Goodwill and Intangible Assets
 3 Months Ended
Mar. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]  
Goodwill and Intangible Assets
Goodwill and Intangible Assets
Definite Lived Intangible Assets

(Dollars in thousands)
March 31, 2015
 
December 31, 2014
 
Gross Carrying Amount (1)
 
Accumulated Amortization
 
Net Carrying Amount
 
Gross Carrying Amount (1)
 
Accumulated Amortization
 
Net Carrying Amount
Trademarks and patents
$
2,583

 
$
432

 
$
2,151

 
$
1,046

 
$
364

 
$
682

Technology
46,481

 
15,639

 
30,842

 
33,942

 
15,958

 
17,984

Covenant-not-to-compete
999

 
856

 
143

 
1,016

 
823

 
193

Customer relationships
50,026

 
5,179

 
44,847

 
19,123

 
4,406

 
14,717

Total definite lived intangible assets
$
100,089

 
$
22,106

 
$
77,983

 
$
55,127

 
$
21,551

 
$
33,576


(1) Gross carrying amounts and accumulated amortization may differ from prior periods due to foreign exchange rate fluctuations.
On January 22, 2015, we acquired Arlon. For further detail on the goodwill and intangible assets recorded on the acquisition, see Note 5 - "Acquisition".
Amortization expense for the three month periods ended March 31, 2015 and March 31, 2014 was approximately $2.4 million, and $1.5 million, respectively. The estimated annual future amortization expense is $8.0 million, $10.2 million, $9.9 million, $9.4 million and $8.9 million for the remainder of 2015, 2016, 2017, 2018 and 2019, respectively. These amounts could vary based on changes in foreign currency exchange rates.
The weighted average amortization period as of March 31, 2015, by intangible asset class, is presented in the table below:

Intangible Asset Class
 
Weighted Average Amortization Period
Trademarks and patents
 
4.2
Technology
 
4.7
Covenant not-to-compete
 
1.0
Customer relationships
 
6.1
Total other intangible assets
 
5.5

Approximately $5.3 million of indefinite-lived intangible assets comprised of trademarks were acquired from the acquisitions of Curamik. These assets are assessed for impairment annually or when changes in circumstances indicated that the carrying values may be recoverable. The definite-lived intangibles are amortized using a fair value methodology that is based on the projected economic use of the related underlying asset.
Goodwill
The changes in the carrying amount of goodwill for the period ending March 31, 2015, by segment, was as follows:

(Dollars in thousands)
Printed Circuit Materials
 
High Performance Foams
 
Power Electronics Solutions
 
Other
 
Total
December 31, 2014
$
—

 
$
23,565

 
$
72,438

 
$
2,224

 
$
98,227

Foreign currency translation adjustment
—

 
(275
)
 
(8,322
)
 
—

 
(8,597
)
Arlon acquisition
51,862

 
33,517

 
—

 
—

 
85,379

March 31, 2015
$
51,862

 
$
56,807

 
$
64,116

 
$
2,224

 
$
175,009