v3.7.0.1
Document and Entity Information - shares
6 Months Ended
Jun. 30, 2017
Aug. 01, 2017
Document and Entity Information    
Entity Registrant Name 2U, Inc.  
Entity Central Index Key 0001459417  
Document Type 10-Q  
Document Period End Date Jun. 30, 2017  
Amendment Flag false  
Current Fiscal Year End Date --12-31  
Entity Current Reporting Status Yes  
Entity Filer Category Large Accelerated Filer  
Entity Common Stock, Shares Outstanding   47,924,767
Document Fiscal Year Focus 2017  
Document Fiscal Period Focus Q2