Ormat (ORA) 10-Q 7 May 15 2015 Q1 Quarterly report Financial data

Document_And_Entity_Informatio

Document And Entity Information	3 Months Ended
	Mar. 31, 2015	7-May-15
Document and Entity Information [Abstract]
Entity Registrant Name	ORMAT TECHNOLOGIES, INC.
Document Type	10-Q
Current Fiscal Year End Date	-19
Entity Common Stock, Shares Outstanding		48,828,331
Amendment Flag	FALSE
Entity Central Index Key	1296445
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Document Period End Date	31-Mar-15
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (Unaudited) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$70,724,000	$40,230,000
Restricted cash and cash equivalents (all related to VIEs)	115,530,000	93,248,000
Receivables:
Trade	56,300,000	48,609,000
Related entity		451,000
Other	9,732,000	10,141,000
Due from Parent		1,337,000
Inventories	17,286,000	16,930,000
Costs and estimated earnings in excess of billings on uncompleted contracts	7,426,000	27,793,000
Deferred income taxes	496,000	251,000
Prepaid expenses and other	29,566,000	34,884,000
Total current assets	307,060,000	273,874,000
Deposits and other	17,963,000	20,044,000
Deferred charges	37,301,000	37,567,000
Property, plant and equipment, net ($1,421,996 and $1,339,342 related to VIEs, respectively)	1,535,757,000	1,437,637,000
Construction-in-process ($82,045 and $162,006 related to VIEs, respectively)	230,037,000	296,722,000
Deferred financing and lease costs, net	27,369,000	27,057,000
Intangible assets, net	27,846,000	28,655,000
Total assets	2,183,333,000	2,121,556,000
Accounts payable and accrued expenses	83,676,000	88,276,000
Deferred income taxes	975,000	974,000
Short term revolving credit lines with banks (full recourse)	30,600,000	20,300,000
Billings in excess of costs and estimated earnings on uncompleted contracts	57,861,000	24,724,000
Limited and non-recourse (all related to VIEs):
Senior secured notes	36,544,000	34,368,000
Other loans	17,995,000	17,995,000
Full recourse	17,203,000	19,116,000
Total current liabilities	244,854,000	205,753,000
Limited and non-recourse (all related to VIEs):
Senior secured notes	355,776,000	360,366,000
Other loans	260,125,000	264,625,000
Full recourse:
Senior unsecured bonds (plus unamortized premium based upon 7% of $744)	250,212,000	250,289,000
Other loans	32,684,000	34,351,000
Unconsolidated investments	7,688,000	3,617,000
Liability associated with sale of tax benefits	33,685,000	39,021,000
Deferred lease income	59,815,000	60,560,000
Deferred income taxes	70,247,000	66,220,000
Liability for unrecognized tax benefits	7,190,000	7,511,000
Liabilities for severance pay	18,499,000	20,399,000
Asset retirement obligation	19,514,000	19,142,000
Other long-term liabilities	3,872,000	2,956,000
Total liabilities	1,364,161,000	1,334,810,000
Commitments and contingencies (Note 10)
The Company's stockholders' equity:
Common stock, par value $0.001 per share; 200,000,000 shares authorized; 48,828,331 and 45,537,162 shares issued and outstanding as of March 31, 2015 and December 31, 2014, respectively	49,000	46,000
Additional paid-in capital	771,591,000	742,006,000
Retained earnings	47,673,000	41,539,000
Accumulated other comprehensive income	-11,971,000	-8,668,000
	807,342,000	774,923,000
Noncontrolling interest	11,830,000	11,823,000
Total equity	819,172,000	786,746,000
Total liabilities and equity	2,183,333,000	2,121,556,000
Variable Interest Entity, Primary Beneficiary [Member]
Receivables:
Property, plant and equipment, net ($1,421,996 and $1,339,342 related to VIEs, respectively)	1,421,996,000	1,339,342,000
Construction-in-process ($82,045 and $162,006 related to VIEs, respectively)	$82,045,000	$162,006,000

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Unaudited) (Parentheticals) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, except Share data, unless otherwise specified
Property, plant and equipment, net (related to VIEs)	$1,535,757	$1,437,637
Construction-in-process (related to VIEs)	230,037	296,722
Senior unsecured bonds %	7.00%	7.00%
Senior unsecured bonds unamortized premium	744	744
Common stock, par value	$0.00	$0.00
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	48,828,331	45,537,162
Common stock, shares outstanding	48,828,331	45,537,162
Variable Interest Entity, Primary Beneficiary [Member]
Property, plant and equipment, net (related to VIEs)	1,421,996	1,339,342
Construction-in-process (related to VIEs)	$82,045	$162,006

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Operations and Comprehensive Income (Unaudited) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Revenues:
Electricity	$89,953	$94,817
Product	30,278	47,619
Total revenues	120,231	142,436
Cost of revenues:
Electricity	55,581	57,034
Product	20,625	31,943
Total cost of revenues	76,206	88,977
Gross margin	44,025	53,459
Operating expenses:
Research and development expenses	363	-87
Selling and marketing expenses	3,433	3,379
General and administrative expenses	10,204	7,596
Write-off of unsuccessful exploration activities	174
Operating income	29,851	42,571
Other income (expense):
Interest income	9	111
Interest expense, net	-17,828	-20,518
Foreign currency translation and transaction losses	-1,366	-638
Income attributable to sale of tax benefits	5,552	6,717
Other non-operating income, net	283	63
Income before income taxes and equity in losses of investees	16,501	28,306
Income tax provision	-5,459	-6,320
Equity in losses of investees, net	-775	-197
Net income	10,267	21,789
Net loss attributable to noncontrolling interest	-235	-237
Net income attributable to the Company's stockholders	10,032	21,552
Comprehensive income:
Net income (in Dollars per share)	$10,267	$21,789
Other comprehensive income (loss), net of related taxes:
Change in unrealized gains or losses in respect of the Company's share in derivatives instruments of unconsolidated investment	-3,296
Loss in respect of derivative instruments designated for cash flow hedge	23
Amortization of unrealized gains in respect of derivative instruments designated for cash flow hedge	-30	-36
Comprehensive income	6,964	21,753
Comprehensive loss attributable to noncontrolling interest	-235	-237
Comprehensive income attributable to the Company's stockholders	$6,729	$21,516
Earnings per share attributable to the Company's stockholders - basic and diluted
Net income (in Dollars per share)	$0.21	$0.47
Weighted average number of shares used in computation of earnings per share attributable to the Company's stockholders:
Basic (in Shares)	47,244	45,479
Diluted (in Shares)	48,079	45,660
Dividend per share declared (in Dollars per share)	$0.08	$0.06

Consolidated_Statements_of_Equ

Consolidated Statements of Equity (Unaudited) (USD $)	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Parent [Member]	Noncontrolling Interest [Member]	Total
In Thousands, unless otherwise specified
Balance at Dec. 31, 2013	$46	$735,295	($3,088)	$487	$732,740	$12,371	$745,111
Balance (in Shares) at Dec. 31, 2013	45,461
Stock-based compensation		1,440			1,440		1,440
Exercise of options by employees and directors (in Shares)	18
Cash paid to noncontrolling interest						-140	-140
Cash dividend declared, per share			-2,727		-2,727		-2,727
Other comprehensive income (loss), net of related taxes:
Increase in noncontrolling interest in ORTP LLC						257	257
Net income			21,552		21,552	237	21,789
Other comprehensive income (loss), net of related taxes:
Amortization of unrealized gains in respect of derivative instruments designated for cash flow hedge (net of related tax)				-36	-36		-36
Balance at Mar. 31, 2014	46	736,735	15,737	451	752,969	12,725	765,694
Balance (in Shares) at Mar. 31, 2014	45,479
Balance at Dec. 31, 2014	46	742,006	41,539	-8,668	774,923	11,823	786,746
Balance (in Shares) at Dec. 31, 2014	45,537
Stock-based compensation		1,127			1,127		1,127
Exercise of options by employees and directors		2,704			2,704		2,704
Exercise of options by employees and directors (in Shares)	295
Share exchange with Parent (Note 1)	3	25,754			25,757		25,757
Share exchange with Parent (Note 1) (in Shares)	2,996
Cash paid to noncontrolling interest						-228	-228
Cash dividend declared, per share			-3,898		-3,898		-3,898
Other comprehensive income (loss), net of related taxes:
Loss in respect of derivative instruments designated for cash flow hedge (net of related tax of $14)				23	23		23
Change in unrealized gains or losses in respect of the Company's share in derivative instruments of unconsolidated investment (net of related tax of $0)				-3,296	-3,296		-3,296
Net income			10,032		10,032	235	10,267
Other comprehensive income (loss), net of related taxes:
Amortization of unrealized gains in respect of derivative instruments designated for cash flow hedge (net of related tax)				-30	-30		-30
Balance at Mar. 31, 2015	$49	$771,591	$47,673	($11,971)	$807,342	$11,830	$819,172
Balance (in Shares) at Mar. 31, 2015	48,828

Consolidated_Statements_of_Equ1

Consolidated Statements of Equity (Unaudited) (Parentheticals) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Cash dividend declared,per share (in Dollars per share)	$0.08	$0.06
Amortization of unrealized gains in respect of derivative instruments designated for cash flow hedge, related tax	$19	$22
Loss in respect of derivative instruments designated for cash flow hedge, related tax	14
Change in unrealized gains or losses in respect of the Company's share in derivative instruments of unconsolidated investment, related tax	$0

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Cash flows from operating activities:
Net income	$10,267	$21,789
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	25,639	23,417
Amortization of premium from senior unsecured bonds	-77	-77
Accretion of asset retirement obligation	372	374
Stock-based compensation	1,127	1,440
Amortization of deferred lease income	-671	-671
Income attributable to sale of tax benefits, net of interest expense	-4,044	-4,472
Equity in losses of investees	775	197
Mark-to-market of derivative instruments	4,129	224
Write-off of unsuccessful exploration activities	174
Loss on severance pay fund asset	140	17
Deferred income tax provision	4,054	5,896
Liability for unrecognized tax benefits	-321	182
Deferred lease revenues	-74	-63
Other		-181
Changes in operating assets and liabilities, net of amounts acquired:
Receivables	-6,201	43,118
Costs and estimated earnings in excess of billings on uncompleted contracts	20,367	-6,572
Inventories	-356	-382
Prepaid expenses and other	1,189	-4,074
Deposits and other	-79	-1,229
Accounts payable and accrued expenses	-4,903	-7,725
Billings in excess of costs and estimated earnings on uncompleted contracts	33,137	-4,086
Liabilities for severance pay	-1,900	341
Other long-term liabilities	916	765
Due from/to Parent	-513	-152
Net cash provided by operating activities	83,147	68,076
Cash flows from investing activities:
Cash acquired in organizational restructuring and share exchange with Ormat Industries (Note 1)	15,391
Net change in restricted cash, cash equivalents and marketable securities	-22,282	-23,341
Cash received from sale of property, plant and equipment		15,000
Capital expenditures	-42,386	-48,330
Cash grant received from the U.S. Treasury under Section 1603 of the ARRA		21,811
Investment in unconsolidated companies		-631
Increase in severance pay fund asset, net of payments made to retired employees	2,020	168
Net cash used in investing activities	-47,257	-35,323
Cash flows from financing activities:
Proceeds from exercise of options by employees	2,704
Purchase of OFC Senior Secured Notes		-12,860
Proceeds from revolving credit lines with banks	489,900	887,583
Repayment of revolving credit lines with banks	-479,600	-902,400
Cash received from non-controlling interest	1,654	2,234
Repayments of long-term debt	-10,494	-10,528
Cash paid to non-controlling interest	-3,503	-3,091
Deferred debt issuance costs	-2,159	-391
Cash dividends paid	-3,898	-2,727
Net cash used in financing activities	-5,396	-42,180
Net change in cash and cash equivalents	30,494	-9,427
Cash and cash equivalents at beginning of period	40,230	57,354
Cash and cash equivalents at end of period	70,724	47,927
Supplemental non-cash investing and financing activities:
Decrease in accounts payable related to purchases of property, plant and equipment	($118)	($5,641)

