Consolidated Balance Sheets (Parenthetical) $ in Thousands	Mar. 29, 2019 vote / shares $ / shares shares	Sep. 29, 2017 vote / shares $ / shares shares
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 Outstanding	63,911,270	63,978,752
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 Outstanding	36,229,820	39,261,035