Note 11 - Income Taxes (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Note 11 - Income Taxes (Details) [Line Items]
Effective Income Tax Rate Reconciliation, Percent	28.10%	1265.10%	34.00%	42.00%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	35.00%
Effective Income Tax Rate Reconciliation, Tax Exempt Income, Amount (in Dollars)	$ 495,000	$ 853,000	$ 1,890,000	$ 3,429,000
Deferred Tax Assets, Investments (in Dollars)					2,000,000
Deferred Tax Assets, Tax Credit Carryforwards, General Business (in Dollars)					69,000,000
Effective Income Tax Amended Rate Start Date			Nov. 11, 2013
Period In Which Investments Expected To Be Made To Benefit From New Tax Law			5 years
Internal Revenue Service (IRS) [Member]
Note 11 - Income Taxes (Details) [Line Items]
Operating Loss Carryforwards (in Dollars)					267,600,000
State and Local Jurisdiction [Member]
Note 11 - Income Taxes (Details) [Line Items]
Operating Loss Carryforwards (in Dollars)					$ 193,400,000
Israel [Member] | Investment One [Member] | Ormat Systems Ltd Member
Note 11 - Income Taxes (Details) [Line Items]
Period For Tax Exemption			2 years
Income Tax Incentive Period	5 years		5 years
Israel [Member] | Investment One [Member] | Ormat Systems Ltd Member | Maximum [Member]
Note 11 - Income Taxes (Details) [Line Items]
Effective Income Tax Rate			25.00%
Israel [Member] | Investment Two [Member] | Ormat Systems Ltd Member
Note 11 - Income Taxes (Details) [Line Items]
Period For Tax Exemption			2 years
Income Tax Incentive Period	5 years		5 years
Israel [Member] | Investment Two [Member] | Ormat Systems Ltd Member | Maximum [Member]
Note 11 - Income Taxes (Details) [Line Items]
Effective Income Tax Rate			25.00%
Israel [Member] | Ormat Systems Ltd Member
Note 11 - Income Taxes (Details) [Line Items]
Effective Income Tax Rate Year One and Year Two			15.00%
Effective Income Tax Rate Year Three and Year Four			12.50%
Effective Income Tax Rate Year Five and Thereafter			12.00%
Investment Tax Credit Carryforward [Member]
Note 11 - Income Taxes (Details) [Line Items]
Tax Credit Carryforward Expiration Period					20 years
General Business Tax Credit Carryforward [Member]
Note 11 - Income Taxes (Details) [Line Items]
Tax Credit Carryforward Expiration Period					20 years