| Fair Value, by Balance Sheet Grouping [Table Text Block] |
| | | June 30, 2026 | |
| | | (in thousands) | |
| | | Level 1 | | | Level 2 | | | Level 3 | | | Total | |
| Assets | | | | | | | | | | | | | | | | |
| Cash Equivalents: | | | | | | | | | | | | | | | | |
| Certificates of deposit (1) | | $ | — | | | $ | 7,557 | | | $ | — | | | $ | 7,557 | |
| Money market funds | | | — | | | | 5,213 | | | | — | | | | 5,213 | |
| U.S. treasury bills | | | — | | | | 292,368 | | | | — | | | | 292,368 | |
| Prepaid expenses and other current assets: | | | | | | | | | | | | | | | | |
| Certificates of deposit (1) | | | — | | | | 198 | | | | — | | | | 198 | |
| Other assets: | | | | | | | | | | | | | | | | |
| Certificates of deposit (1) | | | — | | | | 224 | | | | — | | | | 224 | |
| Total | | $ | — | | | $ | 305,560 | | | $ | — | | | $ | 305,560 | |
| Liabilities: | | | | | | | | | | | | | | | | |
| Accrued expenses and other current liabilities: | | | | | | | | | | | | | | | | |
| Mandatorily redeemable noncontrolling interest (2) | | $ | — | | | $ | — | | | $ | 2,742 | | | $ | 2,742 | |
| Other liabilities: | | | | | | | | | | | | | | | | |
| Mandatorily redeemable noncontrolling interest (2) | | | — | | | | — | | | | 2,907 | | | | 2,907 | |
| Total | | $ | — | | | $ | — | | | $ | 5,649 | | | $ | 5,649 | |
| | | December 31, 2025 | |
| | | (in thousands) | |
| | | Level 1 | | | Level 2 | | | Level 3 | | | Total | |
| Assets | | | | | | | | | | | | | | | | |
| Cash Equivalents: | | | | | | | | | | | | | | | | |
| Certificates of deposit (1) | | $ | — | | | $ | 1,734 | | | $ | — | | | $ | 1,734 | |
| Money market funds | | | — | | | | 4,215 | | | | — | | | | 4,215 | |
| U.S. treasury bills | | | — | | | | 189,012 | | | | — | | | | 189,012 | |
| Prepaid expenses and other current assets: | | | | | | | | | | | | | | | | |
| Certificates of deposit (1) | | | — | | | | 213 | | | | — | | | | 213 | |
| Other assets: | | | | | | | | | | | | | | | | |
| Certificates of deposit (1) | | | — | | | | 206 | | | | — | | | | 206 | |
| Total | | $ | — | | | $ | 195,380 | | | $ | — | | | $ | 195,380 | |
| Liabilities: | | | | | | | | | | | | | | | | |
| Accrued expenses and other current liabilities: | | | | | | | | | | | | | | | | |
| Mandatorily redeemable noncontrolling interest (2) | | $ | — | | | $ | — | | | $ | 1,839 | | | $ | 1,839 | |
| Other liabilities: | | | | | | | | | | | | | | | | |
| Mandatorily redeemable noncontrolling interest (2) | | | — | | | | — | | | | 3,704 | | | | 3,704 | |
| Total | | $ | — | | | $ | — | | | $ | 5,543 | | | $ | 5,543 | |
|
| Debt Securities, Available-for-Sale [Table Text Block] |
| | | June 30, 2026 | |
| | | (in thousands) | |
| | | Amortized Cost | | | Fair Value | | | Gross Unrealized Losses | |
| U.S. treasury bills | | $ | 292,391 | | | $ | 292,368 | | | $ | (23 | ) |
| Total | | $ | 292,391 | | | $ | 292,368 | | | $ | (23 | ) |
| | | December 31, 2025 | |
| | | (in thousands) | |
| | | Amortized Cost | | | Fair Value | | | Gross Unrealized Gains | |
| U.S. treasury bills | | $ | 189,007 | | | $ | 189,012 | | | $ | 5 | |
| Total | | $ | 189,007 | | | $ | 189,012 | | | $ | 5 | |
|