| Intangible Assets | 
Intangible Assets 
The following table summarizes acquired intangible assets as follows: 
 
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   | 
   | 
July 1, 2017  | 
   | 
December 31, 2016  | 
 
(In thousands)  | 
 Weighted 
Average Life 
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   | 
 Gross Carrying 
Amount 
 | 
   | 
 Accumulated 
Amortization 
 | 
   | 
 Gross Carrying 
Amount 
 | 
   | 
 Accumulated 
Amortization 
 | 
 
Patents  | 
4 Years  | 
   | 
$  | 
2,146  | 
 
  | 
   | 
$  | 
1,544  | 
 
  | 
   | 
$  | 
2,146  | 
 
  | 
   | 
$  | 
1,450  | 
 
  | 
 
Non-compete Agreement  | 
3 Years  | 
   | 
2,500  | 
 
  | 
   | 
1,229  | 
 
  | 
   | 
2,500  | 
 
  | 
   | 
979  | 
 
  | 
 
Trade Names  | 
7 Years  | 
   | 
10,433  | 
 
  | 
   | 
3,626  | 
 
  | 
   | 
10,189  | 
 
  | 
   | 
3,153  | 
 
  | 
 
Completed and Unpatented Technology  | 
5 Years  | 
   | 
25,207  | 
 
  | 
   | 
10,481  | 
 
  | 
   | 
24,118  | 
 
  | 
   | 
9,221  | 
 
  | 
 
Backlog  | 
Less than 1 Year  | 
   | 
11,384  | 
 
  | 
   | 
11,277  | 
 
  | 
   | 
11,224  | 
 
  | 
   | 
11,224  | 
 
  | 
 
Customer Relationships  | 
11 Years  | 
   | 
97,245  | 
 
  | 
   | 
26,394  | 
 
  | 
   | 
97,046  | 
 
  | 
   | 
23,093  | 
 
  | 
 
Total Intangible Assets  | 
5 Years  | 
   | 
$  | 
148,915  | 
 
  | 
   | 
$  | 
54,551  | 
 
  | 
   | 
$  | 
147,223  | 
 
  | 
   | 
$  | 
49,120  | 
 
  | 
 
  
 
 
All acquired intangible assets other than goodwill and one trade name are being amortized. Amortization expense for acquired intangibles is summarized as follows: 
 
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   | 
Six Months Ended  | 
   | 
Three Months Ended  | 
 
(In thousands)  | 
July 1,  2017  | 
   | 
July 2,  2016  | 
   | 
July 1,  2017  | 
   | 
July 2,  2016  | 
 
Amortization Expense  | 
$  | 
5,340  | 
 
  | 
   | 
$  | 
5,607  | 
 
  | 
   | 
$  | 
2,722  | 
 
  | 
   | 
$  | 
2,799  | 
 
  | 
 
  
 
 
Amortization expense for acquired intangible assets expected for 2017 and for each of the next five years is summarized as follows:
 
 
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(In thousands)  | 
   | 
 
2017  | 
$  | 
10,756  | 
 
  | 
 
2018  | 
10,314  | 
 
  | 
 
2019  | 
9,935  | 
 
  | 
 
2020  | 
9,379  | 
 
  | 
 
2021  | 
9,333  | 
 
  | 
 
2022  | 
8,937  | 
 
  | 
 
  
 
 
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