GOODWILL (Goodwill Roll Forward) (Details) $ in Thousands	3 Months Ended
Mar. 31, 2020 USD ($)
Goodwill [Roll Forward]
Balance as of January 1, 2020	$ 195,043
Effect of net foreign currency exchange rate changes	(3,515)
Balance as of March 31, 2020	198,534
Other 2019 Acquisitions
Goodwill [Roll Forward]
Purchase accounting adjustments	188
2020 Acquisition
Goodwill [Roll Forward]
Acquisition	6,818
North America
Goodwill [Roll Forward]
Balance as of January 1, 2020	113,426
Effect of net foreign currency exchange rate changes	(373)
Balance as of March 31, 2020	120,081
North America \| Other 2019 Acquisitions
Goodwill [Roll Forward]
Purchase accounting adjustments	210
North America \| 2020 Acquisition
Goodwill [Roll Forward]
Acquisition	6,818
Europe
Goodwill [Roll Forward]
Balance as of January 1, 2020	80,873
Effect of net foreign currency exchange rate changes	(3,078)
Balance as of March 31, 2020	77,753
Europe \| Other 2019 Acquisitions
Goodwill [Roll Forward]
Purchase accounting adjustments	(42)
Europe \| 2020 Acquisition
Goodwill [Roll Forward]
Acquisition	0
Russia
Goodwill [Roll Forward]
Balance as of January 1, 2020	744
Effect of net foreign currency exchange rate changes	(64)
Balance as of March 31, 2020	700
Russia \| Other 2019 Acquisitions
Goodwill [Roll Forward]
Purchase accounting adjustments	20
Russia \| 2020 Acquisition
Goodwill [Roll Forward]
Acquisition	$ 0

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

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Amount of foreign currency translation gain (loss) which increases (decreases) an asset representing future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of increase (decrease) from adjustments after acquisition date under purchase accounting of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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