INTANGIBLE ASSETS (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Intangible assets
Gross Carrying Amount	$ 100,645	$ 100,645
Acquisitions	1,970
Accumulated Amortization	(87,250)	(83,718)
Currency impact	(301)	(322)
Net Book Value	15,064	16,605
Amortization expense	3,532	4,011
Estimated future amortization expense
2021	2,642
2022	2,110
2023	1,814
2024	1,495
2025	1,326
Thereafter	5,677
Estimated future amortization expense	15,064
Customer relationships
Intangible assets
Gross Carrying Amount	73,723	73,723
Acquisitions	1,560
Accumulated Amortization	(66,705)	(63,761)
Currency impact	(108)	(116)
Net Book Value	8,470	9,846
Noncompete agreements
Intangible assets
Gross Carrying Amount	5,952	5,952
Acquisitions	10
Accumulated Amortization	(5,911)	(5,862)
Currency impact		1
Net Book Value	51	91
Software
Intangible assets
Gross Carrying Amount	1,500	1,500
Acquisitions	160
Accumulated Amortization	(1,511)	(1,500)
Net Book Value	149
Backlog
Intangible assets
Gross Carrying Amount	5,002	5,002
Accumulated Amortization	(4,981)	(4,981)
Currency impact	(21)	(21)
Databases
Intangible assets
Gross Carrying Amount	13,218	13,218
Accumulated Amortization	(6,852)	(6,364)
Currency impact	(172)	(186)
Net Book Value	$ 6,194	$ 6,668
Trademarks and trade names
Intangible assets
Estimated Useful Lives (in years)	5 years	5 years
Gross Carrying Amount	$ 1,250	$ 1,250
Acquisitions	240
Accumulated Amortization	(1,290)	$ (1,250)
Net Book Value	$ 200
Minimum \| Customer relationships
Intangible assets
Estimated Useful Lives (in years)	2 years	2 years
Minimum \| Noncompete agreements
Intangible assets
Estimated Useful Lives (in years)	4 years	4 years
Minimum \| Software
Intangible assets
Estimated Useful Lives (in years)	3 years	3 years
Minimum \| Backlog
Intangible assets
Estimated Useful Lives (in years)	1 year	1 year
Minimum \| Databases
Intangible assets
Estimated Useful Lives (in years)	4 years	4 years
Maximum \| Customer relationships
Intangible assets
Estimated Useful Lives (in years)	15 years	15 years
Maximum \| Noncompete agreements
Intangible assets
Estimated Useful Lives (in years)	7 years	7 years
Maximum \| Software
Intangible assets
Estimated Useful Lives (in years)	4 years	4 years
Maximum \| Backlog
Intangible assets
Estimated Useful Lives (in years)	2 years	2 years
Maximum \| Databases
Intangible assets
Estimated Useful Lives (in years)	15 years	15 years

The amount of acquired finite lived intangible assets acquired.

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Accumulated amount of foreign currency translation gain (loss) adjustment of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
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Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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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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Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Amount before accumulated amortization of intangible assets, excluding goodwill.

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Sum of the carrying amounts of all intangible assets, excluding goodwill, as of the balance sheet date, net of accumulated amortization and impairment charges.

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