SEGMENT INFORMATION (Reclassification) (Details)	12 Months Ended
Dec. 31, 2018 USD ($)
Income from operations
Effect of Reclassification Adjustments [Line Items]
Effect of reclassification	$ 0

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	epam_EffectofReclassificationAdjustmentsLineItems
Namespace Prefix:	epam_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration