Business Acquisition, Deferred Equity Interest Issued or Issuable, Number of Shares

No definition available.

Name:	epam_BusinessAcquisitionDeferredEquityInterestIssuedorIssuableNumberofShares
Namespace Prefix:	epam_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Business Acquisition, Equity Interest Issued or Issuable, Evaluation Period

+ References

No definition available.

+ Details

Name:	epam_BusinessAcquisitionEquityInterestIssuedorIssuableEvaluationPeriod
Namespace Prefix:	epam_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

All unvested Jointech Employment Shares will be forfeited upon termination of services for cause by the Company or other than for good reason (as applicable) by either of the two former owners of the acquired business.

+ References

No definition available.

+ Details

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

- Definition

Business acquisition, cash consideration placed in escrow

+ References

No definition available.

+ Details

Name:	epam_CashConsiderationPlacedInEscrow
Namespace Prefix:	epam_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Consideration Placed In Escrow, Percentage

+ References

No definition available.

+ Details

Name:	epam_ConsiderationPlacedInEscrowPercentage
Namespace Prefix:	epam_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The period of time the consideration paid for the acquisition was placed in escrow.

+ References

No definition available.

+ Details

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

- Definition

Consideration Placed In Escrow, Shares

+ References

No definition available.

+ Details

Name:	epam_ConsiderationPlacedInEscrowShares
Namespace Prefix:	epam_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Consideration Placed in Escrow, Value, Shares

+ References

No definition available.

+ Details

Name:	epam_ConsiderationPlacedinEscrowValueShares
Namespace Prefix:	epam_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- 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:	duration

- Definition

Value of equity interests (such as common shares, preferred shares, or partnership interest) issued or issuable to acquire the entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 50

-Paragraph 1

-Subparagraph (b)(4)

-URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479

+ Details

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

- Definition

Number of shares of equity interests issued or issuable to acquire entity.

+ References

+ Details

Name:	us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- 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://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=25497992&loc=d3e1392-128463

+ Details

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

- Definition

This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period to items of consideration transferred in connection with a business combination for which the initial accounting was incomplete.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 6

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=25497992&loc=d3e1500-128463

+ Details

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

- Definition

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_AwardTypeAxis=epam_EmploymentSharesClosingSharesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=epam_EmploymentSharesEarnOutSharesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=epam_EmploymentSharesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_CommonStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

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

- Details

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

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
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- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
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ACQUISITIONS (Narrative) (Details) (USD $)	12 Months Ended	0 Months Ended
ACQUISITIONS (Narrative) (Details) (USD $)	Dec. 31, 2014	Mar. 05, 2014 ITprofessional	Apr. 30, 2014 ITprofessional D Owner	Jun. 06, 2014 ITprofessional	Oct. 31, 2014 CreativeProfessional
Minimum
Business Acquisition [Line Items]
Estimated future operating results period, subsequent to acquisition date (in months)	7 months
Maximum
Business Acquisition [Line Items]
Estimated future operating results period, subsequent to acquisition date (in months)	12 months
Netsoft
Business Acquisition [Line Items]
Number of professionals		40
Cash in escrow		$ 256,000
Purchase price adjustments	378,000
Jointech
Business Acquisition [Line Items]
Number of professionals			216
Evaluation period (in days)			30
Number of former owners			2
Consideration in escrow (as a percent)			15.00%
GGA
Business Acquisition [Line Items]
Number of professionals				329
Purchase price adjustments	(1,366,000)
Great Fridays
Business Acquisition [Line Items]
Number of professionals					50
Percent of equity interest acquired					100.00%
Employment Shares
Business Acquisition [Line Items]
Estimate value of shares		1,017,000
Employment Shares \| Netsoft
Business Acquisition [Line Items]
Share vesting term (in years)	3 years	3 years
Employment Shares \| Jointech
Business Acquisition [Line Items]
Share vesting term (in years)	3 years
Estimate value of shares			7,788,000
Cash in escrow period (in months)	18 months
Employment Shares \| GGA
Business Acquisition [Line Items]
Share vesting term (in years)	3 years
Estimate value of shares				20,655,000
Employment Shares \| Great Fridays
Business Acquisition [Line Items]
Share vesting term (in years)	3 years
Estimate value of shares					4,823,000
Consideration place in escrow, value, shares					28,390
Employment Shares, Closing Shares \| Netsoft
Business Acquisition [Line Items]
Stock issued (in shares)		2,289
Deferred stock issued (in shares)		9,154
Cash in escrow period (in months)		18 months
Employment Shares, Closing Shares \| Jointech
Business Acquisition [Line Items]
Stock issued (in shares)			89,552
Employment Shares, Closing Shares \| GGA
Business Acquisition [Line Items]
Stock issued (in shares)				262,277
Consideration in escrow (in shares)				102,631
Employment Shares, Closing Shares \| Great Fridays
Business Acquisition [Line Items]
Stock issued (in shares)					90,864
Estimate value of shares					10,092
Employment Shares, Earn-Out Shares \| Netsoft \| Maximum
Business Acquisition [Line Items]
Stock issued (in shares)		16,349
Employment Shares, Earn-Out Shares \| Jointech \| Maximum
Business Acquisition [Line Items]
Estimate value of shares			5,000,000
Common Stock \| Netsoft
Business Acquisition [Line Items]
Stock issued (in shares)		0
Estimate value of shares		0
Common Stock \| Jointech
Business Acquisition [Line Items]
Stock issued (in shares)			0
Estimate value of shares			0
Common Stock \| GGA
Business Acquisition [Line Items]
Stock issued (in shares)				0
Estimate value of shares				0
Common Stock \| Great Fridays
Business Acquisition [Line Items]
Stock issued (in shares)					0
Estimate value of shares				0