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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Intangible Assets, Net - Summary (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Intangible assets
Gross Value	$ 317,100		$ 319,796
Accumulated Amortization	(102,434)		(94,343)
Net Carrying Value	214,666		$ 225,453
Amortization expense for intangible assets	$ 8,900	$ 8,700
Weighted Average
Intangible assets
Weighted Average Remaining Useful Life	12 years 3 months 18 days		12 years 4 months 24 days
Client relationships
Intangible assets
Gross Value	$ 232,987		$ 237,182
Accumulated Amortization	(65,733)		(60,647)
Net Carrying Value	$ 167,254		$ 176,535
Client relationships \| Minimum
Intangible assets
Useful life	2 years		2 years
Client relationships \| Maximum
Intangible assets
Useful life	20 years		20 years
Client relationships \| Weighted Average
Intangible assets
Weighted Average Remaining Useful Life	13 years		13 years 1 month 6 days
Non-compete agreements
Intangible assets
Gross Value	$ 4,930		$ 4,958
Accumulated Amortization	(4,366)		(4,260)
Net Carrying Value	$ 564		$ 698
Non-compete agreements \| Minimum
Intangible assets
Useful life	1 year 6 months		1 year 6 months
Non-compete agreements \| Maximum
Intangible assets
Useful life	5 years		5 years
Non-compete agreements \| Weighted Average
Intangible assets
Weighted Average Remaining Useful Life	1 year 2 months 12 days		1 year 4 months 24 days
Trademarks
Intangible assets
Gross Value	$ 41,764		$ 42,606
Accumulated Amortization	(7,727)		(7,143)
Net Carrying Value	$ 34,037		$ 35,463
Trademarks \| Minimum
Intangible assets
Useful life	3 years		3 years
Trademarks \| Maximum
Intangible assets
Useful life	15 years		15 years
Trademarks \| Weighted Average
Intangible assets
Weighted Average Remaining Useful Life	12 years 7 months 6 days		12 years 10 months 24 days
Patents
Intangible assets
Gross Value	$ 200		$ 200
Accumulated Amortization	(200)		(200)
Net Carrying Value	$ 0		$ 0
Useful life	3 years		3 years
Patents \| Weighted Average
Intangible assets
Weighted Average Remaining Useful Life	0 years		0 years
Internal-use software and others
Intangible assets
Gross Value	$ 37,219		$ 34,850
Accumulated Amortization	(24,408)		(22,093)
Net Carrying Value	$ 12,811		$ 12,757
Internal-use software and others \| Minimum
Intangible assets
Useful life	3 years		3 years
Internal-use software and others \| Maximum
Intangible assets
Useful life	5 years		5 years
Internal-use software and others \| Weighted Average
Intangible assets
Weighted Average Remaining Useful Life	2 years 4 months 24 days		2 years 3 months 18 days