Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data	Jun. 26, 2011	Dec. 26, 2010
Consolidated Balance Sheets
Allowance for doubtful accounts receivable	$ 11,161	$ 10,472
Preferred stock, no par value	$ 0	$ 0
Preferred stock, shares authorized	500,000	500,000
Preferred stock, shares issued	0	0
Common stock, par value	$ 0.1	$ 0.1
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	44,131,952	43,843,095
Treasury stock, shares	4,035,912	4,035,912