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The aggregate value (measured at the lower of net carrying value or fair value less cost of disposal) for current assets (assets with expected useful life shorter than one year or one operating cycle, whichever is longer) of a disposal group, including a component of the entity (discontinued operation), to be sold or that has subsequently been disposed of through sale, as of the financial statement date.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 205

-SubTopic 20

-Section 45

-Paragraph 10

-URI http://asc.fasb.org/extlink&oid=6892542&loc=d3e1107-107759

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- Definition

This item represents a non-contingent liability for the fair value of an obligation to stand ready to perform over the term of a guaranty issued in the event that specified triggering events or conditions occur.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

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-Publisher FASB

-Name Accounting Standards Codification

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 460

-SubTopic 10

-Section 25

-Paragraph 4

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 460

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-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=7661617&loc=d3e11019-110243

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- Definition

Fair value portion of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

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Fair Value of Financial Instruments - Assets and Liabilities Measured at Fair Value on Non-Recurring Basis (Detail) (USD $) In Thousands, unless otherwise specified	Apr. 30, 2014	Apr. 30, 2013
Assets:
Asset group	$ 359	$ 61
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| Fair Value, Measurements, Nonrecurring [Member]
Assets:
Asset group
Liabilities:
Guaranty
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| Fair Value, Measurements, Nonrecurring [Member] \| Casella-Altela Regional Environmental Services, LLC [Member]
Assets:
Asset group - CARES
Significant Other Observable Inputs (Level 2) [Member] \| Fair Value, Measurements, Nonrecurring [Member]
Assets:
Asset group
Liabilities:
Guaranty
Significant Other Observable Inputs (Level 2) [Member] \| Fair Value, Measurements, Nonrecurring [Member] \| Casella-Altela Regional Environmental Services, LLC [Member]
Assets:
Asset group - CARES
Significant Unobservable Inputs (Level 3) [Member] \| Fair Value, Measurements, Nonrecurring [Member]
Assets:
Asset group		61
Liabilities:
Guaranty		2,073
Significant Unobservable Inputs (Level 3) [Member] \| Fair Value, Measurements, Nonrecurring [Member] \| Casella-Altela Regional Environmental Services, LLC [Member]
Assets:
Asset group - CARES	$ 650