Note 17 - Income Taxes (Details Textual) - USD ($) $ in Thousands			1 Months Ended	12 Months Ended
		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
Deferred Tax Assets, Tax Credit Carryforwards, Foreign				$ 32,333	$ 92,240
Deferred Tax Assets, Valuation Allowance				2,473	11,298	$ 22,193
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount				8,800
Uncertain Tax Benefit, Reudction to Deferred Tax Asset	[1]			95	95
Israel Tax Authority [Member]
Unrecognized Tax Benefits that Would Impact Effective Tax Rate				$ 6,600	$ 5,700
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				2026
Domestic Tax Authority [Member]
Operating Loss Carryforwards				$ 42,000
Operating Loss Carryforwards Expiring Amount				$ 109,100
Open Tax Year				2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021
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				2027
Deferred Tax Assets, Tax Credit Carryforwards, Foreign				$ 32,300
Foreign Tax Authority [Member] | Israel Tax Authority [Member]
Foreign Income Tax Expense (Benefit), Continuing Operations, Total				$ 16,400
National Corporate Tax Rate							16.00%	23.00%	16.00%
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				25.00%		28.00%	31.00%
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%
State and Local Jurisdiction [Member]
Operating Loss Carryforwards				$ 273,300
Operating Loss Carryforwards Expiring Amount				268,700
Operating Loss Carryforwards Available For Indefinite Period				4,600
Deferred Tax Assets, Investments				$ 1,000
Open Tax Year				2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021
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				2042

[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.