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	Jun. 29, 2019	Sep. 29, 2018
Commodity-Related Derivatives [Member]
Derivatives Fair Value [Line Items]
Fair value - assets	$ 16,852	$ 23,181
Fair value - liabilities	15,414	14,582
Derivatives Not Designated as Hedging Instruments [Member]
Derivatives Fair Value [Line Items]
Fair value - assets	5,253	14,888
Fair value - liabilities	3,815	6,289
Derivatives Not Designated as Hedging Instruments [Member] | Commodity-Related Derivatives [Member] | Other Current Assets [Member]
Derivatives Fair Value [Line Items]
Fair value - assets	5,253	14,875
Derivatives Not Designated as Hedging Instruments [Member] | Commodity-Related Derivatives [Member] | Other Assets [Member]
Derivatives Fair Value [Line Items]
Fair value - assets	0	13
Derivatives Not Designated as Hedging Instruments [Member] | Commodity-Related Derivatives [Member] | Other Current Liabilities [Member]
Derivatives Fair Value [Line Items]
Fair value - liabilities	3,379	6,122
Derivatives Not Designated as Hedging Instruments [Member] | Commodity-Related Derivatives [Member] | Other Liabilities [Member]
Derivatives Fair Value [Line Items]
Fair value - liabilities	$ 436	$ 167