XML 36 R31.htm IDEA: XBRL DOCUMENT v2.4.1.9

Basis of Presentation - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2015 Segment	Apr. 28, 2015 Director
Segment Reporting Information [Line Items]
Operating segments	4us-gaap_NumberOfOperatingSegments
Subsequent Event [Member] | JCP Group [Member]
Segment Reporting Information [Line Items]
Number of nominees for Board of Directors		3cwst_NumberOfBoardOfDirectorNominees / dei_LegalEntityAxis = cwst_JcpGroupMember / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember
Subsequent Event [Member] | JCP Group [Member] | Class A Common Stock [Member]
Segment Reporting Information [Line Items]
JCP Group ownership percentage of Company stock		5.00%cwst_CommonStockOutstandingPercentage / dei_LegalEntityAxis = cwst_JcpGroupMember / us-gaap_StatementClassOfStockAxis = us-gaap_CommonClassAMember / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember
Eastern Region [Member]
Segment Reporting Information [Line Items]
Operating segments	1us-gaap_NumberOfOperatingSegments / us-gaap_StatementBusinessSegmentsAxis = cwst_EasternRegionMember
Western Region [Member]
Segment Reporting Information [Line Items]
Operating segments	1us-gaap_NumberOfOperatingSegments / us-gaap_StatementBusinessSegmentsAxis = cwst_WesternRegionMember
Recycling [Member]
Segment Reporting Information [Line Items]
Operating segments	1us-gaap_NumberOfOperatingSegments / us-gaap_StatementBusinessSegmentsAxis = cwst_RecyclingMember
Other [Member]
Segment Reporting Information [Line Items]
Operating segments	1us-gaap_NumberOfOperatingSegments / us-gaap_StatementBusinessSegmentsAxis = us-gaap_AllOtherSegmentsMember

X

- Definition

Common stock outstanding percentage.

+ References

No definition available.

+ Details

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Namespace Prefix:	cwst_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Number of Board of Director Nominees

+ References

No definition available.

+ Details

Name:	cwst_NumberOfBoardOfDirectorNominees
Namespace Prefix:	cwst_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

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

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_SegmentReportingInformationLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
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_RecyclingMember
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=us-gaap_AllOtherSegmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: