Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 27, 2021	Sep. 26, 2020	Mar. 28, 2020
Accounts receivable allowance for doubtful accounts	$ 29,784	$ 27,661	$ 22,103
Common Stock
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01	$ 0.01
Common stock, shares outstanding (in shares)	11,336,358	11,336,358	11,329,110
Class A Common Stock
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01	$ 0.01
Common stock, shares outstanding (in shares)	42,643,315	41,856,626	41,802,735
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