Amount of letters of credit issued outside of the credit facility. Also includes contract performance guarantees.

No definition available.

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Namespace Prefix:	ttec_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of letters of credit issued under the credit facility that reduces the total amount of borrowings available under the credit facility.

+ References

No definition available.

+ Details

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Namespace Prefix:	ttec_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of borrowing capacity under original line of credit agreement.

+ References

No definition available.

+ Details

Name:	ttec_LineOfCreditInitialBorrowingCapacity
Namespace Prefix:	ttec_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The Credit Agreement permits accounts receivable factoring of a percentage of the average book value of all accounts receivable over the most recent twelve-month period.

+ References

No definition available.

+ Details

Name:	ttec_PercentageOfAverageBookValueOfAccountsReceivablePermittedToBeFactored
Namespace Prefix:	ttec_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Average amount borrowed under the credit facility during the period.

+ References

No definition available.

+ Details

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

- Definition

Discussion of whether the borrowings under the credit facility are secured or unsecured and, if secured, a description of collateral (for example, accounts receivable less than 120 days old, finished goods inventory).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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+ Details

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

- Definition

Date the credit facility terminates, 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

Date the credit facility first became available, in CCYY-MM-DD format.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityInitiationDate1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

The effective interest rate during the reporting period.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityInterestRateDuringPeriod
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- 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

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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

- Definition

The carrying value as of the balance sheet date of the noncurrent portion 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

+ Details

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

- Definition

Indebtedness divided by net capital.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount, before valuation allowance, of accounts and financing receivables held for sale.

+ References

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

- Details

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Balance Type:
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Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
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Balance Type:
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- Details

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- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

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COMMITMENTS AND CONTINGENCIES (NARRATIVE) (Details)		3 Months Ended	9 Months Ended
COMMITMENTS AND CONTINGENCIES (NARRATIVE) (Details)	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)
Initiation date of current line of credit agreement			Jun. 03, 2013
Line of Credit Facility, Expiration Date			Feb. 14, 2024
Initial Borrowing Capacity	$ 900,000,000.0		$ 900,000,000.0
Maximum borrowing capacity	1,200,000,000		1,200,000,000
Proceeds from factored receivables	75,000,000		75,000,000
Percentage of receivables factored	25		$ 25
Credit facility interest rate			1.30%
Line of Credit Facility, Collateral			Letter of credit fees are one eighth of 1% of the stated amount of the letter of credit on the date of issuance, renewal or amendment, plus an annual fee equal to the borrowing margin for Eurodollar loans.
Borrowings outstanding on credit facility	325,000,000		$ 325,000,000	$ 290,000,000
Average daily utilization under credit facility		$ 314,900,000	597,900,000
Remaining borrowing capacity under credit facility	570,000,000		570,000,000
Line Of Credit Facility Letters Of Credit Issued	2,600,000		2,600,000
Letters Of Credit Issued Outside Line Of Credit Facility	$ 400,000		$ 400,000
Fed Funds Effective Rate Overnight Index Swap Rate [Member]
Credit facility interest rate	0.50%
London Interbank Offered Rate (LIBOR) [Member]
Credit facility interest rate	1.25%
Minimum \| Interest coverage ration [Member]
Ratio of Indebtedness to Net Capital	2.50		2.50
Minimum \| Company's net leverage ratio [Member]
Credit facility interest rate	0.00%
Minimum \| Eurodollar [Member]
Credit facility interest rate	1.00%
Maximum
Ratio of Indebtedness to Net Capital	3.50		3.50
Proceeds from factored receivables	$ 75,000,000		$ 75,000,000
Maximum \| Company's net leverage ratio [Member]
Credit facility interest rate	0.75%
Maximum \| Eurodollar [Member]
Credit facility interest rate	1.75%