Income Taxes - MEC - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Components of Income Tax Expense (Benefit) [Line Items]
Production tax credits	$ 1,700	$ 1,700	$ 1,400
MEC
Components of Income Tax Expense (Benefit) [Line Items]
Production tax credits	$ 681	$ 710	$ 574