Intangible Assets (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Apr. 30, 2016	Apr. 30, 2015	Apr. 30, 2016	Apr. 30, 2015	Jul. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 363,895,000		$ 363,895,000		$ 82,995,000
Accumulated amortization	70,334,000		70,334,000		62,986,000
Net carrying amount	293,561,000		293,561,000		$ 20,009,000
Amortization of intangibles	4,776,000	$ 1,561,000	7,348,000	$ 4,682,000
Amortization expense - year one	13,360,000		13,360,000
Amortization expense - year two	22,786,000		22,786,000
Amortization expense - year three	21,150,000		21,150,000
Amortization expense - year four	17,230,000		17,230,000
Amortization expense - year five	17,230,000		$ 17,230,000
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Weighted average amortization period			20 years 6 months		10 years
Gross carrying amount	252,831,000		$ 252,831,000		$ 29,831,000
Accumulated amortization	25,154,000		25,154,000		20,981,000
Net carrying amount	227,677,000		$ 227,677,000		$ 8,850,000
Technologies
Finite-Lived Intangible Assets [Line Items]
Weighted average amortization period			12 years 3 months 18 days		12 years 1 month 6 days
Gross carrying amount	82,370,000		$ 82,370,000		$ 47,370,000
Accumulated amortization	41,419,000		41,419,000		39,266,000
Net carrying amount	40,951,000		$ 40,951,000		$ 8,104,000
Trademarks and other
Finite-Lived Intangible Assets [Line Items]
Weighted average amortization period			16 years 3 months 18 days		20 years
Gross carrying amount	28,694,000		$ 28,694,000		$ 5,794,000
Accumulated amortization	3,761,000		3,761,000		2,739,000
Net carrying amount	$ 24,933,000		$ 24,933,000		$ 3,055,000