| Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] |
| (in thousands) | | Three months ended June 30, 2026 | |
| | | Unrealized Losses on Available-for-Sale Investments | | | Foreign Currency Translation Adjustments | | | Change in Fair Value of Debt Attributable to Instrument-Specific Credit Risk | | | Total Accumulated Other Comprehensive Income | |
| | | | | | | | | | | | | | | | | |
| Balance at March 31, 2026 | | $ | (421 | ) | | $ | (3,286 | ) | | $ | 4,102 | | | $ | 395 | |
| | | | | | | | | | | | | | | | | |
| Other comprehensive loss arising during the period | | | (144 | ) | | | — | | | | (197 | ) | | | (341 | ) |
| Amounts reclassified from accumulated other comprehensive income (loss) | | | — | | | | — | | | | — | | | | — | |
| Net current-period other comprehensive loss | | | (144 | ) | | | — | | | | (197 | ) | | | (341 | ) |
| | | | | | | | | | | | | | | | | |
| Balance at June 30, 2026 | | $ | (565 | ) | | $ | (3,286 | ) | | $ | 3,905 | | | $ | 54 | |
| (in thousands) | | Three months ended June 30, 2025 | |
| | | Unrealized Gains (Losses) on Available-for-Sale Investments | | | Foreign Currency Translation Adjustments | | | Change in Fair Value of Debt Attributable to Instrument-Specific Credit Risk | | | Total Accumulated Other Comprehensive Loss | |
| | | | | | | | | | | | | | | | | |
| Balance at March 31, 2025 | | $ | (768 | ) | | $ | (3,286 | ) | | $ | 3,739 | | | $ | (315 | ) |
| | | | | | | | | | | | | | | | | |
| Other comprehensive income (loss) arising during the period | | | 228 | | | | — | | | | (552 | ) | | | (324 | ) |
| Amounts reclassified from accumulated other comprehensive loss (a) | | | (1 | ) | | | — | | | | — | | | | (1 | ) |
| Net current-period other comprehensive income (loss) | | | 227 | | | | — | | | | (552 | ) | | | (325 | ) |
| | | | | | | | | | | | | | | | | |
| Balance at June 30, 2025 | | $ | (541 | ) | | $ | (3,286 | ) | | $ | 3,187 | | | $ | (640 | ) |
| (in thousands) | | Six months ended June 30, 2026 | |
| | | Unrealized Losses on Available-for-Sale Investments | | | Foreign Currency Translation Adjustments | | | Change in Fair Value of Debt Attributable to Instrument-Specific Credit Risk | | | Total Accumulated Other Comprehensive (Loss) Income | |
| | | | | | | | | | | | | | | | | |
| Balance at January 1, 2026 | | $ | (241 | ) | | $ | (3,286 | ) | | $ | 3,467 | | | $ | (60 | ) |
| | | | | | | | | | | | | | | | | |
| Other comprehensive (loss) income arising during the period | | | (324 | ) | | | — | | | | 438 | | | | 114 | |
| Amounts reclassified from accumulated other comprehensive income (loss) | | | — | | | | — | | | | — | | | | — | |
| Net current-period other comprehensive (loss) income | | | (324 | ) | | | — | | | | 438 | | | | 114 | |
| | | | | | | | | | | | | | | | | |
| Balance at June 30, 2026 | | $ | (565 | ) | | $ | (3,286 | ) | | $ | 3,905 | | | $ | 54 | |
| (in thousands) | | Six months ended June 30, 2025 | |
| | | Unrealized Gains (Losses) on Available-for-Sale Investments | | | Foreign Currency Translation Adjustments | | | Change in Fair Value of Debt Attributable to Instrument-Specific Credit Risk | | | Total Accumulated Other Comprehensive Loss | |
| | | | | | | | | | | | | | | | | |
| Balance at January 1, 2025 | | $ | (1,157 | ) | | $ | (3,286 | ) | | $ | 3,725 | | | $ | (718 | ) |
| | | | | | | | | | | | | | | | | |
| Other comprehensive income (loss) arising during the period | | | 617 | | | | — | | | | (538 | ) | | | 79 | |
| Amounts reclassified from accumulated other comprehensive loss (a) | | | (1 | ) | | | — | | | | — | | | | (1 | ) |
| Net current-period other comprehensive income (loss) | | | 616 | | | | — | | | | (538 | ) | | | 78 | |
| | | | | | | | | | | | | | | | | |
| Balance at June 30, 2025 | | $ | (541 | ) | | $ | (3,286 | ) | | $ | 3,187 | | | $ | (640 | ) |
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