Financial Instruments and Risk Management - Effect of the Partnership's Derivative Instruments on the Condensed Consolidated Statements of Operations (Details) - USD ($) $ in Thousands	3 Months Ended
Dec. 26, 2020	Dec. 28, 2019
Commodity-Related Derivatives [Member] \| Cost of Products Sold [Member] \| Derivatives Not Designated as Hedging Instruments [Member]
Derivative Instruments Gain Loss [Line Items]
Unrealized Gains (Losses) Recognized in Income	$ 4,855	$ 2,776

Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4A
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5618551-113959

Name:	us-gaap_DerivativeGainLossOnDerivativeNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration