v3.25.4
Cover Page - USD ($)
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2023
Mar. 06, 2026
Jun. 30, 2025
Cover [Abstract]        
Document Type 10-K      
Amendment Flag false      
Document Fiscal Year Focus 2025      
Document Fiscal Period Focus FY      
Document Period End Date Dec. 31, 2025      
Document Annual Report true      
Document Transition Report false      
Current Fiscal Year End Date --12-31      
Entity Registrant Name Grayscale Ethereum Classic Trust (ETC)      
Entity Central Index Key 0001705181      
Entity Small Business true      
Entity Emerging Growth Company true      
Entity Ex Transition Period true      
Entity Common Stock, Shares Outstanding     13,993,800  
Entity Public Float       $ 115,325,290
Trading Symbol ETCG      
Entity Shell Company false      
Entity Filer Category Accelerated Filer      
Entity Current Reporting Status Yes      
Entity Interactive Data Current Yes      
Entity File Number 000-56309      
Entity Incorporation, State or Country Code DE      
Entity Tax Identification Number 82-6239281      
Entity Address, Address Line One 290 Harbor Drive, 4th Floor      
City Area Code 212      
Local Phone Number 668-1427      
Entity Address, City or Town Stamford      
Entity Address, Postal Zip Code 06902      
Entity Address, State or Province CT      
Title of 12(g) Security Grayscale Ethereum Classic Trust (ETC) Shares      
Entity Well-known Seasoned Issuer No      
Entity Voluntary Filers No      
ICFR Auditor Attestation Flag false      
Document Financial Statement Error Correction [Flag] false      
Documents Incorporated by Reference None      
Auditor Opinion [Text Block]

We have audited the accompanying statements of assets and liabilities, including the schedules of investment of Grayscale Ethereum Classic Trust (ETC) (the Trust) as of December 31, 2025 and December 31, 2024, the related statements of operations and changes in net assets for the years then ended and the related notes (collectively, the financial statements). In our opinion, the financial statements present fairly, in all material respects, the financial position of the Trust as of December 31, 2025 and December 31, 2024, and the results of its operations and the changes in its net assets for the years then ended, in conformity with U.S. generally accepted accounting principles.

      
Auditor Firm ID 185 688    
Auditor Name KPMG LLP Marcum LLP    
Auditor Location New York, New York New York, New York