Common Stock and Equity Based Compensation (Details 1) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Sep. 30, 2011 States Year bcf	Sep. 30, 2010 Year bcf	Sep. 30, 2009 Year	Sep. 30, 2008 Year
UGI Stock Option Awards
Shares under option, Beginning Balance, Shares	7,557,045	7,501,493	6,652,245
Shares under option, Granted	1,443,558	1,394,300	1,411,200
Share under option, Cancelled	(235,437)	(62,501)	(87,334)
Share under option, Exercised	(1,091,987)	(1,276,247)	(474,618)
Share under option, Ending Balance, Shares	7,673,179	7,557,045	7,501,493
Weighted Average Option Price, Beginning Balance	$ 23.81	$ 22.74	$ 21.71
Weighted Average Option Price, Granted	$ 31.55	$ 24.37	$ 24.65
Weighted Average Option Price, Cancelled	$ 27.79	$ 25.12	$ 25.81
Weighted Average Option Price, Exercised	$ 20.95	$ 18.09	$ 13.30
Weighted Average Option Price, Ending Balance	$ 25.55	$ 23.81	$ 22.74
Shares Under Option, Total Intrinsic Value, Beginning Balance	$ 36.2	$ 23.2	$ 30.9
Exercised Shares, Total Intrinsic Value	11.4	11.7	6.0
Share Under Option, Total Intrinsic Value, Ending Balance	15.1	36.2	23.2
Weighted Average Contract Term (Years)	6.2	6.5	6.4	6.6
Option exercisable, Shares	4,879,784	4,706,376	4,744,054
Option exercisable, Weighted average option price	$ 24.15	$ 22.99	$ 21.00
Option exercisable, Total intrinsic value	12.7
Option exercisable, Weighted Average Contract Term (Years)	5.2
Non vested options, Shares	2,793,395
Non vested options, Weighted average option price	$ 27.99
Non vested options, Total intrinsic value	$ 2.4
Non Vested Options Weighted Average Contract Term (Years)	8.0
Range 1 [Member]
Additional information relating to stock options outstanding and exercisable
Upper range limit	$ 20.00
Number of outstanding options	336,300
Options outstanding , Weighted average remaining contractual life (in years)	1.9
Options outstanding, Weighted average exercise price	$ 15.42
Number of exercisable options	336,300
Options exercisable, Weighted average exercise price	$ 15.42
Range 2 [Member]
Additional information relating to stock options outstanding and exercisable
Lower range limit	$ 20.00
Upper range limit	$ 25.00
Number of outstanding options	3,539,727
Options outstanding , Weighted average remaining contractual life (in years)	6.0
Options outstanding, Weighted average exercise price	$ 23.05
Number of exercisable options	2,351,093
Options exercisable, Weighted average exercise price	$ 22.44
Range 3 [Member]
Additional information relating to stock options outstanding and exercisable
Lower range limit	$ 25.01
Upper range limit	$ 30.00
Number of outstanding options	2,456,694
Options outstanding , Weighted average remaining contractual life (in years)	5.7
Options outstanding, Weighted average exercise price	$ 27.24
Number of exercisable options	2,124,391
Options exercisable, Weighted average exercise price	$ 27.19
Range 4 [Member]
Additional information relating to stock options outstanding and exercisable
Lower range limit	$ 30.00
Number of outstanding options	1,340,458
Options outstanding , Weighted average remaining contractual life (in years)	8.7
Options outstanding, Weighted average exercise price	$ 31.59
Number of exercisable options	68,000
Options exercisable, Weighted average exercise price	$ 31.74