Document and Entity Information - shares	9 Months Ended
	Jun. 27, 2020	Aug. 03, 2020
Cover [Abstract]
Entity Registrant Name	SUBURBAN PROPANE PARTNERS LP
Entity Central Index Key	0001005210
Current Fiscal Year End Date	--09-26
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		62,146,403
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3
Document Type	10-Q
Trading Symbol	SPH
Amendment Flag	false
Document Period End Date	Jun. 27, 2020
Security Exchange Name	NYSE
Title of 12(g) Security	Common Units
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity File Number	1-14222
Entity Interactive Data Current	Yes
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	22-3410353
Entity Address, Address Line One	240 Route 10 West
Entity Address, City or Town	Whippany
Entity Address, State or Province	NJ
Entity Address, Postal Zip Code	07981
City Area Code	973
Local Phone Number	887-5300
Document Quarterly Report	true
Document Transition Report	false