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Derivatives, Hedging Programs and Other Financial Instruments, Narrative (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Derivative [Line Items]
Collateral posted for net derivatives	$ 0						$ 0
Cash collateral posted from customers	$ 2,100,000						200,000
Maturity period of short-term investments	12 months
Designated as Hedging Instrument \| Purchase
Derivative [Line Items]
Derivative net liability	$ 29,200,000						$ 7,200,000
Scenario, Forecast \| Natural Gas
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Percent of Required Need, Coverage		75.00%	80.00%	80.00%	76.00%	75.00%
Scenario, Forecast \| Electricity
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Percent of Required Need, Coverage				46.00%	55.00%	55.00%