Note 9 - Business Segments (Tables)

6 Months Ended

Jun. 30, 2018

Notes Tables

Schedule of Segment Reporting Information, by Segment [Table Text Block]

	Electricity		Product		Other			Consolidated
	(Dollars in thousands)
Three Months Ended June 30, 2018:
Revenues from external customers:
United States (1)	$	73,139	$	27	$	1,205		$	74,371
Foreign (2)		49,040		54,888		—			103,928
Net revenue from external customers		122,179		54,915		1,205			178,299
Intersegment revenue		—		11,453		—			11,453
Operating income		27,462		10,761		(1,590	)		36,633
Segment assets at period end (3) (*)		2,805,182		125,572		63,395			2,994,149
* Including unconsolidated investments		66,551		—		—			66,551
Three Months Ended June 30, 2017:
Net revenue from external customers	$	110,896	$	67,587		881			179,364
Intersegment revenue		—		16,565		—			16,565
Operating income		38,014		17,035		(1,897	)		53,152
Segment assets at period end (3) (*)		2,273,503		187,015		50,115			2,510,633
* Including unconsolidated investments		13,957		—		—			13,957
Six Months Ended June 30, 2018:
Revenues from external customers:
United States (1)	$	156,822	$	221	$	4,067		$	161,110
Foreign (2)		97,846		103,366		—			201,212
Net revenues from external customers		254,668		103,587		4,067			362,322
Intersegment revenues		—		36,280		—			36,280
Operating income		73,874		20,314		(2,962	)		91,226
Segment assets at period end (3) (*)		2,805,182		125,572		63,395			2,994,149
* Including unconsolidated investments		66,551		—		—			66,551
Six Months Ended June 30, 2017:
Net revenues from external customers	$	226,672	$	141,709	$	881		$	369,262
Intersegment revenues		—		32,778		—			32,778
Operating income		78,912		35,633		(1,897	)		112,648
Segment assets at period end (3) (*)		2,273,503		187,015		50,115			2,510,633
* Including unconsolidated investments		13,957		—		—			13,957

Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table Text Block]

	Three Months Ended June 30,						Six Months Ended June 30,
	2018			2017			2018			2017
Revenue:
Total segment revenue	$	178,299		$	179,364		$	362,322		$	369,262
Intersegment revenue		11,453			16,565			36,280			32,778
Elimination of intersegment revenue		(11,453	)		(16,565	)		(36,280	)		(32,778	)
Total consolidated revenue	$	178,299		$	179,364		$	362,322		$	369,262
Operating income:
Operating income	$	36,633		$	53,152		$	91,226		$	112,648
Interest income		189			362			302			606
Interest expense, net		(15,846	)		(14,540	)		(30,190	)		(29,463	)
Derivatives and foreign currency transaction gains (losses)		(529	)		1,703			(2,128	)		3,041
Income attributable to sale of tax benefits		3,556			4,356			10,917			10,513
Other non-operating income (expense), net		7,373			6			7,353			(86	)
Total consolidated income before income taxes and equity in income of investees	$	31,376		$	45,039		$	77,480		$	97,259