Income Taxes - PAC - Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Current:
Federal	$ (1,463)	$ (1,701)	$ (1,537)
State	(65)	(177)	(121)
Total current	(1,449)	(1,778)	(1,572)
Deferred:
Federal	(408)	1,037	1,438
State	(49)	(476)	424
Total deferred	(462)	650	1,883
Investment tax credits	(5)	(4)	(3)
Total	(1,916)	(1,132)	308
PAC
Current:
Federal	(216)	(150)	19
State	(3)	7	30
Total current	(219)	(143)	49
Deferred:
Federal	90	26	(124)
State	71	40	1
Total deferred	161	66	(123)
Investment tax credits	(4)	(2)	(1)
Total	$ (62)	$ (79)	$ (75)