XML 49 R36.htm IDEA: XBRL DOCUMENT
v3.22.0.1

Inventories - Narrative (Details) - USD ($) | 1 Months Ended | 12 Months Ended
--- | --- | ---
Oct. 30, 2021 | Sep. 30, 2021 | Sep. 30, 2020 | Sep. 30, 2019
Inventory Disclosure [Abstract] |  |  |  |
Proceeds from federal relief grants |  | $ 4,299,000 | $ 4,629,000 | $ 15,597,000
Insurance Expenses Incurred |  | $ 2,000,000,000 |  |
Insurance Reimbursement Received | $ 1,000,000,000 |  |  |

X
- Definition Insurance expenses incurred. + References No definition available. + Details
Name: | alco_InsuranceExpensesIncurred
Namespace Prefix: | alco_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Insurance reimbursement received. + References No definition available. + Details
Name: | alco_InsuranceReimbursementReceived
Namespace Prefix: | alco_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Proceeds From Federal Relief Grants + References No definition available. + Details
Name: | alco_ProceedsFromFederalReliefGrants
Namespace Prefix: | alco_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_InventoryDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration