Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 27, 2015	Dec. 28, 2014
Statement of Financial Position [Abstract]
Allowance for doubtful accounts receivable	$ 6,472	$ 8,526
Preferred stock, no par value (USD per share)	$ 0	$ 0
Preferred stock, shares authorized (shares)	500,000	500,000
Preferred stock, shares issued (shares)	0	0
Common stock, par value (USD per share)	$ 0.1	$ 0.1
Common stock, shares authorized (shares)	100,000,000	100,000,000
Common stock, shares issued (shares)	46,197,226	45,840,171
Common stock, shares outstanding (shares)	41,722,379	41,804,259
Treasury stock (shares)	4,474,847	4,035,912