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Fair Value Measurements - Fair Value of Financial Assets Measured on Recurring Basis (Details) - Fair Value Measurements Recurring - USD ($) | Mar. 31, 2023 | Dec. 31, 2022
--- | --- | ---
Assets: |  |
Total | $ 275,125,000 | $ 330,430,000
Level 1 |  |
Assets: |  |
Total | 165,564,000 | 159,757,000
Level 2 |  |
Assets: |  |
Total | 109,561,000 | 170,673,000
Level 3 |  |
Assets: |  |
Total | 0 | 0
Money Market Funds |  |
Assets: |  |
Total | 46,137,000 | 36,486,000
Money Market Funds | Level 1 |  |
Assets: |  |
Total | 46,137,000 | 36,486,000
Commercial Paper |  |
Assets: |  |
Total | 73,834,000 | 87,140,000
Commercial Paper | Level 2 |  |
Assets: |  |
Total | 73,834,000 | 87,140,000
Corporate Debt Securities |  |
Assets: |  |
Total | 17,863,000 | 36,429,000
Corporate Debt Securities | Level 2 |  |
Assets: |  |
Total | 17,863,000 | 36,429,000
Equity Securities |  |
Assets: |  |
Total | 25,028,000 | 32,020,000
Equity Securities | Level 1 |  |
Assets: |  |
Total | 25,028,000 | 32,020,000
Asset-backed Securities |  |
Assets: |  |
Total | 6,562,000 | 14,016,000
Asset-backed Securities | Level 2 |  |
Assets: |  |
Total | 6,562,000 | 14,016,000
U.S. Government Securities |  |
Assets: |  |
Total | 94,399,000 | 91,251,000
U.S. Government Securities | Level 1 |  |
Assets: |  |
Total | 94,399,000 | 91,251,000
U.S. Agency Securities |  |
Assets: |  |
Total | 6,750,000 | 16,607,000
U.S. Agency Securities | Level 2 |  |
Assets: |  |
Total | 6,750,000 | 16,607,000
Supranational Debt Securities |  |
Assets: |  |
Total | 4,552,000 | 16,481,000
Supranational Debt Securities | Level 2 |  |
Assets: |  |
Total | $ 4,552,000 | $ 16,481,000

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- Definition Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126976982&loc=d3e19207-110258 + Details
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