v3.26.1
Cover Page - USD ($)
 12 Months Ended
Dec. 31, 2025
Mar. 23, 2026
Jun. 30, 2025
Cover [Abstract]      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2025    
Current Fiscal Year End Date --12-31    
Document Transition Report false    
Securities Act File Number 814-01698    
Entity Registrant Name Willow Tree Capital Corporation    
Entity Incorporation, State or Country Code MD    
Entity Tax Identification Number 93-2706372    
Entity Address, Address Line One 450 Park Avenue    
Entity Address, Address Line Two 29th Floor    
Entity Address, City or Town New York    
Entity Address, State or Province NY    
Entity Address, Postal Zip Code 10022    
City Area Code 212    
Local Phone Number 218-1090    
Title of 12(g) Security Shares of Common Stock, par value $0.001 per share    
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 false    
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 false    
Entity Public Float     $ 0
Entity Common Stock, Shares Outstanding   24,524,008  
Documents Incorporated by Reference Portions of the registrant’s definitive proxy statement relating to the registrant’s 2026 Annual Meeting of Shareholders to be filed with the Securities and Exchange Commission within 120 days following the end of the registrant’s fiscal year, are incorporated by reference in Part III of this Annual Report on Form 10-K as indicated herein.    
Entity Central Index Key 0001944831    
Document Fiscal Year Focus 2025    
Document Fiscal Period Focus FY    
Amendment Flag false