Derivative Instruments and Hedging Activities, Pro Forma Impact - Offsetting Collateral (Details) - USD ($) $ in Millions	Sep. 30, 2026	Dec. 31, 2025
Derivative Asset [Abstract]
Gross collateral	$ 74.7	$ 26.9
Counterparties with Offsetting Positions or Collateral [Member]
Derivative Asset [Abstract]
Gross collateral	74.7	26.9
Location, Statement of Financial Position, Balance [Axis]: us-gaap:OtherAssetsCurrent
Derivative Asset [Abstract]
Gross collateral	40.6	29.6
Location, Statement of Financial Position, Balance [Axis]: us-gaap:OtherAssetsCurrent \| Counterparties with Offsetting Positions or Collateral [Member]
Derivative Asset [Abstract]
Gross collateral	40.6	29.6
Location, Statement of Financial Position, Balance [Axis]: us-gaap:OtherAssetsNoncurrent
Derivative Asset [Abstract]
Gross collateral	34.1	(2.7)
Location, Statement of Financial Position, Balance [Axis]: us-gaap:OtherAssetsNoncurrent \| Counterparties with Offsetting Positions or Collateral [Member]
Derivative Asset [Abstract]
Gross collateral	$ 34.1	$ (2.7)