Income Taxes (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Current portion of income tax benefit (provision):
Federal		$ 0	$ 0	$ 0	$ 1
State		(7)	(12)	(17)	(17)
Foreign		(3)	0	(3)	(1)
Total current portion		(10)	(12)	(20)	(17)
Deferred portion of income tax benefit (provision):
Federal		(6)	(6)	(13)	(12)
State		(1)	(13)	(3)	(12)
Total deferred portion		(7)	(19)	(16)	(24)
Total provision for income taxes		(17)	$ (31)	(36)	$ (41)
Deferred tax liabilities:
Attributable to investment in OTA		398		398		$ 384
Attributable to property, plant and equipment		120		120		118
Attributable to investments in other entities		6		6		5
Other		36		36		14
Total deferred tax liabilities		560		560		521
Deferred tax assets:
Net operating loss carryovers	[1]	7		7		14
Temporary differences related to Texas Margin Tax		4		4		3
Total deferred tax assets		11		11		17
Valuation allowance		7		7		14
Total deferred tax assets, net of valuation allowance		4		4		3
Total net deferred tax liabilities		$ 556		$ 556		$ 518

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