Commitments and Contingencies (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Dec. 31, 2014 lb competitors lawsuit	Dec. 31, 2013
Commitments and Contingencies
Amount of propane in cylinders before reduction	17
Amount of propane in cylinders after reduction	15
Number of competitors who alleged to have colluded with the Partnership	1
Class action lawsuits (more than 35)	35
PNG MGP
Commitments and Contingencies
Loss contingency, settlement agreement, terms	2 years
Environmental Matters | CPG MGP
Commitments and Contingencies
Environmental expenditures cap during calendar year	1.8
Environmental Matters | PNG MGP
Commitments and Contingencies
Environmental expenditures cap during calendar year	1.1
Environmental Matters | UGI Utilities
Commitments and Contingencies
Base year for determination of investigation and remediation cost (in years)	5 years
CPG and PNG COAs | UGI Utilities
Commitments and Contingencies
Accrual for environmental loss contingencies	11.2	$ 12.1