Exit Activity Costs and Asset Impairments (Summary of Exit Activity Costs and Asset Impairments by Segment) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Restructuring Cost and Reserve [Line Items]
Inventory write-downs &/or asset impairment (recoveries) charges, net	$ 159	$ 479	$ 505	$ 479
Exit activity costs	468	3,504	1,423	5,859
Total	627	3,983	1,928	6,338
Renewable Energy and Conservation
Restructuring Cost and Reserve [Line Items]
Inventory write-downs &/or asset impairment (recoveries) charges, net	0	(9)	72	(9)
Exit activity costs	172	46	506	45
Total	172	37	578	36
Residential Products
Restructuring Cost and Reserve [Line Items]
Inventory write-downs &/or asset impairment (recoveries) charges, net	21	478	21	478
Exit activity costs	165	2,937	649	3,307
Total	186	3,415	670	3,785
Industrial and Infrastructure Products
Restructuring Cost and Reserve [Line Items]
Inventory write-downs &/or asset impairment (recoveries) charges, net	138	10	412	10
Exit activity costs	114	275	152	1,588
Total	252	285	564	1,598
Corporate
Restructuring Cost and Reserve [Line Items]
Inventory write-downs &/or asset impairment (recoveries) charges, net	0	0	0	0
Exit activity costs	17	246	116	919
Total	$ 17	$ 246	$ 116	$ 919