Geographic Areas Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended										12 Months Ended
	Jul. 31, 2014		Apr. 30, 2014	Jan. 31, 2014	Oct. 31, 2013	Jul. 31, 2013		Apr. 30, 2013	Jan. 31, 2013	Oct. 31, 2012	Jul. 31, 2014		Jul. 31, 2013		Jul. 31, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 142,000		$ 124,000	$ 141,400	$ 110,100	$ 166,200		$ 125,800	$ 138,500	$ 119,900	$ 517,548		$ 550,363		$ 516,571
Property, plant and equipment, net	114,165					110,983					114,165		110,983		96,800
UNITED STATES
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues											183,800		209,600		199,500
Property, plant and equipment, net	66,100					62,600					66,100		62,600		50,700
JAPAN
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues											66,200		87,000		81,900
GERMANY
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues											61,800		69,800		63,500
NETHERLANDS
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues											70,200		69,700		61,400
Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues											135,500		114,300		110,300
Property, plant and equipment, net	8,300	[1]				8,500	[1]				8,300	[1]	8,500	[1]	8,500	[1]
DENMARK
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net	19,800					19,700					19,800		19,700		18,600
CHINA
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net	$ 20,000					$ 20,200					$ 20,000		$ 20,200		$ 19,000

[1] Other property, plant and equipment are primarily in Canada.