Percentage of adjustment of redemption price of stock based on market value and newly issued price.

No definition available.

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- Definition

The minimum threshold period during which a written notice is required for redemption of warrants, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Number of fractional warrants issued for units that may be converted.

+ References

No definition available.

+ Details

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Namespace Prefix:	nucl_
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Balance Type:	na
Period Type:	duration

- Definition

Price of the entity's common stock which would be required to be attained to trigger the redemption of warrants.

+ References

No definition available.

+ Details

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Namespace Prefix:	nucl_
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- Definition

Threshold number of specified trading days for stock price trigger considered for redemption of warrants.

+ References

No definition available.

+ Details

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Namespace Prefix:	nucl_
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- Definition

Redemption price per share or per unit of warrants or rights outstanding.

+ References

No definition available.

+ Details

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Data Type:	dtr-types:perShareItemType
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Period Type:	duration

- Definition

The period of time after completion of a business combination in which the reporting entity is required to file a registration statement with the SEC.

+ References

No definition available.

+ Details

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Namespace Prefix:	nucl_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Redemption period.

+ References

No definition available.

+ Details

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Namespace Prefix:	nucl_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The period of time which must elapse after completion of a business combination before the Sponsor can transfer, assign or sell any Founder Shares unless other specified conditions are met.

+ References

No definition available.

+ Details

Name:	nucl_ThresholdPeriodForNotToTransferAssignOrSellAnySharesOrWarrantsAfterCompletionOfInitialBusinessCombination
Namespace Prefix:	nucl_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the warrants exercisable term from the closing of the business combination.

+ References

No definition available.

+ Details

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Namespace Prefix:	nucl_
Data Type:	xbrli:durationItemType
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Period Type:	duration

- Definition

The warrants exercisable term from the closing of the initial public offering, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	nucl_WarrantsAndRightsOutstandingExercisableTermFromClosingOfInitialPublicOffering
Namespace Prefix:	nucl_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Exercise price per share or per unit of warrants or rights outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480738/235-10-S50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(h)(4))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-3

+ Details

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Balance Type:	na
Period Type:	instant

- 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_ClassOfWarrantOrRightLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of warrants or rights outstanding.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- 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

- Definition

Period between issuance and expiration of outstanding warrant and right embodying unconditional obligation requiring redemption by transferring asset at specified or determinable date or upon event certain to occur, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)(i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (bbb)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

+ Details

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Data Type:	xbrli:durationItemType
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- Details

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- Details

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- Details

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- Details

Name:	us-gaap_ClassOfWarrantOrRightAxis=us-gaap_WarrantMember
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Period Type:

- Details

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- Details

Name:	us-gaap_ClassOfWarrantOrRightAxis=nucl_PublicWarrantsMember
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Shareholders' Deficit - Warrants (Details) - $ / shares	12 Months Ended
Shareholders' Deficit - Warrants (Details) - $ / shares	Dec. 31, 2025	Nov. 30, 2025	May 29, 2025	Dec. 31, 2024	Oct. 17, 2022
Shareholders' Deficit
Share Price		$ 0.61	$ 0.61	$ 0.61
CIK_0001843477_Spring Valley Acquisition Corp. II
Shareholders' Deficit
Warrants outstanding	2,300,000			2,300,000
Class A ordinary shares \| CIK_0001843477_Spring Valley Acquisition Corp. II
Shareholders' Deficit
Share Price	$ 9.2
Redemption of warrants when the price per class A ordinary share equals or exceeds $18.00 \| CIK_0001843477_Spring Valley Acquisition Corp. II
Shareholders' Deficit
Redemption price per public warrant (in dollars per share)	$ 0.01
Minimum threshold written notice period for redemption of public warrants	30 days
Threshold trading days for redemption of public warrants	20 days
Redemption period	30 days
Stock price trigger for redemption of public warrants	$ 18,000
Warrants \| CIK_0001843477_Spring Valley Acquisition Corp. II
Shareholders' Deficit
Exercise price of warrants	$ 11.5
Private Placement Warrants \| CIK_0001843477_Spring Valley Acquisition Corp. II
Shareholders' Deficit
Warrants outstanding	13,350,000			13,350,000
Exercise price of warrants					$ 11.5
Threshold period for not to transfer, assign or sell any of their shares or warrants after the completion of the initial business combination	30 days
Public Warrants \| CIK_0001843477_Spring Valley Acquisition Corp. II
Shareholders' Deficit
Warrants outstanding	11,500,000			11,500,000
Fractional warrants issued upon conversion of units	0
Warrants exercisable term from the completion of business combination	30 days
Warrants exercisable term from closing of initial public offering	12 months
Maximum period after business combination in which to file registration statement	20 days
Public Warrants expiration term	5 years
Adjustment one of redemption price of stock based on market value and newly issued price (as a percent)	115.00%