Commitments and Contingencies Qualifying Facilities Liability (Details) - USD ($)	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023
Beginning QF liability	$ 28,670,000
Ending QF liability	23,498,000	$ 28,670,000
Qualifying Facility Contracts [Member]
Beginning QF liability	28,670,000	49,728,000
Settlements	(7,606,000)	(24,707,000)
Interest expense	2,434,000	3,649,000
Ending QF liability	23,498,000	$ 28,670,000
Qualifying Facility Contracts [Member] \| Minimum [Member]
Price per MWH of energy required to be purchased per QF agreement	118
Qualifying Facility Contracts [Member] \| Maximum [Member]
Price per MWH of energy required to be purchased per QF agreement	130
Qualifying Facility Contracts [Member] \| Gross Obligation [Member]
Recorded Unconditional Purchase Obligation	228,952,000
Recorded Unconditional Purchase Obligation, Fiscal Year Maturity Schedule [Abstract]
2025	60,360,000
2026	55,393,000
2027	56,665,000
2028	42,400,000
2029	14,134,000
Recorded Unconditional Purchase Obligation	228,952,000
Qualifying Facility Contracts [Member] \| Recoverable Amounts [Member]
Recorded Unconditional Purchase Obligation	205,787,000
Recorded Unconditional Purchase Obligation, Fiscal Year Maturity Schedule [Abstract]
2025	52,950,000
2026	46,274,000
2027	46,668,000
2028	41,664,000
2029	18,231,000
Recorded Unconditional Purchase Obligation	205,787,000
Qualifying Facility Contracts [Member] \| Net Amount [Member]
Recorded Unconditional Purchase Obligation	23,165,000
Recorded Unconditional Purchase Obligation, Fiscal Year Maturity Schedule [Abstract]
2025	7,410,000
2026	9,119,000
2027	9,997,000
2028	736,000
2029	(4,097,000)
Recorded Unconditional Purchase Obligation	$ 23,165,000

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Amount of interest expense classified as operating and nonoperating. Includes, but is not limited to, cost of borrowing accounted for as interest expense.

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Amount of the recorded obligation to transfer funds in the future for fixed or minimum amounts or quantities of goods or services at fixed or minimum prices (for example, as in take-or-pay contracts or throughput contracts).

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