Stock-Based Compensation (Narrative) (Details) (USD $)	3 Months Ended		9 Months Ended		3 Months Ended	9 Months Ended						9 Months Ended			9 Months Ended			9 Months Ended
	Sep. 27, 2014	Sep. 28, 2013	Sep. 27, 2014 ShareBasedCompensationPlan	Sep. 28, 2013	Sep. 27, 2014 RSU Activity [Member]	Sep. 27, 2014 RSU Activity [Member]	Sep. 27, 2014 RSU Activity [Member] August 25, 2015 [Member]	Sep. 27, 2014 RSU Activity [Member] August 25, 2016 [Member]	Sep. 27, 2014 Employee Stock Purchase Plan [Member]	Sep. 27, 2014 1994 Plan [Member]	Sep. 27, 2014 2001 Plan [Member]	Sep. 27, 2014 2008 Plan [Member]	Sep. 27, 2014 2011 Employee Stock Purchase Plan [Member]	Dec. 28, 2013 2011 Employee Stock Purchase Plan [Member]	Sep. 27, 2014 2012 Annual Plan Of Record [Member]	Sep. 27, 2014 Maximum [Member] 2008 Plan [Member]	Dec. 29, 2012 Maximum [Member] 2008 Plan [Member]	Sep. 27, 2014 Maximum [Member] 2011 Employee Stock Purchase Plan [Member]	Sep. 27, 2014 Pre-Vesting [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock-based compensation programs			2
Proceeds from issuance of stock-based awards	$ 7,300,000	$ 6,800,000	$ 17,900,000	$ 23,500,000
Option expiration period (years)												10 years
Award vesting period (years)						4 years						4 years			3 years
Award vesting percentage							50.00%	50.00%
Common shares reserved for issuance													4,380,208	6,296,935		39,500,000	30,000,000	12,000,000
Additional shares reserved for issuance										0	0	15,000,000					9,500,000
Shares per award, ratio												1.6
Shares issued													1,916,727
Weighted average grant-date fair value per stock option	$ 2.29	$ 2.45	$ 2.29	$ 2.47
Total intrinsic value of stock options	700,000	600,000	2,300,000	2,800,000	8,500,000	13,500,000
Total unrecognized compensation costs	4,600,000		4,600,000		38,700,000	38,700,000			1,300,000
Unrecognized compensation expected to be recognized, average period						2 years 9 months 18 days													2 years 4 months 24 days
Fair value of grants						1,700,000
Stock price as a percentage of fair value													85.00%
Non-GAAP operating income recognized as share based expense						2,000,000
Stock-based compensation expense	5,228,000	5,874,000	16,334,000	19,461,000		1,900,000
Maximum percentage of compensation an employee can use to purchase stock													10.00%
Maximum shares of stock an employee can purchase																		7,500
Maximum amount granted to each employee to purchase common stock under ESPP																		25,000
Weighted average price per share under ESPP													$ 5.66
Weighted average grant-date fair value per ESPP award									$ 1.74
Total intrinsic value of ESPP shares issued			2,300,000
Total forfeitures recorded			$ 1,800,000	$ 2,000,000