Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 25, 2016	Dec. 26, 2015
Allowance for doubtful accounts on accounts receivable	$ 189	$ 244
Common Class A
Common Stock, par value	$ 0.01	$ 0.01
Common Stock, shares authorized	22,700,000	22,700,000
Common Stock, shares issued	9,009,571	9,389,005
Common Stock, shares outstanding	9,009,571	9,389,005
Common Class B
Common Stock, par value	$ 0.01	$ 0.01
Common Stock, shares authorized	4,200,000	4,200,000
Common Stock, shares issued	3,367,355	3,367,355
Common Stock, shares outstanding	3,367,355	3,367,355