Segment Information - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended
	Jan. 31, 2013	Jan. 31, 2012	Jan. 31, 2013	Jan. 31, 2012	Jul. 31, 2012
Segment Reporting Information [Line Items]
Number of operating segments			5
Number of reportable segments			3
Value of long-lived assets located	$ 335,786,000		$ 335,786,000		$ 342,571,000
Americas
Segment Reporting Information [Line Items]
Percentage of long-lived assets located	54.00%		54.00%		63.00%
Value of long-lived assets located	92,334,000		92,334,000		101,931,000
Asia
Segment Reporting Information [Line Items]
Percentage of long-lived assets located	21.00%		21.00%		18.00%
Value of long-lived assets located	105,594,000		105,594,000		111,660,000
Europe
Segment Reporting Information [Line Items]
Percentage of long-lived assets located	25.00%		25.00%		19.00%
Value of long-lived assets located	116,850,000		116,850,000		105,472,000
Singapore
Segment Reporting Information [Line Items]
Value of long-lived assets located	9,200,000		9,200,000		9,200,000
Ireland
Segment Reporting Information [Line Items]
Value of long-lived assets located	5,300,000		5,300,000		4,800,000
China
Segment Reporting Information [Line Items]
Value of long-lived assets located	4,800,000		4,800,000		3,300,000
Company generated revenue	44,700,000	34,500,000	83,100,000	75,700,000
Netherlands
Segment Reporting Information [Line Items]
Value of long-lived assets located	3,700,000		3,700,000		2,300,000
Company generated revenue	25,000,000	26,400,000	47,500,000	58,800,000
Czech Republic
Segment Reporting Information [Line Items]
Value of long-lived assets located	$ 2,500,000		$ 2,500,000		$ 3,400,000