Supplemental Financial Information (Schedule Of Consolidating Statements Of Operations) (Details) (USD $) In Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Net sales	$ 220,096	$ 169,741	$ 592,466	$ 493,339
Cost of sales	177,133	142,243	474,030	405,403
Gross profit	42,963	27,498	118,436	87,936
Selling, general, and administrative expense	24,602	23,262	75,463	72,078
(Loss) income from operations	18,361	4,236	42,973	15,858
Interest (expense) income	(4,869)	(4,429)	(14,321)	(15,351)
Other income (expense)	(15)	30	46	161
(Loss) income before taxes	13,477	(163)	28,698	668
(Benefit of) provision for income taxes	6,094	(944)	12,628	(314)
(Loss) income from continuing operations	7,383	781	16,070	982
(Loss) income before taxes	(276)	677	13,621	(27,949)
(Benefit of) provision for income taxes	193	261	6,563	(10,414)
(Loss) income from discontinued operations	(469)	416	7,058	(17,535)
Equity in earnings from subsidiaries
Net (loss) income	6,914	1,197	23,128	(16,553)
Gibraltar Industries, Inc. [Member]
Net sales
Cost of sales
Gross profit
Selling, general, and administrative expense	183	(312)		201
(Loss) income from operations	(183)	312		(201)
Interest (expense) income	(4,349)	(4,343)	(13,042)	(13,022)
Other income (expense)
(Loss) income before taxes	(4,532)	(4,031)	(13,042)	(13,223)
(Benefit of) provision for income taxes	(1,768)	(1,702)	(5,087)	(5,335)
(Loss) income from continuing operations	(2,764)	(2,329)	(7,955)	(7,888)
(Loss) income before taxes
(Benefit of) provision for income taxes
(Loss) income from discontinued operations
Equity in earnings from subsidiaries	9,742	3,119	32,259	(8,150)
Net (loss) income	6,978	790	24,304	(16,038)
Guarantor Subsidiaries [Member]
Net sales	198,469	151,456	526,963	437,656
Cost of sales	159,372	126,910	419,545	358,642
Gross profit	39,097	24,546	107,418	79,014
Selling, general, and administrative expense	21,915	21,513	68,432	65,263
(Loss) income from operations	17,182	3,033	38,986	13,751
Interest (expense) income	(568)	(89)	(1,330)	(2,339)
Other income (expense)	8	21	46	146
(Loss) income before taxes	16,622	2,965	37,702	11,558
(Benefit of) provision for income taxes	7,398	581	15,990	4,076
(Loss) income from continuing operations	9,224	2,384	21,712	7,482
(Loss) income before taxes	(276)	575	13,402	(28,505)
(Benefit of) provision for income taxes	193	242	6,462	(10,555)
(Loss) income from discontinued operations	(469)	333	6,940	(17,950)
Equity in earnings from subsidiaries	987	402	3,607	2,318
Net (loss) income	9,742	3,119	32,259	(8,150)
Non-Guarantor Subsidiaries [Member]
Net sales	26,134	22,389	81,416	68,964
Cost of sales	22,204	19,844	69,222	59,527
Gross profit	3,930	2,545	12,194	9,437
Selling, general, and administrative expense	2,504	2,061	7,031	6,614
(Loss) income from operations	1,426	484	5,163	2,823
Interest (expense) income	48	3	51	10
Other income (expense)	(23)	9		15
(Loss) income before taxes	1,451	496	5,214	2,848
(Benefit of) provision for income taxes	464	177	1,725	945
(Loss) income from continuing operations	987	319	3,489	1,903
(Loss) income before taxes		102	219	556
(Benefit of) provision for income taxes		19	101	141
(Loss) income from discontinued operations		83	118	415
Equity in earnings from subsidiaries
Net (loss) income	987	402	3,607	2,318
Eliminations [Member]
Net sales	(4,507)	(4,104)	(15,913)	(13,281)
Cost of sales	(4,443)	(4,511)	(14,737)	(12,766)
Gross profit	(64)	407	(1,176)	(515)
Selling, general, and administrative expense
(Loss) income from operations	(64)	407	(1,176)	(515)
Interest (expense) income
Other income (expense)
(Loss) income before taxes	(64)	407	(1,176)	(515)
(Benefit of) provision for income taxes
(Loss) income from continuing operations	(64)	407	(1,176)	(515)
(Loss) income before taxes
(Benefit of) provision for income taxes
(Loss) income from discontinued operations
Equity in earnings from subsidiaries	(10,729)	(3,521)	(35,866)	5,832
Net (loss) income	$ (10,793)	$ (3,114)	$ (37,042)	$ 5,317