Document and Entity Information - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2015
Feb. 10, 2016
Jun. 30, 2015
Document And Entity Information [Abstract]      
Entity Registrant Name EPAM Systems, Inc.    
Entity Central Index Key 0001352010    
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 Large Accelerated Filer    
Entity Common Stock, Shares Outstanding   50,370,482  
Document Fiscal Year Focus 2015    
Document Fiscal Period Focus FY    
Document Period End Date Dec. 31, 2015    
Document Type 10-K    
Amendment Flag false    
Entity Public Float     $ 3,332