Income Taxes - Income Tax Reconciliation (Details) - USD ($) $ in Thousands		12 Months Ended
		Sep. 28, 2019	Sep. 29, 2018	Sep. 30, 2017
Income Tax Reconciliation [Abstract]
Income tax provision at federal statutory tax rate		$ 14,593	$ 15,945	$ 13,459
Impact of Partnership income not subject to federal income taxes		(14,925)	(15,939)	(13,892)
Permanent differences		162	65	3
Change in valuation allowance		115	(21,307)	406
State income taxes		707	656	864
Remeasurement of net deferred tax assets	[1]	0	19,941	0
Other		205	33	(381)
Provision for income taxes - current and deferred		$ 857	$ (606)	$ 459

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