Intangible Assets

12 Months Ended

Dec. 31, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Intangible Assets

INTANGIBLE ASSETS

Intangible assets consist of the following:

	As of December 31, 2018
	Carrying Value		Accumulated  Amortization		Net Intangible
Amortizable intangible assets:
Product technology	$	26,588	$	12,332	$	14,256
Patents and trademarks	14,647		6,601		8,046
Customer relationships	12,027		2,588		9,439
Other	8,693		7,380		1,313
Total	$	61,955	$	28,901	$	33,054

	As of December 31, 2017
	Carrying Value		Accumulated  Amortization		Net Intangible
Amortizable intangible assets:
Product technology	$	19,459	$	10,885	$	8,574
Patents and trademarks	13,948		5,720		8,228
Customer relationships	5,889		1,685		4,204
Other	7,443		5,909		1,534
Total	$	46,739	$	24,199	$	22,540

Amortization expense was $5.4 million, $4.5 million and $2.9 million in 2018, 2017 and 2016, respectively. The estimated amortization expense for each of the years 2019 through 2023 and thereafter is as follows:

Years ending December 31,	Amount
2019	$	5,333
2020	4,886
2021	4,717
2022	4,231
2023	3,804
Thereafter	10,083
	$	33,054