v3.26.1
Document and Entity Information - shares
 3 Months Ended
Mar. 31, 2026
Jun. 02, 2026
Document Information [Line Items]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Mar. 31, 2026  
Document Fiscal Year Focus 2026  
Document Fiscal Period Focus Q1  
Trading Symbol XE  
Title of 12(b) Security Class A common stock, par value $0.0001 per share  
Security Exchange Name NASDAQ  
Entity Registrant Name X-Energy, Inc.  
Central Index Key 0002088896  
Current Fiscal Year End Date --12-31  
Entity Filer Category Non-accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company true  
Entity Current Reporting Status No  
Entity Interactive Data Current Yes  
Entity Shell Company false  
Document Quarterly Report true  
Document Transition Report false  
Entity File Number 001-43246  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 41-3934505  
Entity Address, Address Line One 530 Gaither Road  
Entity Address, Address Line Two Suite 700  
Entity Address, City or Town Rockville  
Entity Address, State or Province MD  
Entity Ex Transition Period false  
Entity Address, Postal Zip Code 20850  
City Area Code 301  
Local Phone Number 358-5600  
Class A common stock    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   287,458,734
Class B common stock    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   118,907,374