Note 4 - Fair Value of Financial Instruments (Tables)

3 Months Ended

Mar. 31, 2024

Notes Tables

Fair Value, by Balance Sheet Grouping [Table Text Block]

				March 31, 2024
				Fair Value
	Carrying Value at March 31, 2024			Total			Level 1		Level 2			Level 3
	(Dollars in thousands)
Assets:
Current assets:
Cash equivalents (including restricted cash accounts)	$	55,316		$	55,316		$	55,316	$	—		$	—
Derivatives:
Interest rate swap (3)		1,502			1,502			—		1,502			—
Currency forward contracts (2)		593			593			—		593			—
Liabilities:
Current liabilities:
Derivatives:
Cross currency swap (1)		(4,323	)		(4,323	)		—		(4,323	)		—
Long term liabilities:
Cross currency swap (1)		(10,174	)		(10,174	)		—		(10,174	)		—
	$	42,914		$	42,914		$	55,316	$	(12,402	)	$	—

				December 31, 2023
				Fair Value
	Carrying Value at December 31, 2023			Total			Level 1		Level 2			Level 3
	(Dollars in thousands)
Assets
Current assets:
Cash equivalents (including restricted cash accounts)	$	53,877		$	53,877		$	53,877	$	—		$	—
Derivatives:
Currency forward contracts (2)		1,406			1,406			—		1,406			—
Liabilities:
Current liabilities:
Derivatives:
Cross currency swap (1)		(3,686	)		(3,686	)		—		(3,686	)		—
Long-term liabilities:
Cross currency swap (1)		(8,137	)		(8,137	)		—		(8,137	)		—
	$	43,461		$	43,461		$	53,877	$	(10,416	)	$	—

Derivative Instruments, Gain (Loss) [Table Text Block]

		Amount of recognized gain (loss)
Derivative instruments	Location of recognized gain (loss)	Three Months Ended March 31,
		2024			2023
		(Dollars in thousands)
Derivatives not designated as hedging instruments
Currency forward contracts (1)	Derivative and foreign currency transaction gains (losses)	$	1,078		$	(1,656	)
Derivatives designated as cash flow hedging instruments
Cross currency swap (2)	Derivative and foreign currency transaction gains (losses)	$	(3,236	)	$	(6,792	)
Interest rate swap (2)	Interest expense, net	$	457		$	—

Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss) [Table Text Block]

	Three Months Ended March 31,
	2024			2023
	(Dollars in thousands)
Cash flow hedges:
Balance in Accumulated other comprehensive income (loss) beginning of period	$	(318	)	$	3,920
Gain or (loss) recognized in Other comprehensive income (loss):
Cross currency swap		(2,675	)		1,389
Interest rate swap		1,523			—
Amount reclassified from Other comprehensive income (loss) into earnings
Cross currency swap		3,236			(6,792	)
Interest rate swap		(457	)		—
Balance in Accumulated other comprehensive income (loss) end of period	$	1,309		$	(1,483	)

Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block]

