Note 4 - Unconsolidated Investments - Unconsolidated Investments Mainly in Power Plants (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Sarulla		$ (11,081)
Sarulla [Member]
Sarulla	$ 13,957	$ (11,081)

Represents the accumulated losses in excess of investments in an entity not consolidated.

No definition available.

Name:	ora_AccumulatedLossesOfUnconsolidatedCompanyInExcessOfInvestment
Namespace Prefix:	ora_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant