Goodwill and Other Intangible Assets Other Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2016	Jul. 31, 2015	Jul. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	$ 194,550	$ 195,569
Finite-Lived Intangible Assets, Accumulated Amortization	(134,744)	(126,681)
Intangible Assets, Net (Excluding Goodwill)	59,806	68,888
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Amortization of Intangible Assets	9,056	12,103	$ 17,871
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months	7,068
Finite-Lived Intangible Assets, Amortization Expense, Year Two	6,379
Finite-Lived Intangible Assets, Amortization Expense, Year Three	6,101
Finite-Lived Intangible Assets, Amortization Expense, Year Four	5,581
Finite-Lived Intangible Assets, Amortization Expense, Year Five	5,534
Impairment of Intangible Assets (Excluding Goodwill) [Abstract]
Impairment of Intangible Assets (Excluding Goodwill)	$ 6,651	$ 6,651
Patents [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	5 years	5 years
Intangible Assets, Gross (Excluding Goodwill)	$ 12,252	$ 12,073
Finite-Lived Intangible Assets, Accumulated Amortization	(11,063)	(10,641)
Intangible Assets, Net (Excluding Goodwill)	$ 1,189	$ 1,432
Tradenames and Other [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	5 years	5 years
Intangible Assets, Gross (Excluding Goodwill)	$ 14,359	$ 14,375
Finite-Lived Intangible Assets, Accumulated Amortization	(13,709)	(12,471)
Intangible Assets, Net (Excluding Goodwill)	$ 650	$ 1,904
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	7 years	7 years
Intangible Assets, Gross (Excluding Goodwill)	$ 135,795	$ 136,693
Finite-Lived Intangible Assets, Accumulated Amortization	(100,830)	(94,537)
Intangible Assets, Net (Excluding Goodwill)	$ 34,965	$ 42,156
Non-compete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	4 years	4 years
Intangible Assets, Gross (Excluding Goodwill)	$ 9,153	$ 9,076
Finite-Lived Intangible Assets, Accumulated Amortization	(9,142)	(9,032)
Intangible Assets, Net (Excluding Goodwill)	11	44
Tradenames and Other - Indefinite Life [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	22,991	23,352
Finite-Lived Intangible Assets, Accumulated Amortization	0	0
Intangible Assets, Net (Excluding Goodwill)	$ 22,991	$ 23,352