Note_1_General_and_Basis_of_Pr

Note 1 - General and Basis of Presentation	3 Months Ended
	Mar. 31, 2015
Disclosure Text Block [Abstract]
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	NOTE 1 — GENERAL AND BASIS OF PRESENTATION
	These unaudited condensed consolidated interim financial statements of Ormat Technologies, Inc. and its subsidiaries (collectively, the “Company”) have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”) for interim financial statements. Accordingly, they do not contain all information and notes required by U.S. GAAP for annual financial statements. In the opinion of management, these unaudited condensed consolidated interim financial statements reflect all adjustments, which include normal recurring adjustments, necessary for a fair statement of the Company’s consolidated financial position as of March 31, 2015, the consolidated results of operations and comprehensive income (loss) for the three-month periods ended March 31, 2015 and 2014 and the consolidated cash flows for the three-month periods ended March 31, 2015 and 2014.
	The financial data and other information disclosed in the notes to the condensed consolidated financial statements related to these periods are unaudited. The results for the three-month period ended March 31, 2015 are not necessarily indicative of the results to be expected for the year ending December 31, 2015.
	These condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in the Company’s annual report on Form 10-K for the year ended December 31, 2014. The condensed consolidated balance sheet data as of December 31, 2014 was derived from the audited consolidated financial statements for the year ended December 31, 2014, but does not include all disclosures required by U.S. GAAP.
	Dollar amounts, except per share data, in the notes to these financial statements are rounded to the closest $1,000.
	Share Exchange Transaction
	On February 12, 2015, the Company completed the share exchange transaction with its then-parent entity, Ormat Industries Ltd. ("OIL") following which, the Company became a noncontrolled public company and its public float increased from approximately 40% to approximately 76% of its total shares outstanding. Under the terms of the share exchange, OIL shareholders received 0.2592 shares for each share in OIL, or an aggregate of approximately 30.2 million shares, reflecting a net issuance of approximately 3.0 million shares (after deducting the 27.2 million shares that OIL held in the Company). Consequently, the number of total shares of the Company outstanding increased from approximately 45.5 million shares to approximately 48.5 million shares.
	In exchange, the Company also received $15.4 million in cash, $0.6 million in other assets and $12.1 million in land and buildings and assumed $0.5 million in liabilities. OIL's principal business purpose was to hold its interest in the Company and the transaction resulted in a transfer of non-material assets from OIL to the Company. Therefore, it does not represent a change in reporting entity and the Company recognized the transfer of net assets at their carrying value as presented in OIL's financial statements. Any activities of OIL will be accounted for prospectively by the Company.
	Other comprehensive income
	For the three months ended March 31, 2015 and 2014, the Company classified $7,000 and $36,000, respectively, from accumulated other comprehensive income, of which $12,000 and $58,000, respectively, were recorded to reduce interest expense and $5,000 and $22,000, respectively, were recorded against the income tax provision, in the condensed consolidated statements of operations and comprehensive income.
	Solar project sale
	On March 26, 2014, the Company signed an agreement with RET Holdings, LLC to sell the Heber Solar project in Imperial County, California for $35.25 million. The Company received the first payment of $15.0 million during the first quarter of 2014 and the second payment for the remaining $20.25 million was paid in the second quarter of 2014. The Company recognized the pre-tax gain of approximately $7.6 million in the second quarter of 2014.
	Concentration of credit risk
	Financial instruments that potentially subject the Company to a concentration of credit risk consist principally of temporary cash investments and accounts receivable.
	The Company places its temporary cash investments with high credit quality financial institutions located in the United States (“U.S.”) and in foreign countries. At March 31, 2015 and December 31, 2014, the Company had deposits totaling $41,175,000 and $23,488,000, respectively, in seven U.S. financial institutions that were federally insured up to $250,000 per account. At March 31, 2015 and December 31, 2014, the Company’s deposits in foreign countries amounted to approximately $41,190,000 and $24,304,000, respectively.
	At March 31, 2015 and December 31, 2014, accounts receivable related to operations in foreign countries amounted to approximately $26,790,000 and $21,935,000, respectively. At March 31, 2015 and December 31, 2014, accounts receivable from the Company’s primary customers amounted to approximately 47.0% and 69.0%, respectively, of the Company’s accounts receivable.
	Sierra Pacific Power Company and Nevada Power Company (subsidiaries of NV Energy, Inc.) accounted for 24.0% and 15.3% of the Company’s total revenues for the three months ended March 31, 2015 and 2014, respectively.
	Southern California Edison accounted for 8.8% and 12.1% of the Company’s total revenues for the three months ended March 31, 2015 and 2014, respectively.
	Kenya Power and Lighting Co. Ltd. accounted for 17.8% and 14.3% of the Company’s total revenues for the three months ended March 31, 2015 and 2014, respectively.
	The Company performs ongoing credit evaluations of its customers’ financial condition. The Company has historically been able to collect on all of its receivable balances, and accordingly, no provision for doubtful accounts has been made.

Note_2_New_Accounting_Pronounc

Note 2 - New Accounting Pronouncements	3 Months Ended
	Mar. 31, 2015
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
New Accounting Pronouncements and Changes in Accounting Principles [Text Block]	NOTE 2 — NEW ACCOUNTING PRONOUNCEMENTS
	New accounting pronouncements effective in the three-month period ended March 31, 2015
	Service Concession Arrangements
	In January 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-05, Service Concession Arrangements, Topic 853. The update provides that an operating entity should not account for a service concession arrangement within the scope of this update as a lease in accordance with Topic 840, Leases. The amendments also specify that the infrastructure used in a service concession arrangement should not be recognized as property, plant, and equipment of the operating entity. A service concession arrangement is an arrangement between a public-sector entity grantor and an operating entity under which the operating entity operates the grantor’s infrastructure and may provide the construction, upgrading, or maintenance services of the grantor’s infrastructure. The amendments apply to an operating entity of a service concession arrangement entered into with a public-sector entity grantor when the arrangement meets both of the following conditions: (1) the grantor controls or has the ability to modify or approve the services that the operating entity must provide with the infrastructure, to whom it must provide them, and at what price and (2) The grantor controls, through ownership, beneficial entitlement, or otherwise, any residual interest in the infrastructure at the end of the term of the arrangement. The guidance was applied on a modified retrospective basis to service concession arrangements in existence at January 1, 2015. The adoption of this guidance did not have a material impact on the Company’s consolidated financial statements.
	New accounting pronouncements effective in future periods
	Amendments to the Consolidation analysis
	In February 2015, the FASB issued ASU 2015-02, Amendments to the Consolidation Analysis, Topic 810. The update provides that all reporting entities that hold a variable interest in other legal entities will need to re-evaluate their consolidation conclusions and potentially revised their disclosures. This amendment affect both variable interest entity (“VIE”) and voting interest entity (“VOE”) consolidation models. The update does not change the general order in which the consolidation models are applied. A reporting entity that holds an economic interest in, or is otherwise involved with, another legal entity (has a “variable interest”) should first determine if the VIE model applies, and if so, whether it holds a controlling financial interest under that model. If the entity being evaluated for consolidation is not a VIE, then the VOE model should be applied to determine whether the entity should be consolidated by the reporting entity. Since consolidation is only assessed for legal entities, the determination of whether there is a legal entity is important. It is often clear when the entity is incorporated, but unincorporated structures can also be legal entities and judgment may be required to make that determination. The update contains a new example that highlights the judgmental nature of this legal entity determination. The update is effective for annual reporting periods beginning after December 15, 2015, including interim periods within that reporting period. The Company is currently evaluating the potential impact, if any, of the adoption of this update on its consolidated financial statements.
	Simplifying the Presentation of Debt Costs
	In April 2015, the FASB issued ASU 2015-03, Interest-Imputation of Interest: Simplifying the Presentation of Debt Costs, Subtopic 835-30. The update provides that debt issuance costs related to a recognized debt liability be presented in the balance sheet as direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The amendments in this update are effective for financial statements issued for fiscal years beginning after December 15, 2015, and interim periods within those fiscal years. Early adoption is permitted. The Company is currently evaluating the potential impact of the adoption of these amendments on its consolidated financial statements.
	Revenues from Contracts with Customers
	In May 2014, the FASB issued ASU 2014-09, Revenues from Contracts with Customers, Topic 606, which was a joint project of the FASB and the International Accounting Standards Board to clarify the principles for recognizing revenue and to develop a common revenue standard for U.S. GAAP and International Financial Reporting Standards. The update provides that an entity should recognize revenue in connection with the transfer of goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. Specifically, an entity is required to apply each of the following steps: (1) identify the contract(s) with the customer; (2) identify the performance obligations in the contracts; (3) determine the transaction price; (4) allocate the transaction price to the performance obligation in the contract; and (5) recognize revenue when (or as) the entity satisfies a performance obligation. The amendments in this update are effective for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period. Early adoption is not permitted. The Company is currently evaluating the potential impact, if any, of the adoption of these amendments on its consolidated financial statements.

Note_3_Inventories

Note 3 - Inventories	3 Months Ended
	Mar. 31, 2015
Inventory Disclosure [Abstract]
Inventory Disclosure [Text Block]	NOTE 3 — INVENTORIES
	Inventories consist of the following:
		March 31,		December 31,
		2015		2014
		(Dollars in thousands)
	Raw materials and purchased parts for assembly	$	6,127	$	4,840
	Self-manufactured assembly parts and finished products		11,159		12,090
	Total	$	17,286	$	16,930

Note_4_Unconsolidated_Investme

Note 4 - Unconsolidated Investments	3 Months Ended
	Mar. 31, 2015
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments and Joint Ventures Disclosure [Text Block]	NOTE 4 — UNCONSOLIDATED INVESTMENTS
	Unconsolidated investments consist of the following:
		March 31,			December 31,
		2015			2014
		(Dollars in thousands)
	Sarulla	$	(7,688	)	$	(3,617	)
	The Sarulla Project
	The Company is a 12.75% member of a consortium which is in the process of developing the Sarulla geothermal power project in Indonesia with expected generating capacity of approximately 330 megawatts (“MW”). The Sarulla project is located in Tapanuli Utara, North Sumatra, Indonesia and will be owned and operated by the consortium members under the framework of a Joint Operating Contract (“JOC”) and Energy Sales Contract (“ESC”) that were signed on April 4, 2013. Under the JOC, PT Pertamina Geothermal Energy (“PGE”), the concession holder for the project, has provided the consortium with the right to use the geothermal field, and under the ESC, PT PLN, the state electric utility, will be the off-taker at Sarulla for a period of 30 years. In addition to its equity holdings in the consortium, the Company designed the Sarulla plant and is expected to supply its Ormat Energy Converters (“OECs”) to the power plant. The supply contract was signed in October 2013.
	The consortium has started preliminary testing and development activities at the site and signed an engineering procurement and construction agreement (“EPC”) with an unrelated third party. The project will be constructed in three phases of approximately 110 MW each, utilizing both steam and brine extracted from the geothermal field to increase the power plant’s efficiency.
	On May 16, 2014, the consortium reached financial closing of $1.17 billion in financing agreements to finance the development of the Sarulla project with a consortium of lenders comprised of Japan Bank for International Cooperation (“JBIC”), the Asian Development Bank and six commercial banks and obtained construction and term loan under limited recourse financing package backed by political risk guarantee from JBIC.
	Of the $1.17 billion, $0.1 billion (which was drawn down by the Sarulla project company on May 23, 2014) bears a fixed interest rate and $1.07 billion bears interest at a rate linked to LIBOR.
	The Sarulla consortium entered into interest rate swap agreements with various international banks in order to fix the Libor interest rate on up to $0.96 billion of the $1.07 billion credit facility at a rate of 3.4565%. The interest rate swap became effective as of June 4, 2014 along with the second draw-down by the project company of $50.0 million.
	The Sarulla project company accounted for the interest rate swap as a cash flow hedge upon which changes in the fair value of the hedging instrument, relative to the effective portion, will be recorded in other comprehensive income. As such, during the three months ended March 31, 2015, the project recorded a loss equal to $25.9 million, of which the Company's share was $3.3 million which was recorded in other comprehensive income. The accumulated loss as of March 31, 2015 is $11.4 million.
	The first phase of operations is expected to commence in 2016 and the remaining two phases of operations are scheduled to commence within 18 months thereafter. The Company will supply its OECs to the power plant and has added the $255.1 million supply contract to its product segment backlog. According to the current plan, the Company started to recognize revenue from the project during the third quarter of 2014 and will continue to recognize revenues over the course of the next three to four years. For the three months ended March 31, 2015, the Company recognized Products revenues of $15.8 million. The Company has eliminated the related intercompany profit of $0.8 million against equity in loss of investees.
	During the three months ended March 31, 2015, the Company did not make any additional investment contributions to the Sarulla project.

