Derivative Instruments and Hedging Activities - Pro Forma Impact Of Offsetting Assets (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Derivative Asset [Abstract]
Derivative assets	$ 182.7	$ 204.4
Pro forma net presentation, asset, current	$ 70.0	$ 44.9
Derivative Asset, Current, Statement of Financial Position [Extensible Enumeration]	Assets from risk management activities	Assets from risk management activities
Pro forma net presentation, asset, noncurrent	$ 13.4	$ 7.3
Derivative Asset, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Long-term assets from risk management activities	Long-term assets from risk management activities
Pro forma net presentation, asset, total	$ 83.4	$ 52.2
Counterparties with Offsetting Positions or Collateral [Member]
Derivative Asset [Abstract]
Derivative assets	165.6	186.7
Pro forma net presentation, asset	66.3	34.5
Counterparties without Offsetting Position [Member]
Derivative Asset [Abstract]
Derivative assets	17.1	17.7
Pro forma net presentation, asset, current	17.1	17.7
Pro forma net presentation, asset, total	14.3	17.7
Current Assets from Risk Management Activities [Member]
Derivative Asset [Abstract]
Derivative assets	146.5	179.9
Current Assets from Risk Management Activities [Member] \| Counterparties with Offsetting Positions or Collateral [Member]
Derivative Asset [Abstract]
Derivative assets	132.2	162.2
Pro forma net presentation, asset	55.7	27.2
Current Assets from Risk Management Activities [Member] \| Counterparties without Offsetting Position [Member]
Derivative Asset [Abstract]
Derivative assets	14.3	17.7
Other Long-term Assets [Member]
Derivative Asset [Abstract]
Derivative assets	36.2	24.5
Other Long-term Assets [Member] \| Counterparties with Offsetting Positions or Collateral [Member]
Derivative Asset [Abstract]
Derivative assets	33.4	24.5
Pro forma net presentation, asset	10.6	$ 7.3
Other Long-term Assets [Member] \| Counterparties without Offsetting Position [Member]
Derivative Asset [Abstract]
Derivative assets	2.8
Pro forma net presentation, asset	$ 2.8

Indicates line item in statement of financial position that includes derivative asset classified as current.

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-Publisher FASB
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Indicates line item in statement of financial position that includes derivative asset classified as noncurrent.

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Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled within one year or normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Fair values as of the balance sheet date of the net amount of all assets and liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments.

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Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

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