Stock-Based Compensation Plans - Schedule of Stock-based Compensation Expense (Details) - Share-based Payment Arrangement - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense included in Operating and maintenance expense	$ 21	$ 41	$ 95
Income tax benefit	(5)	(10)	(25)
Total after-tax stock-based compensation expense	$ 16	$ 31	$ 70