Note_5_Fair_Value_of_Financial

Note 5 - Fair Value of Financial Instruments	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value Disclosures [Text Block]	NOTE 5— FAIR VALUE OF FINANCIAL INSTRUMENTS
	The fair value measurement guidance clarifies that fair value is an exit price, representing the amount that would be received upon selling an asset or paid upon transferring a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. The guidance establishes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). The three levels of the fair value hierarchy under the fair value measurement guidance are described below:
	Level 1 — Unadjusted quoted prices in active markets that are accessible at the measurement date for identical assets or liabilities;
	Level 2 — Quoted prices in markets that are not active, or inputs that are observable, either directly or indirectly, for substantially the full term of the asset or liability;
	Level 3 — Prices or valuation techniques that require inputs that are both significant to the fair value measurement and unobservable (supported by little or no market activity).
	The following table sets forth certain fair value information at March 31, 2015 and 2014 for financial assets and liabilities measured at fair value by level within the fair value hierarchy, as well as cost or amortized cost. As required by the fair value measurement guidance, assets and liabilities are classified in their entirety based on the lowest level of inputs that is significant to the fair value measurement.
							31-Mar-15
							Fair Value
			Carrying Value at March 31, 2015				Total				Level 1			Level 2			Level 3
			(Dollars in thousands)
	Assets
	Current assets:
	Cash equivalents (including restricted cash accounts)		$	97,641			$	97,641			$	97,641		$	—		$	—
	Liabilities:
	Current liabilities:
	Derivatives:
	Currency forward contracts (2)			(2,020	)			(2,020	)			—			(2,020	)		—
			$	95,621			$	95,621			$	97,641		$	(2,020	)	$	—
							31-Dec-14
							Fair Value
			Carrying Value at December 31, 2014				Total				Level 1			Level 2			Level 3
			(Dollars in thousands)
	Assets
	Current assets:
	Cash equivalents (including restricted cash accounts)		$	85,076			$	85,076			$	85,076		$	—		$	—
	Derivatives:
	Swap transaction on natural gas price (1)			4,129				4,129				—			4,129			—
	Liabilities:
	Current liabilities:
	Derivatives:
	Currency forward contracts (2)			(2,882	)			(2,882	)			—			(2,882	)		—
			$	86,323			$	86,323			$	85,076		$	1,247		$	—
	-1	This amount relates to derivatives which represent swap contract on natural gas prices, valued primarily based on observable inputs, including forward and spot prices for related commodity indices, and are included within “accounts payable and accrued expenses” on December 31, 2014, in the consolidated balance sheets with the corresponding gain or loss being recognized within “electricity revenue” in the consolidated statement of operations and comprehensive income.
	-2	These amounts relate to derivatives which represent currency forward contracts valued primarily based on observable inputs, including forward and spot prices for currencies, netted against contracted rates and then multiplied against notional amounts, and are included within “accounts payable and accrued expenses” and “prepaid expenses and other” on March 31, 2015 and December 31, 2014, respectively, in the consolidated balance sheet with the corresponding gain or loss being recognized within “foreign currency translation and transaction losses” in the consolidated statement of operations and comprehensive income.
	The amounts set forth in the tables above include investments in debt instruments and money market funds (which are included in cash equivalents). Those securities and deposits are classified within Level 1 of the fair value hierarchy because they are valued using quoted market prices in an active market.
	The following table presents the amounts of gain (loss) recognized in the consolidated statements of operations and comprehensive income on derivative instruments not designated as hedges:
					Amount of recognized gain (loss)
	Derivatives not designated as				Three Months Ended March 31,
	hedging instruments		Location of recognized gain (loss)		2015				2014
	Swap transaction on oil price		Electricity revenues			—				907
	Swap transactions on natural gas price		Electricity revenues			317				(3,276	)
	Currency forward contracts		Foreign currency translation and transaction losses			(1,251	)			(231	)
					$	(934	)		$	(2,600	)
	On September 3, 2013, the Company entered into a Natural Gas Index (“NGI”) swap contract with a bank for notional quantity of approximately 4.4 million British Thermal Units (“MMbtu”) for settlement effective January 1, 2014 until December 31, 2014, in order to reduce its exposure to NGI below $4.035 per MMbtu under its Power Purchase Agreements (“PPAs”) with Southern California Edison. The contract did not have up-front costs. Under the terms of this contract, the Company made floating rate payments to the bank and received fixed rate payments from the bank on each settlement date. The swap contract had a monthly settlement whereby the difference between the fixed price of $4.035 per MMbtu and the market price on the first commodity business day on which the relevant commodity reference price is published in the relevant calculation period (January 1, 2014 to December 1, 2014) was settled on a cash basis.
	On October 16, 2013, the Company entered into an NGI swap contract with a bank for notional quantity of approximately 4.2 million MMbtu for settlement effective January 1, 2014 until December 31, 2014, in order to reduce its exposure to NGI below $4.103 per MMbtu under its PPAs with Southern California Edison. The contract did not have any up-front costs. Under the terms of this contract, the Company made floating rate payments to the bank and received fixed rate payments from the bank on each settlement date. The swap contract had a monthly settlement whereby the difference between the fixed price of $4.103 per MMbtu and the market price on the first commodity business day on which the relevant commodity reference price is published in the relevant calculation period (January 1, 2014 to December 1, 2014) was settled on a cash basis.
	On October 16, 2013, the Company entered into a New York Harbor Ultra-Low Sulfur Diesel (“ULSD”) swap contract with a bank for notional quantity of 275,000 BBL effective from January 1, 2014 until December 31, 2014 to reduce the Company’s exposure to fluctuations in the energy rate caused by fluctuations in oil prices under the 25 MW PPA for the Puna complex. The Company entered into this contract because the swap had a high correlation with the avoided costs (which are incremental costs that the power purchaser avoids by not having to generate such electrical energy itself or purchase it from others) that Hawaii Electric Light Company’s (“HELCO”) uses to calculate the energy rate. The contract did not have any up-front costs. Under the term of this contract, the Company made floating rate payments to the bank and received fixed rate payments from the bank on each settlement date ($125.15 per BBL). The swap contract had a monthly settlement whereby the difference between the fixed price of $125.15 per BBL and the monthly average market price was settled on a cash basis.
	On March 6, 2014, the Company entered into an NGI swap contract with a bank for notional quantity of approximately 2.2 million MMbtu for settlement effective January 1, 2015 until March 31, 2015, in order to reduce its exposure to NGI below $4.95 per MMbtu under its PPAs with Southern California Edison. The contract did not have any up-front costs. Under the terms of this contract, the Company made floating rate payments to the bank and receive fixed rate payments from the bank on each settlement date. The swap contract had monthly settlements whereby the difference between the fixed price of $4.95 per MMbtu and the market price on the first commodity business day on which the relevant commodity reference price is published in the relevant calculation period (January 1, 2015 to March 1, 2015) was settled on a cash basis.
	The foregoing swap transactions were not designated as hedge transactions and are marked to market with the corresponding gains or losses recognized within “electricity revenues” in the consolidated statements of operations and comprehensive income (loss). The Company recognized a net gain from these transactions of $0.3 million in the three months ended March 31, 2015, compared to net loss of $2.4 million in the three months ended March 31, 2014.
	There were no transfers of assets or liabilities between Level 1, Level 2 and Level 3 during the three months ended March 31, 2015.
	The fair value of the Company’s long-term debt approximates its carrying amount, except for the following:
				Fair Value								Carrying Amount
				March 31,				31-Dec-14				March 31,			31-Dec-14
				2015								2015
				(Dollars in millions)								(Dollars in millions)
	Olkaria III Loan - DEG			$	32.6			$	32.2			$	31.6		$	31.6
	Olkaria III Loan - OPIC				277.5				279.4				278.1			282.6
	Senior Secured Notes:
	Ormat Funding Corp. ("OFC")				72.7				71.4				67.2			67.2
	OrCal Geothermal Inc. ("OrCal")				56.5				55.5				55.1			55.1
	OFC 2 LLC ("OFC 2")				239.5				238.8				270.1			272.5
	Senior Unsecured Bonds				263.8				265.4				250.2			250.4
	Loan from institutional investors				10.2				12.2				10			11.9
	The fair value of OFC Senior Secured Notes is determined using observable market prices as these securities are traded. The fair value of all the long-term debt is determined by a valuation model, which is based on a conventional discounted cash flow methodology and utilizes assumptions of current borrowing rates.The fair value of revolving lines of credit is determined using a comparison of market-based price sources that are reflective of similar credit ratings to those of the Company.
	The carrying value of other financial instruments, such as revolving lines of credit, deposits, and other long-term debt approximates fair value.
The following table presents the fair value of financial instruments as of March 31, 2015:
		Level 1				Level 2				Level 3			Total
		(Dollars in millions)
Olkaria III - DEG		$	—			$	—			$	32.6		$	32.6
Olkaria III - OPIC			—				—				277.5			277.5
Senior Secured Notes:
OFC			—				72.7				—			72.7
OrCal			—				—				56.5			56.5
OFC 2			—				—				239.5			239.5
Senior unsecured bonds			—				—				263.8			263.8
Loan from institutional investors			—				—				10.2			10.2
Other long-term debt			—				8.3				—			8.3
Revolving credit lines with banks			—				30.6				—			30.6
Deposits			15.4				—				—			15.4
The following table presents the fair value of financial instruments as of December 31, 2014:
		Level 1				Level 2				Level 3			Total
		(Dollars in millions)
Olkaria III Loan - DEG		$	—			$	—			$	32.2		$	32.2
Olkaria III Loan - OPIC			—				—				279.4			279.4
Senior Secured Notes:
OFC			—				71.4				—			71.4
OrCal			—				—				55.5			55.5
OFC 2			—				—				238.8			238.8
Senior unsecured bonds			—				—				265.4			265.4
Loan from institutional investors			—				—				12.2			12.2
Other long-term debt			—				10				—			10
Revolving lines of credit			—				20.3				—			20.3
Deposits			17.3				—				—			17.3

Note_6_StockBased_Compensation

Note 6 - Stock-Based Compensation	3 Months Ended
	Mar. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Disclosure of Compensation Related Costs, Share-based Payments [Text Block]	NOTE 6 — STOCK-BASED COMPENSATION
	The 2004 Incentive Compensation Plan
	In 2004, the Company’s Board of Directors adopted the 2004 Incentive Compensation Plan (“2004 Incentive Plan”), which provides for the grant of the following types of awards: incentive stock options, non-qualified stock options, restricted stock, stock appreciation rights (“SARs”), stock units, performance awards, phantom stock, incentive bonuses, and other possible related dividend equivalents to employees of the Company, directors and independent contractors. Under the 2004 Incentive Plan, a total of 3,750,000 shares of the Company’s common stock have been reserved for issuance, all of which could be issued as options or as other forms of awards. Options and SARs granted to employees under the 2004 Incentive Plan cliff vest and are exercisable from the grant date as follows: 25% after 24 months, 25% after 36 months, and the remaining 50% after 48 months. Options granted to non-employee directors under the 2004 Incentive Plan cliff vest and are exercisable one year after the grant date. Vested stock-based awards may be exercised for up to ten years from the date of grant. The shares of common stock will be issued upon exercise of options or SARs from the Company’s authorized share capital. The 2004 Incentive Plan expired in May 2012 upon adoption of the 2012 Incentive Plan, except as to share based awards outstanding on that date.
	The 2012 Incentive Compensation Plan
	In May 2012, the Company’s shareholders adopted the 2012 Incentive Compensation Plan (“2012 Incentive Plan”), which provides for the grant of the following types of awards: incentive stock options, non-qualified stock options, restricted stock, SARs, stock units, performance awards, phantom stock, incentive bonuses, and other possible related dividend equivalents to employees of the Company, directors and independent contractors. Under the 2012 Incentive Plan, a total of 4,000,000 shares of the Company’s common stock have been reserved for issuance, all of which could be issued as options or as other forms of awards. Options and SARs granted to employees under the 2012 Incentive Plan typically vest and become exercisable as follows: 25% vest 24 months after the grant date, an additional 25% vest 36 months after the grant date, and the remaining 50% vest 48 months after the grant date. Options granted to non-employee directors under the 2012 Incentive Plan will vest and become exercisable one year after the grant date. The term of stock-based awards typically ranges from six to ten years from the date of grant. The shares of common stock will be issued upon exercise of options or SARs from the Company’s authorized share capital.
	The 2012 Incentive Plan empowers the Company’s Board of Directors, in its discretion, to amend the 2012 Incentive Plan in certain respects. Consistent with its authority to amend the Incentive Plan, in February 2014 the Board adopted and approved certain amendments to the Incentive Plan. The key amendments are as follows:
	Increase of per grant limit: Section 15(a) of the 2012 Incentive Plan was amended to allow the grant of up to 400,000 shares of the Company’s common stock with respect to the initial grant of an equity award to newly hired executive officers in any calendar year; and
	Acceleration of vesting: Section 15(l) of the 2012 Incentive Plan was amended to clarify our ability to provide in the applicable award agreement that part and/or all of the award will be accelerated upon the occurrence of certain predetermined events and/or conditions, such as a "change in control" (as defined in the 2012 Incentive Plan, as amended).

Note_7_Interest_Expense_Net

Note 7 - Interest Expense, Net	3 Months Ended
	Mar. 31, 2015
Interest Expense Disclosure [Abstract]
Interest Expense Disclosure [Text Block]	NOTE 7 — INTEREST EXPENSE, NET
	The components of interest expense are as follows:
		Three Months Ended March 31,
		2015			2014
	Interest related to sale of tax benefits	$	1,880		$	2,579
	Interest expense		16,895			18,391
	Less — amount capitalized		(947	)		(452	)
		$	17,828		$	20,518

Note_8_Earnings_Per_Share

Note 8 - Earnings Per Share	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Earnings Per Share [Text Block]	NOTE 8 — EARNINGS PER SHARE
	Basic earnings per share attributable to the Company’s stockholders (“earnings per share”) is computed by dividing net income or loss attributable to the Company’s stockholders by the weighted average number of shares of common stock outstanding for the period. The Company does not have any equity instruments that are dilutive, except for employee stock-based awards.
	The table below shows the reconciliation of the number of shares used in the computation of basic and diluted earnings per share:
		Three Months Ended March 31,
		2015		2014
	Weighted average number of shares used in computation of basic earnings per share		47,244		45,479
	Add:
	Additional shares from the assumed exercise of employee stock options		835		181
	Weighted average number of shares used in computation of diluted earnings per share		48,079		45,660
	The number of stock-based awards that could potentially dilute future earnings per share and that were not included in the computation of diluted earnings per share because to do so would have been anti-dilutive was 1,037,612 and 3,349,877 for the three months ended March 31, 2015 and 2014, respectively.

Note_9_Business_Segments

Note 9 - Business Segments	3 Months Ended
	Mar. 31, 2015
Segment Reporting [Abstract]
Segment Reporting Disclosure [Text Block]	NOTE 9 — BUSINESS SEGMENTS
	The Company has two reporting segments: Electricity and Product Segments. These segments are managed and reported separately as each offers different products and serves different markets. The Electricity Segment is engaged in the sale of electricity from the Company’s power plants pursuant to PPAs. The Product Segment is engaged in the manufacture, including design and development, of turbines and power units for the supply of electrical energy and in the associated construction of power plants utilizing the power units manufactured by the Company to supply energy from geothermal fields and other alternative energy sources. Transfer prices between the operating segments are determined based on current market values or cost plus markup of the seller’s business segment.
	Summarized financial information concerning the Company’s reportable segments is shown in the following tables:
		Electricity			Product			Consolidated
		(Dollars in thousands)
	Three Months Ended March 31, 2015:
	Net revenues from external customers	$	89,953		$	30,278		$	120,231
	Intersegment revenues		—			19,757			19,757
	Operating income (loss)		23,954			5,897			29,851
	Segment assets at period end *		1,981,813			201,520			2,183,333
	* Including unconsolidated investments		—			—			—
	Three Months Ended March 31, 2014:
	Net revenues from external customers	$	94,817		$	47,619		$	142,436
	Intersegment revenues		—			20,594			20,594
	Operating income (loss)		30,918			11,653			42,571
	Segment assets at period end *		2,003,991			130,356			2,134,347
	* Including unconsolidated investments		7,510			—			7,510
	Reconciling information between reportable segments and the Company’s consolidated totals is shown in the following table:
		Three Months Ended March 31,
		2015			2014
	Revenues:
	Total segment revenues	$	120,231		$	142,436
	Intersegment revenues		19,757			20,594
	Elimination of intersegment revenues		(19,757	)		(20,594	)
	Total consolidated revenues	$	120,231		$	142,436
	Operating income:
	Operating income	$	29,851		$	42,571
	Interest income		9			111
	Interest expense, net		(17,828	)		(20,518	)
	Foreign currency translation and transaction losses		(1,366	)		(638	)
	Income attributable to sale of equity interest		5,552			6,717
	Other non-operating income, net		283			63
	Total consolidated income before income taxes and equity in income of investees	$	16,501		$	28,306

Note_10_Commitments_and_Contin

Note 10 - Commitments and Contingencies	3 Months Ended
	Mar. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies Disclosure [Text Block]	NOTE 10 — COMMITMENTS AND CONTINGENCIES
	●	Jon Olson and Hilary Wilt, together with Puna Pono Alliance, an unincorporated association, filed suit on February 17, 2015, in the Third Circuit Court for the State of Hawaii, requesting declaratory and injunctive relief requiring that Puna Geothermal Venture (“PGV”) conform to an ordinance that the plaintiffs allege will prohibit PGV from engaging in night drilling operations at its KS-16 well site. PGV believes that the allegations have no merit, and will continue to defend itself vigorously.
	●	On July 8, 2014, Global Community Monitor, LiUNA, and two residents of Bishop, California filed a complaint in the United States District Court for the Eastern District of California, alleging that Mammoth Pacific, L.P., Ormat Technologies, Inc. and Ormat Nevada, Inc. are operating three geothermal generating plants in Mammoth Lakes, California (MP-1; MP-II and PLES-I) in violation of the federal Clean Air Act (“CAA”) and Great Basin Unified Air Pollution Control District (“District”) rules. The Company believes the complaint is without merit, and intends to vigorously defend itself against the allegations set forth in the complaint and to take all necessary legal action to have the complaint dismissed. Filing of the complaint in and of itself does not have any immediate adverse implications for the Mammoth plants.
	●	On April 5, 2012, the International Brotherhood of Electrical Workers Local 1260 (“Union”) filed a petition with the National Labor Relations Board (“NLRB”) seeking to organize the operations and maintenance employees at the Puna Project.  PGV lost the union election by a slim margin in May 2012.  The election results and the Employer’s obligation to negotiate with the Union were appealed to the United States Court of Appeals for the Ninth Circuit, but were remanded back to the NLRB after the U.S. Supreme Court’s decision in Noel Canning, 573 U.S., 134 S.Ct. 2550 (2014). On November 26, 2014, the NLRB found that a certification of representative should be issued. In January 2015, the parties submitted a briefing to the NLRB as to whether summary judgment is appropriate. PGV currently expects a decision in this matter will be rendered within the next two to four months. Depending on the decision, PGV expects to review its options and either accept negotiations with the Union or continue to appeal the decision.
	●	In January 2014, Ormat learned that two former employees alleged in a "qui tam" complaint filed in the United States District Court for the Southern District of California that the Comapny and certain of its subsidiaries (collectively, the "Ormat Parties") submitted fraudulent applications and certifications to obtain grants, particularly for the Puna and North Brawley projects. The United States Department of Justice declined to intervene, and the former employees proceeded on their own and served the Ormat Parties with their initial complaint in April 2014, and then filed an amended complaint in May 2014. Pursuant to the Ormat Parties' motion to move the venue of the proceeding, and despite the complainants’ objection, the file was reassigned from the United States District Court for the Southern District of California to the District of Nevada.
	In July 2014, the Ormat Parties filed a motion to dismiss the amended complaint, as well as a request for the court to take judicial notice of a number of documents, In response to the Ormat Parties’ filings, the complainants filed responses urging the court to reject the motion to dismiss and accompanying request to take judicial notice, and the United States filed a statement of interest urging rejection of the Ormat Parties' arguments raised with respect to the scope of the False Claims Act's “Tax Bar”, while continuing to take no position as to the overall sufficiency of the complainants' complaint. On March 24, 2015, the Nevada United States District Court issued its order regarding the pending motions, in which the Court accepted the Ormat Parties’ motions in part, and rejected them in part.
	In the interim, FIMI and Ormat Industries (who were originally named on the complaint, but never served) have been removed from the complaint as co-defendants pursuant to a Tolling Agreement entered into with the complainants. The Ormat Parties continue to believe that the allegations of the lawsuit have no merit, and will continue to defend themselves vigorously.
	●	In addition, from time to time, the Company is named as a party to various other lawsuits, claims and other legal and regulatory proceedings that arise in the ordinary course of our business. These actions typically seek, among other things, compensation for alleged personal injury, breach of contract, property damage, punitive damages, civil penalties or other losses, or injunctive or declaratory relief. With respect to such lawsuits, claims and proceedings, the Company accrues reserves when a loss is probable and the amount of such loss can be reasonably estimated. It is the opinion of the Company’s management that the outcome of these proceedings, individually and collectively, will not be material to the Company’s consolidated financial statements as a whole.

Note_11_Income_Taxes

Note 11 - Income Taxes	3 Months Ended
	Mar. 31, 2015
Income Tax Disclosure [Abstract]
Income Tax Disclosure [Text Block]	NOTE 11 — INCOME TAXES
	The Company’s effective tax rate for the Three Months Ended March 31, 2015 and 2014 was 33.1% and 22.3%, respectively. The effective tax rate differs from the federal statutory rate of 35% for the three months ended March 31, 2015 due to: (i) a full valuation allowance against the Company’s U.S. deferred tax assets in respect of net operating loss (“NOL”) carryforwards and unutilized tax credits (see below), (ii) lower tax rates in Israel; and (iii) a tax credit and tax exemption related to the Company’s subsidiaries in Guatemala. The effect of the tax credit and tax exemption for the three months ended March 31, 2015 and March 31, 2014 was $1,146,000 and $1,019,000, respectively.
	At December 31, 2014, the Company had U.S. federal net operating loss (“NOL”) carryforwards of approximately $251.4 million and state NOL carryforwards of approximately $216.5 million, net of valuation allowance of $111.3 million available to reduce future taxable income, which expire between 2021 and 2034 for federal NOLs and between 2014 and 2034 for state NOLs. The Investment Tax Credits in the amount of $0.7 million at December 31, 2014 are available for a 20-year period and expire between 2022 and 2024. Production Tax Credits in the amount of $71.4 million at December 31, 2014 are available for a 20-year period and expire between 2026 and 2034.
	Realization of the deferred tax assets and tax credits is dependent on generating sufficient taxable income in appropriate jurisdictions prior to expiration of the NOL carryforwards and tax credits. The most significant factor considered with respect to the ability of the Company to realize these deferred tax assets is the Company’s U.S. cumulative results over the past three years. The Company viewed this factor as a significant piece of negative evidence that made it difficult to support a conclusion that expected taxable income from future operations justifies recognition of deferred tax assets. Based on the results, a valuation allowance in the amount of $111.3 million and $114.8 million was recorded against the U.S. deferred tax assets as of December 31, 2014 and 2013, respectively as, at this point in time, it is more likely than not that the deferred tax assets will not be realized.
	Subsequent to March 31, 2015, and as more fully described in Note 12, the Company entered into a significant non-routine transaction for the partial sale of certain assets which is expected to result in a taxable gain in the U.S., for which the Company expects to utilize a portion of its NOL carryforwards and tax credits. In 2015 or in future years, if sufficient additional evidence of the Company’s ability to generate taxable income is established in the future, the Company may be required to reduce or fully release the valuation allowance, resulting in income tax benefits in its consolidated statement of operations.
	The total amount of undistributed earnings of foreign subsidiaries for income tax purposes was approximately $75.9 million at December 31, 2014. It is the Company’s intention to reinvest undistributed earnings of its foreign subsidiaries and thereby indefinitely postpone their remittance. Accordingly, no provision has been made for foreign withholding taxes or U.S. income taxes which may become payable if undistributed earnings of foreign subsidiaries were paid as dividends to the Company. The additional taxes on that portion of undistributed earnings which is available for dividends are not practicably determinable.
	The Company believes that based on its plans to increase the operations outside of the U.S., the cash generated from the Company’s operations outside of the U.S. will be reinvested outside of the U.S.. In addition, the Company’s U.S. sources of cash and liquidity are sufficient to meet its needs in the U.S. and, accordingly, the Company does not currently plan to repatriate the funds it has designated as being permanently invested outside the U.S. If the Company changes its plans, it may be required to accrue and pay U.S. taxes to repatriate these funds.
	A reconciliation of the beginning and ending amounts of unrecognized tax benefits is as follows:
		Three Months Ended March 31,
		2015			2014
		(Dollars in thousands)
	Balance at beginning of year	$	7,511		$	4,950
	Additions based on tax positions taken in prior years		58			76
	Additions based on tax positions taken in the current year		570			106
	Reduction based on tax positions taken in prior years		(949	)		—
	Balance at end of year	$	7,190		$	5,132

