Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	1 Months Ended	3 Months Ended
	Aug. 29, 2008	Oct. 31, 2013	Oct. 31, 2012	Jul. 31, 2013
Product Information [Line Items]
Inventory reserves		$ 42,800,000		$ 41,800,000
Total Inventories		29,238,000		29,139,000
Amortization of intangible assets		1 year 3 months 18 days
Unrecognized income tax benefits		6,900,000		6,800,000
Unrecognized income tax benefits that would impact income tax rate if recognized		3,300,000		3,200,000
Uncertain tax positions accrued interest and penalties		900,000		900,000
Ownership percentage that trigger limitation on NOL carryforward utilization	50.00%
Operating loss carryforwards, limitations on use	As a result of completion of the Company’s merger with Credence Systems Corporation (“Credence”) on August 29, 2008, a greater than 50% cumulative ownership change in both entities triggered a significant limitation in net operating loss carryforward utilization. The Company’s ability to use operating and acquired net operating loss and credit carryforwards is subject to annual limitation as defined in sections 382 and 383 of the Internal Revenue Code.
Estimated annual limitation on use of net operating loss	10,100,000
Amount of net operating loss able to be used	202,000,000
Share based compensation expense		$ 1,109,000	$ 1,138,000
Maturity period of highly liquid investments to be considered cash equivalent		3 months
Stock Option
Product Information [Line Items]
Anti-dilutive securities excluded from computation of earnings per share		700,000	900,000
Restricted stock units (RSU's)
Product Information [Line Items]
Restricted stock unit awards granted		0	793,900
Restricted stock unit award granted, vesting period			4 years
Restricted stock unit award granted, vesting percentage			25.00%
Anti-dilutive securities excluded from computation of earnings per share		1,300,000
Minimum
Product Information [Line Items]
Property plant and equipment estimated useful life		3 years
Maximum
Product Information [Line Items]
Property plant and equipment estimated useful life		7 years