Derivative Instruments and Hedging Activities, Pro Forma Impact - Offsetting Collateral (Details) - USD ($) $ in Millions |
Jun. 30, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Derivative Asset [Abstract] | ||
| Gross collateral | $ 48.6 | $ 26.9 |
| Counterparties with Offsetting Positions or Collateral [Member] | ||
| Derivative Asset [Abstract] | ||
| Gross collateral | 48.6 | 26.9 |
| Current Assets from Risk Management Activities [Member] | ||
| Derivative Asset [Abstract] | ||
| Gross collateral | 1.9 | 29.6 |
| Current Assets from Risk Management Activities [Member] | Counterparties with Offsetting Positions or Collateral [Member] | ||
| Derivative Asset [Abstract] | ||
| Gross collateral | 1.9 | 29.6 |
| Other Long-term Assets [Member] | ||
| Derivative Asset [Abstract] | ||
| Gross collateral | 46.7 | (2.7) |
| Other Long-term Assets [Member] | Counterparties with Offsetting Positions or Collateral [Member] | ||
| Derivative Asset [Abstract] | ||
| Gross collateral | $ 46.7 | $ (2.7) |