The indenture governing the 2020 Senior Notes, requires the Partnership's consolidated fixed charge coverage ratio, as defined, to exceed a minimum ratio to permit the Partnership to make cash distributions equal to available cash, as defined, as of the end of the immediately preceding quarter, if no event of default exists or would exist upon making such distributions.

No definition available.

Long-Term Borrowings - Additional Information (Details)			3 Months Ended					12 Months Ended
Long-Term Borrowings - Additional Information (Details)	Feb. 14, 2017 USD ($)	Mar. 03, 2016 USD ($)	Sep. 28, 2019 USD ($)	Jun. 29, 2019	Mar. 30, 2019	Dec. 29, 2018	Sep. 29, 2018 USD ($)	Sep. 28, 2019 USD ($)	Sep. 29, 2018 USD ($)	Sep. 30, 2017 USD ($)
Debt Instrument [Line Items]
Ownership interest in Suburban Energy Finance Corp (in hundredths)			100.00%					100.00%
Loss on debt extinguishment								$ 0	$ 0	$ 1,567,000
Long-term borrowings			$ 1,238,500,000				$ 1,268,600,000	$ 1,238,500,000	1,268,600,000
Notional Amount							$ 100,000,000		100,000,000
Consolidated fixed charge coverage ratio, minimum								1.75
Long-term debt maturities, 2020			0					$ 0
Long-term debt maturities, 2021			113,500,000					113,500,000
Long-term debt maturities, 2022			0					0
Long-term debt maturities, 2023			0					0
Long-term debt maturities, 2024			525,000,000					525,000,000
Long-term debt maturities, thereafter			$ 600,000,000					$ 600,000,000
Federal Funds Rate [Member]
Debt Instrument [Line Items]
Description of applicable interest rate on borrowings								Federal Funds Rate
Margin over basis rate (in hundredths)								0.50%
LIBOR [Member]
Debt Instrument [Line Items]
Description of applicable interest rate on borrowings								LIBOR
Margin over basis rate (in hundredths)								1.00%
Amended Credit Agreement Due 2021 [Member]
Debt Instrument [Line Items]
Consolidated interest coverage ratio, minimum			2.5
Total consolidated leverage ratio, maximum			5.5	5.5	5.5	5.5	5.75
Senior secured unconsolidated leverage ratio maximum			3.0
Weighted average interest rate (in hundredths)			4.50%					4.50%
Amended Credit Agreement Due 2021 [Member] \| Federal Funds Rate [Member]
Debt Instrument [Line Items]
Description of applicable interest rate on borrowings								Federal Funds Rate
Margin over basis rate (in hundredths)								0.50%
Amended Credit Agreement Due 2021 [Member] \| LIBOR [Member]
Debt Instrument [Line Items]
Description of applicable interest rate on borrowings								LIBOR
Margin over basis rate (in hundredths)								1.00%
Amended Credit Agreement Due 2017 [Member]
Debt Instrument [Line Items]
Effective date								Jun. 25, 2013
Termination date								Jan. 05, 2017
Fixed interest rate (in hundredths)			1.63%					1.63%
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Maturity date								Mar. 03, 2021
Long-term borrowings			$ 113,500,000				$ 143,600,000	$ 113,500,000	143,600,000
Standby letters of credit issued under the Revolving Credit Facility			65,826,000					$ 65,826,000
Standby letters of credit issued under the Revolving Credit Facility, expiration date								Nov. 01, 2020
Revolving Credit Facility [Member] \| Amended Credit Agreement Due 2021 [Member]
Debt Instrument [Line Items]
Revolving credit facility, term		5 years
Credit Facility, maximum amount		$ 500,000,000
Capitalized debt origination costs			$ 1,550,000				$ 2,644,000	$ 1,550,000	$ 2,644,000
5.5% Senior Notes due June 1, 2024 [Member]
Debt Instrument [Line Items]
Stated interest rate (in hundredths)			5.50%				5.50%	5.50%	5.50%
Maturity date								Jun. 01, 2024
5.75% Senior Notes due March 1, 2025 [Member]
Debt Instrument [Line Items]
Stated interest rate (in hundredths)			5.75%				5.75%	5.75%	5.75%
Maturity date								Mar. 01, 2025
5.875% Senior Notes due March 1, 2027 [Member]
Debt Instrument [Line Items]
Stated interest rate (in hundredths)			5.875%				5.875%	5.875%	5.875%
Maturity date								Mar. 01, 2027
Senior Notes [Member] \| 5.5% Senior Notes due June 1, 2024 [Member]
Debt Instrument [Line Items]
Stated interest rate (in hundredths)			5.50%					5.50%
Date public offering completed								May 27, 2014
Aggregate principal amount			$ 525,000,000					$ 525,000,000
Percentage of principal amount at which debt was issued (in hundredths)			100.00%					100.00%
Maturity date								Jun. 01, 2024
Redemption start date								Jun. 01, 2019
Redemption description								The 2024 Senior Notes are redeemable, at the Partnership’s option, in whole or in part, at any time on or after June 1, 2019, in each case at the redemption prices described in the table below, together with any accrued and unpaid interest to the date of the redemption.
Percentage of the principal amount repurchase offer under change of control provision (in hundredths)			101.00%					101.00%
Repurchase of debt due to decline in rating after consummation of change of control, period								90 days
Long-term borrowings			$ 525,000,000				$ 525,000,000	$ 525,000,000	$ 525,000,000
Senior Notes [Member] \| 7.5% Senior Notes due October 1, 2018 [Member]
Debt Instrument [Line Items]
Stated interest rate (in hundredths)			7.50%					7.50%
Senior Notes [Member] \| 5.75% Senior Notes due March 1, 2025 [Member]
Debt Instrument [Line Items]
Stated interest rate (in hundredths)			5.75%					5.75%
Date public offering completed								Feb. 25, 2015
Aggregate principal amount			$ 250,000,000					$ 250,000,000
Percentage of principal amount at which debt was issued (in hundredths)			100.00%					100.00%
Maturity date								Mar. 01, 2025
Redemption start date								Mar. 01, 2020
Redemption description								The 2025 Senior Notes are redeemable, at the Partnership’s option, in whole or in part, at any time on or after March 1, 2020, in each case at the redemption prices described in the table below, together with any accrued and unpaid interest to the date of the redemption.
Percentage of the principal amount repurchase offer under change of control provision (in hundredths)			101.00%					101.00%
Repurchase of debt due to decline in rating after consummation of change of control, period								90 days
Long-term borrowings			$ 250,000,000				250,000,000	$ 250,000,000	250,000,000
Senior Notes [Member] \| 7.375% Senior Notes due 2020 [Member]
Debt Instrument [Line Items]
Stated interest rate (in hundredths)			7.375%					7.375%
Senior Notes [Member] \| 5.875% Senior Notes due March 1, 2027 [Member]
Debt Instrument [Line Items]
Stated interest rate (in hundredths)			5.875%					5.875%
Date public offering completed								Feb. 14, 2017
Aggregate principal amount			$ 350,000,000					$ 350,000,000
Percentage of principal amount at which debt was issued (in hundredths)			100.00%					100.00%
Maturity date								Mar. 01, 2027
Redemption start date								Mar. 01, 2022
Redemption description								The 2027 Senior Notes are redeemable, at the Partnership’s option, in whole or in part, at any time on or after March 1, 2022, in each case at the redemption prices described in the table below, together with any accrued and unpaid interest to the date of the redemption.
Percentage of the principal amount repurchase offer under change of control provision (in hundredths)			101.00%					101.00%
Repurchase of debt due to decline in rating after consummation of change of control, period								90 days
Long-term borrowings			$ 350,000,000				$ 350,000,000	$ 350,000,000	$ 350,000,000
Capitalized costs										6,100,000
Senior Notes [Member] \| 7.375% Senior Notes due August 1, 2021 [Member]
Debt Instrument [Line Items]
Stated interest rate (in hundredths)			7.375%					7.375%
Loss on debt extinguishment	$ 1,567,000
Redemption premium and related fees	15,078,000
Write-off unamortized debt origination costs	2,272,000									$ 1,567,000
Write-off unamortized premium	$ (15,783,000)