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Exit Activity Costs and Asset Impairments (Summary of Exit Activity Costs and Asset Impairments by Segment) (Details) - USD ($) $ in Thousands | 3 Months Ended
--- | ---
Mar. 31, 2019 | Mar. 31, 2018
Restructuring Cost and Reserve [Line Items] |  |
Inventory write-downs &/or asset impairment charges | $ 0 | $ (727)
Exit activity costs (recoveries), net | 219 | 256
Total exit activity costs & asset impairments | 219 | (471)
Residential Products |  |
Restructuring Cost and Reserve [Line Items] |  |
Inventory write-downs &/or asset impairment charges | 0 | (43)
Exit activity costs (recoveries), net | 151 | (123)
Total exit activity costs & asset impairments | 151 | (166)
Industrial and Infrastructure Products |  |
Restructuring Cost and Reserve [Line Items] |  |
Inventory write-downs &/or asset impairment charges | 0 | (703)
Exit activity costs (recoveries), net | (33) | 218
Total exit activity costs & asset impairments | (33) | (485)
Renewable Energy & Conservation |  |
Restructuring Cost and Reserve [Line Items] |  |
Inventory write-downs &/or asset impairment charges | 0 | 19
Exit activity costs (recoveries), net | 94 | 117
Total exit activity costs & asset impairments | 94 | 136
Corporate |  |
Restructuring Cost and Reserve [Line Items] |  |
Inventory write-downs &/or asset impairment charges | 0 | 0
Exit activity costs (recoveries), net | 7 | 44
Total exit activity costs & asset impairments | $ 7 | $ 44

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