Commitments and Contingencies (Details)	12 Months Ended
	Sep. 30, 2016 USD ($) subsidiary	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)
Contingencies
Rental expense	$ 7,669,000	$ 7,956,000	$ 6,803,000
Minimum future payments under operating leases
2017	5,984,000
2018	5,016,000
2019	3,048,000
2020	1,314,000
2021	560,000
After 2021	209,000
Contractual obligations under suplly, storage and service agreements
2017	205,548,000
2018	142,208,000
2019	120,142,000
2020	80,443,000
2021	54,430,000
After 2021	$ 134,978,000
PNG and CPG
Contingencies
Number of subsidiaries acquired with similar histories | subsidiary	2
UGI Gas-COA
Contingencies
Accrued liabilities for environmental investigation and remediation costs	$ 43,737,000
Environmental Issue | UGI Gas MGP Properties
Contingencies
Expected environmental expenditures cap during year	$ 2,500,000
Gas Utility
Contingencies
Duration of supply agreements - not more than (in months)	16 months
CPG-COA and PNG-COA
Contingencies
Accrued liabilities for environmental investigation and remediation costs	$ 11,326,000	$ 13,758,000
CPG MGP
Contingencies
Environmental expenditures cap during year	1,800,000
PNG MGP
Contingencies
Environmental expenditures cap during year	$ 1,100,000
Option to termination agreement by either party effective at end of any two-year period	2 years