Note_12_Subsequent_Events

Note 12 - Subsequent Events	3 Months Ended
	Mar. 31, 2015
Subsequent Events [Abstract]
Subsequent Events [Text Block]	NOTE 12 — SUBSEQUENT EVENTS
	Entry into a Material Definitive Agreement
	On April 30, 2015, Ormat Nevada Inc. (“Ormat Nevada”), a wholly-owned subsidiary of the Company, closed an equity transaction for the purchase of membership interests under that certain agreement dated April 30, 2015, (the “Purchase Agreement”) between Ormat Nevada and Northleaf Geothermal Holdings, LLC (“Northleaf”), pursuant to which Ormat Nevada sold to Northleaf 100% of the Class B Membership Interests, which represent approximately 36.75% of the aggregate membership interests, in ORPD LLC, a new holding company subsidiary of Ormat Nevada (“ORPD”), and admitted Northleaf as a member of ORPD. In connection with the transaction, Ormat Nevada contributed to ORPD certain of its project company-subsidiaries that own geothermal and recovered energy generation power plants, including the Puna geothermal power plant in Hawaii, the Don A. Campbell geothermal power plant in Nevada, and nine power plant units across three recovered energy generation assets known as OREG 1, OREG 2 and OREG 3. Ormat Nevada continues to operate and maintain the power plants.
	The purchase price for the sale of the ORPD membership interests under the Purchase Agreement is $162.3 million.
	This transaction closed on April 30, 2015 and is expected to result in a taxable gain in the U.S. of approximately $104.0 million, for which the Company expects to utilize a portion of its NOL carryforwards and tax credits.
	Cash dividend
	On May 6, 2015, the Company’s Board of Directors declared, approved and authorized payment of a quarterly dividend of $2.9 million ($0.06 per share) to all holders of the Company’s issued and outstanding shares of common stock on May 19, 2015, payable on May 27, 2015.

Accounting_Policies_by_Policy_

Accounting Policies, by Policy (Policies)	3 Months Ended
	Mar. 31, 2015
Accounting Policies [Abstract]
Basis of Accounting, Policy [Policy Text Block]	These unaudited condensed consolidated interim financial statements of Ormat Technologies, Inc. and its subsidiaries (collectively, the “Company”) have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”) for interim financial statements. Accordingly, they do not contain all information and notes required by U.S. GAAP for annual financial statements. In the opinion of management, these unaudited condensed consolidated interim financial statements reflect all adjustments, which include normal recurring adjustments, necessary for a fair statement of the Company’s consolidated financial position as of March 31, 2015, the consolidated results of operations and comprehensive income (loss) for the three-month periods ended March 31, 2015 and 2014 and the consolidated cash flows for the three-month periods ended March 31, 2015 and 2014.
	The financial data and other information disclosed in the notes to the condensed consolidated financial statements related to these periods are unaudited. The results for the three-month period ended March 31, 2015 are not necessarily indicative of the results to be expected for the year ending December 31, 2015.
	These condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in the Company’s annual report on Form 10-K for the year ended December 31, 2014. The condensed consolidated balance sheet data as of December 31, 2014 was derived from the audited consolidated financial statements for the year ended December 31, 2014, but does not include all disclosures required by U.S. GAAP.
Rounding [Policy Text Block]	Dollar amounts, except per share data, in the notes to these financial statements are rounded to the closest $1,000.
Share Exchange Transaction Policy [Policy Text Block]	Share Exchange Transaction
	On February 12, 2015, the Company completed the share exchange transaction with its then-parent entity, Ormat Industries Ltd. ("OIL") following which, the Company became a noncontrolled public company and its public float increased from approximately 40% to approximately 76% of its total shares outstanding. Under the terms of the share exchange, OIL shareholders received 0.2592 shares for each share in OIL, or an aggregate of approximately 30.2 million shares, reflecting a net issuance of approximately 3.0 million shares (after deducting the 27.2 million shares that OIL held in the Company). Consequently, the number of total shares of the Company outstanding increased from approximately 45.5 million shares to approximately 48.5 million shares.
	In exchange, the Company also received $15.4 million in cash, $0.6 million in other assets and $12.1 million in land and buildings and assumed $0.5 million in liabilities. OIL's principal business purpose was to hold its interest in the Company and the transaction resulted in a transfer of non-material assets from OIL to the Company. Therefore, it does not represent a change in reporting entity and the Company recognized the transfer of net assets at their carrying value as presented in OIL's financial statements. Any activities of OIL will be accounted for prospectively by the Company.
Comprehensive Income, Policy [Policy Text Block]	Other comprehensive income
	For the three months ended March 31, 2015 and 2014, the Company classified $7,000 and $36,000, respectively, from accumulated other comprehensive income, of which $12,000 and $58,000, respectively, were recorded to reduce interest expense and $5,000 and $22,000, respectively, were recorded against the income tax provision, in the condensed consolidated statements of operations and comprehensive income.
Solar Project Sale, Policy [Policy Text Block]	Solar project sale
	On March 26, 2014, the Company signed an agreement with RET Holdings, LLC to sell the Heber Solar project in Imperial County, California for $35.25 million. The Company received the first payment of $15.0 million during the first quarter of 2014 and the second payment for the remaining $20.25 million was paid in the second quarter of 2014. The Company recognized the pre-tax gain of approximately $7.6 million in the second quarter of 2014.
Concentration Risk, Credit Risk, Policy [Policy Text Block]	Concentration of credit risk
	Financial instruments that potentially subject the Company to a concentration of credit risk consist principally of temporary cash investments and accounts receivable.
	The Company places its temporary cash investments with high credit quality financial institutions located in the United States (“U.S.”) and in foreign countries. At March 31, 2015 and December 31, 2014, the Company had deposits totaling $41,175,000 and $23,488,000, respectively, in seven U.S. financial institutions that were federally insured up to $250,000 per account. At March 31, 2015 and December 31, 2014, the Company’s deposits in foreign countries amounted to approximately $41,190,000 and $24,304,000, respectively.
	At March 31, 2015 and December 31, 2014, accounts receivable related to operations in foreign countries amounted to approximately $26,790,000 and $21,935,000, respectively. At March 31, 2015 and December 31, 2014, accounts receivable from the Company’s primary customers amounted to approximately 47.0% and 69.0%, respectively, of the Company’s accounts receivable.
	Sierra Pacific Power Company and Nevada Power Company (subsidiaries of NV Energy, Inc.) accounted for 24.0% and 15.3% of the Company’s total revenues for the three months ended March 31, 2015 and 2014, respectively.
	Southern California Edison accounted for 8.8% and 12.1% of the Company’s total revenues for the three months ended March 31, 2015 and 2014, respectively.
	Kenya Power and Lighting Co. Ltd. accounted for 17.8% and 14.3% of the Company’s total revenues for the three months ended March 31, 2015 and 2014, respectively.
	The Company performs ongoing credit evaluations of its customers’ financial condition. The Company has historically been able to collect on all of its receivable balances, and accordingly, no provision for doubtful accounts has been made.
New Accounting Pronouncements, Policy [Policy Text Block]	New accounting pronouncements effective in the three-month period ended March 31, 2015
	Service Concession Arrangements
	In January 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-05, Service Concession Arrangements, Topic 853. The update provides that an operating entity should not account for a service concession arrangement within the scope of this update as a lease in accordance with Topic 840, Leases. The amendments also specify that the infrastructure used in a service concession arrangement should not be recognized as property, plant, and equipment of the operating entity. A service concession arrangement is an arrangement between a public-sector entity grantor and an operating entity under which the operating entity operates the grantor’s infrastructure and may provide the construction, upgrading, or maintenance services of the grantor’s infrastructure. The amendments apply to an operating entity of a service concession arrangement entered into with a public-sector entity grantor when the arrangement meets both of the following conditions: (1) the grantor controls or has the ability to modify or approve the services that the operating entity must provide with the infrastructure, to whom it must provide them, and at what price and (2) The grantor controls, through ownership, beneficial entitlement, or otherwise, any residual interest in the infrastructure at the end of the term of the arrangement. The guidance was applied on a modified retrospective basis to service concession arrangements in existence at January 1, 2015. The adoption of this guidance did not have a material impact on the Company’s consolidated financial statements.
	New accounting pronouncements effective in future periods
	Amendments to the Consolidation analysis
	In February 2015, the FASB issued ASU 2015-02, Amendments to the Consolidation Analysis, Topic 810. The update provides that all reporting entities that hold a variable interest in other legal entities will need to re-evaluate their consolidation conclusions and potentially revised their disclosures. This amendment affect both variable interest entity (“VIE”) and voting interest entity (“VOE”) consolidation models. The update does not change the general order in which the consolidation models are applied. A reporting entity that holds an economic interest in, or is otherwise involved with, another legal entity (has a “variable interest”) should first determine if the VIE model applies, and if so, whether it holds a controlling financial interest under that model. If the entity being evaluated for consolidation is not a VIE, then the VOE model should be applied to determine whether the entity should be consolidated by the reporting entity. Since consolidation is only assessed for legal entities, the determination of whether there is a legal entity is important. It is often clear when the entity is incorporated, but unincorporated structures can also be legal entities and judgment may be required to make that determination. The update contains a new example that highlights the judgmental nature of this legal entity determination. The update is effective for annual reporting periods beginning after December 15, 2015, including interim periods within that reporting period. The Company is currently evaluating the potential impact, if any, of the adoption of this update on its consolidated financial statements.
	Simplifying the Presentation of Debt Costs
	In April 2015, the FASB issued ASU 2015-03, Interest-Imputation of Interest: Simplifying the Presentation of Debt Costs, Subtopic 835-30. The update provides that debt issuance costs related to a recognized debt liability be presented in the balance sheet as direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The amendments in this update are effective for financial statements issued for fiscal years beginning after December 15, 2015, and interim periods within those fiscal years. Early adoption is permitted. The Company is currently evaluating the potential impact of the adoption of these amendments on its consolidated financial statements.
	Revenues from Contracts with Customers
	In May 2014, the FASB issued ASU 2014-09, Revenues from Contracts with Customers, Topic 606, which was a joint project of the FASB and the International Accounting Standards Board to clarify the principles for recognizing revenue and to develop a common revenue standard for U.S. GAAP and International Financial Reporting Standards. The update provides that an entity should recognize revenue in connection with the transfer of goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. Specifically, an entity is required to apply each of the following steps: (1) identify the contract(s) with the customer; (2) identify the performance obligations in the contracts; (3) determine the transaction price; (4) allocate the transaction price to the performance obligation in the contract; and (5) recognize revenue when (or as) the entity satisfies a performance obligation. The amendments in this update are effective for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period. Early adoption is not permitted. The Company is currently evaluating the potential impact, if any, of the adoption of these amendments on its consolidated financial statements.

