Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
|  |  | 2018 | 2018 | 2018 | 2018 | 2017 | 2017 | 2017 | 2017 |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
|  |  | Total | Level 1 | Level 2 | Level 3 | Total | Level 1 | Level 2 | Level 3 |
| Cash and cash equivalents |  | $1,694 | $1,694 | $— | $— | $1,482 | $1,482 | $— | $— |
| Short-term investments: | Corporate debt | 1,023 | — | 1,023 | — | 958 | — | 958 | — |
| Short-term investments: | Asset-backed securities | 746 | — | 746 | — | 753 | — | 753 | — |
| Short-term investments: | U.S. government and agency notes | 108 | — | 108 | — | 113 | — | 113 | — |
| Short-term investments: | Certificates of deposit placed through an account registry service ("CDARS") | 75 | — | 75 | — | 120 | — | 120 | — |
| Short-term investments: | Other fixed-income securities | 116 | — | 116 | — | 188 | — | 188 | — |
| Short-term investments: | Other investments measured at NAV | 188 | — | — | — | 184 | — | — | — |
| Short-term investments: | Restricted cash | 105 | 105 | — | — | 109 | 109 | — | — |
| Long-term investments: | Equity securities | 249 | 249 | — | — | 99 | 99 | — | — |
| Long-term investments: | Enhanced equipment trust certificates ("EETC") | 18 | — | — | 18 | 22 | — | — | 22 |
| Long-term investments: | Avianca Holdings S.A. ("AVH") Derivative Assets | 11 | — | — | 11 | — | — | — | — |
Question:
What was the fair value of United Airlines' corporate debt at the end of 2017?
Answer:
958