Percentage points added to the reference rate to compute the variable rate on the debt instrument.

No definition available.

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Namespace Prefix:	us-gaap_
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Balance Type:	na
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- 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

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

+ Details

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

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

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

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

+ References

+ Details

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

- Definition

The effective interest rate at the end of the reporting period.

+ References

+ Details

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

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

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

- Details

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- Details

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- Details

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- Details

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- Details

Name:	epam_LineofCreditCurrencyAxis=currency_USD
Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

Name:	epam_LineofCreditCurrencyAxis=epam_OthercurrenciesexcludingU.S.dollarsMember
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- Details

Name:	us-gaap_DebtInstrumentAxis=epam_CreditFacility2017Member
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- Details

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LONG-TERM DEBT (Revolving Line of Credit) (Details) - USD ($) $ in Thousands	May 24, 2017	Sep. 12, 2014	Dec. 31, 2017	Dec. 31, 2016
Revolving Credit Facility \| 2014 Credit Facility \| LIBOR
Debt Instrument [Line Items]
Variable rate spread		1.00%
Revolving Credit Facility \| 2014 Credit Facility \| Federal Funds Open Rate
Debt Instrument [Line Items]
Variable rate spread		0.50%
Revolving Credit Facility \| 2014 Credit Facility \| U.S. dollars
Debt Instrument [Line Items]
Line of credit, borrowing capacity		$ 100,000
Line of credit, maximum borrowing capacity		200,000
Line of credit, remaining borrowing capacity				$ 74,058
Revolving Credit Facility \| 2014 Credit Facility \| U.S. dollars \| LIBOR
Debt Instrument [Line Items]
Outstanding debt				25,000
Revolving Credit Facility \| 2014 Credit Facility \| Other currencies, excluding U.S. dollars
Debt Instrument [Line Items]
Line of credit, maximum borrowing capacity		$ 50,000
Revolving Credit Facility \| 2017 Credit Facility
Debt Instrument [Line Items]
Maturity date	May 24, 2022
Revolving Credit Facility \| 2017 Credit Facility \| LIBOR
Debt Instrument [Line Items]
Variable rate spread	1.00%
Revolving Credit Facility \| 2017 Credit Facility \| Federal Funds Open Rate
Debt Instrument [Line Items]
Variable rate spread	0.50%
Revolving Credit Facility \| 2017 Credit Facility \| U.S. dollars
Debt Instrument [Line Items]
Line of credit, borrowing capacity	$ 300,000
Line of credit, maximum borrowing capacity	400,000
Line of credit, remaining borrowing capacity			$ 273,706
Revolving Credit Facility \| 2017 Credit Facility \| U.S. dollars \| LIBOR
Debt Instrument [Line Items]
Outstanding debt			$ 25,000
Line of credit, interest rate			2.56%
Revolving Credit Facility \| 2017 Credit Facility \| Other currencies, excluding U.S. dollars
Debt Instrument [Line Items]
Line of credit, maximum borrowing capacity	$ 100,000
Standby Letter of Credit \| 2014 Credit Facility
Debt Instrument [Line Items]
Irrevocable standby letters of credit				$ 942
Standby Letter of Credit \| 2017 Credit Facility
Debt Instrument [Line Items]
Irrevocable standby letters of credit			$ 1,294