The number of directors on the board of directors after the acquisition transaction.

No definition available.

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

- Definition

Number of company's shares purchased by an investor.

+ References

No definition available.

+ Details

Name:	ora_NumberOfSharesPurchasedByInvestor
Namespace Prefix:	ora_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of ownership in the company purchased by an investor.

+ References

No definition available.

+ Details

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

- Definition

The effective rate cap on voting rights.

+ References

No definition available.

+ Details

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

- Definition

The number of directors the counterparty may designate.

+ References

No definition available.

+ Details

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

- Definition

Aggregate dividends declared during the period for each share of common stock outstanding.

+ References

+ Details

Name:	us-gaap_CommonStockDividendsPerShareDeclared
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of paid and unpaid common stock dividends declared with the form of settlement in cash, stock and payment-in-kind (PIK).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 405
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6957935&loc=d3e64057-112817

+ Details

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

- Definition

The cash outflow associated with the investment in or advances to an entity in which the reporting entity shares control of the entity with another party or group.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3213-108585

+ Details

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

- Details

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

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_BusinessAcquisitionAxis=ora_ORTPTransactionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Note 12 - Subsequent Events (Details Textual) $ / shares in Units, $ in Thousands, shares in Millions				3 Months Ended		6 Months Ended
	Aug. 03, 2017 USD ($) $ / shares	Jul. 10, 2017 USD ($)	May 04, 2017 shares	Jun. 30, 2017 $ / shares	Jun. 30, 2016 $ / shares	Jun. 30, 2017 USD ($) $ / shares	Jun. 30, 2016 USD ($) $ / shares
Dividends, Common Stock						$ 12,426	$ 18,998
Common Stock, Dividends, Per Share, Declared \| $ / shares				$ 0.08	$ 0.07	$ 0.25	$ 0.38
Voting Rights, Number of Directors Designated			3
Number of Directors after Acquisition Transaction			9
ORIX Corporation [Member]
Number of Shares Purchased by Investor \| shares			11
Percentage Ownership in Company Purchased by Investor			22.00%
Voting Rights, Effective Rate Cap			25.00%
Subsequent Event [Member]
Dividends, Common Stock	$ 4,000
Common Stock, Dividends, Per Share, Declared \| $ / shares	$ 0.08
Subsequent Event [Member] \| Ormat Nevada ORTP LLC [Member] \| ORTP Transaction [Member]
Payments to Acquire Interest in Joint Venture		$ 2,350