Interim Condensed Consolidated Balance Sheets (Parenthetical) $ in Thousands	Mar. 26, 2021 USD ($) vote $ / shares shares	Sep. 25, 2020 USD ($) vote $ / shares shares
Allowance for doubtful accounts | $	$ 11,671	$ 15,908
Contract assets, allowance for credit losses | $	$ 189	$ 0
Class A Common Stock [Member]
Common stock, par value (usd per share) | $ / shares	$ 0.001	$ 0.001
Common stock voting right per share (votes per share) | vote	1
Common stock, shares authorized (shares)	500,000,000	500,000,000
Common stock, shares issued (shares)	65,206,586	64,167,725
Common stock, shares outstanding (shares)	65,206,586	64,167,725
Class B Common Stock [Member]
Common stock, par value (usd per share) | $ / shares	$ 0.001	$ 0.001
Common stock voting right per share (votes per share) | vote	10	10
Common stock, shares authorized (shares)	500,000,000	500,000,000
Common stock, shares issued (shares)	36,107,779	36,128,720
Common stock, shares outstanding (shares)	36,107,779	36,128,720