Regulatory Matters (Details) - USD ($) $ in Thousands	6 Months Ended		12 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Sep. 30, 2022
Regulatory Matters [Line Items]
Reduction of Other Post-Retirement Regulatory Liability	$ 0	$ (18,533)
NEW YORK
Regulatory Matters [Line Items]
Approved Return on Equity	8.70%
Authorized Annual Recovery from Customers for Pension and OPEB Expense	$ 15,000
PENNSYLVANIA
Regulatory Matters [Line Items]
Proposed Base Rate Increase	28,100
Authorized Base Rate Increase	$ 23,000
Approved Base Rate Reduction related to OPEB Expenses			$ (7,700)
Proposed Refund to Customers from Over-Collection of OPEB Expenses			50,000
Reduction of Other Post-Retirement Regulatory Liability			(18,500)
Approved Refund to Customers from Over-Collection of OPEB Expenses			$ 54,000