Note 9 - Business Segments (Tables)

3 Months Ended

Mar. 31, 2018

Notes Tables

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

	Electricity		Product		Other			Consolidated
	(Dollars in thousands)
Three Months Ended March 31, 2018:
Revenues from external customers:
United States (1)		83,683		194		2,862			86,739
Foreign (2)		48,806		48,478		—			97,284
Total net revenues from external customers	$	132,489	$	48,672		2,862			184,023
Intersegment revenues		—		24,827		—			24,827
Operating income		46,412		9,553		(1,372	)		54,593
Segment assets at period end (3) (*)		2,542,154		114,815		53,848			2,710,817
(*) Including unconsolidated investments		63,109		—		—			63,109
Three Months Ended March 31, 2017:
Net revenues from external customers (4)	$	115,776	$	74,122		—			189,898
Intersegment revenues (4)		—		16,213		—			16,213
Operating income (4)		40,898		18,598		—			59,496
Segment assets at period end (3)		2,233,237		217,051		49,600			2,499,888

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

	Three Months Ended March 31,
	2018			2017
Revenue:
Total segment revenue	$	184,023		$	189,898
Intersegment revenue		24,827			16,213
Elimination of intersegment revenue		(24,827	)		(16,213	)
Total consolidated revenue	$	184,023		$	189,898
Operating income:
Operating income	$	54,593		$	59,496
Interest income		113			244
Interest expense, net		(14,344	)		(14,923	)
Derivatives and foreign currency transaction gains (losses)		(1,599	)		1,338
Income attributable to sale of tax benefits		7,361			6,157
Other non-operating income (expense), net		(20	)		(92	)
Total consolidated income before income taxes and equity in earnings of investees	$	46,104		$	52,220