Income Taxes - NPC - Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Components of Income Tax Expense (Benefit) [Line Items]
Current	$ (1,449)	$ (1,778)	$ (1,572)
Deferred	(462)	650	1,883
Total	(1,916)	(1,132)	308
NPC
Components of Income Tax Expense (Benefit) [Line Items]
Current	(13)	37	57
Deferred	49	0	(10)
Total	$ 36	$ 37	$ 47