Leases - Addition Details (Details) $ in Millions	9 Months Ended
	Jun. 30, 2020 USD ($)
Lessor, Lease, Description [Line Items]
Operating leases not yet commenced	$ 0.0
Finance leases not yet commenced	$ 0.0
Renewal term (up to)	9 years
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:OtherAssets
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:PropertyPlantAndEquipmentNet
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilitiesCurrent
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilitiesNoncurrent
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:LongTermDebtAndCapitalLeaseObligationsCurrent
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	us-gaap:FinanceLeaseLiabilityNoncurrent
AmeriGas Propane | Segment Concentration Risk | Lease Liability Total
Lessor, Lease, Description [Line Items]
Risk percent	85.00%
Minimum | Vehicles
Lessor, Lease, Description [Line Items]
Operating lease remaining lease term	1 year
Maximum | Vehicles
Lessor, Lease, Description [Line Items]
Operating lease remaining lease term	10 years