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. 24, 2016	Sep. 24, 2016
Derivatives, Fair Value [Line Items]
Fair value - assets	$ 8,610	$ 7,072
Fair value - liabilities	5,356	4,780
Commodity-Related Derivatives [Member]
Derivatives, Fair Value [Line Items]
Fair value - assets	8,594	6,842
Fair value - liabilities	5,329	4,345
Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Fair value - assets	16	230
Fair value - liabilities	27	435
Derivatives Not Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Fair value - assets	4,491	4,852
Fair value - liabilities	1,226	2,355
Derivatives Not Designated as Hedging Instruments [Member] | Commodity-Related Derivatives [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Fair value - assets	4,491	3,306
Derivatives Not Designated as Hedging Instruments [Member] | Commodity-Related Derivatives [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Fair value - assets	0	1,546
Derivatives Not Designated as Hedging Instruments [Member] | Commodity-Related Derivatives [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Fair value - liabilities	1,226	1,002
Derivatives Not Designated as Hedging Instruments [Member] | Commodity-Related Derivatives [Member] | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Fair value - liabilities	0	1,353
Derivatives Designated as Hedging Instruments [Member] | Interest Rate Swaps [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Fair value - liabilities	$ 11	$ 205