Intangible Assets (Details) (USD $)	3 Months Ended			3 Months Ended
	Oct. 31, 2013	Oct. 31, 2012	Jul. 31, 2013	Oct. 31, 2013 Technologies [Member]	Jul. 31, 2013 Technologies [Member]	Oct. 31, 2013 Customer relationships [Member]	Jul. 31, 2013 Customer relationships [Member]	Oct. 31, 2013 Trademarks and other [Member]	Jul. 31, 2013 Trademarks and other [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted average amortization period				11 years 8 months 12 days	11 years 8 months 12 days	10 years 0 months 0 days	10 years 0 months 0 days	20 years 0 months 0 days	20 years 0 months 0 days
Gross carrying amount	$ 82,995,000		$ 83,269,000	$ 47,370,000	$ 47,494,000	$ 29,831,000	$ 29,831,000	$ 5,794,000	$ 5,944,000
Accumulated amortization	52,072,000		50,764,000	33,926,000	33,264,000	15,818,000	15,081,000	2,328,000	2,419,000
Net carrying amount	30,923,000		32,505,000	13,444,000	14,230,000	14,013,000	14,750,000	3,466,000	3,525,000
Amortization of intangibles	1,582,000	1,582,000
Amortization expense - year one	6,285,000
Amortization expense - year two	6,211,000
Amortization expense - year three	4,962,000
Amortization expense - year four	4,782,000
Amortization expense - year five	$ 4,782,000