Fair Value Measurements (Narrative) (Details)	12 Months Ended	36 Months Ended
	Dec. 31, 2023 USD ($)	Dec. 31, 2025 USD ($) payment	Mar. 31, 2024 USD ($)	Sep. 30, 2023 USD ($)	Mar. 31, 2023 USD ($)	Sep. 30, 2022 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Hedging Collateral Deposits			$ 0	$ 0	$ 0	$ 91,670,000
California Asset Sale | Forecast
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Maximum Annual Contingent Payment		$ 10,000,000
Amount of Each Incremental Contingency Payment		1,000,000
Incremental price, exceeding ICE Brent Average Price (in dollars per barrel)		1
California Asset Sale | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
ICE Brent Average (in dollars per barrel)	$ 95
California Asset Sale | Minimum | Forecast
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
ICE Brent Average (in dollars per barrel)		$ 95
California Asset Sale | Maximum | Forecast
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number Of Annual Contingent Payments | payment		3
ICE Brent Average (in dollars per barrel)		$ 105
Derivative Financial Instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Level 3 Fair Value			$ 0		$ 0