| Summary of Acquired Intangible Assets | 
 
The following table summarizes acquired intangible assets as follows: 
 
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September 29, 2018 | 
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December 31, 2017 | 
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(In thousands)  | 
 Weighted 
Average Life 
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 Gross Carrying 
Amount 
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 | 
 Accumulated 
Amortization 
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 | 
 Gross Carrying 
Amount 
 | 
 | 
 Accumulated 
Amortization 
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Patents  | 
11 years | 
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$ | 
2,146  | 
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$ | 
1,694  | 
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$ | 
2,146  | 
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$ | 
1,629  | 
 
Non-compete Agreement  | 
4 years | 
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10,900  | 
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3,932  | 
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10,900  | 
 | 
1,687  | 
 
Trade Names  | 
10 years | 
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11,465  | 
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4,915  | 
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11,492  | 
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4,114  | 
 
Completed and Unpatented Technology  | 
10 years | 
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38,069  | 
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14,951  | 
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38,114  | 
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11,931  | 
 
Backlog  | 
2 years | 
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14,424  | 
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14,424  | 
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14,424  | 
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12,184  | 
 
Customer Relationships  | 
15 years | 
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137,984  | 
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36,725  | 
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137,967  | 
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30,005  | 
 
Total Intangible Assets  | 
12 years | 
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$ | 
214,988  | 
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$ | 
76,641  | 
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$ | 
215,043  | 
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$ | 
61,550  | 
 
  
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| Summary of Amortization Expense for Acquired Intangibles | 
 
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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Nine Months Ended  | 
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Three Months Ended  | 
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(In thousands)  | 
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September 29, 2018 | 
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September 30, 2017 | 
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September 29, 2018 | 
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September 30, 2017 | 
 
Amortization Expense  | 
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$ | 
15,144  | 
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$ | 
8,269  | 
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$ | 
4,276  | 
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$ | 
2,929  | 
 
  
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| Summary of Amortization Expense for Intangible Assets for Each of Next Five Years | 
 Amortization expense for acquired intangible assets expected for 2018 and for each of the next five years is summarized as follows: 
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(In thousands)  | 
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| 2018  | 
$ | 
19,403  | 
 
| 2019  | 
16,707  | 
 
| 2020  | 
15,981  | 
 
| 2021  | 
14,072  | 
 
| 2022  | 
13,637  | 
 
| 2023  | 
12,470  | 
 
  
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