Consolidated Balance Sheets (Parenthetical) (unaudited) (USD $)	Sep. 27, 2011	Dec. 28, 2010
Common stock, $.0001 par value per share:
Treasury stock, shares	2,020,170	1,119,092
Common Stock Class A [Member]
Common stock, $.0001 par value per share:
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	112,500,000	112,500,000
Common stock, shares issued	30,289,893	30,125,936
Common stock, shares outstanding	28,269,723	29,006,844
Common Stock Class B [Member]
Common stock, $.0001 par value per share:
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	10,000,000	10,000,000
Common stock, shares issued	1,389,087	1,391,607
Common stock, shares outstanding	1,389,087	1,391,607