Income Taxes - MEC - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Components of Income Tax Expense (Benefit) [Line Items]
Years eligible for renewable energy production tax credit	10 years
Production tax credits	$ 1,900	$ 1,700	$ 1,700
Operating loss carryforwards	13,833
Unrecognized tax benefits	95	88
State
Components of Income Tax Expense (Benefit) [Line Items]
Operating loss carryforwards	$ 13,441
MEC
Components of Income Tax Expense (Benefit) [Line Items]
Years eligible for renewable energy production tax credit	10 years
Production tax credits	$ 810	$ 681	$ 710
Unrecognized tax benefits	52
MEC | State
Components of Income Tax Expense (Benefit) [Line Items]
Operating loss carryforwards	$ 981