Derivative and Financial Instruments (Commodity - Net Exposures from Outstanding Derivative Contracts) (Details) - Commodity Contract [Member] - Bcf	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Natural gas and power, Fixed price [Member] | Long [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Commodity derivatives - volumetric material net exposures	4
Natural gas and power, Fixed price [Member] | Short [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Commodity derivatives - volumetric material net exposures		20
Natural gas and power, Basis [Member] | Short [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Commodity derivatives - volumetric material net exposures	22	10