Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2016	Mar. 31, 2015
Segment Reporting, Other Significant Reconciling Item [Line Items]
Net sales:	$ 233,677	$ 200,615
Income (loss) from operations:	50,156	29,915
Unallocated Corporate Expenses	(6,263)	(5,169)
Total income from operations	13,607	8,970
Residential Products
Segment Reporting, Other Significant Reconciling Item [Line Items]
Net sales:	100,147	106,795
Income (loss) from operations:	12,231	12,133
Industrial and Infrastructure Products
Segment Reporting, Other Significant Reconciling Item [Line Items]
Net sales:	80,017	94,285
Income (loss) from operations:	3,326	2,006
Renewable Energy & Conservation
Segment Reporting, Other Significant Reconciling Item [Line Items]
Net sales:	53,880	0
Income (loss) from operations:	4,313	0
Intersegment Sales
Segment Reporting, Other Significant Reconciling Item [Line Items]
Net sales:	(367)	(465)
Intersegment Elimination \| Industrial and Infrastructure Products
Segment Reporting, Other Significant Reconciling Item [Line Items]
Net sales:	$ 79,650	$ 93,820

Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1,2)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.3)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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