Goodwill, Intangible Assets and Impairment Charges (Tables)

12 Months Ended

Dec. 31, 2019

The following table summarizes changes in goodwill during the year ended December 31, 2019 (in thousands):

	December 31, 2019
Balance at beginning of year	$	217,662
Goodwill acquired from acquisitions		56,433
Effect of foreign exchange rate changes		615
Balance at end of year	$	274,710

Goodwill by reportable segment as of December 31, 2019 was as follows (in thousands):

	Reportable Segment
	Photonics			Vision			Precision Motion			Total
Goodwill	$	213,413		$	160,086		$	52,440		$	425,939
Accumulated impairment of goodwill		(102,461	)		(31,722	)		(17,046	)		(151,229	)
Total	$	110,952		$	128,364		$	35,394		$	274,710

Goodwill by reportable segment as of December 31, 2018 was as follows (in thousands):

	Reportable Segment
	Photonics			Vision			Precision Motion			Total
Goodwill	$	168,955		$	155,017		$	44,919		$	368,891
Accumulated impairment of goodwill		(102,461	)		(31,722	)		(17,046	)		(151,229	)
Total	$	66,494		$	123,295		$	27,873		$	217,662

Intangible assets as of December 31, 2019 and 2018, respectively, are summarized as follows (dollar amounts in thousands):

	December 31, 2019
	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Weighted Average Remaining Life (Years)
Amortizable intangible assets:
Patents and developed technologies	$	159,217	$	(97,523	)	$	61,694		9.5
Customer relationships		161,807		(78,206	)		83,601		11.9
Customer backlog		2,316		(2,316	)		—		—
Trademarks and trade names		17,871		(10,018	)		7,853		8.6
Amortizable intangible assets		341,211		(188,063	)		153,148		10.7
Non-amortizable intangible assets:
Trade names		13,027		—			13,027
Total	$	354,238	$	(188,063	)	$	166,175

	December 31, 2018
	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Weighted Average Remaining Life (Years)
Amortizable intangible assets:
Patents and developed technologies	$	134,034	$	(86,623	)	$	47,411		9.0
Customer relationships		139,097		(64,174	)		74,923		11.7
Customer backlog		1,738		(1,191	)		547		0.4
Non-compete covenant		2,514		(2,493	)		21		0.1
Trademarks and trade names		15,915		(8,924	)		6,991		9.1
Amortizable intangible assets		293,298		(163,405	)		129,893		10.5
Non-amortizable intangible assets:
Trade names		13,027		—			13,027
Total	$	306,325	$	(163,405	)	$	142,920

Amortization expense was as follows (in thousands):

	Year Ended December 31,
	2019		2018		2017
Amortization expense – cost of revenue	$	10,588	$	10,060	$	8,824
Amortization expense – operating expenses		15,857		15,550		12,096
Total amortization expense	$	26,445	$	25,610	$	20,920

Estimated future amortization expense for each of the five succeeding years and thereafter is as follows (in thousands):