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	Mar. 30, 2019	Sep. 29, 2018
Commodity-Related Derivatives [Member]
Derivatives Fair Value [Line Items]
Fair value - assets	$ 7,101	$ 23,181
Fair value - liabilities	5,442	14,582
Derivatives Not Designated as Hedging Instruments [Member]
Derivatives Fair Value [Line Items]
Fair value - assets	3,944	14,888
Fair value - liabilities	2,285	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	3,944	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	2,285	6,122
Derivatives Not Designated as Hedging Instruments [Member] | Commodity-Related Derivatives [Member] | Other Liabilities [Member]
Derivatives Fair Value [Line Items]
Fair value - liabilities	$ 0	$ 167