Contingent Liabilities (Narrative) (Details) $ in Millions |
12 Months Ended |
|---|---|
|
Dec. 31, 2019
USD ($)
| |
| Contingent Liabilities | |
| Contractual purchase obligations for 2020 | $ 16,590 |
| Contractual purchase obligations for 2021 and 2022 | 21,121 |
| Contractual purchase obligations for 2023 and 2024 | 11,153 |
| Contractual purchase obligations for years 2025 and thereafter | $ 18,943 |