CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jun. 26, 2016	Dec. 27, 2015
Trade receivables, allowance	$ 3,821	$ 4,451
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Treasury stock, shares	758,673	165,217
Common Class A
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	5,946,969	5,878,253
Common Class B
Common stock, shares authorized	60,000,000	60,000,000
Common stock, shares issued	2,443,191	2,443,191