Long-Term Borrowings - Additional Information (Details) - USD ($)			12 Months Ended
	Feb. 25, 2015	May. 27, 2014	Sep. 26, 2015	Sep. 27, 2014	Sep. 28, 2013	Aug. 06, 2013	Aug. 02, 2013	Aug. 01, 2012
Debt Instrument [Line Items]
Ownership interest in Suburban Energy Finance Corp (in hundredths)			100.00%
Loss on debt extinguishment			$ 15,072,000	$ 11,589,000	$ 2,144,000
Long-term borrowings			$ 1,241,107,000	1,242,685,000
Consolidated interest coverage ratio, minimum			2.5
Total consolidated leverage ratio, maximum			4.75
Consolidated leverage ratio during acquisition period, maximum			5.0
Notional Amount			$ 100,000,000
Consolidated fixed charge coverage ratio, minimum			1.75
Capitalized debt origination costs			$ 18,458,000	21,023,000
Long-term debt maturities, 2016			0
Long-term debt maturities, 2017			100,000,000
Long-term debt maturities, 2018			0
Long-term debt maturities, 2019			0
Long-term debt maturities, 2020			0
Long-term debt maturities, 2020 and thereafter			$ 1,121,180,000
Federal Funds Rate [Member]
Debt Instrument [Line Items]
Description of applicable interest rate on borrowings			Federal Funds Rate
Basis spread (in hundredths)			0.50%
LIBOR [Member]
Debt Instrument [Line Items]
Description of applicable interest rate on borrowings			LIBOR
Basis spread (in hundredths)			1.00%
Amended Credit Agreement Due 2017 [Member]
Debt Instrument [Line Items]
Weighted average interest rate (in hundredths)			2.50%
Effective date			Jun. 25, 2013
Termination date			Jan. 05, 2017
Fixed interest rate (in hundredths)			1.63%
Amended Credit Agreement Due 2017 [Member] | Federal Funds Rate [Member]
Debt Instrument [Line Items]
Description of applicable interest rate on borrowings			Federal Funds Rate
Basis spread (in hundredths)			0.50%
Amended Credit Agreement Due 2017 [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Description of applicable interest rate on borrowings			LIBOR
Basis spread (in hundredths)			1.00%
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Long-term borrowings			$ 100,000,000	$ 100,000,000
Standby letters of credit issued under the Revolving Credit Facility			46,183,000
Available borrowing capacity under Revolving Credit Facility			$ 253,817,000
Revolving Credit Facility [Member] | Amended Credit Agreement Due 2017 [Member]
Debt Instrument [Line Items]
Revolving credit facility, term			5 years
Credit Facility, maximum amount			$ 400,000,000
7.5% Senior Notes due October 1, 2018 [Member]
Debt Instrument [Line Items]
Date public offering completed			Aug. 01, 2012
Aggregate principal amount			$ 496,557,000
Stated interest rate (in hundredths)			7.50%
Maturity date			Oct. 01, 2018
Fair value of debt at acquisition date (in hundredths)								106.875%
Loss on debt extinguishment		$ 11,589,000
Redemption premium and related fees		31,633,000
Write-off unamortized debt origination costs		5,230,000
Write-off unamortized premium		$ (25,274,000)
7.375% Senior Notes due August 1, 2021 [Member]
Debt Instrument [Line Items]
Date public offering completed			Aug. 01, 2012
Aggregate principal amount			$ 503,443,000
Stated interest rate (in hundredths)			7.375%	7.375%
Maturity date			Aug. 01, 2021
Fair value of debt at acquisition date (in hundredths)								108.125%
Debt instrument repurchase amount						$ 23,863,000	$ 133,400,000
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			$ 366,107,000	$ 368,868,000
7.375% Senior Notes due March 15, 2020 [Member]
Debt Instrument [Line Items]
Date public offering completed			Mar. 23, 2010
Aggregate principal amount			$ 250,000,000
Stated interest rate (in hundredths)			7.375%	7.375%
Maturity date			Mar. 15, 2020
Loss on debt extinguishment	$ 15,072,000
Redemption premium and related fees	11,124,000
Write-off unamortized debt origination costs	2,855,000
Percentage of principal amount at which debt was issued (in hundredths)			99.136%
Write-off unamortized discount	$ 1,093,000
Long-term borrowings				$ 248,817,000
5.5% Senior Notes due June 1, 2024 [Member]
Debt Instrument [Line Items]
Date public offering completed			May 27, 2014
Aggregate principal amount			$ 525,000,000
Stated interest rate (in hundredths)			5.50%	5.50%
Maturity date			Jun. 01, 2024
Percentage of principal amount at which debt was issued (in hundredths)			100.00%
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
5.75% Senior Notes due March 1, 2025 [Member]
Debt Instrument [Line Items]
Date public offering completed			Feb. 25, 2015
Aggregate principal amount			$ 250,000,000
Stated interest rate (in hundredths)			5.75%
Maturity date			Mar. 01, 2025
Percentage of principal amount at which debt was issued (in hundredths)			100.00%
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