Changes in Stockholders' Equity and Accumulated Other Comprehensive Loss (Details) (USD $) Share data in Millions, unless otherwise specified	3 Months Ended		9 Months Ended		3 Months Ended	12 Months Ended			9 Months Ended
	Sep. 27, 2014	Sep. 28, 2013	Sep. 27, 2014	Sep. 28, 2013	Sep. 27, 2014 Share Repurchase Program approved on Feb 27, 2013	Dec. 28, 2013 Share Repurchase Program approved on Feb 27, 2013	Feb. 27, 2013 Share Repurchase Program approved on Feb 27, 2013	Mar. 03, 2014 Share Repurchase Program approved on Feb 27, 2014	Sep. 27, 2014 Common stock	Sep. 27, 2014 Paid-in capital	Sep. 27, 2014 Treasury Stock [Member]	Sep. 27, 2014 Accumulated deficit	Sep. 27, 2014 Accumulated other comprehensive loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			$ 385,680,000						$ 1,157,000	$ 626,861,000	$ 0	$ (242,193,000)	$ (145,000)
Net Income	9,406,000	8,844,000	33,161,000	15,774,000						0		33,161,000
Unrealized (loss) gain related to marketable securities, net	(210,000)	221,000	(280,000)	(11,000)						0	0		(280,000)
Realized gain on sale of auction rate securities, previously unrealized, net of tax	0	0	(1,147,000)	0						0	0		(1,147,000)
Recognized loss on redemption of marketable securities, previously unrealized	(1,000)	1,000	98,000	303,000						0	0		98,000
Translation adjustments	(159,000)	225,000	579,000	(205,000)						0			579,000
Common stock issued in connection with the exercise of stock options, ESPP and vested RSUs, net of tax			8,495,000						32,000	8,463,000
Stock repurchase			1,700,000							0	1,700,000
Stock-based compensation expense related to stock options, ESPP and RSUs			9,543,000							9,543,000
Ending balance	434,429,000		434,429,000						1,189,000	644,867,000	(1,700,000)	(209,032,000)	(895,000)
Stock repurchase program, authorized amount							20,000,000	20,000,000
Shares repurchased (in shares)			0.2			0.8
Shares repurchased					$ 1,700,000	$ 3,700,000