Income Taxes - Income Tax Reconciliation (Details) - USD ($) $ in Thousands		12 Months Ended
		Sep. 29, 2018	Sep. 30, 2017	Sep. 24, 2016
Income Tax Reconciliation [Abstract]
Income tax provision at federal statutory tax rate		$ 15,945	$ 13,459	$ 5,260
Impact of Partnership income not subject to federal income taxes		(15,939)	(13,892)	(9,844)
Permanent differences		65	3	182
Change in valuation allowance		(21,307)	406	4,737
State income taxes		656	864	(211)
Remeasurement of net deferred tax assets	[1]	19,941	0	0
Other		33	(381)	464
Provision for income taxes - current and deferred		$ (606)	$ 459	$ 588

[1] As described above, federal net deferred tax assets were remeasured, pursuant to the 2017 Act, using the new 21% federal income tax rate and the full valuation allowance was adjusted accordingly.