Earnings Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Apr. 02, 2011
Earnings Per Share
Net income (loss)	$ 14,320	$ (1,960)
Shares used in computing basic earnings per share	42,458,000	44,269,000
Effect of dilutive securities:
Stock options and other stock-based awards (in shares)	1,392,000
Shares used in computing diluted earnings per share	43,850,000	44,269,000
Earnings (loss) per share:
Basic (in dollars per share)	$ 0.34	$ (0.04)
Diluted (in dollars per share)	$ 0.33	$ (0.04)
Shares excluded from computation of diluted earning per share	300,000	300,000
Dilutive securities excluded due to entity's net loss (in shares)		1,800,000