Financial Instruments and Risk Management - Fair Value of the Partnership's Derivative Instruments and their Location in the Condensed Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 25, 2021	Sep. 25, 2021
Commodity-Related Derivatives [Member]
Derivatives, Fair Value [Line Items]
Fair value - assets	$ 22,708	$ 76,508
Fair value - liabilities	11,399	32,023
Derivatives Not Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Fair value - assets	13,800	54,832
Fair value - liabilities	2,491	10,347
Derivatives Not Designated as Hedging Instruments [Member] | Commodity-Related Derivatives [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Fair value - assets	13,800	53,019
Derivatives Not Designated as Hedging Instruments [Member] | Commodity-Related Derivatives [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Fair value - assets	0	1,813
Derivatives Not Designated as Hedging Instruments [Member] | Commodity-Related Derivatives [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Fair value - liabilities	2,491	8,715
Derivatives Not Designated as Hedging Instruments [Member] | Commodity-Related Derivatives [Member] | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Fair value - liabilities	$ 0	$ 1,632