Income Taxes (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Current portion of income tax provision:
Federal		$ 0	$ 4
State		(12)	(11)
Total current portion		(12)	(7)
Deferred portion of income tax provision:
Federal		(4)	(7)
State		(5)	4
Total deferred portion		(9)	(3)
Total provision for income taxes		(21)	$ (10)
Deferred tax liabilities:
Attributable to investment in OTA	[1]	441		$ 436
Attributable to property, plant and equipment		143		138
Attributable to investments in other entities		5		4
Other		83		83
Total deferred tax liabilities		672		661
Deferred tax assets:
Net operating loss carryovers	[2]	48		46
Temporary differences related to Texas Margin Tax		4		4
Total deferred tax assets		52		50
Total net deferred tax liabilities		$ 620		$ 611

[1] Represents the deferred tax liability balance held by our wholly owned subsidiary, OTA Holdings, Inc. ("OTA"), which we acquired in March 2020.

[2] The loss amount presented as of March 31, 2024 has an indefinite carryover period.  All losses are subject to limitations on their utilization.