Future value of liabilities incurred by the acquirer to former owners of the acquiree.

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Amortization expense recorded by the acquired companies since the acquisition date. Amortization expense is specific to acquired intangible assets.

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No definition available.

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Amount of cash paid up-front to acquire the entity.

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Date when the business acquisition agreement was executed, in CCYY-MM-DD format.

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With respect to a business combination completed during the period, this element provides a description of the business, other than the name, which may include the industry, size, products and other important information.

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No definition available.

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

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Amount of increase (decrease) in the value of a contingent consideration liability, including, but not limited to, differences arising upon settlement.

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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.

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Amount of liability recognized arising from contingent consideration in a business combination.

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Value of input used to measure contingent consideration liability from business combination.

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This element represents the amount of earnings or loss of the acquiree since the acquisition date included in the consolidated income statement for the reporting period.

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This element represents the amount of revenue of the acquiree since the acquisition date included in the consolidated income statement for the reporting period.

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Amount recognized for assets, including goodwill, in excess of (less than) the aggregate liabilities assumed.

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The fair value of assets acquired in noncash investing or financing activities.

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ACQUISITIONS AND DIVESTITURES (NARRATIVE) (Details) £ in Millions					3 Months Ended	9 Months Ended
	Oct. 26, 2019 USD ($)	Apr. 30, 2018 GBP (£) item	Apr. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($)	Dec. 31, 2018 USD ($)	Apr. 30, 2018 USD ($) item
Business Acquisition [Line Items]
Other liabilities, noncurrent						$ 74,226,000	$ 126,532,000
Contingent Consideration, at fair value							2,363,000
Revenue of Acquirees since Acquisition Date, Actual						2,300,000
Income (loss) from operations of Acquirees since Acquisition Date, Actual						800,000
Acquired intangible amortization of acquirees since acquisition						300,000
SCS
Business Acquisition [Line Items]
Payments to Acquire Businesses		£ 4.4	$ 6,100,000
Total purchase price								$ 9,511,000
Future Value of Liabilities Incurred From Business Acquisitions						$ 0		2,900,000
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High								4,100,000
Contingent Consideration, at fair value							$ 2,363,000	$ 2,700,000
SCS \| Discount Rate
Business Acquisition [Line Items]
Business combination contingent consideration measurement input \| item		4.7						4.7
SCS \| United Kingdom, Pounds
Business Acquisition [Line Items]
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High \| £		£ 3.0
SCS \| TTEC Digital
Business Acquisition [Line Items]
Description of Acquired Entity		Strategic Communications ServicesOn April 30, 2018, the Company acquired all of the outstanding equity securities of Strategic Communications Services, Ltd ("SCS"). SCS provides services as a system integrator for multichannel contact center platforms, including CISCO. The Company offers in-house, managed and outsourced network, information, communications and contact center services to leading brands throughout Europe. This business has been integrated into the Company's TTEC Digital segment.	Strategic Communications ServicesOn April 30, 2018, the Company acquired all of the outstanding equity securities of Strategic Communications Services, Ltd ("SCS"). SCS provides services as a system integrator for multichannel contact center platforms, including CISCO. The Company offers in-house, managed and outsourced network, information, communications and contact center services to leading brands throughout Europe. This business has been integrated into the Company's TTEC Digital segment.
Increase (decrease) in contingent consideration payable					$ 210,000
BH
Business Acquisition [Line Items]
Date of Acquisition				Mar. 31, 2018
Description of Acquired Entity				Berkshire Hathaway Specialty ConciergeOn March 31, 2018, the Company, through its subsidiary Percepta, acquired certain assets from Berkshire Hathaway Specialty Concierge, LLC ("BH") related to a customer engagement center and the related customer contracts. This acquisition is being accounted for as a business combination. These assets have been integrated into the Company's TTEC Engage segment.
Total purchase price				$ 1
BH \| Customer Relationships [Member]
Business Acquisition [Line Items]
Fair Value of Assets Acquired				257,000
BH \| Lease Agreements [Member]
Business Acquisition [Line Items]
Fair Value of Assets Acquired				330,000
BH \| Fixed Assets
Business Acquisition [Line Items]
Fair Value of Assets Acquired				$ 98,000
FCR
Business Acquisition [Line Items]
Date of Acquisition	Oct. 26, 2019
Percentage of Voting Interests Acquired	70.00%
Description of Acquired Entity	On October 26, 2019, the Company acquired, through its subsidiary TTEC Services Corporation ("TSC"), 70% of the outstanding membership interest in First Call Resolution, LLC ("FCR"), an Oregon limited liability company ("the Transaction"). FCR is a customer care, social networking and business process solutions service provider with approximately 2,000 employees based in the U.S.
Cost of Acquired Entity, Up Front Cash Consideration	$ 104,200,000
Future Value of Liabilities Incurred From Business Acquisitions	$ 10,900,000