Income per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jul. 01, 2012	Jul. 03, 2011	Jul. 01, 2012	Jul. 03, 2011
Numerator:
Income from continuing operations	$ 42,390	$ 34,881	$ 66,665	$ 56,899
Loss from discontinued operations, net of tax		(156)		(284)
Net income	$ 42,390	$ 34,725	$ 66,665	$ 56,615
Denominator:
Weighted average shares outstanding, basic	45,526	47,401	45,720	47,304
Effect of dilutive common stock equivalents	779	1,013	903	1,068
Weighted average shares outstanding, diluted	46,305	48,414	46,623	48,372
Income per Share (Textual) [Abstract]
Diluted weighted average shares outstanding do not include outstanding equity awards	1,300,000	700,000	1,000,000	600,000