Condensed Consolidated Balance Sheets (unaudited) (Parenthetical) - USD ($) $ in Thousands	Dec. 26, 2020	Sep. 26, 2020	Dec. 28, 2019
Accounts receivable allowance for doubtful accounts	$ 30,951	$ 27,661	$ 21,257
Common stock, par value (in dollars per share)	$ 0.01
Common Class
Common stock, par value (in dollars per share)		$ 0.01	$ 0.01
Common stock, shares outstanding (in shares)	11,336,358	11,336,358	11,484,297
Class A Common Stock
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01	$ 0.01
Common stock, shares outstanding (in shares)	42,171,329	41,856,626	42,289,882
Class B Stock
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01	$ 0.01
Common stock, shares outstanding (in shares)	1,612,374	1,612,374	1,647,922