v3.25.2
Document and Entity Information - shares
6 Months Ended
Jun. 30, 2025
Aug. 12, 2025
Cover [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Jun. 30, 2025  
Document Fiscal Year Focus 2025  
Document Fiscal Period Focus Q2  
Entity Registrant Name TCW DIRECT LENDING VIII LLC  
Entity Central Index Key 0001825265  
Current Fiscal Year End Date --12-31  
Entity Current Reporting Status Yes  
Entity Filer Category Non-accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company true  
Entity Ex Transition Period false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   12,745,660
Entity File Number 814-01420  
Entity Tax Identification Number 86-3307898  
Entity Address, Address Line One 200 Clarendon Street  
Entity Address City Or Town Boston  
Entity Address State Or Province MA  
Entity Address Postal Zip Code 02116  
City Area Code 617  
Local Phone Number 936-2275  
Entity Interactive Data Current Yes  
Entity Incorporation State Country Code DE  
Document Quarterly Report true  
Document Transition Report false