The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6388964&loc=d3e16225-109274

Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 230
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Goodwill and Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Oct. 31, 2017	Oct. 31, 2016	Jul. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Amortization of Intangible Assets	$ 3,800	$ 1,300
Amortized intangibles:
Accumulated amortization	(34,787)		$ (30,470)
Net intangibles	73,285		75,938
Covenants not to compete
Amortized intangibles:
Gross carrying amount	1,693		1,702
Supply contracts & customer relationships
Amortized intangibles:
Gross carrying amount	73,977		75,462
Trade name
Amortized intangibles:
Gross carrying amount	23,827		23,859
Licenses and databases
Amortized intangibles:
Gross carrying amount	$ 8,575		$ 5,385