The effective date of the contract.

No definition available.

Name:	ora_ContractEffectiveDate
Namespace Prefix:	ora_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Expected power generating capacity.

+ References

No definition available.

+ Details

Name:	ora_ExpectedPowerGeneratingCapacity
Namespace Prefix:	ora_
Data Type:	num:energyItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the number of commercial lenders in the funding consortium.

+ References

No definition available.

+ Details

Name:	ora_NumberOfCommercialLendersInFundingConsortium
Namespace Prefix:	ora_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of phases of construction.

+ References

No definition available.

+ Details

Name:	ora_NumberOfPhasesOfConstruction
Namespace Prefix:	ora_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the percentage of required injection capacity.

+ References

No definition available.

+ Details

Name:	ora_PercentageOfRequiredInjectionCapacity
Namespace Prefix:	ora_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the percentage of required production capacity.

+ References

No definition available.

+ Details

Name:	ora_PercentageOfRequiredProductionCapacity
Namespace Prefix:	ora_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Power utilization.

+ References

No definition available.

+ Details

Name:	ora_PowerUtilization
Namespace Prefix:	ora_
Data Type:	num:energyItemType
Balance Type:	na
Period Type:	duration

- Definition

The length of the agreement term on the power plant usage.

+ References

No definition available.

+ Details

Name:	ora_PowerplantUsageAgreementTerm
Namespace Prefix:	ora_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Accumulated change, net of tax, in accumulated gains and losses from derivative instruments designated and qualifying as the effective portion of cash flow hedges. Includes an entity's share of an equity investee's Increase or Decrease in deferred hedging gains or losses.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 10A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=66004124&loc=SL7669646-108580

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=66004124&loc=d3e637-108580

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 14A
-URI http://asc.fasb.org/extlink&oid=66004124&loc=SL7669686-108580

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 14
-URI http://asc.fasb.org/extlink&oid=66004124&loc=d3e681-108580

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 30
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=35736893&loc=d3e80784-113994

+ Details

Name:	us-gaap_AccumulatedOtherComprehensiveIncomeLossCumulativeChangesInNetGainLossFromCashFlowHedgesEffectNetOfTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The proportionate share of interest (percent) in a jointly owned utility plant.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 980
-SubTopic 360
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 10.C)
-URI http://asc.fasb.org/extlink&oid=6500719&loc=d3e659983-123033

+ Details

Name:	us-gaap_JointlyOwnedUtilityPlantProportionateOwnershipShare
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount after tax of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 10A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=66004124&loc=SL7669646-108580

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=66004124&loc=d3e637-108580

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6441202&loc=d3e80720-113993

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624171-113959

+ Details

Name:	us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash outflow from the amount invested for projects in hopes of getting a future return or interest from it.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Investing Activities
-URI http://asc.fasb.org/extlink&oid=6516133

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3213-108585

+ Details

Name:	us-gaap_PaymentsToAcquireProjects
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash inflow from a borrowing with the highest claim on the assets of the entity in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle, if longer).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Financing Activities
-URI http://asc.fasb.org/extlink&oid=6513228

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3255-108585

+ Details

Name:	us-gaap_ProceedsFromIssuanceOfSeniorLongTermDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 55
-Paragraph 4K
-URI http://asc.fasb.org/extlink&oid=65897068&loc=SL4591552-111686

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 45
-Paragraph 19
-URI http://asc.fasb.org/extlink&oid=68079674&loc=SL4569616-111683

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=64809438&loc=SL4573702-111684

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 55
-Paragraph 4J
-URI http://asc.fasb.org/extlink&oid=65897068&loc=SL4591551-111686

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=64809438&loc=SL4573702-111684

+ Details

Name:	us-gaap_ProfitLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Including the current and noncurrent portions, carrying value as of the balance sheet date of Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.16(a))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.16)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

Name:	us-gaap_SeniorNotes
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The floor amount as of the balance sheet date that the entity must expend to satisfy the terms of disclosed arrangements (excluding long-term commitments) in which the entity must commit resources to supply goods or services to one or more customers.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.17)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.25)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.(a)(19))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

+ Details

Name:	us-gaap_SignificantSupplyCommitmentRemainingMinimumAmountCommitted
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_ConsolidationItemsAxis=us-gaap_IntersegmentEliminationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=ora_SarullaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CounterpartyNameAxis=ora_LendersConsortiumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_JointlyOwnedUtilityPlantAxis=ora_SarullaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateSwapMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=ora_SarullaProjectCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementScenarioAxis=ora_SubjectToFixedInterestRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementScenarioAxis=ora_SubjectToFixedLIBORInterestRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Note 6 - Accumulated Loss of Unconsolidated Company in Excess of Investment (Details Textual) $ in Thousands		3 Months Ended								12 Months Ended
	Jun. 04, 2014 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2016 USD ($) MWh	Dec. 31, 2016 USD ($)	Dec. 31, 2016 USD ($) Boe	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	May 23, 2014 USD ($)	May 16, 2014 USD ($)	Oct. 31, 2013 USD ($)
Number of Commercial Lenders in Funding Consortium																		6
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax													$ 1,185		$ 1,028	$ (8,112)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest		$ 31,232	$ 14,406	$ 24,933	$ 30,945	$ 24,148	$ 73,661	$ 15,273	$ 10,267				101,516		$ 123,349	$ 55,015
Intersegment Eliminations [Member]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest													$ 12,000
London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument, Basis Spread on Variable Rate															1.00%
Sarulla [Member] \| Lenders Consortium [Member]
Senior Notes																		$ 1,170,000
Sarulla [Member]
Jointly Owned Utility Plant, Proportionate Ownership Share		12.75%								12.75%	12.75%	12.75%	12.75%	12.75%
Expected Power Generating Capacity												330		321
Contract Effective Date										April 4, 2013
Power Plant Usage Agreement Term										30 years
Number Of Phases Of Construction											3
Power Utilization \| Boe														110
Percentage of Required Production Capacity		80.00%								80.00%	80.00%	80.00%	80.00%	80.00%
Percentage of Required Injection Capacity		85.00%								85.00%	85.00%	85.00%	85.00%	85.00%
Supply Commitment, Remaining Minimum Amount Committed																			$ 255,600
Payments to Acquire Projects													$ 3,600
Sarulla [Member] \| Interest Rate Swap [Member]
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax													1,200		$ 1,000
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax		$ (5,900)								$ (5,900)	$ (5,900)	$ (5,900)	(5,900)	$ (5,900)
Sarulla [Member] \| Interest Rate Swap [Member] \| Sarulla Project Company [Member]
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax													$ 9,300		$ 8,000
Sarulla [Member] \| Lenders Consortium [Member] \| Interest Rate Swap [Member]
Proceeds from Issuance of Senior Long-term Debt	$ 50,000
Sarulla [Member] \| Lenders Consortium [Member] \| Interest Rate Swap [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument, Basis Spread on Variable Rate	3.4565%
Sarulla [Member] \| Lenders Consortium [Member] \| Subject to Fixed Interest Rate [Member]
Senior Notes																	$ 100,000
Sarulla [Member] \| Lenders Consortium [Member] \| Subject to Fixed LIBOR Interest Rate [Member]
Senior Notes																	$ 1,070,000
Sarulla [Member] \| Lenders Consortium [Member] \| Subject to Fixed LIBOR Interest Rate [Member] \| Interest Rate Swap [Member]
Senior Notes	$ 960,000