Note_3_Inventories_Tables

Note 3 - Inventories (Tables)	3 Months Ended
	Mar. 31, 2015
Inventory Disclosure [Abstract]
Schedule of Inventory, Current [Table Text Block]		March 31,		December 31,
		2015		2014
		(Dollars in thousands)
	Raw materials and purchased parts for assembly	$	6,127	$	4,840
	Self-manufactured assembly parts and finished products		11,159		12,090
	Total	$	17,286	$	16,930

Note_4_Unconsolidated_Investme1

Note 4 - Unconsolidated Investments (Tables)	3 Months Ended
	Mar. 31, 2015
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments [Table Text Block]		March 31,			December 31,
		2015			2014
		(Dollars in thousands)
	Sarulla	$	(7,688	)	$	(3,617	)

Note_5_Fair_Value_of_Financial1

Note 5 - Fair Value of Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value, by Balance Sheet Grouping [Table Text Block]						31-Mar-15
						Fair Value
		Carrying Value at March 31, 2015				Total				Level 1			Level 2			Level 3
		(Dollars in thousands)
	Assets
	Current assets:
	Cash equivalents (including restricted cash accounts)	$	97,641			$	97,641			$	97,641		$	—		$	—
	Liabilities:
	Current liabilities:
	Derivatives:
	Currency forward contracts (2)		(2,020	)			(2,020	)			—			(2,020	)		—
		$	95,621			$	95,621			$	97,641		$	(2,020	)	$	—
						31-Dec-14
						Fair Value
		Carrying Value at December 31, 2014				Total				Level 1			Level 2			Level 3
		(Dollars in thousands)
	Assets
	Current assets:
	Cash equivalents (including restricted cash accounts)	$	85,076			$	85,076			$	85,076		$	—		$	—
	Derivatives:
	Swap transaction on natural gas price (1)		4,129				4,129				—			4,129			—
	Liabilities:
	Current liabilities:
	Derivatives:
	Currency forward contracts (2)		(2,882	)			(2,882	)			—			(2,882	)		—
		$	86,323			$	86,323			$	85,076		$	1,247		$	—
Derivative Instruments, Gain (Loss) [Table Text Block]				Amount of recognized gain (loss)
	Derivatives not designated as			Three Months Ended March 31,
	hedging instruments	Location of recognized gain (loss)		2015				2014
	Swap transaction on oil price	Electricity revenues			—				907
	Swap transactions on natural gas price	Electricity revenues			317				(3,276	)
	Currency forward contracts	Foreign currency translation and transaction losses			(1,251	)			(231	)
				$	(934	)		$	(2,600	)
Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block]			Fair Value								Carrying Amount
			March 31,				31-Dec-14				March 31,			31-Dec-14
			2015								2015
			(Dollars in millions)								(Dollars in millions)
	Olkaria III Loan - DEG		$	32.6			$	32.2			$	31.6		$	31.6
	Olkaria III Loan - OPIC			277.5				279.4				278.1			282.6
	Senior Secured Notes:
	Ormat Funding Corp. ("OFC")			72.7				71.4				67.2			67.2
	OrCal Geothermal Inc. ("OrCal")			56.5				55.5				55.1			55.1
	OFC 2 LLC ("OFC 2")			239.5				238.8				270.1			272.5
	Senior Unsecured Bonds			263.8				265.4				250.2			250.4
	Loan from institutional investors			10.2				12.2				10			11.9
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	$	—			$	—			$	32.6		$	32.6
	Olkaria III - OPIC		—				—				277.5			277.5
	Senior Secured Notes:
	OFC		—				72.7				—			72.7
	OrCal		—				—				56.5			56.5
	OFC 2		—				—				239.5			239.5
	Senior unsecured bonds		—				—				263.8			263.8
	Loan from institutional investors		—				—				10.2			10.2
	Other long-term debt		—				8.3				—			8.3
	Revolving credit lines with banks		—				30.6				—			30.6
	Deposits		15.4				—				—			15.4
		Level 1				Level 2				Level 3			Total
		(Dollars in millions)
	Olkaria III Loan - DEG	$	—			$	—			$	32.2		$	32.2
	Olkaria III Loan - OPIC		—				—				279.4			279.4
	Senior Secured Notes:
	OFC		—				71.4				—			71.4
	OrCal		—				—				55.5			55.5
	OFC 2		—				—				238.8			238.8
	Senior unsecured bonds		—				—				265.4			265.4
	Loan from institutional investors		—				—				12.2			12.2
	Other long-term debt		—				10				—			10
	Revolving lines of credit		—				20.3				—			20.3
	Deposits		17.3				—				—			17.3

Note_7_Interest_Expense_Net_Ta

Note 7 - Interest Expense, Net (Tables)	3 Months Ended
	Mar. 31, 2015
Interest Expense Disclosure [Abstract]
Schedule of Other Nonoperating Expense, by Component [Table Text Block]		Three Months Ended March 31,
		2015			2014
	Interest related to sale of tax benefits	$	1,880		$	2,579
	Interest expense		16,895			18,391
	Less — amount capitalized		(947	)		(452	)
		$	17,828		$	20,518

Note_8_Earnings_Per_Share_Tabl

Note 8 - Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Schedule of Weighted Average Number of Shares [Table Text Block]		Three Months Ended March 31,
		2015		2014
	Weighted average number of shares used in computation of basic earnings per share		47,244		45,479
	Add:
	Additional shares from the assumed exercise of employee stock options		835		181
	Weighted average number of shares used in computation of diluted earnings per share		48,079		45,660

Note_9_Business_Segments_Table

Note 9 - Business Segments (Tables)	3 Months Ended
	Mar. 31, 2015
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment [Table Text Block]		Electricity			Product			Consolidated
		(Dollars in thousands)
	Three Months Ended March 31, 2015:
	Net revenues from external customers	$	89,953		$	30,278		$	120,231
	Intersegment revenues		—			19,757			19,757
	Operating income (loss)		23,954			5,897			29,851
	Segment assets at period end *		1,981,813			201,520			2,183,333
	* Including unconsolidated investments		—			—			—
	Three Months Ended March 31, 2014:
	Net revenues from external customers	$	94,817		$	47,619		$	142,436
	Intersegment revenues		—			20,594			20,594
	Operating income (loss)		30,918			11,653			42,571
	Segment assets at period end *		2,003,991			130,356			2,134,347
	* Including unconsolidated investments		7,510			—			7,510
Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table Text Block]		Three Months Ended March 31,
		2015			2014
	Revenues:
	Total segment revenues	$	120,231		$	142,436
	Intersegment revenues		19,757			20,594
	Elimination of intersegment revenues		(19,757	)		(20,594	)
	Total consolidated revenues	$	120,231		$	142,436
	Operating income:
	Operating income	$	29,851		$	42,571
	Interest income		9			111
	Interest expense, net		(17,828	)		(20,518	)
	Foreign currency translation and transaction losses		(1,366	)		(638	)
	Income attributable to sale of equity interest		5,552			6,717
	Other non-operating income, net		283			63
	Total consolidated income before income taxes and equity in income of investees	$	16,501		$	28,306

Note_11_Income_Taxes_Tables

Note 11 - Income Taxes (Tables)	3 Months Ended
	Mar. 31, 2015
Income Tax Disclosure [Abstract]
Summary of Income Tax Contingencies [Table Text Block]		Three Months Ended March 31,
		2015			2014
		(Dollars in thousands)
	Balance at beginning of year	$	7,511		$	4,950
	Additions based on tax positions taken in prior years		58			76
	Additions based on tax positions taken in the current year		570			106
	Reduction based on tax positions taken in prior years		(949	)		—
	Balance at end of year	$	7,190		$	5,132

Note_1_General_and_Basis_of_Pr1

Note 1 - General and Basis of Presentation (Details) (USD $)	0 Months Ended	3 Months Ended		12 Months Ended	0 Months Ended	3 Months Ended
	Feb. 15, 2015	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Mar. 26, 2014	Jun. 30, 2014	Feb. 14, 2015	Dec. 31, 2013
Note 1 - General and Basis of Presentation (Details) [Line Items]
Percentage of Public Float Before Transition to Noncontrolled Public Company							40.00%
Percentage of Public Float After Transition to Noncontrolled Public Company	76.00%
Share Exchange Shares Granted Per Share (in Shares)	0.2592
Common Stock, Shares, Issued (in Shares)	3,000,000	48,828,331		45,537,162
Common Stock, Shares, Outstanding (in Shares)	48,500,000	48,828,331		45,537,162			45,500,000
Sale of Stock, Consideration Received on Transaction	$15,400,000
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax		7,000	36,000
Interest Expense		17,828,000	20,518,000
Income Tax Expense (Benefit)		5,459,000	6,320,000
Cash, Cash Equivalents, and Short-term Investments		70,724,000	47,927,000	40,230,000				57,354,000
Accounts Receivable, Net, Current		56,300,000		48,609,000
Provision for Doubtful Accounts		0
Primary Customers [Member] | Customer Concentration Risk [Member] | Accounts Receivable [Member]
Note 1 - General and Basis of Presentation (Details) [Line Items]
Concentration Risk, Percentage		47.00%		69.00%
Sierra Pacific Power Company And Nevada Power Company [Member] | Customer Concentration Risk [Member] | Sales Revenue, Net [Member]
Note 1 - General and Basis of Presentation (Details) [Line Items]
Concentration Risk, Percentage		24.00%	15.30%
Southern California Edison Company [Member] | Customer Concentration Risk [Member] | Sales Revenue, Net [Member]
Note 1 - General and Basis of Presentation (Details) [Line Items]
Concentration Risk, Percentage		8.80%	12.10%
Kenya Power And Lighting Co Limited [Member] | Customer Concentration Risk [Member] | Sales Revenue, Net [Member]
Note 1 - General and Basis of Presentation (Details) [Line Items]
Concentration Risk, Percentage		17.80%	14.30%
Heber Solar Project [Member]
Note 1 - General and Basis of Presentation (Details) [Line Items]
Sales Price of Disposition					35,250,000
Proceeds from Sales of Business, Affiliate and Productive Assets			15,000,000			20,250,000
Gain (Loss) on Sale of Project						7,600,000
Reclassification out of Accumulated Other Comprehensive Income [Member]
Note 1 - General and Basis of Presentation (Details) [Line Items]
Interest Expense		12,000	58,000
Income Tax Expense (Benefit)		5,000	22,000
UNITED STATES
Note 1 - General and Basis of Presentation (Details) [Line Items]
Cash, Cash Equivalents, and Short-term Investments		41,175,000		23,488,000
Foreign Countries [Member]
Note 1 - General and Basis of Presentation (Details) [Line Items]
Cash, Cash Equivalents, and Short-term Investments		41,190,000		24,304,000
Accounts Receivable, Net, Current		26,790,000		21,935,000
Maximum [Member]
Note 1 - General and Basis of Presentation (Details) [Line Items]
Cash, FDIC Insured Amount								250,000
Aggregate Shares Issued [Member]
Note 1 - General and Basis of Presentation (Details) [Line Items]
Conversion of Stock, Shares Issued (in Shares)	30,200,000
Shares Issued to Self, Deducted [Member]
Note 1 - General and Basis of Presentation (Details) [Line Items]
Conversion of Stock, Shares Issued (in Shares)	27,200,000
Sale of Stock, Other Assets Received [Member]
Note 1 - General and Basis of Presentation (Details) [Line Items]
Sale of Stock, Consideration Received Per Transaction	600,000
Sale of Stock, Land and Buildings Received [Member]
Note 1 - General and Basis of Presentation (Details) [Line Items]
Sale of Stock, Consideration Received Per Transaction	12,100,000
Sale of Stock, Liabilities Assumed [Member]
Note 1 - General and Basis of Presentation (Details) [Line Items]
Sale of Stock, Consideration Received Per Transaction	$500,000

Note_3_Inventories_Details_Inv

Note 3 - Inventories (Details) - Inventories, Current (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Inventories, Current [Abstract]
Raw materials and purchased parts for assembly	$6,127	$4,840
Self-manufactured assembly parts and finished products	11,159	12,090
Total	$17,286	$16,930

