Utility Regulatory Assets and Liabilities and Regulatory Matters - Narrative (Details) - USD ($)	Feb. 08, 2021	Oct. 08, 2020	Jan. 28, 2020	Oct. 11, 2019	Jan. 28, 2019	Mar. 31, 2021	Sep. 30, 2020	Mar. 31, 2020
UGI Electric | PAPUC
Regulatory Assets
Public utilities, requested rate increase (decrease), amount	$ 9,000,000
UGI Gas | PAPUC
Regulatory Assets
Public utilities, requested rate increase (decrease), amount			$ 75,000,000		$ 71,000,000
Public utilities, approved rate increase (decrease), amount		$ 20,000,000		$ 30,000,000
Property, plant and equipment, net threshold		$ 2,875,000,000
Amortization period		10 years
Tax benefit to be returned, period				5 years
Tax benefit to be returned					$ 24,000,000
Public utilities, tax benefits, effective period				12 months
UGI Gas | PAPUC | Beginning January 1, 2021
Regulatory Assets
Public utilities, approved rate increase (decrease), amount		$ 10,000,000
UGI Gas | PAPUC | Beginning July 1, 2021
Regulatory Assets
Public utilities, approved rate increase (decrease), amount		$ 10,000,000
Gas Utility
Regulatory Assets
Fair value of unrealized gains (losses)						$ 1,000,000	$ 8,000,000	$ (1,000,000)