Condensed Financial Information of Registrant (Parent Company) - Balance Sheets (Details) (USD $) In Millions, except Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Current assets
Cash and cash equivalents	$ 419.5	$ 389.3	$ 319.9	$ 238.5
Deferred income taxes	10.1	10.6
Total current assets	1,663.0	1,627.3
Other assets	209.0	182.6
Total assets	10,093.0	10,008.8	9,676.9
Current liabilities
Derivative instruments	40.2	30.0
Total current liabilities	1,430.9	1,424.9
Commitments and contingencies (Note 1)
Common stockholders’ equity:
UGI Common Stock, without par value (authorized - 450,000,000 shares; issued - 173,770,641 and 173,675,691 shares, respectively)	1,215.6	1,208.1
Retained earnings	1,509.4	1,308.3
Accumulated other comprehensive (loss) income	(21.2)	8.4
Treasury stock, at cost	(44.7)	(32.3)
Total UGI Corporation stockholders’ equity	2,659.1	2,492.5
Total liabilities and equity	10,093.0	10,008.8
Condensed Financial Information of Registrant [Abstract]
UGI Common Stock, without par value (in dollars per share)	$ 0.00	$ 0.00
UGI Common Stock, without par value authorized (in shares)	450,000,000	450,000,000
UGI Common Stock, without par value, issued (in shares)	173,770,641	173,675,691
Parent Company
Current assets
Cash and cash equivalents	0.8	0.9	1.9	0.4
Accounts and notes receivable	3.9	2.9
Deferred income taxes	0.4	0.4
Prepaid expenses and other current assets	0.3	0.3
Total current assets	5.4	4.5
Investments in subsidiaries	2,663.9	2,488.7
Other assets	55.5	49.9
Total assets	2,724.8	2,543.1
Current liabilities
Accounts and notes payable	11.8	11.0
Derivative instruments	0	0
Accrued liabilities	6.0	3.9
Total current liabilities	17.8	14.9
Noncurrent liabilities	47.9	35.7
Commitments and contingencies (Note 1)
Common stockholders’ equity:
UGI Common Stock, without par value (authorized - 450,000,000 shares; issued - 173,770,641 and 173,675,691 shares, respectively)	1,215.6	1,208.1
Retained earnings	1,509.4	1,308.3
Accumulated other comprehensive (loss) income	(21.2)	8.4
Treasury stock, at cost	(44.7)	(32.3)
Total UGI Corporation stockholders’ equity	2,659.1	2,492.5
Total liabilities and equity	$ 2,724.8	$ 2,543.1
Condensed Financial Information of Registrant [Abstract]
UGI Common Stock, without par value (in dollars per share)	$ 0	$ 0
UGI Common Stock, without par value authorized (in shares)	450,000,000	450,000,000
UGI Common Stock, without par value, issued (in shares)	173,770,641	173,675,691