Risk Management, Derivative Instruments and Hedging Activities - Schedule of Net Notional Volumes of Open Commodity Derivatives and Interest Rate Derivatives (Details) $ in Millions |
3 Months Ended | 12 Months Ended |
|---|---|---|
|
Mar. 31, 2026
USD ($)
MMBTU
MWh
T
|
Dec. 31, 2025
USD ($)
MWh
MMBTU
T
|
|
| Commodity derivatives | Short | ||
| Derivative [Line Items] | ||
| Commodity purchase (sales) derivatives, power and natural gas | MWh | 66,143,342 | 59,634,723 |
| Commodity derivatives | Long | ||
| Derivative [Line Items] | ||
| Commodity purchase (sales) derivatives, power and natural gas | MMBTU | 189,897,762 | 169,209,022 |
| Commodity purchase (sales) derivatives, emission allowances | T | 0 | 0 |
| Interest rate derivatives | ||
| Derivative [Line Items] | ||
| Interest rate (in millions) | $ | $ 990 | $ 990 |