XML 60 R46.htm IDEA: XBRL DOCUMENT
v3.22.2.2

CEO SEPARATION AGREEMENT (Details) - USD ($) $ / shares in Units, $ in Millions | May 24, 2022 | Sep. 30, 2022 | Jun. 30, 2022
--- | --- | --- | ---
Separation Agreement [Abstract] |  |  |
Share price (in dollars per share) |  | $ 4.94 | $ 10.4
Dr. Federoff's [Member] |  |  |
Separation Agreement [Abstract] |  |  |
Severance benefit | $ 0.2 |  |
Payment of annual base salary | $ 0.5 |  |
Stock option outstanding (in shares) | 76,000 |  |
Options exercisable period | 36 months |  |
Severance benefit receivable based on performance restricted stock | $ 0.1 |  |
Share price (in dollars per share) | $ 16.2 |  |
Dr. Federoff's [Member] | Milestone Options [Member] |  |  |
Separation Agreement [Abstract] |  |  |
Stock option outstanding (in shares) | 21,000 |  |
Options exercisable period | 36 months |  |

X
- Definition Amount of cash outflows for payment of annual base salary for a period of twelve months after the expiration of the applicable revocation period. + References No definition available. + Details
Name: | erna_PaymentToOfficerBaseSalary
Namespace Prefix: | erna_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- References No definition available. + Details
Name: | erna_SeparationAgreementAbstract
Namespace Prefix: | erna_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of severance benefit, would have received if he was entitled to receive a settlement of a pro rata portion of his performance restricted stock units through the expiration of the Separation Period. + References No definition available. + Details
Name: | erna_SeveranceBenefitReceivableBasedOnPerformanceRestrictedStockUnits
Namespace Prefix: | erna_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Cash outflows for payments of postemployment benefits (such as severance pay and health insurance benefits) recognized during the period. Postemployment benefits are benefits paid to employees after employment but before retirement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 25 -Subparagraph (g) -URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3536-108585 + Details
Name: | us-gaap_PaymentsForPostemploymentBenefits
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Number of options outstanding, including both vested and non-vested options. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(ii) -URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(i) -URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Price of a single share of a number of saleable stocks of a company. + References No definition available. + Details
Name: | us-gaap_SharePrice
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + 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 -URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901 + Details
Name: | us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | srt_TitleOfIndividualAxis=srt_ChiefExecutiveOfficerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=erna_MilestoneOptionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |