Note 7 – Goodwill and Other Intangible Assets

On July 6, 2018, we acquired Griswold. For further detail on the goodwill and other intangible assets recorded in connection with the acquisition, refer to “Note 5 – Acquisitions.”

Goodwill

The changes in the carrying amount of goodwill for the period ending December 31, 2018, by operating segment, were as follows:



(Dollars in thousands)	Advanced Connectivity Solutions		Elastomeric Material Solutions			Power Electronics Solutions			Other		Total
December 31, 2017	$	51,693	$	111,575		$	71,615		$	2,224	$	237,107
Acquisition	—		32,305			—			—		32,305
Purchase accounting adjustment	—		(567		)	—			—		(567		)
Foreign currency translation adjustment	—		(724		)	(3,236		)	—		(3,960		)
December 31, 2018	$	51,693	$	142,589		$	68,379		$	2,224	$	264,885

Other Intangible Assets

The changes in the carrying amount of other intangible assets for the two-year period ending December 31, 2018, were as follows:



	December 31, 2018						December 31, 2017
(Dollars in thousands)	Gross Carrying Amount		Accumulated Amortization		Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization		Net Carrying Amount
Customer relationships	$	149,753	$	30,078	$	119,675	$	128,907	$	22,514	$	106,393
Technology	81,535		38,624		42,911		73,891		33,491		40,400
Trademarks and trade names	12,019		3,213		8,806		10,213		2,157		8,056
Covenants not to compete	1,340		249		1,091		1,799		1,108		691
Total definite-lived other intangible assets	244,647		72,164		172,483		214,810		59,270		155,540
Indefinite-lived other intangible asset	4,525		—		4,525		4,738		—		4,738
Total other intangible assets	$	249,172	$	72,164	$	177,008	$	219,548	$	59,270	$	160,278

In the table above, gross carrying amounts and accumulated amortization may differ from prior periods due to foreign exchange rate fluctuations.

Amortization expense was approximately $16.5 million, $14.8 million and $11.2 million in 2018, 2017 and 2016, respectively. The estimated annual future amortization expense is $17.7 million, $14.6 million, $13.8 million, $13.3 million and $12.7 million in 2019, 2020, 2021, 2022 and 2023, respectively. These amounts could vary based on changes in foreign currency exchange rates.

The weighted average amortization period as of December 31, 2018, by definite-lived other intangible asset class, is presented in the table below:



Definite-Lived Other Intangible Asset Class	Weighted Average Remaining Amortization Period
Customer relationships	7.6
Technology	4.4
Trademarks and trade names	5.0
Covenants not to compete	2.1
Total definite-lived other intangible assets	6.6