Common Stock and Equity Based Compensation (Details 1) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2009
UGI Stock Option Awards
Shares under option, Beginning Balance, Shares	7,673,179	7,557,045	7,501,493
Shares under option, Granted	1,508,050	1,443,558	1,394,300
Share under option, Cancelled	(321,600)	(235,437)	(62,501)
Share under option, Exercised	(801,857)	(1,091,987)	(1,276,247)
Share under option, Ending Balance, Shares	8,057,772	7,673,179	7,557,045	7,501,493
Weighted Average Option Price, Beginning Balance	$ 25.55	$ 23.81	$ 22.74
Weighted Average Option Price, Granted	$ 29.26	$ 31.55	$ 24.37
Weighted Average Option Price, Cancelled	$ 27.74	$ 27.79	$ 25.12
Weighted Average Option Price, Exercised	$ 20.93	$ 20.95	$ 18.09
Weighted Average Option Price, Ending Balance	$ 26.62	$ 25.55	$ 23.81	$ 22.74
Shares Under Option, Total Intrinsic Value, Beginning Balance	$ 15.1	$ 36.2	$ 23.2
Exercised Shares, Total Intrinsic Value	7.2	11.4	11.7
Share Under Option, Total Intrinsic Value, Ending Balance	41.4	15.1	36.2	23.2
Weighted Average Contract Term	6 years 1 month 6 days	6 years 2 months 12 days	6 years 6 months	6 years 4 months 24 days
Option exercisable, Shares	5,317,698	4,879,784	4,706,376
Option exercisable, Weighted average option price	$ 25.32	$ 24.15	$ 22.99
Option exercisable, Total intrinsic value	34.2
Option exercisable, Weighted Average Contract Term	5 years
Non vested options, Shares	2,740,074
Non vested options, Weighted average option price	$ 29.13
Non vested options, Total intrinsic value	$ 7.2
Non Vested Options Weighted Average Contract Term	8 years 3 months 18 days
Range 1 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Lower range limit	$ 0
Upper range limit	$ 19.99
Additional information relating to stock options outstanding and exercisable
Number of outstanding options	162,300
Options outstanding , Weighted average remaining contractual life (in years)	1 year 6 months
Options outstanding, Weighted average exercise price	$ 16.92
Number of exercisable options	162,300
Options exercisable, Weighted average exercise price	$ 16.92
Range 2 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Lower range limit	$ 20
Upper range limit	$ 25
Additional information relating to stock options outstanding and exercisable
Number of outstanding options	2,996,470
Options outstanding , Weighted average remaining contractual life (in years)	5 years 3 months 18 days
Options outstanding, Weighted average exercise price	$ 23.29
Number of exercisable options	2,546,170
Options exercisable, Weighted average exercise price	$ 23.12
Range 3 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Lower range limit	$ 25.01
Upper range limit	$ 30
Additional information relating to stock options outstanding and exercisable
Number of outstanding options	3,529,044
Options outstanding , Weighted average remaining contractual life (in years)	6 years 3 months 18 days
Options outstanding, Weighted average exercise price	$ 27.99
Number of exercisable options	2,164,909
Options exercisable, Weighted average exercise price	$ 27.26
Range 4 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Lower range limit	$ 30.01
Additional information relating to stock options outstanding and exercisable
Number of outstanding options	1,369,958
Options outstanding , Weighted average remaining contractual life (in years)	7 years 9 months 18 days
Options outstanding, Weighted average exercise price	$ 31.53
Number of exercisable options	444,319
Options exercisable, Weighted average exercise price	$ 31.60