| Fair Value of Assets and Liabilities Measured on Recurring Basis |
| | | | | | | | | | | | | | | | | | | | | | | | | | (In thousands) | | Balance at
September 30,
2024 | | Level 1 | | Level 2 | | Level 3 | Assets: | | | | | | | | | | | | | Cash equivalents | | $ | 296,668 | | $ | 296,169 | | $ | 499 | | $ | — | Municipal bonds | | | 7,194 | | | — | | | 7,194 | | | — | Corporate debt securities | | | 35,032 | | | — | | | 35,032 | | | — | Asset-backed securities | | | 10,569 | | | — | | | 10,569 | | | — | Government, federal agency, and other sovereign obligations | | | 31,442 | | | — | | | 31,442 | | | — | 2025 Hedge | | | 471 | | | — | | | 471 | | | — | Liabilities: | | | | | | | | | | | | | Senior Convertible Notes due 2025 | | | 439,179 | | | 439,179 | | | — | | | — | Bifurcated Conversion Option of the Senior Convertible Notes due 2025 | | | 471 | | | — | | | 471 | | | — | Business acquisition liabilities | | | 113,858 | | | — | | | — | | | 113,858 |
| | | | | | | | | | | | | | | | | | | | | | | | | | (In thousands) | | Balance at
December 31,
2023 | | Level 1 | | Level 2 | | Level 3 | Assets: | | | | | | | | | | | | | Cash equivalents | | $ | 203,689 | | $ | 203,689 | | $ | — | | $ | — | Municipal bonds | | | 18,057 | | | — | | | 18,057 | | | — | Corporate debt securities | | | 58,838 | | | — | | | 58,838 | | | — | Asset-backed securities | | | 17,161 | | | — | | | 17,161 | | | — | Government, federal agency, and other sovereign obligations | | | 31,869 | | | 2,928 | | | 28,941 | | | — | 2025 Hedge | | | 687 | | | — | | | 687 | | | — | | | | | | | | | | | | | | Liabilities: | | | | | | | | | | | | | Senior Convertible Notes due 2025 | | | 417,363 | | | 417,363 | | | — | | | — | Bifurcated Conversion Option of the Senior Convertible Notes due 2025 | | | 687 | | | — | | | 687 | | | — | Business acquisition liabilities | | | 139,358 | | | — | | | — | | | 139,358 |
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| Changes in Carrying Value of Business Acquisition Liabilities |
| | | | | | | | | | | | | | | | | | | | | | | | | Three Months Ended | | Nine Months Ended | | September 30, | | September 30, | (In thousands) | 2024 | | 2023 | | 2024 | | 2023 | Beginning balance | $ | 121,332 | | $ | 65,352 | | $ | 139,358 | | $ | 68,258 | Purchase price contingent consideration | | 1,603 | | | 66,873 | | | 22,669 | | | 66,873 | Changes resulting from foreign currency fluctuations | | — | | | — | | | 246 | | | — | Contingent cash payments | | (4,201) | | | (2,754) | | | (55,087) | | | (8,278) | Contingent RSU grants | | (1,339) | | | (951) | | | (1,856) | | | (1,510) | Changes in fair value of business acquisition liabilities | | (4,132) | | | 1,151 | | | 8,608 | | | 4,431 | Contractual payable reclassification | | 595 | | | 295 | | | (80) | | | 192 | Ending balance | $ | 113,858 | | $ | 129,966 | | $ | 113,858 | | $ | 129,966 |
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