XML 15 R1.htm IDEA: XBRL DOCUMENT v3.26.1
Cover - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Mar. 31, 2026
Document Information [Line Items]    
Document Type 10-K  
Document Annual Report true  
Document Transition Report false  
Document Financial Statement Error Correction [Flag] false  
Entity Interactive Data Current Yes  
Document Period End Date Dec. 31, 2025  
Document Fiscal Year Focus 2025  
Document Fiscal Period Focus FY  
Documents Incorporated by Reference [Text Block] None  
Entity File Number 001-42867  
Entity Tax Identification Number 00-0000000  
Entity Incorporation, State or Country Code E9  
Entity Central Index Key 0002074697  
Entity Public Float $ 290  
Entity Ex Transition Period false  
Entity Emerging Growth Company true  
Entity Small Business true  
Entity Filer Category Non-accelerated Filer  
Entity Shell Company true  
Entity Current Reporting Status Yes  
Entity Voluntary Filers No  
Entity Well-known Seasoned Issuer No  
Local Phone Number 698-8220  
City Area Code (732)  
Entity Address, Address Line One 150 East 52nd Street  
Entity Address, Address Line Two 3rd Floor  
Entity Address, City or Town New York  
Entity Address, Postal Zip Code 10022  
Amendment Flag false  
Entity Registrant Name FutureCrest Acquisition Corp.  
Current Fiscal Year End Date --12-31  
Entity Address, State or Province NY  
Units, each consisting of one Class A ordinary share and one-quarter of one redeemable warrant    
Document Information [Line Items]    
Title of 12(b) Security Units, each consisting of one Class A ordinary share and one-quarter of one redeemable warrant  
Trading Symbol FCRS.U  
Security Exchange Name NYSE  
Class A ordinary shares, par value $0.0001 per share    
Document Information [Line Items]    
Title of 12(b) Security Class A ordinary shares, par value $0.0001 per share  
Trading Symbol FCRS  
Security Exchange Name NYSE  
Redeemable warrants, each whole warrant exercisable for one Class A ordinary share at a price of $11.50 per share    
Document Information [Line Items]    
Title of 12(b) Security Redeemable warrants, each whole warrant exercisable for one Class A ordinary share at a price of $11.50 per share  
Trading Symbol FCRS.WS  
Security Exchange Name NYSE  
Class A Ordinary Shares    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   28,750,000
Class B Ordinary Shares    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   7,187,500