Amount of escrow deposit related to business acquisition released during the period

No definition available.

Name:	epam_EscrowDepositReleased
Namespace Prefix:	epam_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Estimated Future Operating Results Period, Subsequent to Acquisition Date

+ References

No definition available.

+ Details

Name:	epam_EstimatedFutureOperatingResultsPeriodSubsequenttoAcquisitionDate
Namespace Prefix:	epam_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Numbers Of Employees From Acquired Company Accepting Positions, Business Acquisitions

+ References

No definition available.

+ Details

Name:	epam_NumbersOfEmployeesFromAcquiredCompanyAcceptingPositionsBusinessAcquisitions
Namespace Prefix:	epam_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Date when the acquirer obtains control of the acquiree, in CCYY-MM-DD format.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 25
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=116868678&loc=d3e848-128460

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 25
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=116868678&loc=d3e845-128460

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463

+ Details

Name:	us-gaap_BusinessAcquisitionEffectiveDateOfAcquisition1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

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.

+ References

No definition available.

+ Details

Name:	us-gaap_BusinessAcquisitionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of voting equity interests acquired at the acquisition date in the business combination.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463

+ Details

Name:	us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

For contingent consideration arrangements recognized in connection with a business combination, this element represents an estimate of the high-end of the potential range (undiscounted) of the consideration which may be paid.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (c)(3)
-URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479

+ Details

Name:	us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3213-108585

+ Details

Name:	us-gaap_PaymentsToAcquireBusinessesGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_BusinessAcquisitionAxis=epam_ContinuumInnovationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	epam_EmployeesbyspecializationAxis=epam_DesignConsultantMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=epam_ThinkLimitedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=epam_TestIOGmbHMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

ACQUISITIONS (Narrative) (Details) $ in Thousands				3 Months Ended
ACQUISITIONS (Narrative) (Details) $ in Thousands	Apr. 30, 2019 USD ($)	Nov. 01, 2018 USD ($)	Mar. 15, 2018 USD ($)	Dec. 31, 2018 USD ($)
Continuum
Business Acquisition [Line Items]
Acquisition date			Mar. 15, 2018
Cash consideration			$ 52,515
Estimated future operating results, period			12 months
Maximum amount of earnout payable			$ 3,135
Cash collection resulted from working capital adjustment				$ 76
Continuum \| Design Consultants
Business Acquisition [Line Items]
Numbers of employees acquired			125
Think
Business Acquisition [Line Items]
Acquisition date		Nov. 01, 2018
Cash consideration		$ 26,254
Estimated future operating results, period		12 months
Maximum amount of earnout payable		$ 8,156
test IO
Business Acquisition [Line Items]
Acquisition date	Apr. 30, 2019
Cash consideration	$ 17,204
Equity interest acquired	100.00%