XML 94 R68.htm IDEA: XBRL DOCUMENT v2.4.0.8

Goodwill and Intangible Assets - Schedule of Activity and Balances Related to Goodwill (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended								12 Months Ended
	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2014 Eastern Region [Member]	Apr. 30, 2013 Eastern Region [Member]	Apr. 30, 2014 Western Region [Member]	Apr. 30, 2013 Western Region [Member]	Apr. 30, 2014 Recycling [Member]	Apr. 30, 2012 Recycling [Member]	Apr. 30, 2014 Other [Member]
Goodwill And Intangible Assets [Line Items]
Goodwill, beginning balance	$ 115,928	$ 101,706	$ 16,858	$ 58	$ 86,880	$ 89,458	$ 12,190	$ 12,190
Acquisitions	3,183	14,222	539	12,939	790	1,283	125		1,729
Other	28		32	3,861	(4)	(3,861)
Goodwill, ending balance	$ 119,139	$ 115,928	$ 17,429	$ 16,858	$ 87,666	$ 86,880	$ 12,315	$ 12,190	$ 1,729

X

- Details

Name:	cwst_GoodwillAndIntangibleAssetsLineItems
Namespace Prefix:	cwst_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

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

-URI http://asc.fasb.org/extlink&oid=14024403&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

+ 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 (a)

-URI http://asc.fasb.org/extlink&oid=14024403&loc=d3e13816-109267

+ Details

Name:	us-gaap_GoodwillAcquiredDuringPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Amount of other (increase) decrease of an asset representing the 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 (g)

-URI http://asc.fasb.org/extlink&oid=14024403&loc=d3e13816-109267

+ Details

Name:	us-gaap_GoodwillOtherChanges
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration