Goodwill and Other Intangible Assets Other Intangible Assets (Details) - USD ($)	12 Months Ended
	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Fully Amortized Intangible Assets	$ 107,741
Intangible Assets, Gross (Excluding Goodwill)	89,685,000	$ 194,550,000
Finite-Lived Intangible Assets, Accumulated Amortization	(36,609,000)	(134,744,000)
Intangible Assets, Net (Excluding Goodwill)	53,076,000	59,806,000
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Amortization of Intangible Assets	7,113,000	$ 9,056,000	$ 12,103,000
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months	6,456,000
Finite-Lived Intangible Assets, Amortization Expense, Year Two	6,199,000
Finite-Lived Intangible Assets, Amortization Expense, Year Three	5,201,000
Finite-Lived Intangible Assets, Amortization Expense, Year Four	5,160,000
Finite-Lived Intangible Assets, Amortization Expense, Year Five	$ 5,010,000
Patents [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	5 years	5 years
Intangible Assets, Gross (Excluding Goodwill)	$ 1,358,000	$ 12,252,000
Finite-Lived Intangible Assets, Accumulated Amortization	(471,000)	(11,063,000)
Intangible Assets, Net (Excluding Goodwill)	$ 887,000	$ 1,189,000
Tradenames and Other [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	9 years	5 years
Intangible Assets, Gross (Excluding Goodwill)	$ 4,528,000	$ 14,359,000
Finite-Lived Intangible Assets, Accumulated Amortization	(4,229,000)	(13,709,000)
Intangible Assets, Net (Excluding Goodwill)	$ 299,000	$ 650,000
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	8 years	7 years
Intangible Assets, Gross (Excluding Goodwill)	$ 60,759,000	$ 135,795,000
Finite-Lived Intangible Assets, Accumulated Amortization	(31,909,000)	(100,830,000)
Intangible Assets, Net (Excluding Goodwill)	28,850,000	$ 34,965,000
Non-compete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life		4 years
Intangible Assets, Gross (Excluding Goodwill)		$ 9,153,000
Finite-Lived Intangible Assets, Accumulated Amortization	0	(9,142,000)
Intangible Assets, Net (Excluding Goodwill)	0	11,000
Tradenames and Other - Indefinite Life [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	23,040,000	22,991,000
Finite-Lived Intangible Assets, Accumulated Amortization	0	0
Intangible Assets, Net (Excluding Goodwill)	$ 23,040,000	$ 22,991,000