XML 42 R32.htm IDEA: XBRL DOCUMENT
v3.22.1

STOCKHOLDERS' EQUITY - 2018 INDUCEMENT AWARD PLAN (Details) - 2018 Inducement Award Plan - shares | 1 Months Ended
--- | ---
Feb. 28, 2022 | May 31, 2021 | Feb. 28, 2021 | Feb. 29, 2020 | Jan. 31, 2019 | Dec. 31, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |
Common stock, shares reserved for future issuance (in shares) | 16,100,000 |  |  |  |  |
Common stock, increase in option reserves (in shares) | 1,000,000 | 5,000,000 | 800,000 | 1,300,000 | 5,000,000 | 3,000,000

X
- Definition Aggregate number of common shares reserved for future issuance. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.29) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_CommonStockCapitalSharesReservedForFutureIssuance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
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_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The addition or reduction in the number of reserved shares that could potentially be issued under the option plan attributable to reasons other than grants, exercises, forfeitures, and expirations during the reporting period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOtherIncreasesDecreasesInPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_PlanNameAxis=gern_TwoThousandAndEighteenInducementAwardPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |