Document and Entity Information - shares
9 Months Ended
Sep. 30, 2018
Nov. 09, 2018
Document And Entity Information    
Entity Registrant Name THESTREET, INC.  
Entity Central Index Key 0001080056  
Document Type 10-Q  
Trading Symbol TST  
Document Period End Date Sep. 30, 2018  
Amendment Flag false  
Current Fiscal Year End Date --12-31  
Entity's Reporting Status Current Yes  
Entity Small Business true  
Entity Filer Category Non-accelerated Filer  
Entity Emerging Growth Company false  
Entity Ex Transition Period false  
Entity Common Stock, Shares Outstanding   49,612,180
Document Fiscal Period Focus Q3  
Document Fiscal Year Focus 2018