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Goodwill and Related Intangible Assets (Narrative) (Details) $ in Thousands | 1 Months Ended | 12 Months Ended |  |
--- | --- | --- | --- | ---
Oct. 31, 2015 reporting_unit | Dec. 31, 2016 USD ($) reporting_unit | Dec. 31, 2015 USD ($) | Dec. 31, 2014 USD ($) | Oct. 31, 2016 USD ($) | Oct. 11, 2016 USD ($)
Goodwill [Line Items] |  |  |  |  |  |
Goodwill |  | $ 304,032 | $ 292,390 | $ 236,044 |  |
Accumulated impairment losses |  | $ 235,419 | 255,530 |  |  |
Number of reporting units tested | reporting_unit | 9 |  |  |  |  |
Number of reporting units | reporting_unit |  | 10 |  |  |  |
Goodwill impairment |  | $ (929) |  | (104,565) |  |
Impairment of indefinite-lived intangibles |  | 9,048 | 4,863 | 2,700 |  |
Impairment of indefinite-lived intangible assets attributable to annual impairment testing |  | 1,200 |  |  |  |
Impairment of definite-lived intangibles |  | 198 | 0 | 705 |  |
Industrial and Infrastructure Products |  |  |  |  |  |
Goodwill [Line Items] |  |  |  |  |  |
Goodwill impairment |  |  |  | (90,330) |  |
Impairment of indefinite-lived intangibles |  | 7,980 | 4,423 | 1,500 |  |
Impairment of definite-lived intangibles |  | 0 | 0 | 705 |  |
Residential Products |  |  |  |  |  |
Goodwill [Line Items] |  |  |  |  |  |
Goodwill impairment |  |  |  | (14,235) |  |
Impairment of indefinite-lived intangibles |  | 0 | 440 | 1,200 |  |
Impairment of definite-lived intangibles |  | 0 | $ 0 | $ 0 |  |
Carrying Value |  |  |  |  |  |
Goodwill [Line Items] |  |  |  |  |  |
Goodwill net book value |  |  |  |  | $ 23,300 |
Solar | Residential Products |  |  |  |  |  |
Goodwill [Line Items] |  |  |  |  |  |
Goodwill impairment |  | (929) |  |  |  |
Disposal Group, Not Discontinued Operations |  |  |  |  |  |
Goodwill [Line Items] |  |  |  |  |  |
Impairment of indefinite-lived intangibles |  | $ 7,800 |  |  |  |
Nexus |  |  |  |  |  |
Goodwill [Line Items] |  |  |  |  |  |
Goodwill |  |  |  |  |  | $ 12,283

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