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	Sep. 24, 2016	Sep. 26, 2015
Derivatives, Fair Value [Line Items]
Fair value - assets	$ 7,072	$ 13,803
Fair value - liabilities	4,780	10,184
Commodity-Related Derivatives [Member]
Derivatives, Fair Value [Line Items]
Fair value - assets	6,842	13,063
Fair value - liabilities	4,345	8,132
Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Fair value - assets	230	740
Fair value - liabilities	435	2,052
Derivatives Not Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Fair value - assets	4,852	7,498
Fair value - liabilities	2,355	2,567
Derivatives Not Designated as Hedging Instruments [Member] | Commodity-Related Derivatives [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Fair value - assets	3,306	7,013
Derivatives Not Designated as Hedging Instruments [Member] | Commodity-Related Derivatives [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Fair value - assets	1,546	485
Derivatives Not Designated as Hedging Instruments [Member] | Commodity-Related Derivatives [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Fair value - liabilities	1,002	0
Derivatives Not Designated as Hedging Instruments [Member] | Commodity-Related Derivatives [Member] | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Fair value - liabilities	1,353	2,567
Derivatives Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Fair value - liabilities	205	1,312
Derivatives Designated as Hedging Instruments [Member] | Interest Rate Swaps [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Fair value - liabilities	205	1,112
Derivatives Designated as Hedging Instruments [Member] | Interest Rate Swaps [Member] | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Fair value - liabilities	$ 0	$ 200