XML 32 R30.htm IDEA: XBRL DOCUMENT
v3.3.0.814

Basis of Presentation - Additional Information (Detail) | 9 Months Ended
--- | ---
Sep. 30, 2015 Segment
Organization Consolidation And Presentation Of Financial Statements [Line Items] |
Operating segments | 4
Eastern Region [Member] |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |
Operating segments | 1
Western Region [Member] |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |
Operating segments | 1
Recycling [Member] |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |
Operating segments | 1
Other [Member] |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |
Operating segments | 1

X
- Definition Organization Consolidation And Presentation Of Financial Statements [Line Items] + References No definition available. + Details
Name: | cwst_OrganizationConsolidationAndPresentationOfFinancialStatementsLineItems
Namespace Prefix: | cwst_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues. + References No definition available. + Details
Name: | us-gaap_NumberOfOperatingSegments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=cwst_EasternRegionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=cwst_WesternRegionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=cwst_RecyclingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=us-gaap_AllOtherSegmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |