GOODWILL AND INTANGIBLE ASSETS, NET (Tables)

12 Months Ended

Dec. 31, 2019

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill by reportable segment was as follows:



	North America			Europe			Russia		Total
Balance as of January 1, 2018	$	77,290		$	42,241		$	—	$	119,531
Continuum acquisition (Note 2)	26,617			—			—		26,617
Think acquisition (Note 2)	—			22,482			—		22,482
Effect of currency translation	(365		)	(1,433		)	—		(1,798		)
Balance as of December 31, 2018	103,542			63,290			—		166,832
test IO acquisition (Note 2)	3,301			8,849			—		12,150
Other 2019 acquisitions (Note 2)	6,503			9,546			738		16,787
Think purchase accounting adjustments	—			(2,043		)	—		(2,043		)
Effect of currency translation	$	80		$	1,231		$	6	1,317
Balance as of December 31, 2019	$	113,426		$	80,873		$	744	$	195,043

Components of Intangible Assets

Intangible assets other than goodwill as of December 31, 2019 and 2018 were as follows:



	As of December 31, 2019
	Weighted average life at acquisition (in years)	Gross carrying amount		Accumulated amortization			Net carrying amount
Customer relationships	9	$	87,489	$	(38,526	)	$	48,963
Software	6	4,472		(486		)	3,986
Trade names	5	6,439		(4,753		)	1,686
Contract royalties	8	1,900		(435		)	1,465
Assembled workforce	3	158		—			158
Total		$	100,458	$	(44,200	)	$	56,258



	As of December 31, 2018
	Weighted average life at acquisition (in years)	Gross carrying amount		Accumulated amortization			Net carrying amount
Customer relationships	9.5	$	78,042	$	(29,580	)	$	48,462
Favorable lease	11.2	5,500		(410		)	5,090
Trade names	5.3	6,111		(4,300		)	1,811
Contract royalties	8	1,900		(198		)	1,702
Total		$	91,553	$	(34,488	)	$	57,065

Intangible Assets Amortization Expense Recognized

The following table presents amortization expense recognized for the periods indicated:



	For the Years Ended December 31,
	2019		2018		2017
Customer relationships	$	8,743	$	7,637	$	6,643
Software	486		—		—
Trade names	447		266		896
Contract royalties	238		198		—
Favorable lease	—		410		—
Non-competition agreements	—		—		23
Total	$	9,914	$	8,511	$	7,562

Estimated Amortization Expense

Based on the carrying value of the Company’s existing intangible assets as of December 31, 2019, the estimated amortization expense for the future years is as follows:



Year ending December 31,	Amount
2020	$	11,322
2021	11,322
2022	11,126
2023	9,526
2024	7,023
Thereafter	5,939
Total	$	56,258