Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Cash and cash equivalents	$ 114	$ 230
Accounts receivable, less allowance for credit losses	773	690
Allowance for credit losses	36	44
Accrued unbilled revenues, allowance for credit losses	2	6
Prepaid expenses and other current assets	141	132
Regulatory assets	$ 2,212	$ 2,321
Preferred Stock [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, authorized (in shares)	20,000,000	20,000,000
Preferred stock, outstanding (in shares)	800,000	800,000
Preferred stock aggregate liquidation preference	$ 800	$ 800
Common Stock [Abstract]
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized (in shares)	1,000,000,000	1,000,000,000
Common stock, outstanding (in shares)	629,532,024	628,923,534
Variable Interest Entity, Primary Beneficiary
Cash and cash equivalents	$ 110	$ 92
Accounts receivable, less allowance for credit losses	30	29
Prepaid expenses and other current assets	12	19
Regulatory assets	$ 265	$ 420