Impact of Derivative Activities on Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Derivative [Line Items]
Fair Value Hedges, Net	$ 0	$ 0	$ 0
Not Designated as Hedging Instrument | Natural Gas Commodity Contract
Derivative [Line Items]
Derivative Instruments Gain (Loss) Reclassified To Regulatory Assets And Liabilities Net	$ 1	1	1
Pre-tax gains (losses) reclassified into income during the period from regulatory assets and (liabilities)		$ 1	$ 1