Related Party Transactions (Details) $ in Thousands	3 Months Ended	6 Months Ended
Mar. 31, 2018 USD ($) Bcf	Mar. 31, 2017 USD ($) Bcf	Mar. 31, 2018 USD ($) Bcf	Mar. 31, 2017 USD ($) Bcf	Sep. 30, 2017 USD ($) Bcf
Related Party Transaction
Related party costs incurred	$ 3,766	$ 4,534	$ 6,455	$ 7,098
UGI and Subsidiaries \| Administrative Services
Related Party Transaction
Amount of related party transaction	$ 1,359	$ 1,632	$ 2,405	$ 2,801
Energy Services
Related Party Transaction
Volume of gas storage inventory (in bcf of natural gas) \| Bcf	0.9	0.8	0.9	0.8	6.8
Natural gas storage inventory, related parties, current	$ 2,532	$ 1,964	$ 2,532	$ 1,964	$ 19,323
Revenue from related parties	61,245	22,310	$ 82,392	33,282
Term of agreements (in years)			1 year
Purchases from related party	83,429	39,085	$ 121,026	61,108
Energy Services \| SCAAs
Related Party Transaction
Amount of related party transaction	708	734	$ 1,426	1,298
SCAA contract term (in years)			3 years
Related party costs incurred	179	201	$ 3,280	2,495
Related party security deposits		11,040		11,040
Energy Services \| Exclusive of Transactions Pursuant SCAAs
Related Party Transaction
Related party costs incurred	$ 47,366	$ 41,225	$ 81,954	$ 71,735

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
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Amount of revenue, fees and commissions earned from transactions between (a) a parent company and its subsidiaries; (b) subsidiaries of a common parent; (c) an entity and trusts for the benefit of employees, for example, but not limited to, pension and profit-sharing trusts that are managed by or under the trusteeship of the entity's management; (d) an entity and its principal, owners, management, or members of their immediate families; and (e) affiliates.

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