v2.4.0.8
Document and Entity Information (USD $)
12 Months Ended
Dec. 31, 2014
Feb. 24, 2015
Jun. 30, 2014
Document and Entity Information      
Entity Registrant Name 2U, Inc.    
Entity Central Index Key 0001459417    
Document Type 10-K    
Document Period End Date Dec. 31, 2014    
Amendment Flag false    
Current Fiscal Year End Date --12-31    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Filer Category Non-accelerated Filer    
Entity Public Float     $ 451,962,721
Entity Common Stock, Shares Outstanding   41,018,404  
Document Fiscal Year Focus 2014    
Document Fiscal Period Focus FY