CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023	Dec. 31, 2022
Statement of Cash Flows [Abstract]
Net income	$ 365	$ 341	$ 1,096	$ 1,193
Depreciation and amortization			557	607
Deferred income taxes			(23)	(21)
Provision for uncollectible accounts			35	51
Accounts receivable			9	(9)
Accounts payable			(16)	11
Accrued income and other taxes			12	22
Other current assets and liabilities, net			(6)	(23)
Changes in other noncurrent assets and liabilities, net			30	33
Changes in affiliate obligations, net			(41)	(46)
Other, net			(7)	4
Capital expenditures			(776)	(773)
Changes in advances to affiliates			(576)	(1,057)
Proceeds from sale of property, plant and equipment and other assets			6	10
Payments of long-term debt			(227)	(2)
Changes in advances from affiliates			(61)	0
Net increase in cash, cash equivalents and restricted cash			12	0
Cash, cash equivalents and restricted cash at beginning of period	24	10	24	10	$ 12	$ 10
Income taxes paid, net			(393)	(423)
Interest paid, including affiliate interest (net of capitalized interest of $60 and $37)			(47)	(79)
Repayment of long-term debt in exchange for advances from affiliates			(215)	0
Cash and cash equivalents	22	8	22	8	$ 10
Restricted cash - noncurrent	$ 2	$ 2	2	2
Interest paid, capitalized interest			$ 60	$ 37