Commitments and Contingencies (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 30, 2014 lawsuit	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2014 CPG MGP Properties	Sep. 30, 2014 PNG MGP Properties	Sep. 30, 2008 Partnership lb	Sep. 30, 2014 Environmental Issue	Sep. 30, 2014 Maximum Gas Utility	Sep. 30, 2014 Maximum Midstream and Marketing	Sep. 30, 2014 Maximum Partnership	Sep. 30, 2014 Maximum UGI International	Sep. 30, 2014 The Partnership and UGI International Minimum	Sep. 30, 2014 The Partnership and UGI International Maximum	Sep. 30, 2014 UGI International Minimum	Sep. 30, 2014 UGI International Maximum
Commitments and Contingencies
Aggregate rental expense for leases	$ 79.7	$ 82.5	$ 77.9
Term of contracts								16 months	2 years	3 years	3 years
Contract terms subject to annual price and quantity ddjustments (in years)												1 year	3 years	1 year	3 years
Environmental expenditures				1.8	1.1
Accrued liabilities for environmental investigation and remediation costs related to CPG-COA and PNG-COA	$ 10.7	$ 14.0
Base year for determination of investigation and remediation cost (in years)							5 years
Amount of propane in cylinders being sold						17
Reduced amount of propane in cylinders being sold						15
Loss Contingency Class Action Lawsuit	35