Risk Management and Hedging Activities - PAC - Derivative Contract Volumes (Details) - PAC - Commodity derivatives MWh in Millions, Dth in Millions	Mar. 31, 2022 Dth MWh	Dec. 31, 2021 MWh Dth
Electricity purchases, net
Notional Amounts of Outstanding Derivative Positions [Line Items]
Nonmonetary notional amount | MWh	1	2
Natural gas purchases
Notional Amounts of Outstanding Derivative Positions [Line Items]
Nonmonetary notional amount | Dth	105	106