity in Construction and Development [Line Items]
Balance	$ 288,827,000	$ 396,141,000	$ 33,985,000	$ 36,832,000	$ 33,600,000	$ 32,302,000	$ 40,223,000	$ 20,997,000	$ 1,598,000	$ 100,000	$ 1,278,000	$ 67,565,000	$ 78,653,000	$ 54,697,000	$ 29,160,000	$ 31,179,000	$ 31,179,000	$ 283,873,000	$ 246,878,000	$ 176,968,000	$ 15,543,000	$ 13,841,000	$ 7,790,000	$ 328,576,000	$ 291,898,000	$ 215,937,000
Cost incurred during the year					3,232,000	6,168,000	3,782,000	19,226,000	420,000	1,498,000		6,168,000	4,202,000	23,956,000				203,859,000	216,894,000	242,066,000	7,609,000	11,541,000	10,207,000	211,468,000	228,435,000	252,273,000
Reclassification of completed projects to property, plant and equipment															(1,687,000)	(3,706,000)		(302,966,000)	(190,123,000)	(172,156,000)	(16,204,000)	(10,579,000)	(4,156,000)	320,857,000	(204,408,000)	(176,312,000)
Write off of unsuccessful exploration costs			(3,844,000)	(1,160,000)		(250,000)	(1,479,000)					(4,094,000)	(2,639,000)
Reclassification of exploration and development projects to drilling and construction				(1,687,000)			(10,224,000)		(740,000)				(12,651,000)			1,687,000			10,224,000			740,000			12,651,000
Balance	$ 288,827,000	$ 396,141,000	$ 30,141,000	$ 33,985,000	$ 36,832,000	$ 38,220,000	$ 32,302,000	$ 40,223,000	$ 1,278,000	$ 1,598,000	$ 1,278,000	$ 69,639,000	$ 67,565,000	$ 78,653,000	$ 27,473,000	$ 29,160,000	$ 31,179,000	$ 184,766,000	$ 283,873,000	$ 246,878,000	$ 6,948,000	$ 15,543,000	$ 13,841,000	$ 219,188,000	$ 328,576,000	$ 291,898,000