Note 5 - Fair Value of Financial Instruments (Tables)

3 Months Ended

Mar. 31, 2017

Notes Tables

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

				March 31, 2017
				Fair Value
	Carrying Value at March 31, 2017			Total			Level 1		Level 2		Level 3
	(Dollars in thousands)
Assets:
Current assets:
Cash equivalents (including restricted cash accounts)	$	19,276		$	19,276		$	19,276	$	—	$	—
Derivatives:
Put options on gas price (3)		298			298			—		298		—
Contingent receivable (1)		1,472			1,472			—		—		1,472
Currency forward contracts (2)		1,517			1,517			—		1,517		—
Liabilities:
Current liabilities:
Derivatives:
Contingent payables (1)		(24,662	)		(24,662	)		—		—		(24,662	)
Warrants (1)		(3,507	)		(3,507	)						(3,507	)
	$	(5,606	)	$	(5,606	)	$	19,276	$	1,815	$	(26,697	)

				December 31, 2016
				Fair Value
	Carrying Value at December 31, 2016			Total			Level 1		Level 2			Level 3
	(Dollars in thousands)
Assets
Current assets:
Cash equivalents (including restricted cash accounts)	$	14,922		$	14,922		$	14,922	$	—		$	—
Derivatives:
Contingent receivable (1)		1,443			1,443			—		—			1,443
Liabilities:
Current liabilities:
Derivatives:
Contingent payables (1)		(11,581	)		(11,581	)		—		—			(11,581	)
Warrants (1)		(3,429	)		(3,429	)		—		—			(3,429	)
Currency forward contracts (2)		(481	)		(481	)		—		(481	)		—
	$	874		$	874		$	14,922	$	(481	)	$	(13,567	)

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

		Amount of recognized gain (loss)
		Three Months Ended March 31,
Derivatives not designated as hedging instruments	Location of recognized gain (loss)	2017			2016
Put options on natural gas price	Derivatives and foreign currency transaction gains (losses)		(193	)		—
Call options on natural gas price	Derivatives and foreign currency transaction gains (losses)		—			518
Call and put options on oil price	Derivatives and foreign currency transaction gains (losses)		—			(643	)
Contingent considerations	Derivative and foreign currency transaction gains (losses)		(50	)
Currency forward contracts	Derivative and foreign currency transaction gains (losses)		2,262			1,814
		$	2,019		$	1,689

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

	Fair Value				Carrying Amount
	March 31, 2017		December 31, 2016		March 31, 2017		December 31, 2016
	(Dollars in millions)				(Dollars in millions)
Olkaria III Loan - DEG	$	16.2	$	16.3	$	15.8	$	15.8
Olkaria III Loan - OPIC		248.9		253.4		242.1		246.6
Olkaria IV Loan - DEG 2		51.6		50.9		50.0		50.0
Amatitlan Loan		36.2		37.3		35.9		36.8
Senior Secured Notes:
Ormat Funding Corp. ("OFC")		17.0		17.0		17.0		17.0
OrCal Geothermal Inc. ("OrCal")		37.7		37.4		35.2		35.2
OFC 2 LLC ("OFC 2")		244.6		249.0		242.7		247.2
Don A. Campbell 1 ("DAC1")		87.4		88.9		90.8		92.4
Senior Unsecured Bonds		198.9		200.1		204.3		204.3
Other long-term debt		8.6		10.4		9.5		11.2

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

	Level 1		Level 2		Level 3		Total
	(Dollars in millions)
Olkaria III - DEG	$	—	$	—	$	16.2	$	16.2
Olkaria III - OPIC		—		—		248.9		248.9
Olkaria IV - DEG 2		—		—		51.6		51.6
Amatitlan loan		—		36.2		—		36.2
Senior Secured Notes:
OFC		—		17.0		—		17.0
OrCal		—		—		37.7		37.7
OFC 2		—		—		244.6		244.6
Don A. Campbell 1 ("DAC1")		—		—		87.4		87.4
Senior unsecured bonds		—		—		198.9		198.9
Other long-term debt		—		1.7		6.9		8.6
Revolving lines of credit		—		30.0		—		30.0
Deposits		15.2		—		—		15.2

	Level 1		Level 2		Level 3		Total
	(Dollars in millions)
Olkaria III Loan - DEG	$	—	$	—	$	16.3	$	16.3
Olkaria III Loan - OPIC		—		—		253.4		253.4
Olkaria IV - DEG 2		—		—		50.9		50.9
Amatitlan Loan		—		37.3		—		37.3
Senior Secured Notes:
OFC		—		17.0		—		17.0
OrCal		—		—		37.4		37.4
OFC 2		—		—		249.0		249.0
Don A. Campbell 1 ("DAC1")		—		—		88.9		88.9
Senior unsecured bonds		—		—		200.1		200.1
Other long-term debt		—		3.3		7.1		10.4
Deposits		14.4		—		—		14.4