| Document And Entity Information | Aug. 04, 2020 |
| Document Information [Line Items] | |
| Entity, Registrant Name | Ormat Technologies, Inc. |
| Document, Type | 8-K |
| Document, Period End Date | Aug. 4, 2020 |
| Entity, Incorporation, State or Country Code | DE |
| Entity, File Number | 001-32347 |
| Entity, Tax Identification Number | 88-0326081 |
| Entity, Address, Address Line One | 6140 Plumas Street |
| Entity, Address, City or Town | Reno |
| Entity, Address, State or Province | NV |
| Entity, Address, Postal Zip Code | 89519-6075 |
| City Area Code | 775 |
| Local Phone Number | 356-9029 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Shares |
| Trading Symbol | ORA |
| Security Exchange Name | NYSE |
| Entity, Emerging Growth Company | false |
| Amendment Flag | false |
| Entity, Central Index Key | 0001296445 |
