v3.6.0.2
Document and Entity Information - USD ($)
12 Months Ended
Dec. 31, 2016
Feb. 17, 2017
Jun. 30, 2016
Document and Entity Information      
Entity Registrant Name 2U, Inc.    
Entity Central Index Key 0001459417    
Document Type 10-K    
Document Period End Date Dec. 31, 2016    
Amendment Flag false    
Current Fiscal Year End Date --12-31    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Filer Category Large Accelerated Filer    
Entity Public Float     $ 1,236,579,271
Entity Common Stock, Shares Outstanding   47,229,877  
Document Fiscal Year Focus 2016    
Document Fiscal Period Focus FY