Condensed Financial Information of Registrant (Parent Company) (Details) (USD $) In Millions, except Share data	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2009	Sep. 30, 2008
Current assets
Cash and cash equivalents	$ 238.5	$ 260.7	$ 280.1	$ 245.2
Deferred income taxes	44.9	32.6
Total current assets	1,306.1	1,220.1
Derivative financial instruments	10.2	11.3
Total assets	6,663.3	6,374.3	6,042.6
Current liabilities
Derivative financial instruments	49.7	58.0
Total current liabilities	1,077.9	1,674.7
Commitments and contingencies (note 1)
UGI Corporation stockholders' equity:
Common Stock, without par value (authorized - 300,000,000 shares; issued - 115,507,094 and 115,400,294 shares, respectively)	937.4	906.1
Retained earnings	1,085.8	966.7
Accumulated other comprehensive loss	(17.7)	(10.1)
Treasury stock, at cost	(27.8)	(38.2)
Total UGI Corporation stockholders' equity	1,977.7	1,824.5
Total liabilities and equity	6,663.3	6,374.3
Condensed financial information of registrant (Textual) [Abstract]
UGI Common Stock, without par value
UGI Common Stock, without par value authorized	300,000,000	300,000,000
UGI Common Stock, without par value, issued	115,507,094	115,400,294	115,261,294	115,247,694
Parent Company [Member]
Current assets
Cash and cash equivalents	0.4	1.0	1.4	1.4
Accounts and notes receivable	4.9	18.8
Deferred income taxes	0.4	0.4
Prepaid expenses and other current assets	1.4	0.3
Total current assets	7.1	20.5
Investments in subsidiaries	1,992.1	1,830.1
Derivative financial instruments	0	0.8
Deferred income taxes	22.3	20.9
Total assets	2,021.5	1,872.3
Current liabilities
Accounts and notes payable	11.4	15.8
Derivative financial instruments	3.3	0
Accrued liabilities	1.7	5.0
Total current liabilities	16.4	20.8
Noncurrent liabilities	27.4	27.0
Commitments and contingencies (note 1)
UGI Corporation stockholders' equity:
Common Stock, without par value (authorized - 300,000,000 shares; issued - 115,507,094 and 115,400,294 shares, respectively)	937.4	906.1
Retained earnings	1,085.8	966.7
Accumulated other comprehensive loss	(17.7)	(10.1)
Treasury stock, at cost	(27.8)	(38.2)
Total UGI Corporation stockholders' equity	1,977.7	1,824.5
Total liabilities and equity	$ 2,021.5	$ 1,872.3
Condensed financial information of registrant (Textual) [Abstract]
UGI Common Stock, without par value
UGI Common Stock, without par value authorized	300,000,000	300,000,000
UGI Common Stock, without par value, issued	115,507,094	115,400,294