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Goodwill and Related Intangible Assets (Schedule of Changes in Carrying Amount of Goodwill) (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018
Goodwill [Roll Forward] |  |
Balance at | $ 323,671 | $ 321,074
Acquired goodwill | 5,857 | 3,051
Adjustments to prior year acquisitions | (172) | (38)
Foreign currency translation | 349 | (416)
Balance at | 329,705 | 323,671
Renewable Energy & Conservation |  |
Goodwill [Roll Forward] |  |
Balance at | 71,827 | 68,719
Acquired goodwill | 5,857 | 3,051
Adjustments to prior year acquisitions | (172) | 0
Foreign currency translation | 90 | 57
Balance at | 77,602 | 71,827
Residential Products |  |
Goodwill [Roll Forward] |  |
Balance at | 198,075 | 198,075
Acquired goodwill | 0 | 0
Adjustments to prior year acquisitions | 0 | 0
Foreign currency translation | 0 | 0
Balance at | 198,075 | 198,075
Industrial and Infrastructure Products |  |
Goodwill [Roll Forward] |  |
Balance at | 53,769 | 54,280
Acquired goodwill | 0 | 0
Adjustments to prior year acquisitions | 0 | (38)
Foreign currency translation | 259 | (473)
Balance at | $ 54,028 | $ 53,769

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- Definition Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=99380562&loc=d3e13770-109266 + Details
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- Definition Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267 + Details
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- Definition Amount of foreign currency translation gain (loss) which increases (decreases) an asset representing future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (f) -URI http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267 + Details
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- Definition Amount of increase (decrease) from adjustments after acquisition date under purchase accounting of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 25 -Paragraph 16 -URI http://asc.fasb.org/extlink&oid=116868678&loc=d3e961-128460 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (g) -URI http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267 + Details
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- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
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- Details
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