Note 6 - Accumulated Loss of Unconsolidated Company in Excess of Investment - Unconsolidated Investments Mainly in Power Plants (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Sarulla	$ (11,081)	$ (8,100)
Sarulla [Member]
Sarulla	$ (11,081)	$ (8,100)

Losses related to 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