Note_4_Unconsolidated_Investme2

Note 4 - Unconsolidated Investments (Details) (USD $)	3 Months Ended		0 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Jun. 04, 2014	Jun. 30, 2014	16-May-14
Note 4 - Unconsolidated Investments (Details) [Line Items]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	$23,000
Sales Revenue, Goods, Net	30,278,000	47,619,000
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	10,267,000	21,789,000
Sarulla [Member] | Intersegment Eliminations [Member]
Note 4 - Unconsolidated Investments (Details) [Line Items]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	800,000
Sarulla [Member] | Subject to Fixed Interest Rate [Member] | Lenders Consortium [Member]
Note 4 - Unconsolidated Investments (Details) [Line Items]
Senior Notes	100,000,000
Sarulla [Member] | Subject to LIBOR based Interest Rate [Member] | Lenders Consortium [Member]
Note 4 - Unconsolidated Investments (Details) [Line Items]
Senior Notes	1,070,000,000
Sarulla [Member] | Subject to Fixed LIBOR Interest Rate [Member] | Lenders Consortium [Member] | Interest Rate Swap [Member]
Note 4 - Unconsolidated Investments (Details) [Line Items]
Senior Notes				960,000,000
Sarulla [Member] | Lenders Consortium [Member] | London Interbank Offered Rate (LIBOR) [Member] | Interest Rate Swap [Member]
Note 4 - Unconsolidated Investments (Details) [Line Items]
Debt Instrument, Basis Spread on Variable Rate			3.46%
Sarulla [Member] | Lenders Consortium [Member] | Interest Rate Swap [Member]
Note 4 - Unconsolidated Investments (Details) [Line Items]
Proceeds from Issuance of Senior Long-term Debt			50,000,000
Sarulla [Member] | Interest Rate Swap [Member]
Note 4 - Unconsolidated Investments (Details) [Line Items]
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax	11,400,000
Sarulla [Member]
Note 4 - Unconsolidated Investments (Details) [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	12.75%
Expected Power Generating Capacity	330
Contract Effective Date	4-Apr-13
Power Plant Usage Agreement Term	30 years
Number Of Phases Of Construction	3
Power Utilization	110
Period To Start Remaining Phases Of Construction After Commencement Of First Phase	18 months
Supply Commitment, Remaining Minimum Amount Committed	255,100,000
Sales Revenue, Goods, Net	15,800,000
Payments to Acquire Projects	0
Lenders Consortium [Member] | Sarulla [Member]
Note 4 - Unconsolidated Investments (Details) [Line Items]
Senior Notes	1,170,000,000
Sarulla [Member] | Interest Rate Swap [Member]
Note 4 - Unconsolidated Investments (Details) [Line Items]
Derivative Instruments, Loss Recognized in Other Comprehensive Income (Loss), Effective Portion	25,900,000
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	$3,300,000
Sarulla [Member]
Note 4 - Unconsolidated Investments (Details) [Line Items]
Number of Commercial Lenders in Funding Consortium					6

Note_4_Unconsolidated_Investme3

Note 4 - Unconsolidated Investments (Details) - Unconsolidated Investments Mainly in Power Plants (USD $)	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
In Thousands, unless otherwise specified
Schedule of Equity Method Investments [Line Items]
Sarulla	($7,688)	($3,617)	$7,510
Sarulla [Member]
Schedule of Equity Method Investments [Line Items]
Sarulla	($7,688)	($3,617)

Note_5_Fair_Value_of_Financial2

Note 5 - Fair Value of Financial Instruments (Details) (USD $)	3 Months Ended	0 Months Ended			3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 06, 2014	Oct. 16, 2013	Sep. 03, 2013	Mar. 31, 2014
		mJ	mJ	mJ
Note 5 - Fair Value of Financial Instruments (Details) [Line Items]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax (in Dollars)	$23
NGI Swap Contract [Member]
Note 5 - Fair Value of Financial Instruments (Details) [Line Items]
Derivative, Nonmonetary Notional Amount, Energy Measure (in Millijoules)		2,200,000	4,200,000	4,400,000
Underlying, Derivative Energy Measure		4.95	4.103	4.035
New York Harbor ULSD Swap Contract [Member]
Note 5 - Fair Value of Financial Instruments (Details) [Line Items]
Underlying, Derivative Energy Measure			125.15
Derivative, Nonmonetary Notional Amount, Volume (in Barrels (of Oil))			275,000
Fluctuation in Energy Rate (in Megawatt-hours)			25
Interest Rate Cap [Member]
Note 5 - Fair Value of Financial Instruments (Details) [Line Items]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax (in Dollars)	($300)				$2,400

Note_5_Fair_Value_of_Financial3

Note 5 - Fair Value of Financial Instruments (Details) - Financial Assets and Liabilities at Fair Value (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Thousands, unless otherwise specified
Current assets:
Cost or Amortized Cost	$70,724		$40,230
Fair Value	97,641		85,076
Derivatives:
Fair Value	95,621		86,323
Forward Contracts [Member] | Fair Value, Inputs, Level 1 [Member]
Derivatives:
Fair Value		[1]		[1]
Forward Contracts [Member] | Fair Value, Inputs, Level 2 [Member]
Derivatives:
Fair Value	-2,020	[1]	-2,882	[1]
Forward Contracts [Member] | Fair Value, Inputs, Level 3 [Member]
Derivatives:
Fair Value		[1]		[1]
Forward Contracts [Member]
Derivatives:
Fair Value	-2,020	[1]	-2,882	[1]
Forward Contracts [Member] | Reported Value Measurement [Member]
Derivatives:
Cost or Amortized Cost	-2,020	[1]	-2,882	[1]
Fair Value, Inputs, Level 1 [Member] | Natural Gas Price Swap [Member]
Derivatives:
Swap transaction on natural gas price (1)				[2]
Fair Value, Inputs, Level 1 [Member]
Current assets:
Fair Value	97,641		85,076
Derivatives:
Fair Value	97,641		85,076
Fair Value, Inputs, Level 2 [Member] | Natural Gas Price Swap [Member]
Derivatives:
Swap transaction on natural gas price (1)			4,129	[2]
Fair Value, Inputs, Level 2 [Member]
Derivatives:
Fair Value	-2,020		1,247
Fair Value, Inputs, Level 3 [Member] | Natural Gas Price Swap [Member]
Derivatives:
Swap transaction on natural gas price (1)				[2]
Natural Gas Price Swap [Member]
Derivatives:
Swap transaction on natural gas price (1)			4,129	[2]
Reported Value Measurement [Member] | Natural Gas Price Swap [Member]
Derivatives:
Swap transaction on natural gas price (1)			4,129	[2]
Reported Value Measurement [Member]
Current assets:
Cost or Amortized Cost	97,641		85,076
Derivatives:
Cost or Amortized Cost	$95,621		$86,323
[1]	These amounts relate to derivatives which represent currency forward contracts valued primarily based on observable inputs, including forward and spot prices for currencies, netted against contracted rates and then multiplied against notional amounts, and are included within "accounts payable and accrued expenses" and "prepaid expenses and other" on March 31, 2015 and December 31, 2014, respectively, in the consolidated balance sheet with the corresponding gain or loss being recognized within "foreign currency translation and transaction losses" in the consolidated statement of operations and comprehensive income.
[2]	This amount relates to derivatives which represent swap contract on natural gas prices, valued primarily based on observable inputs, including forward and spot prices for related commodity indices, and are included within "accounts payable and accrued expenses" on December 31, 2014, in the consolidated balance sheets with the corresponding gain or loss being recognized within "electricity revenue" in the consolidated statement of operations and comprehensive income.

Note_5_Fair_Value_of_Financial4

Note 5 - Fair Value of Financial Instruments (Details) - Amounts of Gain (Loss) Recognized in Condensed Consolidated Statements on Derivative Instruments not Designated as Hedges (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized	($934)	($2,600)
Electricity Revenues [Member] | Crude Oil Price Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized		907
Electricity Revenues [Member] | Natural Gas Price Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized	317	-3,276
Foreign Currency Gain (Loss) [Member] | Forward Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized	($1,251)	($231)

Note_5_Fair_Value_of_Financial5

Note 5 - Fair Value of Financial Instruments (Details) - Fair Value of Long-term Debt Approximates its Carrying Amount, Exceptions (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Senior Secured Notes:
Loan from institutional investors	$8.30	$10
Olkaria III - DEG [Member]
Senior Secured Notes:
Loan from institutional investors	32.6	32.2
Olkaria III - OPIC [Member]
Senior Secured Notes:
Loan from institutional investors	277.5	279.4
Ormat Funding Corp [Member]
Senior Secured Notes:
Loan from institutional investors	72.7	71.4
Orcal Geothermal Inc [Member]
Senior Secured Notes:
Loan from institutional investors	56.5	55.5
OFC Two Senior Secured Notes [Member]
Senior Secured Notes:
Loan from institutional investors	239.5	238.8
Senior Unsecured Bonds Member
Senior Secured Notes:
Loan from institutional investors	263.8	265.4
Institutional Investors [Member]
Senior Secured Notes:
Loan from institutional investors	10.2	12.2
Estimate of Fair Value Measurement [Member] | Olkaria III - DEG [Member]
Note 5 - Fair Value of Financial Instruments (Details) - Fair Value of Long-term Debt Approximates its Carrying Amount, Exceptions [Line Items]
Loan	32.6	32.2
Estimate of Fair Value Measurement [Member] | Olkaria III - OPIC [Member]
Note 5 - Fair Value of Financial Instruments (Details) - Fair Value of Long-term Debt Approximates its Carrying Amount, Exceptions [Line Items]
Loan	277.5	279.4
Estimate of Fair Value Measurement [Member] | Ormat Funding Corp [Member]
Senior Secured Notes:
Senior Secured Notes	72.7	71.4
Estimate of Fair Value Measurement [Member] | Orcal Geothermal Inc [Member]
Senior Secured Notes:
Senior Secured Notes	56.5	55.5
Estimate of Fair Value Measurement [Member] | OFC Two Senior Secured Notes [Member]
Senior Secured Notes:
Senior Secured Notes	239.5	238.8
Estimate of Fair Value Measurement [Member] | Senior Unsecured Bonds Member
Senior Secured Notes:
Senior Unsecured Bonds	263.8	265.4
Estimate of Fair Value Measurement [Member] | Institutional Investors [Member]
Senior Secured Notes:
Loan from institutional investors	10.2	12.2
Reported Value Measurement [Member] | Olkaria III - DEG [Member]
Note 5 - Fair Value of Financial Instruments (Details) - Fair Value of Long-term Debt Approximates its Carrying Amount, Exceptions [Line Items]
Loan	31.6	31.6
Reported Value Measurement [Member] | Olkaria III - OPIC [Member]
Note 5 - Fair Value of Financial Instruments (Details) - Fair Value of Long-term Debt Approximates its Carrying Amount, Exceptions [Line Items]
Loan	278.1	282.6
Reported Value Measurement [Member] | Ormat Funding Corp [Member]
Senior Secured Notes:
Senior Secured Notes	67.2	67.2
Reported Value Measurement [Member] | Orcal Geothermal Inc [Member]
Senior Secured Notes:
Senior Secured Notes	55.1	55.1
Reported Value Measurement [Member] | OFC Two Senior Secured Notes [Member]
Senior Secured Notes:
Senior Secured Notes	270.1	272.5
Reported Value Measurement [Member] | Senior Unsecured Bonds Member
Senior Secured Notes:
Senior Unsecured Bonds	250.2	250.4
Reported Value Measurement [Member] | Institutional Investors [Member]
Senior Secured Notes:
Loan from institutional investors	$10	$11.90

