Inventories - Narrative (Details) - UGI Utilities $ in Millions	9 Months Ended
	Jun. 30, 2017 USD ($) storage_agreement Bcf	Sep. 30, 2016 USD ($) Bcf	Jun. 30, 2016 USD ($) Bcf
Inventory
Number of storage agreements | storage_agreement	5
Volume of gas storage inventories released under SCAAs with non-affiliates (in bcf) | Bcf	1.1	3.5	1.8
Carrying value of gas storage inventories released under SCAAs with non-affiliates | $	$ 3.5	$ 7.6	$ 3.3
Minimum
Inventory
SCAA contract term (in years)	1 year
Maximum
Inventory
SCAA contract term (in years)	3 years