Goodwill and Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2018

Dec. 31, 2017

Goodwill and Intangible Assets Disclosure [Abstract]

Changes in the carrying amount of Goodwill

The changes in the carrying amount of Goodwill are as follows:

	Goodwill			Accumulated Impairment Losses			Total
Balance as of December 31, 2016	$	58,397		$	(37,332	)	$	21,065
Additions	147,845			—			147,845
Purchase accounting adjustments	(1,865		)	—			(1,865		)
Foreign currency fluctuations	22,847			(3,848		)	18,999
Balance as of December 31, 2017	$	227,224		$	(41,180	)	$	186,044
Additions	—			—			—
Purchase accounting adjustments	4,627			—			4,627
Foreign currency fluctuations	(10,141		)	2,142			(8,000		)
Balance as of December 31, 2018	$	221,710		$	(39,038	)	$	182,671

Acquired Intangible Assets excluding Goodwill

The balances of acquired Intangible Assets, excluding Goodwill, as of December 31, are as follows:

	Customer Lists			Trade Names			Technology			Total
Balance as of December 31, 2018
Original cost	$	143,059		$	30,592		$	17,436		$	191,087
Accumulated amortization	(33,714		)	(5,327		)	(5,500		)	(44,541		)
Carrying amount	$	109,345		$	25,265		$	11,936		$	146,546
Weighted-average original life (in years)	15			10			10
Balance as of December 31, 2017
Original cost	$	149,355		$	31,968		$	14,589		$	195,912
Accumulated amortization	(17,870		)	(2,436		)	(3,259		)	(23,565		)
Carrying amount	$	131,485		$	29,532		$	11,330		$	172,347
Weighted-average original life (in years)	15			10			11

Estimated aggregate amortization expense of Intangible Assets

Estimated aggregate amortization expense based on the current carrying amount of amortizable Intangible Assets for each of the five succeeding years is as follows:

2019	$	21,297
2020	19,873
2021	18,092
2022	15,913
2023	14,352
Thereafter	57,019
Total	$	146,546