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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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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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.

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No definition available.

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

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Amount of liability recognized arising from contingent consideration in a business combination, expected to be settled within one year or the normal operating cycle, if longer.

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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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Amount of liabilities classified as other, due after one year or the normal operating cycle, if longer.

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

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ACQUISITIONS AND DIVESTITURES (NARRATIVE) (Details) £ in Millions				3 Months Ended
	Apr. 30, 2018 GBP (£) item	Apr. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Apr. 30, 2018 USD ($) item
Business Acquisition [Line Items]
Other liabilities, noncurrent				$ 121,301,000	$ 126,532,000
Contingent Consideration, at fair value				2,456,000	2,363,000
Revenue of Acquirees since Acquisition Date, Actual				1,100,000
Income (loss) from operations of Acquirees since Acquisition Date, Actual				0
Acquired intangible amortization of acquirees since acquisition				100,000
SCS
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 CTS 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 CTS segment.
Payments to Acquire Businesses	£ 4.4	$ 6,100,000
Total purchase price						$ 9,511,000
Future Value of Liabilities Incurred From Business Acquisitions						2,900,000
Contingent Consideration, at fair value				2,456,000	$ 2,363,000	$ 4,100,000
SCS \| Discount Rate
Business Acquisition [Line Items]
Business combination contingent consideration measurement input \| item	0.047					0.047
SCS \| Other accrued expenses
Business Acquisition [Line Items]
Contingent Consideration, at Fair Value, Current Portion				1,300,000
SCS \| Other Noncurrent Liabilities [Member]
Business Acquisition [Line Items]
Contingent Consideration, at Fair Value, Current Portion				$ 1,200,000
SCS \| United Kingdom, Pounds
Business Acquisition [Line Items]
Contingent Consideration, at Fair Value, Current Portion \| £	£ 3.0
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 CMS 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