Utility Regulatory Assets and Liabilities and Regulatory Matters - Narrative (Details) - USD ($) $ in Millions								3 Months Ended	6 Months Ended
	Jan. 28, 2019	Oct. 27, 2018	Oct. 25, 2018	Jan. 26, 2018	Jul. 02, 2017	Jun. 30, 2017	Jan. 19, 2017	Mar. 31, 2019	Mar. 31, 2019	Jun. 30, 2018	Sep. 30, 2018	Mar. 31, 2018
UGI South
Regulatory Assets
PUC temporary rates order, percent of reduction in base rate revenues								4.71%
UGI North
Regulatory Assets
PUC temporary rates order, percent of reduction in base rate revenues								2.87%
UGI Central
Regulatory Assets
PUC temporary rates order, percent of reduction in base rate revenues								6.34%
UGI Utilities
Regulatory Assets
Public utilities, civil penalties					$ 2.1
Pennsylvania Public Utility Commission | UGI Gas
Regulatory Assets
Public utilities, proposed negative surcharge in customer distribution service bills	4.50%
Public utilities, tax benefits received										$ 24.0
Public utilities, requested rate increase (decrease), amount	$ 71.1
Pennsylvania Public Utility Commission | Electric Utility
Regulatory Assets
Public utilities, requested rate increase (decrease), amount			$ 3.2	$ 7.7
Public utilities, requested increase in annual base distribution revenues				$ 9.2
Public utilities, customer billing credit		$ 0.2
Pennsylvania Public Utility Commission | PNG
Regulatory Assets
Public utilities, requested rate increase (decrease), amount							$ 21.7
Public utilities, approved rate increase (decrease), amount						$ 11.3
Gas Utility
Regulatory Assets
Fair value of unrealized gains (losses)								$ 1.0	$ 1.0		$ 2.9	$ 0.3
Minimum
Regulatory Assets
Average remaining depreciable lives of associated property									1 year
Maximum
Regulatory Assets
Average remaining depreciable lives of associated property									65 years