Note 1 - General and Basis of Presentation (Details) - Effect of Revision on Line Items in Condensed Consolidated Balance Sheet (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2012
Condensed Balance Sheet Statements, Captions [Line Items]
Deferred income taxes				$ 17,181	$ 21,283
Property, plant and equipment	1,463,574		1,452,336	1,233,525	1,252,873
Total assets	2,134,347	[1]	2,159,433	2,133,925	2,087,523
Accumulated deficit	15,737		(3,088)	(49,360)	(44,326)
Total equity	765,694		745,111	696,876	695,607
Total liabilities and equity	2,134,347		2,159,433	2,133,925	2,087,523
Scenario, Previously Reported [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Deferred income taxes				52,939	53,989
Property, plant and equipment				1,207,410	1,226,758
Total assets				2,143,568	2,094,114
Accumulated deficit				(39,717)	(37,735)
Total equity				706,519	702,189
Total liabilities and equity				2,143,568	2,094,114
Restatement Adjustment [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Deferred income taxes				(35,758)	(32,706)
Property, plant and equipment				26,115	26,115
Total assets				(9,643)	(6,591)
Accumulated deficit				(9,643)	(6,591)
Total equity				(9,643)	(6,591)
Total liabilities and equity				$ (9,643)	$ (6,591)

[1] Including unconsolidated investments