Income Taxes, Reconciliation (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Reconciliation of the benefit from (provision for) income taxes [Abstract]
Pre-Tax Net Book Income ("NBI")		$ 1,410	$ 1,198	$ 4,217	$ 3,748
Texas Margin Tax	[1]	(10)	(10)	(29)	(37)
State income tax provision, net of federal benefit		0	0	(1)	(1)
Federal income tax provision computed by applying the federal statutory rate to NBI of corporate entities		(4)	(3)	(11)	(10)
Valuation allowance	[2]	(3)	(3)	(10)	(9)
Other		(1)	0	(3)	0
Total provision for income taxes		$ (18)	$ (16)	$ (54)	$ (57)
Effective income tax rate		(1.30%)	(1.30%)	(1.30%)	(1.50%)

[1] Although the Texas Margin Tax is not considered a state income tax, it has the characteristics of an income tax since it is determined by applying a tax rate to a base that considers our Texas-sourced revenues and expenses.

[2] Management believes that it is more likely than not that the net deferred tax assets attributable to OTA will not be fully realizable.  Accordingly, we provided for a valuation allowance against OTA’s net deferred tax assets.