Earnings Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 29, 2012	Dec. 31, 2011	Jan. 01, 2011
Earnings Per Share
Net income	$ 63,548	$ 35,472	$ 73,242
Shares used in computing basic earnings per share	42,136,000	43,421,000	44,845,000
Effect of dilutive securities:
Stock options and other stock-based awards (in shares)	970,000	1,411,000	1,897,000
Shares used in computing diluted earnings per share	43,106,000	44,832,000	46,742,000
Earnings per share:
Basic (in dollars per share)	$ 1.51	$ 0.82	$ 1.63
Diluted (in dollars per share)	$ 1.47	$ 0.79	$ 1.57
Shares excluded from computation of diluted earning per share	500,000	400,000	600,000