Unit-Based Compensation Arrangements - Summary of Activity In the Restricted Units Plans (Details) - 2009 Restricted Unit Plan [Member] - $ / shares		12 Months Ended
		Sep. 25, 2021	Sep. 26, 2020	Sep. 28, 2019
Units [Rollforward]
Outstanding, beginning of period (in units)		961,816	988,339	696,131
Awarded (in units)		779,837	471,111	618,268
Forfeited (in units)		(26,070)	(9,975)	(5,904)
Vested (in units)	[1]	(483,720)	(487,659)	(320,156)
Outstanding, end of period (in units)		1,231,863	961,816	988,339
Weighted Average Grant Date Fair Value Per Unit [Abstract]
Outstanding, beginning of period (in dollars per unit)		$ 17.60	$ 18.12	$ 19.47
Awarded (in dollars per unit)		14.43	18.19	18.13
Forfeited (in dollars per unit)		(15.29)	(18.01)	(18.34)
Vested (in dollars per unit)	[1]	(18.58)	(19.22)	(21.08)
Outstanding, end of period (in dollars per unit)		$ 15.26	$ 17.60	$ 18.12

[1] During fiscal 2021, 2020 and 2019, the Partnership withheld 92,336, 76,453 and 59,227 Common Units, respectively, from participants for income tax withholding purposes for those executive officers of the Partnership whose shares of restricted units vested during the period.