Partnership Organization and Formation - Additional Information (Details) Customer in Millions	Sep. 30, 2017 Customer Location State shares	Sep. 24, 2016 shares
Consolidation Less Than Wholly Owned Subsidiary Parent Ownership Interest Effects Of Changes Net [Line Items]
Common units outstanding (in units)	61,104,544	60,789,000
Ownership interest in Suburban Energy Finance Corp (in hundredths)	100.00%
Number of residential, commercial, industrial and agricultural customers | Customer	1.0
Number of locations served by the partnership | Location	668
Number of states in which the partnership operates | State	41
General Partner [Member] | Common Unitholders [Member]
Consolidation Less Than Wholly Owned Subsidiary Parent Ownership Interest Effects Of Changes Net [Line Items]
Common units outstanding (in units)	784