Consolidated Balance Sheets (Parenthetical) $ in Thousands	Sep. 28, 2018 USD ($) vote / shares $ / shares shares	Sep. 29, 2017 USD ($) vote / shares $ / shares shares
Allowance for doubtful accounts | $	$ 5,352	$ 2,967
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 / shares	1	1
Common Stock, Shares Authorized	500,000,000	500,000,000
Common Stock, Shares Issued	63,978,752	59,281,837
Common Stock, Shares Outstanding	63,978,752	59,281,837
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 / shares	10	10
Common Stock, Shares Authorized	500,000,000	500,000,000
Common Stock, Shares Issued	39,261,035	42,873,597
Common Stock, Shares Outstanding	39,261,035	42,873,597