XML 76 R62.htm IDEA: XBRL DOCUMENT
v3.8.0.1

GOODWILL AND INTANGIBLE ASSETS - Schedule of Activity and Balances Related to Goodwill by Reporting Segment (Detail) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016
Goodwill [Roll Forward] |  |
Goodwill, beginning balance | $ 119,899 | $ 118,976
Acquisitions | 2,706 | 923
Goodwill, ending balance | 122,605 | 119,899
Eastern |  |
Goodwill [Roll Forward] |  |
Goodwill, beginning balance | 17,429 | 17,429
Acquisitions | 1,763 | 0
Goodwill, ending balance | 19,192 | 17,429
Western |  |
Goodwill [Roll Forward] |  |
Goodwill, beginning balance | 88,426 | 87,503
Acquisitions | 943 | 923
Goodwill, ending balance | 89,369 | 88,426
Recycling |  |
Goodwill [Roll Forward] |  |
Goodwill, beginning balance | 12,315 | 12,315
Acquisitions | 0 | 0
Goodwill, ending balance | 12,315 | 12,315
Other |  |
Goodwill [Roll Forward] |  |
Goodwill, beginning balance | 1,729 | 1,729
Acquisitions | 0 | 0
Goodwill, ending balance | $ 1,729 | $ 1,729

X
- Definition Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975 + Details
Name: | us-gaap_Goodwill
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267 + Details
Name: | us-gaap_GoodwillAcquiredDuringPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
Name: | us-gaap_GoodwillRollForward
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_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: |