Utility Regulatory Assets and Liabilities and Regulatory Matters (Details) - UGI Utilities - USD ($) $ in Millions	Mar. 31, 2021	Sep. 30, 2020	Mar. 31, 2020
Regulatory Assets
Regulatory assets	$ 398	$ 397	$ 391
Regulatory Liabilities
Regulatory liabilities	335	353	346
Postretirement benefit overcollections
Regulatory Liabilities
Regulatory liabilities	12	13	14
Deferred fuel and power refunds
Regulatory Liabilities
Regulatory liabilities	17	29	11
State tax benefits — distribution system repairs
Regulatory Liabilities
Regulatory liabilities	29	28	28
PAPUC temporary rates order
Regulatory Liabilities
Regulatory liabilities	2	7	15
Excess federal deferred income taxes
Regulatory Liabilities
Regulatory liabilities	270	274	277
Other
Regulatory Liabilities
Regulatory liabilities	5	2	1
Income taxes recoverable
Regulatory Assets
Regulatory assets	128	124	127
Underfunded pension and postretirement plans
Regulatory Assets
Regulatory assets	169	175	172
Environmental costs
Regulatory Assets
Regulatory assets	59	61	57
Removal costs, net
Regulatory Assets
Regulatory assets	24	26	25
Other
Regulatory Assets
Regulatory assets	$ 18	$ 11	$ 10