CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 27, 2015	Dec. 28, 2014
Trade receivables, allowance	$ 4,451	$ 5,900
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Treasury stock, shares	1,652,165	45,374
Common Class A
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	58,782,535	62,600,676
Common Class B
Common stock, shares authorized	60,000,000	60,000,000
Common stock, shares issued	24,431,962	24,585,962