XML 128 R106.htm IDEA: XBRL DOCUMENT v2.4.1.9

Related Party Transactions - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	8 Months Ended		12 Months Ended
	Dec. 31, 2014 Lease	Dec. 31, 2013	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Related Party Transaction [Line Items]
Total services purchased	$ 5,562us-gaap_RelatedPartyTransactionPurchasesFromRelatedParty		$ 7,818us-gaap_RelatedPartyTransactionPurchasesFromRelatedParty	$ 6,574us-gaap_RelatedPartyTransactionPurchasesFromRelatedParty	$ 2,612us-gaap_RelatedPartyTransactionPurchasesFromRelatedParty
Outstanding accounts payable	2us-gaap_AccountsPayableRelatedPartiesCurrent		890us-gaap_AccountsPayableRelatedPartiesCurrent	1,187us-gaap_AccountsPayableRelatedPartiesCurrent
Number of leases	2cwst_NumberOfLeases
Capital lease expiration date	Apr. 30, 2023
Total expense charged to operations under lease agreement	263us-gaap_CapitalLeasesIncomeStatementAmortizationExpense		386us-gaap_CapitalLeasesIncomeStatementAmortizationExpense	286us-gaap_CapitalLeasesIncomeStatementAmortizationExpense	300us-gaap_CapitalLeasesIncomeStatementAmortizationExpense
Accrued costs associated with post-closure obligations	39,829us-gaap_AssetRetirementObligation		44,654us-gaap_AssetRetirementObligation	43,170us-gaap_AssetRetirementObligation	39,629us-gaap_AssetRetirementObligation
Loan to an employee outstanding			149us-gaap_NotesReceivableRelatedPartiesNoncurrent	147us-gaap_NotesReceivableRelatedPartiesNoncurrent
Charges in general and administration to reserve for the notes	45,732us-gaap_GeneralAndAdministrativeExpense	40,803us-gaap_GeneralAndAdministrativeExpense	61,865us-gaap_GeneralAndAdministrativeExpense	58,205us-gaap_GeneralAndAdministrativeExpense	60,264us-gaap_GeneralAndAdministrativeExpense
Landfills [Member]
Related Party Transaction [Line Items]
Landfill owned	2cwst_NumberOfMajorShareholders / us-gaap_PropertyPlantAndEquipmentByTypeAxis = us-gaap_LandfillMember
Landfill post-closure cost	8us-gaap_AssetRetirementObligationCashPaidToSettle / us-gaap_PropertyPlantAndEquipmentByTypeAxis = us-gaap_LandfillMember		8us-gaap_AssetRetirementObligationCashPaidToSettle / us-gaap_PropertyPlantAndEquipmentByTypeAxis = us-gaap_LandfillMember	8us-gaap_AssetRetirementObligationCashPaidToSettle / us-gaap_PropertyPlantAndEquipmentByTypeAxis = us-gaap_LandfillMember	8us-gaap_AssetRetirementObligationCashPaidToSettle / us-gaap_PropertyPlantAndEquipmentByTypeAxis = us-gaap_LandfillMember
Accrued costs associated with post-closure obligations	84us-gaap_AssetRetirementObligation / us-gaap_PropertyPlantAndEquipmentByTypeAxis = us-gaap_LandfillMember		94us-gaap_AssetRetirementObligation / us-gaap_PropertyPlantAndEquipmentByTypeAxis = us-gaap_LandfillMember	100us-gaap_AssetRetirementObligation / us-gaap_PropertyPlantAndEquipmentByTypeAxis = us-gaap_LandfillMember
Cash [Member] | Southbridge Landfill [Member]
Related Party Transaction [Line Items]
Related party contributions on business divestitures	350cwst_CashRemediationSettlement / us-gaap_CashAndCashEquivalentsAxis = us-gaap_CashMember / us-gaap_EnvironmentalRemediationSiteAxis = cwst_SouthbridgeLandfillMember
Non Cash [Member] | Southbridge Landfill [Member]
Related Party Transaction [Line Items]
Related party contributions on business divestitures	390cwst_NonCashRemediationSettlement / us-gaap_CashAndCashEquivalentsAxis = cwst_NonCashMember / us-gaap_EnvironmentalRemediationSiteAxis = cwst_SouthbridgeLandfillMember
Allowance for Notes Receivable [Member]
Related Party Transaction [Line Items]
Charges in general and administration to reserve for the notes			149us-gaap_GeneralAndAdministrativeExpense / us-gaap_IncomeStatementLocationAxis = us-gaap_AllowanceForNotesReceivableMember
Related Party [Member]
Related Party Transaction [Line Items]
Leases monthly payments	$ 27us-gaap_DebtInstrumentPeriodicPayment / us-gaap_RelatedPartyTransactionsByRelatedPartyAxis = cwst_RelatedPartyMember

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Number of related party capital lease agreements entered into.

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The charge for the use of long-lived depreciable capital leased assets for the period.

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Date which lease or group of leases is set to expire, in CCYY-MM-DD format.

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Amounts due from parties associated with the reporting entity as evidenced by a written promise to pay, due after 1 year (or 1 business cycle).

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Purchases during the period (excluding transactions that are eliminated in consolidated or combined financial statements) with related party.

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