Quarterly report pursuant to Section 13 or 15(d)

Assets Held for Sale (Details)

v2.4.1.9
Assets Held for Sale (Details) (USD $)
3 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Sep. 30, 2014
Nov. 21, 2014
acre
Long Lived Assets Held-for-sale [Line Items]        
Gain on sale of real estate $ 13,613,000us-gaap_GainsLossesOnSalesOfInvestmentRealEstate       
Deferred gain on sale 29,140,000us-gaap_DeferredGainOnSaleOfProperty       
Hendry County Sugarcane Property [Member]        
Long Lived Assets Held-for-sale [Line Items]        
Acres held for sale       36,000alco_LongLivedAssetsHeldForSaleAcresOfLand
/ us-gaap_LongLivedAssetsHeldForSaleByAssetTypeAxis
= alco_HendryCountySugarcanePropertyMember
Sales price       97,913,921us-gaap_SignificantAcquisitionsAndDisposalsAcquisitionCostsOrSaleProceeds
/ us-gaap_LongLivedAssetsHeldForSaleByAssetTypeAxis
= alco_HendryCountySugarcanePropertyMember
Proceeds deposited with intermediary 97,126,000us-gaap_PaymentsForDelayedTaxExemptExchange
/ us-gaap_LongLivedAssetsHeldForSaleByAssetTypeAxis
= alco_HendryCountySugarcanePropertyMember
     
Realized gain on disposal 42,753,000alco_DisposalGroupNotDiscontinuedOperationRealizedGainLossOnDisposal
/ us-gaap_LongLivedAssetsHeldForSaleByAssetTypeAxis
= alco_HendryCountySugarcanePropertyMember
     
Gain on sale of real estate 13,613,000us-gaap_GainsLossesOnSalesOfInvestmentRealEstate
/ us-gaap_LongLivedAssetsHeldForSaleByAssetTypeAxis
= alco_HendryCountySugarcanePropertyMember
     
Deferred gain on sale       $ 29,140,000us-gaap_DeferredGainOnSaleOfProperty
/ us-gaap_LongLivedAssetsHeldForSaleByAssetTypeAxis
= alco_HendryCountySugarcanePropertyMember