Document and Entity Information
| Document and Entity Information - USD ($) | 12 Months Ended | ||
| Sep. 30, 2018 | Dec. 03, 2018 | Mar. 29, 2018 | |
| Document and Entity Information: | |||
| Document Type | 10-K | ||
| Amendment Flag | false | ||
| Document Period End Date | Sep. 30, 2018 | ||
| Document Fiscal Year Focus | 2,018 | ||
| Document Fiscal Period Focus | FY | ||
| Entity Registrant Name | ALICO INC | ||
| Entity Central Index Key | 3,545 | ||
| Current Fiscal Year End Date | --09-30 | ||
| Entity Filer Category | Accelerated Filer | ||
| Entity Well-Known Seasoned Issuer | No | ||
| Entity Voluntary Filers | No | ||
| Entity Current Reporting Status | Yes | ||
| Entity Emerging Growth Company | false | ||
| Entity Smaller Reporting Company | false | ||
| Entity Shell Company | false | ||
| Entity Common Stock, Shares Outstanding (in shares) | 7,454,795 | ||
| Entity Public Float | $ 89,596,038 |