Summary of Accrued Restructuring Costs Activity (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Jan. 31, 2011	Jul. 31, 2010	Jul. 31, 2012	Jul. 31, 2011	Jul. 31, 2010
Restructuring Cost and Reserve [Line Items]
Balance at beginning period			$ 5,190	$ 875	$ 3,812
Restructuring charge				7,147	1,184
Adjustments				(81)	(494)
Cash payments			(4,715)	(2,832)	(3,636)
Foreign exchange			(198)	81	9
Balance at end period		875	277	5,190	875
Involuntary Employee Severance
Restructuring Cost and Reserve [Line Items]
Balance at beginning period			5,035	153	2,728
Restructuring charge				7,147	764
Adjustments	134	494		(134)	(494)
Cash payments			(4,560)	(2,212)	(2,854)
Foreign exchange			(198)	81	9
Balance at end period		153	277	5,035	153
Facility Exit Costs
Restructuring Cost and Reserve [Line Items]
Balance at beginning period			155	722	1,058
Restructuring charge					420
Adjustments				53
Cash payments			(155)	(620)	(756)
Balance at end period		722		155	722
Copley Acquisition
Restructuring Cost and Reserve [Line Items]
Balance at beginning period					26
Cash payments					$ (26)