Related Party Transactions (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2019 USD ($) Bcf	Mar. 31, 2018 USD ($) Bcf	Mar. 31, 2019 USD ($) Bcf	Mar. 31, 2018 USD ($) Bcf	Sep. 30, 2018 USD ($) Bcf
Related Party Transaction
Related party costs incurred	$ 5,198	$ 3,766	$ 8,710	$ 6,455
UGI and Subsidiaries | Administrative Services
Related Party Transaction
Amount of related party transaction	$ 1,510	$ 1,359	$ 2,692	$ 2,405
Energy Services
Related Party Transaction
Volume of gas storage inventory (in bcf of natural gas) | Bcf	0.8	0.9	0.8	0.9	6.7
Natural gas storage inventory, related parties, current	$ 2,075	$ 2,532	$ 2,075	$ 2,532	$ 17,701
Revenue from related parties	24,564	61,245	$ 47,426	82,392
Term of agreements (in years)			1 year
Purchases from related party	46,295	83,429	$ 90,677	121,026
Energy Services | SCAAs
Related Party Transaction
Amount of related party transaction	776	708	$ 1,519	1,426
SCAA contract term (in years)			3 years
Related party costs incurred	168	179	$ 3,269	3,280
Related party security deposits	9,040	11,040	9,040	11,040	$ 11,040
Energy Services | Exclusive of Transactions Pursuant SCAAs
Related Party Transaction
Related party costs incurred	$ 54,120	$ 47,366	$ 90,357	$ 81,954