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Segment Information - Disaggregation of Revenue (Details) - USD ($) $ in Thousands | 3 Months Ended
--- | ---
Mar. 31, 2020 | Mar. 31, 2019
Disaggregation of Revenue [Line Items] |  |
Net Sales | $ 249,439 | $ 227,417
Renewable Energy and Conservation |  |
Disaggregation of Revenue [Line Items] |  |
Net Sales | 96,497 | 68,837
Residential Products |  |
Disaggregation of Revenue [Line Items] |  |
Net Sales | 103,419 | 103,709
Industrial and Infrastructure Products |  |
Disaggregation of Revenue [Line Items] |  |
Net Sales | 49,523 | 54,871
Point in Time |  |
Disaggregation of Revenue [Line Items] |  |
Net Sales | 156,414 | 155,469
Point in Time | Renewable Energy and Conservation |  |
Disaggregation of Revenue [Line Items] |  |
Net Sales | 14,588 | 7,290
Point in Time | Residential Products |  |
Disaggregation of Revenue [Line Items] |  |
Net Sales | 102,331 | 102,892
Point in Time | Industrial and Infrastructure Products |  |
Disaggregation of Revenue [Line Items] |  |
Net Sales | 39,495 | 45,287
Over Time |  |
Disaggregation of Revenue [Line Items] |  |
Net Sales | 93,025 | 71,948
Over Time | Renewable Energy and Conservation |  |
Disaggregation of Revenue [Line Items] |  |
Net Sales | 81,909 | 61,547
Over Time | Residential Products |  |
Disaggregation of Revenue [Line Items] |  |
Net Sales | 1,088 | 817
Over Time | Industrial and Infrastructure Products |  |
Disaggregation of Revenue [Line Items] |  |
Net Sales | $ 10,028 | $ 9,584

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