Utility Regulatory Assets and Liabilities and Regulatory Matters (Details Textual) (USD $) In Millions, unless otherwise specified				12 Months Ended						12 Months Ended
	Sep. 30, 2011	Dec. 01, 2010 mi	Sep. 30, 2010	Sep. 30, 2011 UGI Central Penn Gas Inc [Member]	Jan. 14, 2011 UGI Central Penn Gas Inc [Member]	Aug. 27, 2009 UGI Central Penn Gas Inc [Member]	Jan. 28, 2009 UGI Central Penn Gas Inc [Member]	Aug. 27, 2009 UGI Penn Natural Gas Inc [Member]	Jan. 28, 2009 UGI Penn Natural Gas Inc [Member]	Sep. 30, 2011 Maximum [Member] Year	Sep. 30, 2011 Minimum [Member] Year
Schedule of Regulatory Assets and Liabilities [Line Items]
Request to increase base operating revenues to fund system improvements and operations					$ 16.5		$ 19.6		$ 38.1
Resultant increase base operating revenues to fund system improvements and operations						10.0		19.8
Additional base rate revenue using for increased distribution rates per settlement agreement				8.0
Base rate revenue increase for use in CPG's Energy and Efficiency Program				0.9
Average remaining depreciable lives of the associated property										50	1
Unrealized gains or losses on derivative financial instruments contracts	3.1		1.4
Fair value of electric utility electricity supply contracts	8.7		19.7
Maximum period to recover costs related to other regulatory assets	5 years
Minimum period to recover costs related to other regulatory assets	1 year
Net book value of the storage facility assets	10.9
Approval of the transfer length of natural gas pipeline		9.0
Net book value of the Auburn line		$ 1.1