Net Loss per Share (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended											12 Months Ended
	Dec. 29, 2012		Sep. 29, 2012	Jun. 30, 2012		Mar. 31, 2012	Dec. 31, 2011	Sep. 24, 2011	Jun. 25, 2011		Mar. 26, 2011	Dec. 29, 2012	Dec. 31, 2011	Dec. 25, 2010
Accounting Policies [Abstract]
Net loss	$ 603	[1]	$ (14,478)	$ (4,217)	[2]	$ (17,454)	$ (26,975)	$ (9,904)	$ (7,678)	[3]	$ (21,424)	$ (35,546)	$ (65,981)	$ (188,286)
Weighted-average shares used in computing basic net loss per share	52,745		50,154	49,817		49,487	49,967	50,747	50,773		50,636	50,551	50,521	50,246
Add potentially dilutive securities (Shares)												0	0	0
Weighted-average shares used in computing diluted net loss per share	52,921	[1]	50,154	49,817	[2]	49,487	49,967	50,747	50,773	[3]	50,636	50,551	50,521	50,246

[1] In the fourth quarter of fiscal 2012, we recorded an income tax benefit in the amount of $25.5 million from the release of deferred tax asset valuation allowances due to deferred tax liabilities established on the acquired identifiable intangible assets from our acquisition of MicroProbe and $3.3 million benefit from the settlement of patent litigation in conjunction with the acquisition of MicroProbe. The fourth quarter of fiscal 2012 includes the following Microprobe operating activity: $19.8 million in revenue, $5.4 million amortization of intangibles, $2.6 million release of pre-existing backlog, $3.5 million release of inventory fair value step-up and $0.2 million charge for step-up depreciation on fixed assets resulting in a net loss of $6.4 million.

[2] In the second quarter of fiscal 2012, we recorded a tax benefit in the amount of $1.6 million from the release of a deferred tax valuation allowance recorded in a non-U.S. jurisdiction. This benefit resulted in an overall income tax benefit, rather than an income tax provision in the second quarter of fiscal 2012.

[3] In the second quarter of fiscal 2011, we recorded a tax benefit in the amount of $2.5 million from the release of a deferred tax valuation allowance recorded in a non-U.S. jurisdiction. This benefit resulted in an overall income tax benefit, rather than an income tax provision in the second quarter of fiscal 2011.