Note 1 - Business and Significant Accounting Policies - Redeemable Noncontrolling Interest (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Redeemable noncontrolling interest as of January 1,	$ 8,603	$ 6,416
Redeemable noncontrolling interest in results of operation of a consolidated subsidiary	1,132	990
Cash paid to noncontrolling interest	(252)	0
Increase in share of redeemable noncontrolling interest	0	1,528
Currency translation adjustments	(233)	(331)
Redeemable noncontrolling interest as of December 31,	$ 9,250	$ 8,603

Represents currency adjustment for redeemable noncontrolling interest related to currency translation adjustment.

No definition available.

Name:	ora_RedeemableNoncontrollingInterestEquityCurrencyTranslationAdjustment
Namespace Prefix:	ora_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Represents increase in share of redeemable noncontrolling interest for redeemable noncontrolling interest.

+ References

No definition available.

+ Details

Name:	ora_RedeemableNoncontrollingInterestEquityIncreaseInShareOfRedeemableNoncontrollingInterest
Namespace Prefix:	ora_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Represents operation of consolidated subsidiary for redeemable noncontrolling interest.

+ References

No definition available.

+ Details

Name:	ora_RedeemableNoncontrollingInterestEquityOperationOfConsolidatedSubsidiary
Namespace Prefix:	ora_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The amount of payment to minority for dividend-return on investment which changes the equity of a redeemable noncontrolling interest.

+ References

No definition available.

+ Details

Name:	ora_RedeemableNoncontrollingInterestEquityPaymentToMinorityForDividendreturnOnInvestment
Namespace Prefix:	ora_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

As of the reporting date, the aggregate carrying amount of all noncontrolling interests which are redeemable by the (parent) entity (1) at a fixed or determinable price on a fixed or determinable date, (2) at the option of the holder of the noncontrolling interest, or (3) upon occurrence of an event that is not solely within the control of the (parent) entity. This item includes noncontrolling interest holder's ownership (or holders' ownership) regardless of the type of equity interest (common, preferred, other) including all potential organizational (legal) forms of the investee entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 480
-SubTopic 10
-Section S99
-Paragraph 3A
-Subparagraph (16)(c)
-URI http://asc.fasb.org/extlink&oid=65877616&loc=SL6540498-122764

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 480
-SubTopic 10
-Section S99
-Paragraph 3A
-Subparagraph 15
-URI http://asc.fasb.org/extlink&oid=65877616&loc=SL6540498-122764

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 480
-SubTopic 10
-Section S99
-Paragraph 3A
-Subparagraph (12)(c)
-URI http://asc.fasb.org/extlink&oid=65877616&loc=SL6540498-122764

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 480
-SubTopic 10
-Section S99
-Paragraph 3A
-Subparagraph 14
-URI http://asc.fasb.org/extlink&oid=65877616&loc=SL6540498-122764

+ Details

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