Goodwill and Intangible Assets (Tables)

6 Months Ended

Jun. 30, 2020

The following table represents changes in the carrying amount of goodwill:


	December 31, 2019		Additions		Foreign currency exchange rate fluctuations		June 30, 2020

	(In thousands)
Goodwill	$	336,539	$	—	$	(1,505)	$	335,034

The carrying amounts and useful lives of intangible assets as of June 30, 2020 and December 31, 2019 were as follows:


	June 30, 2020
	Gross carrying amount ⁽¹⁾		Accumulated amortization		Foreign currency exchange rate fluctuations		Net carrying amount		Useful life (years)

	(In thousands, except for years)
Customer relationships	$	134,889	$	(58,871)	$	(1,360)	$	74,658	10 - 30
Acquired technology	77,029		(40,033)		5		37,001		5 - 20
Backlog	1,150		(934)		—		216		4
Trade names	7,650		(5,374)		10		2,286		6 - 12
Patents	3,217		(1,669)		1		1,549		2 - 20


Total intangibles assets, net	$	223,935	$	(106,881)	$	(1,344)	$	115,710


	December 31, 2019
	Gross carrying amount ⁽¹⁾		Accumulated amortization		Foreign currency exchange rate fluctuations		Net carrying amount		Useful life (years)

	(In thousands, except for years)
Customer relationships	$	135,234	$	(54,860)	$	(1,058)	$	79,316	10 - 30
Acquired technology	77,142		(36,194)		5		40,953		3 - 20
Backlog	1,150		(791)		—		359		4
Trade names	7,650		(5,037)		11		2,624		6 - 12
Patents	3,217		(1,603)		1		1,615		2 - 20


Total intangibles assets, net	$	224,393	$	(98,485)	$	(1,041)	$	124,867

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(1) The differences in gross carrying amounts between periods are primarily due to the write-off of certain fully amortized intangible assets.

The estimated future amortization expenses for amortizable intangible assets were as follows: