XML 86 R52.htm IDEA: XBRL DOCUMENT
v3.21.2

Inventories - Narrative (Details) - USD ($) | 1 Months Ended | 12 Months Ended
--- | --- | ---
Oct. 31, 2021 | Sep. 30, 2021 | Sep. 30, 2020 | Sep. 30, 2019
Inventory [Line Items] |  |  |  |
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 |  |  |
Year-End Adjustment |  |  |  |
Inventory [Line Items] |  |  |  |
Inventory casualty loss |  |  |  | $ 808,000

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
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_InventoryLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of loss from reductions in inventory due to subsequent measurement adjustments, including, but not limited to, physical deterioration, obsolescence, or changes in price levels. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 330 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=116847112&loc=d3e4542-108314 + Details
Name: | us-gaap_InventoryWriteDown
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_EffectOfFourthQuarterEventsByTypeAxis=us-gaap_YearEndAdjustmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |