Long-Term Borrowings - Additional Information (Details) - USD ($)		6 Months Ended
	Mar. 03, 2016	Mar. 30, 2019	Sep. 29, 2018
Debt Instrument [Line Items]
Ownership interest in Suburban Energy Finance Corp (in hundredths)		100.00%
Long-term borrowings		$ 1,268,500,000	$ 1,268,600,000
Margin over basis rate (in hundredths)		1.00%
Consolidated fixed charge coverage ratio, minimum		1.75
Long-term debt maturities, 2019		$ 0
Long-term debt maturities, 2020		0
Long-term debt maturities, 2021		143,500,000
Long-term debt maturities, 2022		0
Long-term debt maturities, 2023		0
Long-term debt maturities, 2023 and thereafter		$ 1,125,000,000
Amended Credit Agreement Due 2021 [Member]
Debt Instrument [Line Items]
Consolidated interest coverage ratio, minimum		2.5
Total consolidated leverage ratio, maximum		5.5
Senior secured unconsolidated leverage ratio maximum		3.0
Weighted average interest rate (in hundredths)		5.00%
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%
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Maturity date		Mar. 03, 2021
Long-term borrowings		$ 143,500,000	$ 143,600,000
Standby letters of credit issued under the Revolving Credit Facility		62,426,000
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	$ 0
5.5% Senior Notes due June 1, 2024 [Member]
Debt Instrument [Line Items]
Stated interest rate (in hundredths)		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%
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%
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%
Date public offering completed		May 27, 2014
Aggregate principal amount		$ 525,000,000
Percentage of principal amount at which debt was issued (in hundredths)		100.00%
Maturity date		Jun. 01, 2024
Percentage of the principal amount repurchase offer under change of control provision (in hundredths)		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
Senior Notes [Member] | 7.5% Senior Notes due October 1, 2018 [Member]
Debt Instrument [Line Items]
Stated interest rate (in hundredths)		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%
Date public offering completed		Feb. 25, 2015
Aggregate principal amount		$ 250,000,000
Percentage of principal amount at which debt was issued (in hundredths)		100.00%
Maturity date		Mar. 01, 2025
Percentage of the principal amount repurchase offer under change of control provision (in hundredths)		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
Senior Notes [Member] | 7.375% Senior Notes due 2020 [Member]
Debt Instrument [Line Items]
Stated interest rate (in hundredths)		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%
Date public offering completed		Feb. 14, 2017
Aggregate principal amount		$ 350,000,000
Percentage of principal amount at which debt was issued (in hundredths)		100.00%
Maturity date		Mar. 01, 2027
Percentage of the principal amount repurchase offer under change of control provision (in hundredths)		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
Senior Notes [Member] | 7.375% Senior Notes due August 1, 2021 [Member]
Debt Instrument [Line Items]
Stated interest rate (in hundredths)		7.375%