Quarterly report pursuant to Section 13 or 15(d)

Description of Business and Basis of Presentation (Details)

v2.4.1.9
Description of Business and Basis of Presentation (Details) (USD $)
6 Months Ended
Mar. 31, 2015
Sep. 30, 2014
Related Party Transaction [Line Items]    
Common Stock, Par or Stated Value Per Share $ 1us-gaap_CommonStockParOrStatedValuePerShare $ 1us-gaap_CommonStockParOrStatedValuePerShare
Land [Member]    
Related Party Transaction [Line Items]    
Area of land owned 121,000us-gaap_AreaOfRealEstateProperty
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_LandMember
 
Mineral Rights [Member]    
Related Party Transaction [Line Items]    
Area of land owned 90,000us-gaap_AreaOfRealEstateProperty
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_MiningPropertiesAndMineralRightsMember
 
Silver Nip Citrus Agreement [Member]    
Related Party Transaction [Line Items]    
Number of shares issuable 923,257us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued
/ us-gaap_BusinessAcquisitionAxis
= alco_SilverNipCitrusAgreementMember
 
Amount of indebtedness $ 40,278,000us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt
/ us-gaap_BusinessAcquisitionAxis
= alco_SilverNipCitrusAgreementMember
 
Other liabilities 6,952,000us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther
/ us-gaap_BusinessAcquisitionAxis
= alco_SilverNipCitrusAgreementMember
 
Book value of assets acquired 65,739,000us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets
/ us-gaap_BusinessAcquisitionAxis
= alco_SilverNipCitrusAgreementMember
 
Net assets acquired 18,509,000us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_BusinessAcquisitionAxis
= alco_SilverNipCitrusAgreementMember
 
Professional and legal fees $ 811,000us-gaap_BusinessAcquisitionCostOfAcquiredEntityTransactionCosts
/ us-gaap_BusinessAcquisitionAxis
= alco_SilverNipCitrusAgreementMember
 
734 Agriculture [Member]    
Related Party Transaction [Line Items]    
Ownership interest in subsidiary 51.00%us-gaap_MinorityInterestOwnershipPercentageByParent
/ dei_LegalEntityAxis
= us-gaap_ParentCompanyMember
 
Silver Nip [Member] | 734 Agriculture [Member]    
Related Party Transaction [Line Items]    
Ownership interest in subsidiary 74.89%us-gaap_MinorityInterestOwnershipPercentageByParent
/ dei_LegalEntityAxis
= us-gaap_ParentCompanyMember
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= alco_SilverNipMember
 
Silver Nip [Member] | Mr Wilson [Member]    
Related Party Transaction [Line Items]    
Ownership interest in subsidiary 5.00%us-gaap_MinorityInterestOwnershipPercentageByParent
/ dei_LegalEntityAxis
= alco_MrWilsonMember
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= alco_SilverNipMember
 
Silver Nip [Member] | Rio Verde Ventures, LLC [Member]    
Related Party Transaction [Line Items]    
Ownership interest in subsidiary 20.11%us-gaap_MinorityInterestOwnershipPercentageByParent
/ dei_LegalEntityAxis
= alco_RioVerdeVenturesLlcMember
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= alco_SilverNipMember