Note 1 - Business and Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2022

Notes Tables

Schedule of Cash and Cash Equivalents [Table Text Block]

	December 31,
	2022		2021		2020
	(Dollars in thousands)
Cash and cash equivalents	$	95,872	$	239,278	$	448,252
Restricted cash and cash equivalents		130,804		104,166		88,526
Total cash and cash equivalents and restricted cash and cash equivalents	$	226,676	$	343,444	$	536,778

Schedule Of Estimated Useful Lives [Table Text Block]

	Years
Buildings		25
Leasehold improvements	15	-	30
Machinery and equipment — manufacturing and drilling		10
Machinery and equipment — computers	3	-	5
Energy storage equipment		15
Solar facility equipment		30
Office equipment — furniture and fixtures	5	-	15
Office equipment — other	5	-	10
Vehicles	5	-	7

Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block]

	December 31,			December 31,
	2022			2021
	(Dollars in thousands)
Contract assets (*)	$	16,405		$	9,692
Contract liabilities (*)	$	(8,785	)	$	(9,248	)

	Years Ended December 31,
	2022						2021
	Contract assets			Contract liabilities			Contract assets			Contract liabilities
	(Dollars in thousands)
Recognition of contract liabilities as revenue as a result of performance obligations satisfied	$	—		$	—		$	—		$	3,566
Cash received in advance for which revenues have not yet recognized, net of expenditures made		—			(2,604	)		—			(2,146	)
Reduction of contract assets as a result of rights to consideration becoming unconditional		(23,000	)		—			(43,518	)		—
Contract assets recognized, net of recognized receivables		32,780			—			29,177			—
Net change in contract assets and contract liabilities	$	9,780		$	(2,604	)	$	(14,341	)	$	1,420

Accounting Standards Update and Change in Accounting Principle [Table Text Block]

	Year Ended December 31,
	2022		2021		2020
	(Dollars in thousands)
Electricity revenues accounted under lease accounting	$	529,264	$	502,355	$	473,260
Electricity, Product and Energy Storage revenues accounted under ASC 606		204,895		160,729		232,082
Total consolidated revenues	$	734,159	$	663,084	$	705,342

Accounts Receivable, Allowance for Credit Loss [Table Text Block]

	Years Ended December 31,
	2022		2021
	(Dollars in thousands)
Beginning balance of the allowance for expected credit losses	$	90	$	597
Change in the provision for expected credit losses for the period		—		(507	)
Ending balance of the allowance for expected credit losses	$	90	$	90

Schedule of Weighted Average Number of Shares [Table Text Block]

	Year Ended December 31,
	2022		2021		2020
	(In thousands)
Weighted average number of shares used in computation of basic earnings per share		56,063		56,004		51,567
Add:
Additional shares from the assumed exercise of employee stock-based awards		440		398		370
Weighted average number of shares used in computation of diluted earnings per share		56,503		56,402		51,937

Redeemable Noncontrolling Interest [Table Text Block]

	2022			2021
	(Dollars in thousands)
Redeemable noncontrolling interest as of January 1,	$	9,329		$	9,830
Redeemable noncontrolling interest in results of operation of a consolidated subsidiary		638			619
Cash paid to noncontrolling interest		—			(268	)
Currency translation adjustments		(377	)		(852	)
Redeemable noncontrolling interest as of December 31,	$	9,590		$	9,329