Regulatory Assets and Liabilities and Regulatory Matters - Schedule of Regulatory Assets and Liabilities Associated With Gas Utility and Electric Utility (Details) - USD ($) $ in Thousands		Mar. 31, 2016	Sep. 30, 2015	Mar. 31, 2015
Regulatory Assets and Liabilities
Regulatory Assets		$ 348,212	$ 304,208	$ 252,570
Regulatory Liabilities	[1]	66,803	71,004	72,585
Postretirement Benefits
Regulatory Assets and Liabilities
Regulatory Liabilities		19,307	19,975	19,323
Deferred Fuel and Power Refunds
Regulatory Assets and Liabilities
Regulatory Liabilities		30,838	36,638	40,542
State Tax Benefits -- Distribution System Repairs
Regulatory Assets and Liabilities
Regulatory Liabilities		14,158	13,266	10,621
Other
Regulatory Assets and Liabilities
Regulatory Liabilities		2,500	1,125	2,099
Income Taxes Recoverable
Regulatory Assets and Liabilities
Regulatory Assets		118,160	115,946	111,441
Underfunded Pension and Postretirement Plans
Regulatory Assets and Liabilities
Regulatory Assets		135,825	140,762	105,539
Environmental Costs
Regulatory Assets and Liabilities
Regulatory Assets	[2]	60,494	19,983	14,110
Removal Costs, Net
Regulatory Assets and Liabilities
Regulatory Assets		25,030	21,223	18,377
Other
Regulatory Assets and Liabilities
Regulatory Assets		$ 8,703	$ 6,294	$ 3,103

[1] Regulatory liabilities, other than deferred fuel and power refunds, are recorded in other current and other noncurrent liabilities in the Condensed Consolidated Balance Sheets.

[2] Environmental costs at March 31, 2016, include amounts probable of recovery recorded in conjunction with UGI Gas’ Consent Order and Agreement with the Pennsylvania Department of Environmental Protection (see Note 7).