| Fair Value Measurements, Recurring and Nonrecurring [Table Text Block] |
| | | As of December 31, 2021 | |
| | | Adjusted | | | Unrealized | | | Unrealized | | | Market | |
| | | Cost | | | Gains | | | Losses | | | Value | |
| Level 1: | | | | | | | | | | | | | | | | |
| Money Market Funds | | $ | 1,670 | | | $ | - | | | $ | - | | | $ | 1,670 | |
| U.S. Treasury securities considered cash equivalents | | | - | | | | - | | | | - | | | | - | |
| U.S. Treasury securities in short-term investments | | | 29,989 | | | | - | | | | (6 | ) | | | 29,983 | |
| Total Financial Assets | | $ | 31,659 | | | $ | - | | | $ | (6 | ) | | $ | 31,653 | |
| | | As of December 31, 2020 | |
| | | Adjusted | | | Unrealized | | | Unrealized | | | Market | |
| | | Cost | | | Gains | | | Losses | | | Value | |
| Level 1: | | | | | | | | | | | | | | | | |
| Money Market Funds | | $ | 6,035 | | | $ | - | | | $ | - | | | $ | 6,035 | |
| U.S. Treasury securities considered cash equivalents | | | 9,998 | | | | - | | | | - | | | | 9,998 | |
| U.S. Treasury securities in short-term investments | | | 24,979 | | | | 15 | | | | - | | | | 24,994 | |
| Total Financial Assets | | $ | 41,012 | | | $ | 15 | | | $ | - | | | $ | 41,027 | |
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