XML 79 R41.htm IDEA: XBRL DOCUMENT
v3.20.1

BUSINESS COMBINATIONS - Narrative (Details) - business | 3 Months Ended
--- | ---
Mar. 31, 2020 | Mar. 31, 2019
Business Acquisition [Line Items] |  |
Number of businesses acquired | 2 | 0
Minimum |  |
Business Acquisition [Line Items] |  |
Useful life of finite lived intangible assets | 5 years |
Maximum |  |
Business Acquisition [Line Items] |  |
Useful life of finite lived intangible assets | 10 years |
Western | Tuck-in Solid Waste Collection Business |  |
Business Acquisition [Line Items] |  |
Number of businesses acquired | 1 |
Resource Solutions | Recycling Operation |  |
Business Acquisition [Line Items] |  |
Number of businesses acquired | 1 |

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_BusinessAcquisitionLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | us-gaap_FiniteLivedIntangibleAssetUsefulLife
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The number of businesses acquired by the entity during the period. + References No definition available. + Details
Name: | us-gaap_NumberOfBusinessesAcquired
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
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_BusinessAcquisitionAxis=cwst_TuckinSolidWasteCollectionBusinessMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=cwst_RecyclingOperationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |