Equity (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Changes in UGI's equity and the equity of the noncontrolling interests
Beginning Balance			$ 2,191.1	$ 2,061.6
Net income	(76.5)	(13.5)	260.6	357.1
Net gains/(losses) on derivative instruments	(63.2)	(10.8)	(143.9)	25.6
Reclassifications of net losses (gains) on derivative instruments	24.8	(2.9)	69.5	11.0
Benefit plans	0.1	0	0.3	2.1
Foreign currency translation and transaction adjustments			(33.9)	37.8
Dividends and distributions			(215.5)	(154.4)
AmeriGas Partners Common Unit public offering			276.6
AmeriGas Common Units issued in connection with Heritage Acquisition			1,132.6
Adjustments to reflect change in ownership of AmeriGas Partners			(125.1)
Equity transactions - other			25.2	38.9
Other			(0.7)	1.2
Ending Balance	3,436.8	2,380.9	3,436.8	2,380.9
Noncontrolling Interest [Member]
Changes in UGI's equity and the equity of the noncontrolling interests
Beginning Balance			213.4	237.1
Net income			46.5	101.8
Net gains/(losses) on derivative instruments			(69.8)	14.8
Reclassifications of net losses (gains) on derivative instruments			23.7	(16.0)
Dividends and distributions			(126.8)	(69.7)
AmeriGas Partners Common Unit public offering			276.6
AmeriGas Common Units issued in connection with Heritage Acquisition			1,132.6
Adjustments to reflect change in ownership of AmeriGas Partners			(321.4)
Equity transactions - other			4.7	0.5
Other			(0.7)	1.2
Ending Balance	1,178.8	269.7	1,178.8	269.7
Common Stock [Member]
Changes in UGI's equity and the equity of the noncontrolling interests
Beginning Balance			937.4	906.1
Adjustments to reflect change in ownership of AmeriGas Partners			194.4
Equity transactions - other			17.0	28.8
Ending Balance	1,148.8	934.9	1,148.8	934.9
Retained Earnings [Member]
Changes in UGI's equity and the equity of the noncontrolling interests
Beginning Balance			1,085.8	966.7
Net income			214.1	255.3
Dividends and distributions			(88.7)	(84.7)
Ending Balance	1,211.2	1,137.3	1,211.2	1,137.3
Accumulated Other Comprehensive Income (Loss) [Member]
Changes in UGI's equity and the equity of the noncontrolling interests
Beginning Balance			(17.7)	(10.1)
Net gains/(losses) on derivative instruments			(74.1)	10.8
Reclassifications of net losses (gains) on derivative instruments			45.8	27.0
Benefit plans			0.3	2.1
Foreign currency translation and transaction adjustments			(33.9)	37.8
Adjustments to reflect change in ownership of AmeriGas Partners			1.9
Ending Balance	(77.7)	67.6	(77.7)	67.6
Treasury stock [Member]
Changes in UGI's equity and the equity of the noncontrolling interests
Beginning Balance			(27.8)	(38.2)
Equity transactions - other			3.5	9.6
Ending Balance	$ (24.3)	$ (28.6)	$ (24.3)	$ (28.6)