Common Stock And Equity Based Compensation (Details 8) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Sep. 30, 2012		Sep. 30, 2011	Sep. 30, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of UGI Units, Granted	239,845		285,470	231,710
AmeriGas Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of UGI Units, Granted	193,668
AmeriGas Performance Unit [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of UGI Units, Granted	55,150
AmeriGas Common Unit based awards in common Units and cash
Number of Common Units subject to original awards granted	60,200	[1]	41,064	49,650
Fiscal year granted	2009	[1]	2008	2007
Payment of Awards:
AmeriGas Partners common Units issued	3,500	[1]	35,787	42,121
Cash Paid	0.1	[1]	1.2	1.2
Heritage Propane [Member]
Payment of Awards:
Cash Paid	0.9
Heritage Propane [Member] | AmeriGas Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of UGI Units, Granted	40,516

[1] In addition, 40,516 AmeriGas Stock Units, and $0.9 in cash, were paid to Heritage Propane employees associated with awards granted in Fiscal 2012.