Risk Management and Hedging Activities - EEGH - Schedule of Notional Amounts (Details) - EEGH € in Millions, Dth in Millions, $ in Millions	Dec. 31, 2021 USD ($) Dth	Dec. 31, 2021 EUR (€) Dth	Dec. 31, 2020 USD ($) Dth	Dec. 31, 2020 EUR (€) Dth
Interest rate contracts
Derivative [Line Items]
Notional amount | $	$ 0		$ 500
Foreign currency exchange rate derivatives
Derivative [Line Items]
Notional amount | €		€ 250		€ 250
Commodity derivatives | Natural gas purchases
Derivative [Line Items]
Derivative, nonmonetary notional amount | Dth	2	2	5	5