Long-Term Debt and Short-Term Borrowings - Short-Term Borrowings and Current Portion of Long-Term Debt (Details) - USD ($) $ in Millions |
Dec. 31, 2018 |
Dec. 31, 2017 |
|---|---|---|
| Long-Term Debt | ||
| Total long-term debt | $ 14,156 | $ 13,198 |
| Short-Term Borrowings and Current Portion of Long-Term Debt | ||
| Short-term borrowings and current portion of long-term debt | $ 1,211 | 1,853 |
| Current portion of long-term debt | ||
| Long-Term Debt | ||
| Interest rate - effective | 1.85% | |
| Total long-term debt | $ 745 | 1,102 |
| Commercial paper | ||
| Long-Term Debt | ||
| Interest rate - effective | 2.33% | |
| Short-Term Borrowings and Current Portion of Long-Term Debt | ||
| Short-term borrowings and current portion of long-term debt | $ 435 | 745 |
| Other borrowings | ||
| Long-Term Debt | ||
| Interest rate - effective | 5.95% | |
| Short-Term Borrowings and Current Portion of Long-Term Debt | ||
| Short-term borrowings and current portion of long-term debt | $ 31 | $ 6 |