Regulatory Matters (Details) $ in Millions	9 Months Ended
	Jun. 30, 2018 USD ($)
Regulatory Matters [Line Items]
Required Temporary Refund on Customer Rates	2.20%
Empire [Member]
Regulatory Matters [Line Items]
Proposed Annual Cost of Service	$ 71.5
Proposed Rate Base	$ 246.8
Proposed Return on Equity	14.00%