Fair Value Measurements - Schedule of Fair Value and Carrying Value of Long-term Debt (Details) - Level 2 - USD ($) $ in Millions |
Dec. 31, 2019 |
Dec. 31, 2018 |
---|---|---|
Fair Value | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Long-term Debt (Including Current Maturities) | $ 18,503 | $ 14,914 |
Carrying Value | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Long-term Debt (Including Current Maturities) | $ 16,238 | $ 14,757 |