XML 35 R24.htm IDEA: XBRL DOCUMENT
v3.21.1

FAIR VALUE MEASUREMENTS - RECURRING BASIS (Details) - Recurring basis - USD ($) $ in Thousands | Mar. 31, 2021 | Dec. 31, 2020
--- | --- | ---
Fair Value on a Recurring Basis |  |
Total | $ 235,778 | $ 254,454
Money market funds |  |
Fair Value on a Recurring Basis |  |
Total | 18,000 | 4,356
U.S. Treasury securities |  |
Fair Value on a Recurring Basis |  |
Total | 15,733 | 10,705
Government-sponsored enterprise securities |  |
Fair Value on a Recurring Basis |  |
Total | 28,755 | 28,757
Commercial paper |  |
Fair Value on a Recurring Basis |  |
Total | 80,459 | 112,409
Corporate notes |  |
Fair Value on a Recurring Basis |  |
Total | 92,831 | 97,866
Equity Investment |  |
Fair Value on a Recurring Basis |  |
Total |  | 361
Level 1 |  |
Fair Value on a Recurring Basis |  |
Total | 18,000 | 4,356
Level 1 | Money market funds |  |
Fair Value on a Recurring Basis |  |
Total | 18,000 | 4,356
Level 2 |  |
Fair Value on a Recurring Basis |  |
Total | 217,778 | 250,098
Level 2 | U.S. Treasury securities |  |
Fair Value on a Recurring Basis |  |
Total | 15,733 | 10,705
Level 2 | Government-sponsored enterprise securities |  |
Fair Value on a Recurring Basis |  |
Total | 28,755 | 28,757
Level 2 | Commercial paper |  |
Fair Value on a Recurring Basis |  |
Total | 80,459 | 112,409
Level 2 | Corporate notes |  |
Fair Value on a Recurring Basis |  |
Total | $ 92,831 | 97,866
Level 2 | Equity Investment |  |
Fair Value on a Recurring Basis |  |
Total |  | $ 361

X
- 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 http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 + Details
Name: | us-gaap_AssetsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsRecurringMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_MoneyMarketFundsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_USTreasuryNotesSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_CommercialPaperMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_CorporateNoteSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_EquitySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |