Derivative Instruments and Hedging Activities - Pro Forma Impact Of Offsetting Assets (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Derivative Asset [Abstract]
Derivative assets	$ 87.1	$ 145.2
Pro forma net presentation, asset, current	$ 9.3	$ 69.4
Derivative Asset, Current, Statement of Financial Position [Extensible Enumeration]	Derivative Asset Before Effects Of Master Netting Arrangements Current	Derivative Asset Before Effects Of Master Netting Arrangements Current
Pro forma net presentation, asset, noncurrent	$ 5.3	$ 18.6
Derivative Asset, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Derivative Asset Before Effects Of Master Netting Arrangements Noncurrent	Derivative Asset Before Effects Of Master Netting Arrangements Noncurrent
Pro forma net presentation, asset, total	$ 14.6	$ 88.0
Counterparties with Offsetting Positions or Collateral [Member]
Derivative Asset [Abstract]
Derivative assets	85.9	143.4
Pro forma net presentation, asset, total	13.4	86.2
Counterparties without Offsetting Position [Member]
Derivative Asset [Abstract]
Derivative assets	1.2	1.8
Pro forma net presentation, asset, current	0.1	0.2
Pro forma net presentation, asset, noncurrent	1.1	1.6
Pro forma net presentation, asset, total	1.2	1.8
Current Assets from Risk Management Activities [Member]
Derivative Asset [Abstract]
Derivative assets	61.8	111.9
Current Assets from Risk Management Activities [Member] | Counterparties with Offsetting Positions or Collateral [Member]
Derivative Asset [Abstract]
Derivative assets	61.7	111.7
Pro forma net presentation, asset	9.2	69.2
Current Assets from Risk Management Activities [Member] | Counterparties without Offsetting Position [Member]
Derivative Asset [Abstract]
Derivative assets	0.1	0.2
Other Long-term Assets [Member]
Derivative Asset [Abstract]
Derivative assets	25.3	33.3
Other Long-term Assets [Member] | Counterparties with Offsetting Positions or Collateral [Member]
Derivative Asset [Abstract]
Derivative assets	24.2	31.7
Pro forma net presentation, asset	4.2	17.0
Other Long-term Assets [Member] | Counterparties without Offsetting Position [Member]
Derivative Asset [Abstract]
Derivative assets	$ 1.1	$ 1.6