Earnings Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 29, 2014	Mar. 30, 2013
Earnings Per Share
Net income	$ 8,110	$ 20,034
Shares used in computing basic earnings per share	43,081,000	42,186,000
Effect of dilutive securities:
Stock options and other stock-based awards (in shares)	975,000	924,000
Shares used in computing diluted earnings per share	44,056,000	43,110,000
Earnings per share:
Basic (in dollars per share)	$ 0.19	$ 0.47
Diluted (in dollars per share)	$ 0.18	$ 0.46
Shares excluded from computation of diluted earning per share	200,000	600,000