Inventories - Narrative (Details) $ in Millions	9 Months Ended
	Jun. 30, 2019 USD ($) storage_agreement	Sep. 30, 2018 USD ($) Bcf	Jun. 30, 2018 USD ($) Bcf
Inventory
Carrying value of gas storage inventories released under SCAAs with non-affiliates	$ 0.0
UGI Utilities
Inventory
Number of storage agreements | storage_agreement	4
Volume of gas storage inventories released under SCAAs with non-affiliates (in bcf) | Bcf		2.3	1.2
Carrying value of gas storage inventories released under SCAAs with non-affiliates		$ 5.4	$ 2.7
UGI Utilities | Maximum
Inventory
SCAA contract term (in years)	3 years