| Cover | Sep. 14, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Sep. 14, 2021 |
| Entity File Number | 001-33886 |
| Entity Registrant Name | ACORN ENERGY, INC. |
| Entity Central Index Key | 0000880984 |
| Entity Tax Identification Number | 22-2786081 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 1000 N West St. |
| Entity Address, Address Line Two | Suite 1200 |
| Entity Address, City or Town | Wilmington |
| Entity Address, State or Province | DE |
| Entity Address, Postal Zip Code | 19801 |
| City Area Code | (410) |
| Local Phone Number | 654-3315 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
