Income Taxes - EGTS - Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Current:
Federal	$ (1,650)	$ (1,463)	$ (1,701)
State	118	(65)	(177)
Total current	(1,442)	(1,449)	(1,778)
Deferred:
Federal	(114)	(408)	1,037
State	(275)	(49)	(476)
Total deferred	(356)	(462)	650
Total	(1,699)	(1,916)	(1,132)
EGTS
Current:
Federal	(28)	5	(22)
State	(12)	12	(10)
Total current	(40)	17	(32)
Deferred:
Federal	91	64	67
State	28	28	26
Total deferred	119	92	93
Total	$ 79	$ 109	$ 61