v3.26.1
Document And Entity Information
Aug. 19, 2026
Document Information [Line Items]  
Entity, Registrant Name ALTERNUS CLEAN ENERGY, INC.
Current Fiscal Year End Date --12-31
Document, Type 8-K
Document, Period End Date Aug. 19, 2026
Entity, Incorporation, State or Country Code DE
Entity, File Number 001-41306
Entity, Tax Identification Number 87-1431377
Entity, Address, Address Line One 17 State Street
Entity, Address, Address Line Two Suite 4000
Entity, Address, City or Town New York City
Entity, Address, State or Province NY
Entity, Address, Postal Zip Code 10004
City Area Code 212
Local Phone Number 739-0727
Written Communications false
Soliciting Material false
Pre-commencement Tender Offer false
Pre-commencement Issuer Tender Offer false
Entity, Emerging Growth Company true
Entity, Ex Transition Period false
Amendment Flag false
Entity, Central Index Key 0001883984
CommonStockParValue00001PerShare Custom [Member]  
Document Information [Line Items]  
Title of 12(b) Security None
Trading Symbol N/A