Significant Accounting Policies - Schedule of Changes in Accumulated Other Comprehensive Income (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013	Sep. 30, 2013
Schedule of Changes in Accumulated Other Comprehensive Income
Accumulated other comprehensive loss	$ 24.3	$ (46.5)	$ 24.3	$ (46.5)	$ 32.2	$ 8.4
Other Comprehensive Income (Loss) Before Reclassifications Net Of Tax	5.7		58.5
Reclassification Adjustment of Other Comprehensive Income, Before Tax	(34.4)		(49.9)
Tax on reclassifications on derivative instruments	3.3	(4.2)	5.3	(7.7)
Tax on foreign currency adjustments	0.6	8.2	(3.1)	4.2
Reclassification Adjustment of Other Comprehensive Income, Tax	3.2		5.3
Reclassifications of net losses on derivative instruments	31.4	(25.2)	45.2	(42.6)
Foreign currency, net of tax	(0.6)	(23.6)	11.7	(7.5)
Reclassification Adjustment of Other Comprehensive Income, After Tax	(31.2)		(44.6)
Other comprehensive income (loss)	(25.5)	7.8	13.9	36.3
Reclassification Adjustment of Other Comprehensive Income, Net of Tax, attributable to Noncontrolling Interest	17.6		2.0
Other comprehensive income (loss) attributable to UGI	(7.9)		15.9
Foreign Currency Translation
Schedule of Changes in Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax	63.4		63.4		64.0	51.7
Other Comprehensive Income (Loss) Before Reclassifications Net Of Tax	(0.6)		11.7
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, before Tax	0		0
Tax on foreign currency adjustments	0		0
Foreign currency, net of tax	0		0
Other comprehensive income (loss)	(0.6)		11.7
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax, Portion Attributable to Noncontrolling Interest	0		0
Other comprehensive income (loss) attributable to UGI	(0.6)		11.7
Derivative
Schedule of Changes in Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax	(23.3)		(23.3)		(15.8)	(26.9)
Other Comprehensive Income (Loss) Before Reclassifications Net Of Tax	6.3		46.8
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, before Tax	(34.7)		(50.5)
Tax on reclassifications on derivative instruments	3.3		5.3
Reclassifications of net losses on derivative instruments	(31.4)		(45.2)
Other comprehensive income (loss)	(25.1)		1.6
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax, Portion Attributable to Noncontrolling Interest	17.6		2.0
Other comprehensive income (loss) attributable to UGI	(7.5)		3.6
Postretirement Benefit Plan Adjustments
Schedule of Changes in Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax	(15.8)		(15.8)		(16.0)	(16.4)
Other Comprehensive Income (Loss) Before Reclassifications Net Of Tax	0		0
Other Comprehensive Income (Loss), Reclassification, Pension and Other Postretirement Benefit Plans, Net Gain (Loss) Recognized in Net Periodic Benefit Cost, before Tax	0.3		0.6
Other Comprehensive Income (Loss), Reclassification, Pension and Other Postretirement Benefit Plans, Net Gain (Loss) Recognized in Net Periodic Benefit Cost, Tax	(0.1)		0
Other Comprehensive Income (Loss), Reclassification, Pension and Other Postretirement Benefit Plans, Net Gain (Loss) Recognized in Net Periodic Benefit Cost, Net of Tax	0.2		0.6
Other comprehensive income (loss)	0.2		0.6
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax, Portion Attributable to Noncontrolling Interest	0		0
Other comprehensive income (loss) attributable to UGI	$ 0.2		$ 0.6