Note 12 - Tax Monetization Transaction (Details) (USD $)	12 Months Ended		1 Months Ended	0 Months Ended	1 Months Ended			3 Months Ended	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Jan. 31, 2014	Feb. 03, 2011	Jan. 31, 2013	Oct. 30, 2009	Jun. 30, 2007	Dec. 31, 2009	Dec. 31, 2008	Dec. 31, 2007	Jan. 31, 2015	Dec. 31, 2011	Dec. 31, 2010
Note 12 - Tax Monetization Transaction (Details) [Line Items]
Noncontrolling Interest, Increase from Subsidiary Equity Issuance (in Dollars)	$ 257,000	$ 5,151,000
Proceeds from Additional Payments (in Dollars)			2,200,000
Common Class A [Member] | Ormat Nevada Ortp LLC [Member]
Note 12 - Tax Monetization Transaction (Details) [Line Items]
Common Stock Voting Rights Percentage			75.00%
Common Class B [Member] | Ormat Nevada Ortp LLC [Member]
Note 12 - Tax Monetization Transaction (Details) [Line Items]
Common Stock Voting Rights Percentage			25.00%
Subsequent Event [Member]
Note 12 - Tax Monetization Transaction (Details) [Line Items]
Proceeds from Additional Payments (in Dollars)											1,600,000
Capital Unit, Class A [Member] | Ormat Nevada Ortp LLC [Member]
Note 12 - Tax Monetization Transaction (Details) [Line Items]
Percentage Of Ownership Interests				75.00%								75.00%
Capital Unit, Class B [Member] | Ormat Nevada Ortp LLC [Member]
Note 12 - Tax Monetization Transaction (Details) [Line Items]
Percentage Of Ownership Interests				7.50%								25.00%
Ownership Percentage Of Common Shares Outstanding				30.00%
Ownership Percentage Of Common Shares Outstanding By NonControlling Interest													70.00%
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners													17.50%
Maximum [Member] | Ormat Nevada Ortp LLC [Member]
Note 12 - Tax Monetization Transaction (Details) [Line Items]
Expected Future Payments (in Dollars)			11,000,000
Ormat Nevada Ortp LLC [Member]
Note 12 - Tax Monetization Transaction (Details) [Line Items]
Number Of Facilities							4
Proceeds From Sale Of Equity Units (in Dollars)									63,000,000	71,800,000
Percentage Of Ownership Interests Flip Date													95.00%
Percentage Of Ownership Interests By Noncontrolling Owners Flip Date				5.00%		3.50%							5.00%
Percentage Of Ownership Interests													82.50%
Payments for Repurchase of Redeemable Noncontrolling Interest (in Dollars)						18,500,000
Gain From Repurchase Of Interests At Discount (in Dollars)								13,300,000
Adjustments To Additional Paid In Capital Purchase Of Noncontrolling Interest (in Dollars)								1,100,000
Percentage Of Ownership Interests Purchased From Noncontrolling Owners				1.50%				1.50%
Proceeds Sale Minority Interest (in Dollars)				24,900,000
Noncontrolling Interest, Increase from Subsidiary Equity Issuance (in Dollars)				2,300,000
Proceeds from Sales of Business, Affiliate and Productive Assets (in Dollars)					$ 35,700,000
Additional Proceeds as Percentage of Production Tax Credit					25.00%
Final Additional Payments Expected Date			Dec. 31, 2016
Percentage of Distributable Cash After Flip Date			97.50%
Percentage of Taxable Income After Flip Date			95.00%
Percentage Allocation Of Income and Loss			5.00%
Percentage Allocation of Cash			2.50%