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Goodwill and Related Intangible Assets (Tables) | 9 Months Ended
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Sep. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract] |
Schedule Of Changes In Carrying Amount Of Goodwill | The changes in the carrying amount of goodwill for the nine months ended September 30, 2019 are as follows (in thousands):
| Renewable Energy & Conservation |  | Residential Products |  | Industrial and Infrastructure Products |  | Total
Balance at December 31, 2018 | $ | 71,827 |  |  | $ | 198,075 |  |  | $ | 53,769 |  |  | $ | 323,671 |
Acquired goodwill | 4,185 |  |  | — |  |  |  |  | 4,185 |
Adjustments to prior year acquisitions | (172 | ) |  |  |  | — |  |  | (172 | )
Foreign currency translation | 137 |  |  | — |  |  | 162 |  |  | 299 |
Balance at September 30, 2019 | $ | 75,977 |  |  | $ | 198,075 |  |  | $ | 53,931 |  |  | $ | 327,983 |
Schedule Of Acquired Intangible Assets | Acquired intangible assets consist of the following (in thousands):
| September 30, 2019 |  | December 31, 2018 |  |
| Gross Carrying Amount |  | Accumulated Amortization |  | Gross Carrying Amount |  | Accumulated Amortization |  | Weighted-Average Amortization Period
Indefinite-lived intangible assets: |  |  |  |  |  |  |  |  |
Trademarks | $ | 44,770 |  |  | $ | — |  |  | $ | 43,870 |  |  | $ | — |  |  | Indefinite
Finite-lived intangible assets: |  |  |  |  |  |  |  |  |
Trademarks | 6,122 |  |  | 3,954 |  |  | 6,094 |  |  | 3,518 |  |  | 3 to 15 Years
Unpatented technology | 29,444 |  |  | 15,301 |  |  | 28,644 |  |  | 13,881 |  |  | 5 to 20 Years
Customer relationships | 74,072 |  |  | 39,187 |  |  | 70,419 |  |  | 35,678 |  |  | 5 to 17 Years
Non-compete agreements | 1,649 |  |  | 1,430 |  |  | 1,649 |  |  | 1,224 |  |  | 4 to 10 Years
| 111,287 |  |  | 59,872 |  |  | 106,806 |  |  | 54,301 |  |  |
Total acquired intangible assets | $ | 156,057 |  |  | $ | 59,872 |  |  | $ | 150,676 |  |  | $ | 54,301 |  |  |
Schedule of Acquired Intangible Asset Amortization Expense | The following table summarizes the acquired intangible asset amortization expense for the three and nine months ended September 30 (in thousands):
| Three Months Ended September 30, |  | Nine Months Ended September 30,
| 2019 |  | 2018 |  | 2019 |  | 2018
Amortization expense | $ | 1,840 |  |  | $ | 2,121 |  |  | $ | 5,434 |  |  | $ | 6,408 |
Schedule Of Amortization Expense | Amortization expense related to acquired intangible assets for the remainder of fiscal 2019 and the next five years thereafter is estimated as follows (in thousands):
| 2019 |  | 2020 |  | 2021 |  | 2022 |  | 2023 |  | 2024
Amortization expense | $ | 1,798 |  |  | $ | 6,904 |  |  | $ | 6,709 |  |  | $ | 6,231 |  |  | $ | 5,693 |  |  | $ | 5,437 |

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- Definition Tabular disclosure of the characteristics, including initial carrying value, residual amount, weighted average useful life, of finite-lived intangible assets acquired during the period by major class. A major class is composed of intangible assets that can be grouped together because they are similar, either by nature or by their use in the operations of the company. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16265-109275 + Details
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