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, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Restructuring Cost and Reserve [Line Items]
Inventory write-downs &/or asset impairment recoveries, net	$ 806	$ 2,802	$ (1,931)	$ 3,876
Exit activity costs	761	963	6,706	2,696
Net asset impairment and exit activity charges (gains)	1,567	3,765	4,775	6,572
Residential Products
Restructuring Cost and Reserve [Line Items]
Inventory write-downs &/or asset impairment recoveries, net	442	373	295	1,179
Exit activity costs	566	207	958	677
Net asset impairment and exit activity charges (gains)	1,008	580	1,253	1,856
Industrial and Infrastructure Products
Restructuring Cost and Reserve [Line Items]
Inventory write-downs &/or asset impairment recoveries, net	98	2,429	(2,492)	2,697
Exit activity costs	(12)	756	2,959	2,019
Net asset impairment and exit activity charges (gains)	86	3,185	467	4,716
Renewable Energy & Conservation
Restructuring Cost and Reserve [Line Items]
Inventory write-downs &/or asset impairment recoveries, net	266	0	266	0
Exit activity costs	191	0	2,610	0
Net asset impairment and exit activity charges (gains)	457	0	2,876	0
Corporate
Restructuring Cost and Reserve [Line Items]
Inventory write-downs &/or asset impairment recoveries, net	0	0	0	0
Exit activity costs	16	0	179	0
Net asset impairment and exit activity charges (gains)	$ 16	$ 0	$ 179	$ 0