Utility Regulatory Assets and Liabilities and Regulatory Matters - Narrative (Details) - USD ($) $ in Millions										6 Months Ended	12 Months Ended
	Jan. 28, 2019	Dec. 31, 2018	Oct. 27, 2018	Oct. 25, 2018	May 17, 2018	Jan. 26, 2018	Oct. 20, 2017	Jul. 02, 2017	Jan. 19, 2017	Jun. 30, 2018	Sep. 30, 2018	Dec. 31, 2017
UGI South
Regulatory Assets
PUC temporary rates order, percent of reduction in base rate revenues					5.78%
UGI Utilities
Regulatory Assets
Public utilities, civil penalties								$ 2.1
UGI North
Regulatory Assets
PUC temporary rates order, percent of reduction in base rate revenues					3.90%
UGI Central
Regulatory Assets
PUC temporary rates order, percent of reduction in base rate revenues					8.19%
Pennsylvania Public Utility Commission | UGI Gas
Regulatory Assets
Public utilities, tax benefits received										$ 26.2
Pennsylvania Public Utility Commission | Electric Utility
Regulatory Assets
Public utilities, requested rate increase (decrease), amount		$ 7.7		$ 3.2
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)		$ 0.8									$ 2.9	$ (1.7)
Subsequent Event | Pennsylvania Public Utility Commission | UGI Gas
Regulatory Assets
Public utilities, requested rate increase (decrease), amount	$ 71.1
Public utilities, proposed negative surcharge in customer distribution service bills	4.50%
Minimum
Regulatory Assets
Average remaining depreciable lives of associated property											1 year
Maximum
Regulatory Assets
Average remaining depreciable lives of associated property											65 years