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Segment Information - Disaggregation of Revenue (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2019 | Sep. 30, 2018 | Sep. 30, 2019 | Sep. 30, 2018
Disaggregation of Revenue [Line Items] |  |  |  |
Net Sales | $ 299,236 | $ 280,086 | $ 789,308 | $ 761,459
Renewable Energy and Conservation |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Net Sales | 116,771 | 98,486 | 261,612 | 229,187
Residential Products |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Net Sales | 126,275 | 125,839 | 360,417 | 360,915
Industrial and Infrastructure Products |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Net Sales | 56,190 | 55,761 | 167,279 | 171,357
Point in Time |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Net Sales | 184,813 | 183,588 | 524,632 | 529,745
Point in Time | Renewable Energy and Conservation |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Net Sales | 12,682 | 10,784 | 28,441 | 25,128
Point in Time | Residential Products |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Net Sales | 125,350 | 125,118 | 357,808 | 358,960
Point in Time | Industrial and Infrastructure Products |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Net Sales | 46,781 | 47,686 | 138,383 | 145,657
Over Time |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Net Sales | 114,423 | 96,498 | 264,676 | 231,714
Over Time | Renewable Energy and Conservation |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Net Sales | 104,089 | 87,702 | 233,171 | 204,059
Over Time | Residential Products |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Net Sales | 925 | 721 | 2,609 | 1,955
Over Time | Industrial and Infrastructure Products |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Net Sales | $ 9,409 | $ 8,075 | $ 28,896 | $ 25,700

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- Definition Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 32 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8933-108599 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(1)) -URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227 + Details
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