Description of business.

No definition available.

Name:	eldn_DescriptionOfBusinessLineItems
Namespace Prefix:	eldn_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of common stockholders receive cash and other assets.

+ References

No definition available.

+ Details

Name:	eldn_PercentageOfCommonStockholdersReceiveCashAndOtherAssets
Namespace Prefix:	eldn_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Date when acquirer obtains control of acquiree in business combination, in YYYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479328/805-10-50-8

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 38
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479303/805-10-55-38

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479328/805-10-50-2

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 25
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479405/805-10-25-7

Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 25
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479405/805-10-25-6

+ Details

Name:	us-gaap_BusinessAcquisitionEffectiveDateOfAcquisition1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Face amount or stated value per share of common stock.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

+ Details

Name:	us-gaap_CommonStockParOrStatedValuePerShare
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Per share amount of par value or stated value of stock classified as temporary equity. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(27))
-SubTopic 10
-Topic 210
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

+ Details

Name:	us-gaap_TemporaryEquityParOrStatedValuePerShare
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_StatementClassOfStockAxis=eldn_SeriesXAndX1NonVotingConvertiblePreferredStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=eldn_AnelixisTherapeuticsIncorporationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Description of Business - Additional Information (Detail) - $ / shares	Sep. 14, 2020	Jun. 30, 2025	Dec. 31, 2024
Description Of Business [Line Items]
Convertible preferred stock, par value		$ 0.001
Common stock par value		$ 0.001	$ 0.001
Percentage of common stockholders receive cash and other assets		50.00%
Series X and Series X1 Non-voting Convertible Preferred Stock [Member]
Description Of Business [Line Items]
Convertible preferred stock, par value		$ 0.001
Anelixis [Member]
Description Of Business [Line Items]
Date of acquisition	Sep. 14, 2020