Long-Term Borrowings - Additional Information (Details)				3 Months Ended									9 Months Ended
	May 01, 2017	Feb. 14, 2017 USD ($)	Mar. 03, 2016 USD ($)	Dec. 29, 2018	Sep. 29, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 30, 2017	Sep. 30, 2017	Jun. 24, 2017 USD ($)	Jun. 25, 2016 USD ($)	Mar. 26, 2016 USD ($)	Jun. 24, 2017 USD ($)	Jun. 25, 2016 USD ($)	Sep. 24, 2016 USD ($)		Aug. 06, 2013 USD ($)	Aug. 02, 2013 USD ($)
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	$ 292,000
Long-term borrowings										1,250,159,000			$ 1,250,159,000		$ 1,224,502,000	[1]
Consolidated interest coverage ratio, minimum													2.5
Total consolidated leverage ratio, maximum													5.5
Senior secured unconsolidated leverage ratio maximum													3.0
Margin over basis rate (in hundredths)													1.00%
Notional Amount										100,000,000			$ 100,000,000
Consolidated fixed charge coverage ratio, minimum													1.75
Long-term debt maturities, 2017										0			$ 0
Long-term debt maturities, 2018										0			0
Long-term debt maturities, 2019										0			0
Long-term debt maturities, 2020										0			0
Long-term debt maturities, 2021										141,145,000			141,145,000
Long-term debt maturities, 2021 and thereafter										1,125,000,000			1,125,000,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Standby letters of credit issued under the Revolving Credit Facility										$ 43,256,000			$ 43,256,000
Amended Credit Agreement Due 2021 [Member]
Debt Instrument [Line Items]
Weighted average interest rate (in hundredths)										3.60%			3.60%
Amended Credit Agreement Due 2021 [Member] | Federal Funds Rate [Member]
Debt Instrument [Line Items]
Margin over basis rate (in hundredths)													0.50%
Description of applicable interest rate on borrowings													Federal Funds Rate
Amended Credit Agreement Due 2021 [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Margin over basis rate (in hundredths)													1.00%
Description of applicable interest rate on borrowings													LIBOR
Amendment to Amended Credit Agreement Due 2021 [Member]
Debt Instrument [Line Items]
Total consolidated leverage ratio, maximum										5.95			5.5
Amendment to Amended Credit Agreement Due 2021 [Member] | Scenario, Forecast [Member]
Debt Instrument [Line Items]
Total consolidated leverage ratio, maximum				5.5	5.75	5.95	5.95	5.95	5.95
Amendment to Amended Credit Agreement Due 2021 [Member] | Eurodollar Rate Loans [Member]
Debt Instrument [Line Items]
Margin over basis rate (in hundredths)	3.00%
Amendment to Amended Credit Agreement Due 2021 [Member] | Letter of Credit Fees [Member]
Debt Instrument [Line Items]
Margin over basis rate (in hundredths)	3.00%
Amendment to Amended Credit Agreement Due 2021 [Member] | Base Rate Loans [Member]
Debt Instrument [Line Items]
Margin over basis rate (in hundredths)	2.00%
Amendment to Amended Credit Agreement Due 2021 [Member] | Commitment Fee [Member]
Debt Instrument [Line Items]
Margin over basis rate (in hundredths)	0.50%
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%
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			$ 503,443,000
Stated interest rate (in hundredths)										7.375%			7.375%		7.375%
Maturity date													Aug. 01, 2021
Debt instrument repurchase amount																	$ 23,863,000	$ 133,400,000
Loss on debt extinguishment		$ 1,567,000
Redemption premium and related fees		15,078,000
Write-off unamortized debt origination costs		2,272,000
Write-off unamortized premium		$ (15,783,000)
Long-term borrowings										$ 0			$ 0		$ 363,172,000	[1]
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			$ 525,000,000
Stated interest rate (in hundredths)										5.50%			5.50%		5.50%
Maturity date													Jun. 01, 2024
Percentage of principal amount at which debt was issued (in hundredths)										100.00%			100.00%
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	[1]
7.5% Senior Notes due October 1, 2018 [Member]
Debt Instrument [Line Items]
Stated interest rate (in hundredths)										7.50%			7.50%
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			$ 250,000,000
Stated interest rate (in hundredths)										5.75%			5.75%		5.75%
Maturity date													Mar. 01, 2025
Percentage of principal amount at which debt was issued (in hundredths)										100.00%			100.00%
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	[1]
7.375% Senior Notes due 2020 [Member]
Debt Instrument [Line Items]
Stated interest rate (in hundredths)										7.375%			7.375%
5.875% Senior Notes due March 1, 2027 [Member]
Debt Instrument [Line Items]
Date public offering completed													Feb. 14, 2017
Aggregate principal amount										$ 350,000,000			$ 350,000,000
Stated interest rate (in hundredths)										5.875%			5.875%		5.875%
Maturity date													Mar. 01, 2027
Percentage of principal amount at which debt was issued (in hundredths)										100.00%			100.00%
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		$ 0	[1]
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Long-term borrowings										$ 141,145,000			$ 141,145,000		$ 100,000,000
Revolving Credit Facility [Member] | Amended Credit Agreement Due 2021 [Member]
Debt Instrument [Line Items]
Write-off unamortized debt origination costs												$ 292,000
Credit Facility, maximum amount			$ 500,000,000
Revolving credit facility, term			5 years

[1] Long-term borrowings as of September 24, 2016 reflect the retrospective impact from the adoption of new accounting guidance regarding the balance sheet classification of debt issuance costs (See Note 2).