Income Taxes (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Current portion of income tax benefit (provision):
Federal		$ (1)	$ 1	$ (1)	$ 2
State		(9)	(8)	(26)	(25)
Foreign		0	0	(3)	(1)
Total current portion		(10)	(7)	(30)	(24)
Deferred portion of income tax benefit (provision):
Federal		(6)	(7)	(19)	(19)
State		(2)	(2)	(5)	(14)
Total deferred portion		(8)	(9)	(24)	(33)
Total provision for income taxes		(18)	$ (16)	(54)	$ (57)
Deferred tax liabilities:
Attributable to investment in OTA		405		405		$ 384
Attributable to property, plant and equipment		122		122		118
Attributable to investments in other entities		6		6		5
Other		36		36		14
Total deferred tax liabilities		569		569		521
Deferred tax assets:
Net operating loss carryovers	[1]	10		10		14
Temporary differences related to Texas Margin Tax		4		4		3
Total deferred tax assets		14		14		17
Valuation allowance		10		10		14
Total deferred tax assets, net of valuation allowance		4		4		3
Total net deferred tax liabilities		$ 565		$ 565		$ 518

[1] The loss amount presented as of September 30, 2022 has an indefinite carryover period.  All losses are subject to limitations on their utilization.