Short-Term Borrowings (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Short-term Debt [Line Items]
Amount outstanding at period end	$ 34	$ 34	$ 137
Money Pool
Short-term Debt [Line Items]
Borrowing limit	100	100	100	$ 100
Amount outstanding at period end	0	0	91	0
Average amount outstanding	7	35	51	43
Maximum amount outstanding	$ 42	$ 100	$ 100	$ 100
Weighted average interest rate, computed on a daily basis (percentage)	3.17%	0.44%	0.05%	0.54%
Line of Credit Facility, Interest Rate at Period End			0.05%
Commercial Paper
Short-term Debt [Line Items]
Borrowing limit	$ 500	$ 500	$ 500	$ 500
Amount outstanding at period end	34	34	137	250
Average amount outstanding	20	100	63	44
Maximum amount outstanding	$ 65	$ 324	$ 342	$ 250
Weighted average interest rate, computed on a daily basis (percentage)	4.08%	0.79%	0.21%	1.11%
Weighted average interest rate at period end (percentage)	4.55%	4.55%	0.26%	0.29%