Unit-Based Compensation Arrangements - Summary of Activity For Restricted Units Plans (Details) - 2009 Restricted Unit Plan [Member]	9 Months Ended
	Jun. 26, 2021 $ / shares shares
Units [Rollforward]
Outstanding, beginning of period (in units) | shares	961,816
Awarded (in units) | shares	779,837
Forfeited (in units) | shares	(24,937)
Vested (in units) | shares	(475,168)	[1]
Outstanding, end of period (in units) | shares	1,241,548
Weighted Average Grant Date Fair Value Per Unit [Abstract]
Outstanding, beginning of period (in dollars per unit) | $ / shares	$ 17.60
Awarded (in dollars per unit) | $ / shares	14.43
Forfeited (in dollars per unit) | $ / shares	(15.29)
Vested (in dollars per unit) | $ / shares	(18.63)	[1]
Outstanding, end of period (in dollars per unit) | $ / shares	$ 15.26

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