Note_5_Fair_Value_of_Financial6

Note 5 - Fair Value of Financial Instruments (Details) - Fair Value of Financial Instruments (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Note 5 - Fair Value of Financial Instruments (Details) - Fair Value of Financial Instruments [Line Items]
Fair value levels-secured,unsecured and long term debt	$8.30	$10
Revolving credit lines with banks	30.6	20.3
Deposits	15.4	17.3
Olkaria III - DEG [Member] | Fair Value, Inputs, Level 3 [Member]
Note 5 - Fair Value of Financial Instruments (Details) - Fair Value of Financial Instruments [Line Items]
Fair value levels-secured,unsecured and long term debt	32.6	32.2
Olkaria III - DEG [Member]
Note 5 - Fair Value of Financial Instruments (Details) - Fair Value of Financial Instruments [Line Items]
Fair value levels-secured,unsecured and long term debt	32.6	32.2
Olkaria III - OPIC [Member] | Fair Value, Inputs, Level 3 [Member]
Note 5 - Fair Value of Financial Instruments (Details) - Fair Value of Financial Instruments [Line Items]
Fair value levels-secured,unsecured and long term debt	277.5	279.4
Olkaria III - OPIC [Member]
Note 5 - Fair Value of Financial Instruments (Details) - Fair Value of Financial Instruments [Line Items]
Fair value levels-secured,unsecured and long term debt	277.5	279.4
Ormat Funding Corp [Member] | Fair Value, Inputs, Level 2 [Member]
Note 5 - Fair Value of Financial Instruments (Details) - Fair Value of Financial Instruments [Line Items]
Fair value levels-secured,unsecured and long term debt	72.7	71.4
Ormat Funding Corp [Member]
Note 5 - Fair Value of Financial Instruments (Details) - Fair Value of Financial Instruments [Line Items]
Fair value levels-secured,unsecured and long term debt	72.7	71.4
Orcal Geothermal Inc [Member] | Fair Value, Inputs, Level 3 [Member]
Note 5 - Fair Value of Financial Instruments (Details) - Fair Value of Financial Instruments [Line Items]
Fair value levels-secured,unsecured and long term debt	56.5	55.5
Orcal Geothermal Inc [Member]
Note 5 - Fair Value of Financial Instruments (Details) - Fair Value of Financial Instruments [Line Items]
Fair value levels-secured,unsecured and long term debt	56.5	55.5
OFC Two Senior Secured Notes [Member] | Fair Value, Inputs, Level 3 [Member]
Note 5 - Fair Value of Financial Instruments (Details) - Fair Value of Financial Instruments [Line Items]
Fair value levels-secured,unsecured and long term debt	239.5	238.8
OFC Two Senior Secured Notes [Member]
Note 5 - Fair Value of Financial Instruments (Details) - Fair Value of Financial Instruments [Line Items]
Fair value levels-secured,unsecured and long term debt	239.5	238.8
Senior Unsecured Bonds Member | Fair Value, Inputs, Level 3 [Member]
Note 5 - Fair Value of Financial Instruments (Details) - Fair Value of Financial Instruments [Line Items]
Fair value levels-secured,unsecured and long term debt	263.8	265.4
Senior Unsecured Bonds Member
Note 5 - Fair Value of Financial Instruments (Details) - Fair Value of Financial Instruments [Line Items]
Fair value levels-secured,unsecured and long term debt	263.8	265.4
Institutional Investors [Member] | Fair Value, Inputs, Level 3 [Member]
Note 5 - Fair Value of Financial Instruments (Details) - Fair Value of Financial Instruments [Line Items]
Fair value levels-secured,unsecured and long term debt	10.2	12.2
Institutional Investors [Member]
Note 5 - Fair Value of Financial Instruments (Details) - Fair Value of Financial Instruments [Line Items]
Fair value levels-secured,unsecured and long term debt	10.2	12.2
Fair Value, Inputs, Level 1 [Member]
Note 5 - Fair Value of Financial Instruments (Details) - Fair Value of Financial Instruments [Line Items]
Deposits	15.4	17.3
Fair Value, Inputs, Level 2 [Member]
Note 5 - Fair Value of Financial Instruments (Details) - Fair Value of Financial Instruments [Line Items]
Fair value levels-secured,unsecured and long term debt	8.3	10
Revolving credit lines with banks	$30.60	$20.30

Note_6_StockBased_Compensation1

Note 6 - Stock-Based Compensation (Details)	12 Months Ended	1 Months Ended	3 Months Ended
	Dec. 31, 2004	31-May-12	Mar. 31, 2015
Stock Options And Stock Appreciation Rights [Member] | 2004 Stock Incentive Plan [Member] | Share-based Compensation Award, Tranche One [Member]
Note 6 - Stock-Based Compensation (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	25.00%
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	24 months
Stock Options And Stock Appreciation Rights [Member] | 2004 Stock Incentive Plan [Member] | Share-based Compensation Award, Tranche Two [Member]
Note 6 - Stock-Based Compensation (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	25.00%
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	36 months
Stock Options And Stock Appreciation Rights [Member] | 2004 Stock Incentive Plan [Member] | Share-based Compensation Award, Tranche Three [Member]
Note 6 - Stock-Based Compensation (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	50.00%
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	48 months
Stock Options And Stock Appreciation Rights [Member] | 2012 Stock Incentive Plan [Member] | Share-based Compensation Award, Tranche One [Member]
Note 6 - Stock-Based Compensation (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage		25.00%
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		24 months
Stock Options And Stock Appreciation Rights [Member] | 2012 Stock Incentive Plan [Member] | Share-based Compensation Award, Tranche Two [Member]
Note 6 - Stock-Based Compensation (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage		25.00%
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		36 months
Stock Options And Stock Appreciation Rights [Member] | 2012 Stock Incentive Plan [Member] | Share-based Compensation Award, Tranche Three [Member]
Note 6 - Stock-Based Compensation (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage		50.00%
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		48 months
Employee Stock Option [Member] | 2004 Stock Incentive Plan [Member] | Non Employee Director [Member]
Note 6 - Stock-Based Compensation (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	1 year
Employee Stock Option [Member] | 2012 Stock Incentive Plan [Member] | Non Employee Director [Member]
Note 6 - Stock-Based Compensation (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		1 year
2004 Stock Incentive Plan [Member]
Note 6 - Stock-Based Compensation (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	3,750,000
Share Based Compensation Arrangement By Share Based Payment Award Awards Exercise Period	10 years
2012 Stock Incentive Plan [Member] | Minimum [Member]
Note 6 - Stock-Based Compensation (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period		6 years
2012 Stock Incentive Plan [Member] | Maximum [Member]
Note 6 - Stock-Based Compensation (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period		10 years
2012 Stock Incentive Plan [Member] | Officer [Member]
Note 6 - Stock-Based Compensation (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized			400,000
2012 Stock Incentive Plan [Member]
Note 6 - Stock-Based Compensation (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized		4,000,000

Note_7_Interest_Expense_Net_De

Note 7 - Interest Expense, Net (Details) - Components of Interest Expense (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Components of Interest Expense [Abstract]
Interest related to sale of tax benefits	$1,880	$2,579
Interest expense	16,895	18,391
Less b amount capitalized	-947	-452
	$17,828	$20,518

Note_8_Earnings_Per_Share_Deta

Note 8 - Earnings Per Share (Details) (Stock Compensation Plan [Member])	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Stock Compensation Plan [Member]
Note 8 - Earnings Per Share (Details) [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	1,037,612	3,349,877

Note_8_Earnings_Per_Share_Deta1

Note 8 - Earnings Per Share (Details) - Reconciliation of Number of Shares Used in Computation of Basic and Diluted Earnings (Loss) Per Share	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Reconciliation of Number of Shares Used in Computation of Basic and Diluted Earnings (Loss) Per Share [Abstract]
Weighted average number of shares used in computation of basic earnings per share	47,244	45,479
Additional shares from the assumed exercise of employee stock options	835	181
Weighted average number of shares used in computation of diluted earnings per share	48,079	45,660

Note_9_Business_Segments_Detai

Note 9 - Business Segments (Details)	3 Months Ended
	Mar. 31, 2015
Segment Reporting [Abstract]
Number of Reportable Segments	2

Note_9_Business_Segments_Detai1

Note 9 - Business Segments (Details) - Summarized Financial Information Concerning Reportable Segments (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Segment Reporting Information [Line Items]
Net revenues from external customers	$120,231	$142,436
Intersegment revenues	120,231	142,436
Operating income	29,851	42,571
Segment assets at period end *	2,183,333	2,134,347	2,121,556
* Including unconsolidated investments	-7,688	7,510	-3,617
Intersegment Eliminations [Member] | Product Segment [Member]
Segment Reporting Information [Line Items]
Intersegment revenues	19,757	20,594
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Intersegment revenues	19,757	20,594
Electricity Member
Segment Reporting Information [Line Items]
Net revenues from external customers	89,953	94,817
Operating income	23,954	30,918
Segment assets at period end *	1,981,813	2,003,991
* Including unconsolidated investments		7,510
Product Segment [Member]
Segment Reporting Information [Line Items]
Net revenues from external customers	30,278	47,619
Operating income	5,897	11,653
Segment assets at period end *	$201,520	$130,356

Note_9_Business_Segments_Detai2

Note 9 - Business Segments (Details) - Reconciling Information Between Reportable Segments and Consolidated Totals (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Revenues:
Revenue	$120,231,000	$142,436,000
Operating income:
Operating income	29,851,000	42,571,000
Interest income	9,000	111,000
Interest expense, net	-17,828,000	-20,518,000
Foreign currency translation and transaction losses	-1,366,000	-638,000
Income attributable to sale of equity interest	5,552,000	6,717,000
Other non-operating income, net	283,000	63,000
Total consolidated income before income taxes and equity in income of investees	16,501,000	28,306,000
Total Segment Revenues [Member]
Revenues:
Revenue	120,231,000	142,436,000
Intersegment Eliminations [Member]
Revenues:
Revenue	19,757,000	20,594,000
Consolidation, Eliminations [Member]
Revenues:
Revenue	($19,757,000)	($20,594,000)

Note_11_Income_Taxes_Details

Note 11 - Income Taxes (Details) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Dec. 31, 2013
Note 11 - Income Taxes (Details) [Line Items]
Effective Income Tax Rate Reconciliation, Percent	33.10%	22.30%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	35.00%
Effective Income Tax Rate Reconciliation, Tax Exempt Income, Amount	$1,019,000	$1,146,000
Operating Loss Carryforwards, Valuation Allowance			111,300,000
Deferred Tax Assets, Investments			700,000
Deferred Tax Assets, Tax Credit Carryforwards, General Business			71,400,000
Deferred Tax Assets, Valuation Allowance			111,300,000	114,800,000
Undistributed Earnings of Foreign Subsidiaries			75,900,000
Domestic Tax Authority [Member]
Note 11 - Income Taxes (Details) [Line Items]
Operating Loss Carryforwards			251,400,000
State and Local Jurisdiction [Member]
Note 11 - Income Taxes (Details) [Line Items]
Operating Loss Carryforwards			216,500,000
Minimum [Member] | Investment Tax Credit Carryforward [Member]
Note 11 - Income Taxes (Details) [Line Items]
Tax Credit Carryforward Expiration Year			2022
Minimum [Member] | General Business Tax Credit Carryforward [Member]
Note 11 - Income Taxes (Details) [Line Items]
Tax Credit Carryforward Expiration Year			2026
Maximum [Member] | Investment Tax Credit Carryforward [Member]
Note 11 - Income Taxes (Details) [Line Items]
Tax Credit Carryforward Expiration Year			2024
Maximum [Member] | General Business Tax Credit Carryforward [Member]
Note 11 - Income Taxes (Details) [Line Items]
Tax Credit Carryforward Expiration Year			2034
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

Note_11_Income_Taxes_Details_R

Note 11 - Income Taxes (Details) - Reconciliation of Beginning and Ending Amounts of Unrecognized Tax Benefits (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Reconciliation of Beginning and Ending Amounts of Unrecognized Tax Benefits [Abstract]
Balance at beginning of year	$7,511	$4,950
Additions based on tax positions taken in prior years	58	76
Additions based on tax positions taken in the current year	570	106
Reduction based on tax positions taken in prior years	-949
Balance at end of year	$7,190	$5,132

Note_12_Subsequent_Events_Deta

Note 12 - Subsequent Events (Details) (USD $)	3 Months Ended		0 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Apr. 30, 2015	6-May-15
Note 12 - Subsequent Events (Details) [Line Items]
Dividends, Common Stock	$3,898,000	$2,727,000
Common Stock, Dividends, Per Share, Declared	$0.08	$0.06
Subsequent Event [Member] | Northleaf Geothermal Holdings (Northleaf) [Member] | Class B Membership Interests [Member]
Note 12 - Subsequent Events (Details) [Line Items]
Sale of Stock, Percentage of Ownership after Transaction			100.00%
Subsequent Event [Member] | Northleaf Geothermal Holdings (Northleaf) [Member]
Note 12 - Subsequent Events (Details) [Line Items]
Equity Method Investment, Ownership Percentage			36.75%
Number of Power Plants Acquired			9
Business Combination, Consideration Transferred			162,300,000
Business Combination, Bargain Purchase, Gain Recognized, Amount			104,000,000
Subsequent Event [Member]
Note 12 - Subsequent Events (Details) [Line Items]
Dividends, Common Stock				$2,900,000
Common Stock, Dividends, Per Share, Declared				$0.06