Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Mar. 27, 2018	Dec. 26, 2017
Class A Common Stock [Member]
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	70,000,000	70,000,000
Common stock, shares issued	20,488,849	20,378,452
Common stock, shares outstanding	20,488,849	20,378,452
Class B Common Stock [Member]
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	70,000,000	70,000,000
Common stock, shares issued	5,578,616	5,646,572
Common stock, shares outstanding	5,578,616	5,646,572