Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 27, 2015	Dec. 28, 2014
Statement of Financial Position [Abstract]
Allowance for doubtful accounts receivable	$ 6,059	$ 8,526
Preferred stock, no par value (usd per share)	$ 0	$ 0
Preferred stock, shares authorized	500,000	500,000
Preferred stock, shares issued	0	0
Common stock, par value (usd per share)	$ 0.1	$ 0.1
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	46,303,849	45,840,171
Common stock, shares, outstanding	41,379,002	41,804,259
Treasury stock, shares	4,924,847	4,035,912