CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2019	Sep. 30, 2018	Jun. 30, 2018
Statement of Financial Position [Abstract]
Accounts receivable (less allowances for doubtful accounts of $42.8, $35.1 and $43.4, respectively)	$ 42.8	$ 35.1	$ 43.4
Property, plant and equipment, at cost (less accumulated depreciation of $3,353.0, $3,153.9 and $3,131.0, respectively)	$ 3,353.0	$ 3,153.9	$ 3,131.0
UGI Common Stock, without par value, shares authorized (in shares)	450,000,000	450,000,000	450,000,000
UGI Common Stock, without par value, shares issued (in shares)	174,678,299	174,142,997	174,111,691