Financial Instruments and Risk Management - Fair Value of the Partnership's Senior Notes (Details) - USD ($) $ in Thousands	Dec. 26, 2020	Sep. 26, 2020
Bank Debt and Senior Notes [Abstract]
Fair value of Senior Notes	$ 1,156,331	$ 1,147,251
5.5% Senior Notes due June 1, 2024 [Member]
Bank Debt and Senior Notes [Abstract]
Fair value of Senior Notes	535,500	531,563
5.75% Senior Notes due March 1, 2025 [Member]
Bank Debt and Senior Notes [Abstract]
Fair value of Senior Notes	255,938	255,625
5.875% Senior Notes due March 1, 2027 [Member]
Bank Debt and Senior Notes [Abstract]
Fair value of Senior Notes	$ 364,893	$ 360,063