Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2013	Dec. 30, 2012
Allowance for doubtful accounts receivable	$ 12,366	$ 13,242
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	44,944,529	44,763,404
Treasury stock, shares	4,035,912	4,035,912