v3.25.3
Cover - shares
 9 Months Ended
Sep. 30, 2025
Nov. 14, 2025
Document Information [Line Items]    
Document Type 10-Q  
Document Quarterly Report true  
Document Transition Report false  
Entity Interactive Data Current Yes  
Amendment Flag false  
Document Period End Date Sep. 30, 2025  
Document Fiscal Year Focus 2025  
Document Fiscal Period Focus Q3  
Entity Information [Line Items]    
Entity Registrant Name FUTURECREST ACQUISITION CORP.  
Entity Central Index Key 0002074697  
Entity File Number 001-42867  
Entity Tax Identification Number 98-1871328  
Entity Incorporation, State or Country Code E9  
Current Fiscal Year End Date --12-31  
Entity Current Reporting Status No  
Entity Shell Company true  
Entity Filer Category Non-accelerated Filer  
Entity Small Business true  
Entity Emerging Growth Company true  
Entity Ex Transition Period false  
Entity Incorporation, Date of Incorporation Jun. 09, 2025  
Entity Contact Personnel [Line Items]    
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, State or Province NY  
Entity Address, Postal Zip Code 10022  
Entity Phone Fax Numbers [Line Items]    
City Area Code (732)  
Local Phone Number 698-8220  
Units, each consisting of one Class A ordinary share and one-quarter of one redeemable warrant    
Entity Listings [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    
Entity Listings [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 an exercise price of $11.50 per share    
Entity Listings [Line Items]    
Title of 12(b) Security Redeemable warrants, each whole warrant exercisable for one Class A ordinary share at an exercise price of $11.50 per share  
Trading Symbol FCRS WS  
Security Exchange Name NYSE  
Class A Ordinary Shares    
Entity Listings [Line Items]    
Entity Common Stock, Shares Outstanding   28,750,000
Class B Ordinary Shares    
Entity Listings [Line Items]    
Entity Common Stock, Shares Outstanding   7,187,500