| Fair Value, by Balance Sheet Grouping [Table Text Block] |
| | | March 31, 2025 | |
| | | (in thousands) | |
| | | Level 1 | | | Level 2 | | | Level 3 | | | Total | |
| Assets | | | | | | | | | | | | | | | | |
| Cash Equivalents: | | | | | | | | | | | | | | | | |
| Certificates of deposit (1) | | $ | — | | | $ | 1,575 | | | $ | — | | | $ | 1,575 | |
| Money market funds | | | — | | | | 4,177 | | | | — | | | | 4,177 | |
| U.S. treasury bills | | | — | | | | 183,139 | | | | — | | | | 183,139 | |
| Short-term investments: | | | | | | | | | | | | | | | | |
| Certificates of deposit (1) | | | — | | | | 326 | | | | — | | | | 326 | |
| Other assets: | | | | | | | | | | | | | | | | |
| Certificates of deposit (1) | | | — | | | | 195 | | | | — | | | | 195 | |
| Notes receivables (2) | | | — | | | | — | | | | 4,065 | | | | 4,065 | |
| Total | | $ | — | | | $ | 189,412 | | | $ | 4,065 | | | $ | 193,477 | |
| Liabilities: | | | | | | | | | | | | | | | | |
| Accrued expenses and other current liabilities: | | | | | | | | | | | | | | | | |
| Mandatorily redeemable noncontrolling interest (3) | | $ | — | | | $ | — | | | $ | 6,306 | | | $ | 6,306 | |
| Other non-current liabilities: | | | | | | | | | | | | | | | | |
| Warrant liabilities (4) | | | — | | | | 1,387 | | | | — | | | | 1,387 | |
| Total | | $ | — | | | $ | 1,387 | | | $ | 6,306 | | | $ | 7,693 | |
| | | December 31, 2024 | |
| | | (in thousands) | |
| | | Level 1 | | | Level 2 | | | Level 3 | | | Total | |
| Assets | | | | | | | | | | | | | | | | |
| Cash Equivalents: | | | | | | | | | | | | | | | | |
| Certificates of deposit (1) | | $ | — | | | $ | 1,504 | | | $ | — | | | $ | 1,504 | |
| Money market funds | | | — | | | | 4,188 | | | | — | | | | 4,188 | |
| U.S. treasury bills | | | — | | | | 181,210 | | | | — | | | | 181,210 | |
| Short term investments: | | | | | | | | | | | | | | | | |
| Certificates of deposit (1) | | | — | | | | 165 | | | | — | | | | 165 | |
| Other assets: | | | | | | | | | | | | | | | | |
| Certificates of deposit (1) | | | — | | | | 39 | | | | — | | | | 39 | |
| Notes receivables (2) | | | — | | | | — | | | | 3,938 | | | | 3,938 | |
| Total | | $ | — | | | $ | 187,106 | | | $ | 3,938 | | | $ | 191,044 | |
| Liabilities: | | | | | | | | | | | | | | | | |
| Other liabilities: | | | | | | | | | | | | | | | | |
| Warrant liabilities (4) | | $ | — | | | $ | 1,861 | | | $ | — | | | $ | 1,861 | |
| Total | | $ | — | | | $ | 1,861 | | | $ | — | | | $ | 1,861 | |
|
| Debt Securities, Available-for-Sale [Table Text Block] |
| | | March 31, 2025 | |
| | | (in thousands) | |
| | | Amortized Cost | | | Fair Value | | | Gross Unrealized Losses | |
| U.S. treasury bills | | $ | 183,158 | | | $ | 183,139 | | | $ | (19 | ) |
| Total | | $ | 183,158 | | | $ | 183,139 | | | $ | (19 | ) |
| | | December 31, 2024 | |
| | | (in thousands) | |
| | | Amortized Cost | | | Fair Value | | | Gross Unrealized Losses | |
| U.S. treasury bills | | $ | 181,217 | | | $ | 181,210 | | | $ | (7 | ) |
| Total | | $ | 181,217 | | | $ | 181,210 | | | $ | (7 | ) |
|