Intangibles, Net (Details) - USD ($) $ in Thousands	12 Months Ended
Jul. 31, 2018	Jul. 31, 2017
Amortized intangible assets:
Gross Carrying Amount	$ 106,917	$ 106,408
Accumulated Amortization	(42,025)	(30,470)
Intangibles, net	64,892	75,938
Covenants not to compete
Amortized intangible assets:
Gross Carrying Amount	1,666	1,702
Accumulated Amortization	(1,656)	(1,389)
Intangibles, net	$ 10	$ 313
Useful life of intangible assets	0 years	1 year
Supply contracts and customer relationships
Amortized intangible assets:
Gross Carrying Amount	$ 71,787	$ 75,462
Accumulated Amortization	(29,601)	(22,248)
Intangibles, net	$ 42,186	$ 53,214
Useful life of intangible assets	10 years	9 years
Trade names
Amortized intangible assets:
Gross Carrying Amount	$ 24,173	$ 23,859
Accumulated Amortization	(6,405)	(4,989)
Intangibles, net	$ 17,768	$ 18,870
Useful life of intangible assets	1 year	2 years
Licenses and databases
Amortized intangible assets:
Gross Carrying Amount	$ 9,291	$ 5,385
Accumulated Amortization	(4,363)	(1,844)
Intangibles, net	$ 4,928	$ 3,541
Useful life of intangible assets	2 years	3 years

Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

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

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 928
-SubTopic 340
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6473545&loc=d3e61844-108004

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
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Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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