GOODWILL AND INTANGIBLE ASSETS, NET (Tables)

12 Months Ended

Dec. 31, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill By Reportable Segment

Goodwill by reportable segment was as follows:

	North America			Europe			Total
Balance as of January 1, 2017	$	76,812		$	32,477		$	109,289
Other acquisitions	199			4,533			4,732
Other acquisitions purchase accounting adjustments	(285		)	2,100			1,815
Effect of currency translation	564			3,131			3,695
Balance as of December 31, 2017	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

Components of Intangible Assets

Intangible assets other than goodwill as of December 31, 2018 and 2017 were as follows:

	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

	As of December 31, 2017
	Weighted average life at acquisition (in years)	Gross carrying amount		Accumulated amortization			Net  carrying amount
Customer relationships	10	$	66,646	$	(22,200	)	$	44,446
Trade names	5	4,099		(4,034		)	65
Total		$	70,745	$	(26,234	)	$	44,511

Intangible Assets Amortization Expense Recognized

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

	For the Years Ended December 31,
	2018		2017		2016
Customer relationships	$	7,637	$	6,643	$	6,858
Favorable lease	410		—		—
Trade names	266		896		1,139
Contract royalties	198		—		—
Non-competition agreements	—		23		173
Total	$	8,511	$	7,562	$	8,170

Estimated Amortization Expense

The following table presents estimated amortization expense related to the Company’s existing intangible assets for the years ended December 31:

	Amount
2019	$	9,520
2020	9,520
2021	9,520
2022	9,379
2023	8,153
Thereafter	10,973
Total	$	57,065