Restructuring Accrual Activity (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Oct. 31, 2013	Oct. 31, 2012
Restructuring Cost and Reserve [Line Items]
Beginning Balance	$ 2,774	$ 4,068
Additions to expense	0	231
Accretion	62	50
Stock based compensation		(48)
Cash paid	(312)	(594)
Ending Balance	2,524	3,707
Accrued expenses
Restructuring Cost and Reserve [Line Items]
Restructuring reserve, current	960	1,334
Other long-term liabilities
Restructuring Cost and Reserve [Line Items]
Restructuring reserve, noncurrent	1,564	2,373
Employee Severance
Restructuring Cost and Reserve [Line Items]
Beginning Balance	2	364
Additions to expense		231
Stock based compensation		(48)
Cash paid	(2)	(195)
Ending Balance		352
Employee Severance | Accrued expenses
Restructuring Cost and Reserve [Line Items]
Restructuring reserve, current		352
Facility Lease
Restructuring Cost and Reserve [Line Items]
Beginning Balance	2,772	3,704
Accretion	62	50
Cash paid	(310)	(399)
Ending Balance	2,524	3,355
Facility Lease | Accrued expenses
Restructuring Cost and Reserve [Line Items]
Restructuring reserve, current	960	982
Facility Lease | Other long-term liabilities
Restructuring Cost and Reserve [Line Items]
Restructuring reserve, noncurrent	$ 1,564	$ 2,373