Note 17 - Business Segments (Tables)

12 Months Ended

Dec. 31, 2023

Notes Tables

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

	Electricity		Product			Energy Storage			Consolidated
	(Dollars in thousands)
Year Ended December 31, 2023:
Revenues from external customers:
United States (1)	$	473,323	$	7,610		$	28,894		$	509,827
Foreign (2)		193,444		126,153			—			319,597
Net revenues from external customers		666,767		133,763			28,894			829,424
Intersegment revenues		—		48,494			—			—
Depreciation and amortization expense		199,344		10,908			14,545			224,797
Operating income (loss)		168,834		3,536			(5,785	)		166,585
Segment assets at period end (3) (*)		4,652,392		199,897			355,990			5,208,279
Expenditures for long-lived assets		474,592		20,599			123,192			618,383
* Including unconsolidated investments		125,439		—			—			125,439
Year Ended December 31, 2022:
Revenues from external customers:
United States (1)		446,000		7,037			31,018			484,055
Foreign (2)		185,727		64,377			—			250,104
Net revenues from external customers	$	631,727	$	71,414		$	31,018		$	734,159
Intersegment revenues		—		83,394			—			—
Depreciation and amortization expense		179,966		7,302			11,524			198,792
Operating income (loss)		156,178		(1,084	)		(2,291	)		152,803
Segment assets at period end (3) (*)		4,253,910		118,018			239,651			4,611,579
Expenditures for long-lived assets		462,269		16,352			84,855			563,476
* Including unconsolidated investments		115,693		—			—			115,693
Year Ended December 31, 2021:
Revenues from external customers:
United States (1)		404,303		5,414			30,393			440,110
Foreign (2)		181,468		41,506			—			222,974
Net revenues from external customers		585,771		46,920			30,393			663,084
Intersegment revenues		—		129,589			—			—
Depreciation and amortization expense		164,490		7,719			10,763			182,972
Operating income (loss)		171,550		(3,641	)		1,448			169,357
Segment assets at period end (3) (*)		4,142,341		113,817			169,520			4,425,678
Expenditures for long-lived assets		383,307		10,687			25,278			419,272
* Including unconsolidated investments		105,886		—			—			105,886

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

	Year Ended December 31,
	2023			2022			2021
	(Dollars in thousands)
Revenues:
Total segment revenues	$	829,424		$	734,159		$	663,084
Intersegment revenues		48,494			83,394			129,589
Elimination of intersegment revenues		(48,494	)		(83,394	)		(129,589	)
Total consolidated revenues	$	829,424		$	734,159		$	663,084
Operating income (expense):
Operating income	$	166,585		$	152,803		$	169,357
Interest income		11,983			3,417			2,124
Interest expense, net		(98,881	)		(87,743	)		(82,658	)
Derivatives and foreign currency transaction gains (losses)		(3,278	)		(6,044	)		(14,720	)
Income attributable to sale of tax benefits		61,157			33,885			29,582
Other non-operating income (expense), net		1,519			(709	)		(134	)
Total consolidated income before income taxes and equity in earnings (losses) of investees	$	139,085		$	95,609		$	103,551

Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas [Table Text Block]

	Year Ended December 31,
	2023		2022		2021
	(Dollars in thousands)
Revenues from external customers attributable to:
United States	$	509,827	$	484,055	$	440,110
Indonesia		26,732		15,631		8,056
Kenya		109,217		105,837		102,844
Turkey		2,469		1,961		2,723
Chile		—		579		7,035
Guatemala		30,174		28,831		26,868
New Zealand		66,526		17,130		6,770
Honduras		31,589		33,837		35,233
Other foreign countries		52,889		46,298		33,445
Consolidated total	$	829,424	$	734,159	$	663,084

Schedule of Disclosure on Geographic Areas, Long-Lived Assets in Individual Foreign Countries by Country [Table Text Block]

	Year Ended December 31,
	2023		2022		2021
	(Dollars in thousands)
Long-lived assets (primarily power plants and related assets) located in:
United States	$	3,085,892	$	2,857,503	$	2,527,429
Kenya		377,563		301,491		297,427
Other foreign countries		378,028		254,878		217,371
Consolidated total	$	3,841,483	$	3,413,872	$	3,042,227

Schedule of Revenue by Major Customers by Reporting Segments [Table Text Block]

	Year Ended December 31,
	2023				2022				2021
	Revenues		%		Revenues		%		Revenues		%
	(Dollars in thousands)				(Dollars in thousands)				(Dollars in thousands)
Southern California Public Power (1)	$	181,656		21.2	$	157,663		21.5	$	157,318		23.7
Sierra Pacific Power Company and Nevada Power Company (1)(2)		116,797		14.1		124,116		16.9		123,333		18.6
KPLC (1)		109,217		13.2		105,837		14.4		102,844		15.5