Fair Value Measurements - MEC - Debt (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	$ 55,257	$ 52,172
Level 2 | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	50,179	48,624
MEC | Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	8,824	8,766
MEC | Level 2 | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	$ 7,911	$ 8,252