Note 17 - Income Taxes (Details Textual) - USD ($) $ in Thousands					1 Months Ended	12 Months Ended
		Dec. 21, 2020	Oct. 19, 2019	Apr. 24, 2018	Sep. 30, 2019	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2014	Dec. 28, 2020
Deferred Tax Assets, Tax Credit Carryforwards, Foreign							$ 92,240	$ 92,077
Deferred Tax Assets, Investments							813	813
Deferred Tax Assets, Valuation Allowance, Total							11,298	22,193	$ 17,412
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount							10,900
Uncertain Tax Benefit, Reudction to Deferred Tax Asset	[1]						$ 95	95
Depreciation Bonus Permitted Write Off Equipment Cost Percentage							100.00%
Placed in Service After December 31, 2022 and Before January 1, 2024 [Member]
Depreciation Bonus Permitted Write Off Equipment Cost Percentage							80.00%
Placed in Service After December 31, 2023 and Before January 1, 2025 [Member]
Depreciation Bonus Permitted Write Off Equipment Cost Percentage							60.00%
Placed in Service After December 31, 2024 and Before January 1, 2026 [Member]
Depreciation Bonus Permitted Write Off Equipment Cost Percentage							40.00%
Placed in Service After December 31, 2025 and Before January 1, 2027 [Member]
Depreciation Bonus Permitted Write Off Equipment Cost Percentage							20.00%
Israel Tax Authority [Member]
Unrecognized Tax Benefits that Would Impact Effective Tax Rate							$ 5,700	$ 2,000
Accounting Standards Update 2013-11 [Member]
Uncertain Tax Benefit, Reudction to Deferred Tax Asset											$ 100
U.S. Geothermal [Member]
Business Acquisition, Percentage of Voting Interests Acquired				100.00%
Business Combination, Consideration Transferred, Total				$ 110,000
Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Assets (Liabilities), Net				1,700
Deferred Taxes, Business Combination, Valuation Allowance, Available to Reduce Deferred Tax Asset				1,800
General Business Tax Credit Carryforward [Member]
Tax Credit Carryforward Expiration Period (Year)							20 years
General Business Tax Credit Carryforward [Member] | Minimum [Member]
Tax Credit Carryforward Expiration Year							2022
Domestic Tax Authority [Member]
Operating Loss Carryforwards, Total							$ 57,300
Operating Loss Carryforwards Expiring Amount							$ 108,100
Open Tax Year							2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019
Domestic Tax Authority [Member] | U.S. Geothermal [Member]
Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Assets				113,900
Foreign Tax Authority [Member]
Tax Credit Carryforward Expiration Period (Year)							10 years
Tax Credit Carryforward Expiration Year							2022
Deferred Tax Assets, Tax Credit Carryforwards, Foreign							$ 92,200
Foreign Tax Authority [Member] | Israel Tax Authority [Member]
Foreign Income Tax Expense (Benefit), Continuing Operations, Total							$ 17,300
National Corporate Tax Rate									16.00%	23.00%	16.00%
Income Tax Examination, Liability (Refund) Adjustment from Settlement with Taxing Authority													$ 4,300
Foreign Tax Authority [Member] | Israel Tax Authority [Member] | Ormat Systems Ltd [Member]
Effective Income Tax Rate, Year Four and Thereafter												16.00%
Foreign Tax Authority [Member] | Ministry of the Economy, Finance and Industry, France [Member]
National Corporate Tax Rate								28.00%	31.00%
Foreign Tax Authority [Member] | Ministry of the Economy, Finance and Industry, France [Member] | Forecast [Member]
National Corporate Tax Rate						25.00%
Foreign Tax Authority [Member] | Guadeloupe Tax Authority [Member]
National Corporate Tax Rate							26.50%
Foreign Tax Authority [Member] | Tax Authority of Guatemala in Guatemala [Member]
National Corporate Tax Rate							25.00%
Tax Exemption Period (Year)							10 years
Effective Income Tax Rate							7.00%
Foreign Tax Authority [Member] | Sistema de Administración de Rentas [Member]
Income Taxes Exempt Period (Year)					10 years
Foreign Tax Authority [Member] | Kenya Revenue Authority [Member]
National Corporate Tax Rate							37.50%
Income Tax Examination, Liability (Refund) Adjustment from Settlement with Taxing Authority													$ 1,500
Income Tax Examination, Year under Examination								2013 2014 2015 2016 2017 2018 2019
Income Tax Examination, Estimate of Possible Loss		$ 9,000	$ 190,000
Income Tax Examination, Deferral of Tax Benefits			28,000
Foreign Tax Authority [Member] | Kenya Revenue Authority [Member] | Tax Year 2019 [Member]
Income Tax Examination, Estimate of Possible Loss			$ 28,000
State and Local Jurisdiction [Member]
Operating Loss Carryforwards, Total							$ 297,700
Operating Loss Carryforwards Expiring Amount							294,400
Operating Loss Carryforwards Available For Indefinite Period							2,800
Deferred Tax Assets, Investments							$ 1,000
Open Tax Year							2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019
State and Local Jurisdiction [Member] | U.S. Geothermal [Member]
Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Assets				$ 49,900
State and Local Jurisdiction [Member] | Minimum [Member]
Tax Credit Carryforward Expiration Year							2025
State and Local Jurisdiction [Member] | Maximum [Member]
Tax Credit Carryforward Expiration Year							2040

[1] The non-current deferred tax asset has been reduced by the uncertain tax benefit of $0.1 million in accordance with ASU 2013-11, Income Taxes.