Consolidated Balance Sheets (Parenthetical) $ in Thousands	Sep. 30, 2016 USD ($) vote / shares $ / shares shares	Sep. 25, 2015 USD ($) vote / shares $ / shares shares
Allowance for doubtful accounts | $	$ 2,370	$ 1,542
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	57,018,362	50,291,426
Common Stock, Shares Outstanding	57,018,362	50,291,426
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	44,403,847	50,743,311
Common Stock, Shares Outstanding	44,403,847	50,743,311