Segment Information (Measurements Used by Management to Assess Performance of Segments) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting, Other Significant Reconciling Item [Line Items]
Net sales									$ 862,087	$ 827,567	$ 790,058
Income (loss) from operations	(103,872)	18,392	14,730	333	6,153	(6,152)	16,283	5,196	(70,417)	21,480	40,261
Depreciation and amortization									25,432	27,050	26,344
Total assets	814,160				894,162				814,160	894,162	883,674
Capital expenditures									23,291	14,940	11,351
Intersegment sales
Segment Reporting, Other Significant Reconciling Item [Line Items]
Net sales									(1,260)	(1,672)	(1,336)
Unallocated Corporate Expenses
Segment Reporting, Other Significant Reconciling Item [Line Items]
Income (loss) from operations									(12,199)	(20,654)	(18,275)
Depreciation and amortization									823	941	1,207
Total assets	111,918				93,563				111,918	93,563	46,107
Capital expenditures									135	248	628
Residential Products | Operating Segments
Segment Reporting, Other Significant Reconciling Item [Line Items]
Net sales									431,915	394,071	375,105
Income (loss) from operations									16,416	34,965	23,902
Depreciation and amortization									10,699	11,421	11,572
Total assets	394,092				389,506				394,092	389,506	399,986
Capital expenditures									12,731	5,937	5,252
Industrial and Infrastructure Products | Operating Segments
Segment Reporting, Other Significant Reconciling Item [Line Items]
Net sales									431,432	435,168	416,289
Income (loss) from operations									(74,634)	7,169	34,634
Depreciation and amortization									13,910	14,688	13,565
Total assets	308,150				411,093				308,150	411,093	437,581
Capital expenditures									$ 10,425	$ 8,755	$ 5,471