Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2017	Oct. 31, 2017
Document Documentand 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		52,812,586
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q3
Document Period End Date	Sep. 30, 2017
Document Type	10-Q
Amendment Flag	false
Trading Symbol	EPAM