Interest Rate Derivatives (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Natural Gas Commodity Contract | Other Derivative Instruments
Interest Rate Derivatives [Abstract]
Derivative Instruments Gain (Loss) Reclassified To Regulatory Assets And Liabilities Net	$ 1	$ 1	$ 1