Goodwill and Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	Jan. 31, 2014	Jul. 31, 2013
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization	$ (38,818)	$ (34,824)
Net intangibles	19,709	17,706
Covenants not to compete
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	17,525	12,515
Supply contracts
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	28,364	26,322
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	7,478	7,389
Trade name
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	3,066	2,998
Licenses and databases
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 2,094	$ 3,306

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

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- Definition

Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

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- Definition

Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

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