	Fair Value				Carrying Amount (*)
	March 31, 2024		December 31, 2023		March 31, 2024		December 31, 2023
	(Dollars in millions)				(Dollars in millions)
Hapoalim 2024 Loan	$	75.9	$	—	$	75.0	$	—
HSBC Bank 2024 Loan		126.5		—		125.0		—
Mammoth Senior Secured Notes		137.4		—		135.1		—
Mizrahi Loan		61.2		61.4		60.9		60.9
Mizrahi Loan 2023		51.8		52.0		50.0		50.0
Convertible Senior Notes		417.4		444.6		431.3		431.3
HSBC Loan		30.1		33.8		32.1		35.7
Hapoalim Loan		76.0		75.0		80.4		80.4
Hapoalim Loan 2023		93.5		99.7		90.0		95.0
Discount Loan		63.2		69.9		68.8		75.0
Finance liability - Dixie Valley		224.2		207.2		223.3		225.8
Olkaria III Loan - DFC		111.6		116.4		116.2		120.7
Olkaria III plant 4 Loan - DEG 2		22.0		21.6		22.5		22.5
Olkaria III plant 1 Loan - DEG 3	19.3		19.0		19.7		19.7
Platanares Loan - DFC		68.8		71.3		69.6		71.7
OFC 2 LLC ("OFC 2")		128.9		134.2		142.5		142.5
Don A. Campbell 1 ("DAC 1")		50.5		52.3		55.8		57.4
USG Prudential - NV		22.0		22.3		23.8		23.9
USG Prudential - ID Refinancing		51.2		54.1		57.2		58.9
USG DOE		28.2		30.0		28.7		30.2
Senior Unsecured Bonds		198.5		202.8		217.3		220.6
Senior Unsecured Loan		139.7		150.4		149.6		158.0
Other long-term debt		6.7		6.8		6.8		7.7

Fair Value, Liabilities Measured on Recurring and Nonrecurring Basis [Table Text Block]

	Level 1		Level 2		Level 3		Total
	(Dollars in millions)
Hapoalim 2024 Loan	$	—	$	—	$	75.9	$	75.9
HSBC Bank 2024 Loan		—		—		126.5		126.5
Mammoth Senior Secured Notes		—		—		137.4		137.4
Mizrahi Loan		—		—		61.2		61.2
Mizrahi Loan 2023		—		—		51.8		51.8
Convertible Senior Notes		—		417.4		—		417.4
HSBC Loan		—		—		30.1		30.1
Hapoalim Loan		—		—		76.0		76.0
Hapoalim Loan 2023		—		—		93.5		93.5
Discount Loan		—		—		63.2		63.2
Finance liability - Dixie Valley		—		—		224.2		224.2
Olkaria III Loan - DFC		—		—		111.6		111.6
Olkaria III plant 4 Loan - DEG 2		—		—		22.0		22.0
Olkaria III plant 1 Loan - DEG 3		—		—		19.3		19.3
Platanares Loan - DFC		—		—		68.8		68.8
OFC 2 Senior Secured Note		—		—		128.9		128.9
DAC 1 Senior Secured Note		—		—		50.5		50.5
USG Prudential - N		—		—		22.0		22.0
USG Prudential - I		—		—		51.2		51.2
USG DO		—		—		28.2		28.2
Senior Unsecured Bond		—		—		198.5		198.5
Senior Unsecured Loa		—		—		139.7		139.7
Other long-term deb		—		—		6.7		6.7
Deposit	20.0			—		—		20.0

	Level 1		Level 2		Level 3		Total
	(Dollars in millions)
Mizrahi Loan	$	—	$	—	$	61.4	$	61.4
Mizrahi Loan 2023		—		—		52.0		52.0
Convertible Senior Notes		—		444.6		—		444.6
HSBC Loan		—		—		33.8		33.8
Hapoalim Loan		—		—		75.0		75.0
Hapoalim Loan 2023		—		—		99.7		99.7
Discount Loan		—		—		69.9		69.9
Financing Liability - Dixie Valley		—		—		207.2		207.2
Olkaria III Loan - DFC		—		—		116.4		116.4
Olkaria IV - DEG 2		—		—		21.6		21.6
Olkaria IV - DEG 3		—		—		19.0		19.0
Platanares Loan - DFC		—		—		71.3		71.3
OFC 2 Senior Secured Notes		—		—		134.2		134.2
DAC 1 Senior Secured Notes		—		—		52.3		52.3
USG Prudential - NV		—		—		22.3		22.3
USG Prudential - ID		—		—		54.1		54.1
USG DOE		—		—		30.0		30.0
Senior Unsecured Bonds		—		—		202.8		202.8
Senior Unsecured Loan		—		—		150.4		150.4
Other long-term debt		—		—		6.8		6.8
Deposits	20.9			—		—		20.9