Income Taxes - Schedule of Reconciliation of Provision for Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Income Tax Disclosure [Abstract]
Pre-Tax Net Book Income (“NBI”)	$ 1,470	$ 1,437	$ 2,900	$ 2,941
Texas Margin Tax	(11)	(10)	(30)	(27)
State income tax provision, net of federal benefit	0	0	(1)	0
Federal income tax provision computed by applying the federal statutory rate to NBI of corporate entities	(5)	(5)	(9)	(8)
Other	0	0	0	(1)
Total provision for income taxes	$ (16)	$ (15)	$ (40)	$ (36)
Effective income tax rate	(1.10%)	(1.00%)	(1.40%)	(1.20%)