v3.26.1
Document and Entity Information - USD ($)
 12 Months Ended
Dec. 31, 2025
Mar. 30, 2026
Jun. 30, 2025
Document and Entity Information      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2025    
Document Transition Report false    
Securities Act File Number 001-41757    
Entity Registrant Name HAYMAKER ACQUISITION CORP. 4    
Entity Incorporation, State or Country Code E9    
Entity Tax Identification Number 86-2213850    
Entity Address, Address Line One 324 Royal Palm Way    
Entity Address, Address Line Two Suite 300-i    
Entity Address, City or Town Palm Beach    
Entity Address, State or Province FL    
Entity Address, Postal Zip Code 33480    
City Area Code 929    
Local Phone Number 280-1912    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Non-accelerated Filer    
Entity Small Business true    
Entity Emerging Growth Company true    
Entity Ex Transition Period false    
ICFR Auditor Attestation Flag false    
Document Financial Statement Error Correction [Flag] false    
Entity Shell Company true    
Entity Public Float     $ 0
Entity Central Index Key 0001970509    
Current Fiscal Year End Date --12-31    
Document Fiscal Year Focus 2025    
Document Fiscal Period Focus FY    
Amendment Flag false    
Auditor Name WithumSmith+Brown, PC    
Auditor Location New York, New York    
Auditor Firm ID 100    
Units, each consisting of one Class A Ordinary Share and one-half of one redeemable Warrant      
Document and Entity Information      
Title of 12(b) Security Units, each consisting of one Class A Ordinary Share and one-half of one redeemable Warrant    
Trading Symbol HYAC.U    
Security Exchange Name NYSE    
Class A Ordinary Shares, par value $0.0001 per share      
Document and Entity Information      
Title of 12(b) Security Class A Ordinary Shares, par value $0.0001 per share    
Trading Symbol HYAC    
Security Exchange Name NYSE    
Entity Common Stock, Shares Outstanding   23,425,499  
Warrants, each whole warrant exercisable for one Class A Ordinary Share at an exercise price of $11.50 per share      
Document and Entity Information      
Title of 12(b) Security Warrants, each whole warrant exercisable for one Class A Ordinary Share at an exercise price of $11.50 per share    
Trading Symbol HYAC.WS    
Security Exchange Name NYSE    
Class B Ordinary Shares      
Document and Entity Information      
Entity Common Stock, Shares Outstanding   5,750,000