Net Income Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jul. 01, 2014	Jul. 02, 2013	Jul. 01, 2014	Jul. 02, 2013
Net income per share
Antidilutive securities excluded from calculation of basic earnings per share (in shares)	400,000	500,000	800,000	1,100,000
Net income per share, basic and diluted
Net income	$ 30,049	$ 28,583	$ 52,567	$ 53,875
Basic weighted average shares outstanding (in shares)	49,349,000	52,892,000	50,044,000	52,574,000
Dilutive effect of equity awards (in shares)	2,009,000	2,181,000	2,054,000	2,118,000
Diluted weighted average shares outstanding (in shares)	51,358,000	55,073,000	52,098,000	54,692,000
Basic net income per share (in dollars per share)	$ 0.61	$ 0.54	$ 1.05	$ 1.02
Diluted net income per share (in dollars per share)	$ 0.59	$ 0.52	$ 1.01	$ 0.99
Restricted Shares and Restricted Share Units [Member]
Net income per share
Antidilutive securities excluded from calculation of basic earnings per share (in shares)			1,800,000	1,500,000