XML 36 R26.htm IDEA: XBRL DOCUMENT
v3.22.1

FAIR VALUE MEASUREMENTS - SECURITIES WITH UNREALIZED LOSSES (Details) - USD ($) $ in Thousands | Mar. 31, 2022 | Dec. 31, 2021
--- | --- | ---
Schedule Of Available For Sale Securities [Line Items] |  |
Less Than 12 Months - Estimated Fair Value | $ 150,080 | $ 128,591
Less Than 12 Months - Gross Unrealized Losses | (673) | (170)
12 Months or Longer - Estimated Fair Value | 4,961 | 4,993
12 Months or Longer - Gross Unrealized Losses | (39) | (7)
Total - Estimated Fair Value | 155,041 | 133,584
Total - Gross Unrealized Losses | (712) | (177)
U.S. Treasury securities (due in less than one year) |  |
Schedule Of Available For Sale Securities [Line Items] |  |
Less Than 12 Months - Estimated Fair Value | 20,543 | 15,567
Less Than 12 Months - Gross Unrealized Losses | (107) | (18)
Total - Estimated Fair Value | 20,543 | 15,567
Total - Gross Unrealized Losses | (107) | (18)
U.S. Treasury securities (due in one to two years) |  |
Schedule Of Available For Sale Securities [Line Items] |  |
Less Than 12 Months - Estimated Fair Value |  | 1,521
Less Than 12 Months - Gross Unrealized Losses |  | (3)
Total - Estimated Fair Value |  | 1,521
Total - Gross Unrealized Losses |  | (3)
Municipal securities (due in less than one year) |  |
Schedule Of Available For Sale Securities [Line Items] |  |
Less Than 12 Months - Estimated Fair Value | 2,947 |
Less Than 12 Months - Gross Unrealized Losses | (53) |
Total - Estimated Fair Value | 2,947 |
Total - Gross Unrealized Losses | (53) |
Municipal securities (due in one to two years) |  |
Schedule Of Available For Sale Securities [Line Items] |  |
Less Than 12 Months - Estimated Fair Value |  | 2,985
Less Than 12 Months - Gross Unrealized Losses |  | (15)
Total - Estimated Fair Value |  | 2,985
Total - Gross Unrealized Losses |  | (15)
Government-sponsored enterprise securities (due in less than one year) |  |
Schedule Of Available For Sale Securities [Line Items] |  |
Less Than 12 Months - Estimated Fair Value |  | 1,500
12 Months or Longer - Estimated Fair Value | 4,961 | 4,993
12 Months or Longer - Gross Unrealized Losses | (39) | (7)
Total - Estimated Fair Value | 4,961 | 6,493
Total - Gross Unrealized Losses | (39) | (7)
Commercial paper (due in less than one year) |  |
Schedule Of Available For Sale Securities [Line Items] |  |
Less Than 12 Months - Estimated Fair Value | 75,202 | 66,872
Less Than 12 Months - Gross Unrealized Losses | (233) | (38)
Total - Estimated Fair Value | 75,202 | 66,872
Total - Gross Unrealized Losses | (233) | (38)
Corporate notes (due in less than one year) |  |
Schedule Of Available For Sale Securities [Line Items] |  |
Less Than 12 Months - Estimated Fair Value | 40,443 | 16,001
Less Than 12 Months - Gross Unrealized Losses | (212) | (17)
Total - Estimated Fair Value | 40,443 | 16,001
Total - Gross Unrealized Losses | (212) | (17)
Corporate notes (due in one to two years) |  |
Schedule Of Available For Sale Securities [Line Items] |  |
Less Than 12 Months - Estimated Fair Value | 10,945 | 24,145
Less Than 12 Months - Gross Unrealized Losses | (68) | (79)
Total - Estimated Fair Value | 10,945 | 24,145
Total - Gross Unrealized Losses | $ (68) | $ (79)

X
- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=124269663&loc=SL82922890-210455 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=123581744&loc=d3e27337-111563 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=121590138&loc=SL82922954-210456 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for 12 months or longer, without allowance for credit loss. Includes beneficial interest in securitized financial asset. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=123581744&loc=d3e27337-111563 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=124269663&loc=SL82922890-210455 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for less than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=123581744&loc=d3e27337-111563 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=124269663&loc=SL82922890-210455 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=121590138&loc=SL82922954-210456 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for less than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=124269663&loc=SL82922890-210455 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=123581744&loc=d3e27337-111563 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position without allowance for credit loss. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=123581744&loc=d3e27290-111563 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 50 -Paragraph 4 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=124269663&loc=SL82922888-210455 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=121590138&loc=SL82922954-210456 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position, without allowance for credit loss. Includes beneficial interest in securitized financial asset. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=123581744&loc=d3e27290-111563 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 50 -Paragraph 4 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=124269663&loc=SL82922888-210455 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss
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_ScheduleOfAvailableForSaleSecuritiesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=gern_USTreasurySecuritiesDueInLessThanOneYearMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=gern_USTreasurySecuritiesDueInOneToTwoYearsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=gern_MunicipalSecuritiesDueInLessThanOneYearMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=gern_MunicipalSecuritiesDueInOneToTwoYearsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=gern_GovernmentSponsoredEnterpriseSecuritiesDueInLessThanOneYearMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=gern_CommercialPaperDueInLessThanOneYearMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=gern_CorporateNoteSecuritiesDueInLessThanOneYearMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=gern_CorporateNoteSecuritiesDueInOneToTwoYearsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |