v3.25.3
Document and Entity Information - shares
9 Months Ended
Sep. 30, 2025
Nov. 07, 2025
Document and Entity Information    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Sep. 30, 2025  
Document Transition Report false  
Entity File Number 000-16335  
Entity Registrant Name RIDGEFIELD ACQUISITION CORP  
Entity Incorporation, State or Country Code NV  
Entity Tax Identification Number 84-0922701  
Entity Address, Address Line One 3827 S Carson St, Unit 505-25  
Entity Address, Address Line Two PMB 1078,  
Entity Address, City or Town Carson City  
Entity Address, State or Province NV  
Entity Address, Postal Zip Code 89701  
City Area Code 805  
Local Phone Number 484-8855  
Title of 12(b) Security None  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Non-accelerated Filer  
Entity Small Business true  
Entity Emerging Growth Company false  
Entity Shell Company true  
Entity Common Stock, Shares Outstanding   27,860,773
Entity Central Index Key 0000812152  
Current Fiscal Year End Date --12-31  
Document Fiscal Year Focus 2025  
Document Fiscal Period Focus Q3  
Amendment Flag false  
No Trading Symbol Flag true