Condensed Financial Information of Registrant (Parent Company) - Balance Sheets (Details) - USD ($) $ in Millions	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Current assets
Cash and cash equivalents	$ 369.7	$ 419.5	$ 389.3	$ 319.9
Deferred income taxes	7.8	10.1
Total current assets	1,459.8	1,663.0
Other assets	212.8	209.0
Total assets	10,546.6	10,093.0	10,008.8
Current liabilities
Total current liabilities	$ 1,678.9	$ 1,430.9
Commitments and contingencies
Common stockholders’ equity:
UGI Common Stock, without par value (authorized - 450,000,000 shares; issued - 173,806,991 and 173,770,641 shares, respectively)	$ 1,214.6	$ 1,215.6
Retained earnings	1,636.9	1,509.4
Accumulated other comprehensive loss	(114.6)	(21.2)	8.4
Treasury stock, at cost	(44.9)	(44.7)
Total UGI Corporation stockholders’ equity	2,692.0	2,659.1
Total liabilities and equity	$ 10,546.6	$ 10,093.0
Condensed Financial Information of Registrant [Abstract]
Common stock, shares authorized	450,000,000	450,000,000
Common stock, shares issued	173,806,991	173,770,641
Parent Company
Current assets
Cash and cash equivalents	$ 1.9	$ 0.8	$ 0.9	$ 1.9
Accounts receivable - related parties	3.3	3.9
Deferred income taxes	0.4	0.4
Prepaid expenses and other current assets	4.3	0.3
Total current assets	9.9	5.4
Investments in subsidiaries	2,689.7	2,663.9
Other assets	58.7	55.5
Total assets	2,758.3	2,724.8
Current liabilities
Accounts and notes payable	10.9	11.8
Accrued liabilities	5.0	6.0
Total current liabilities	15.9	17.8
Noncurrent liabilities	$ 50.4	$ 47.9
Commitments and contingencies
Common stockholders’ equity:
UGI Common Stock, without par value (authorized - 450,000,000 shares; issued - 173,806,991 and 173,770,641 shares, respectively)	$ 1,214.6	$ 1,215.6
Retained earnings	1,636.9	1,509.4
Accumulated other comprehensive loss	(114.6)	(21.2)
Treasury stock, at cost	(44.9)	(44.7)
Total UGI Corporation stockholders’ equity	2,692.0	2,659.1
Total liabilities and equity	$ 2,758.3	$ 2,724.8
Condensed Financial Information of Registrant [Abstract]
Common stock, shares authorized	450,000,000	450,000,000
Common stock, shares issued	173,806,991	173,770,641