CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2020	Sep. 30, 2019	Mar. 31, 2019
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 39.4	$ 31.6	$ 43.6
Accumulated depreciation	$ 3,555.2	$ 3,385.2	$ 3,274.6
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)	209,439,475	209,304,129	174,596,873