Supplemental Financial Information (Schedule Of Consolidating Statements Of Operations, Supplemental Disclosures) (Details) (USD $) In Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Net sales	$ 208,807	$ 176,924	$ 372,370	$ 323,598
Cost of sales	163,379	142,943	296,897	263,160
Gross profit	45,428	33,981	75,473	60,438
Selling, general, and administrative expense	28,038	24,544	50,861	48,816
(Loss) income from operations	17,390	9,437	24,612	11,622
Interest (expense) income	(4,998)	(4,352)	(9,452)	(10,922)
Other income	38	60	61	131
(Loss) income before taxes	12,430	5,145	15,221	831
(Benefit of) provision for income taxes	5,184	2,552	6,534	630
(Loss) income from continuing operations	7,246	2,593	8,687	201
(Loss) income from discontinued operations before taxes	951	1,459	13,897	(28,626)
(Benefit of) provision for income taxes	392	571	6,370	(10,675)
(Loss) income from discontinued operations	559	888	7,527	(17,951)
Net (loss) income	7,805	3,481	16,214	(17,750)
Gibraltar Industries, Inc. [Member]
Net sales
Cost of sales
Gross profit
Selling, general, and administrative expense	(53)	285	(183)	513
(Loss) income from operations	53	(285)	183	(513)
Interest (expense) income	(4,348)	(4,340)	(8,693)	(8,679)
Other income
(Loss) income before taxes	(4,295)	(4,625)	(8,510)	(9,192)
(Benefit of) provision for income taxes	(1,675)	(1,852)	(3,319)	(3,633)
(Loss) income from continuing operations	(2,620)	(2,773)	(5,191)	(5,559)
(Benefit of) provision for income taxes
Equity in earnings from subsidiaries	10,919	6,907	22,517	(11,269)
Net (loss) income	8,299	4,134	17,326	(16,828)
Guarantor Subsidiaries [Member]
Net sales	186,222	158,202	328,494	286,200
Cost of sales	144,954	127,073	260,173	231,732
Gross profit	41,268	31,129	68,321	54,468
Selling, general, and administrative expense	25,739	21,816	46,517	43,750
(Loss) income from operations	15,529	9,313	21,804	10,718
Interest (expense) income	(651)	(11)	(762)	(2,250)
Other income	22	56	38	125
(Loss) income before taxes	14,900	9,358	21,080	8,593
(Benefit of) provision for income taxes	6,159	4,051	8,592	3,495
(Loss) income from continuing operations	8,741	5,307	12,488	5,098
(Loss) income from discontinued operations before taxes	951	1,290	13,678	(29,080)
(Benefit of) provision for income taxes	392	533	6,269	(10,797)
(Loss) income from discontinued operations	559	757	7,409	(18,283)
Equity in earnings from subsidiaries	1,619	843	2,620	1,916
Net (loss) income	10,919	6,907	22,517	(11,269)
Non-Guarantor Subsidiaries [Member]
Net sales	27,557	23,431	55,282	46,575
Cost of sales	22,903	19,926	47,018	39,683
Gross profit	4,654	3,505	8,264	6,892
Selling, general, and administrative expense	2,352	2,443	4,527	4,553
(Loss) income from operations	2,302	1,062	3,737	2,339
Interest (expense) income	1	(1)	3	7
Other income	16	4	23	6
(Loss) income before taxes	2,319	1,065	3,763	2,352
(Benefit of) provision for income taxes	700	353	1,261	768
(Loss) income from continuing operations	1,619	712	2,502	1,584
(Loss) income from discontinued operations before taxes		169	219	454
(Benefit of) provision for income taxes		38	101	122
(Loss) income from discontinued operations		131	118	332
Net (loss) income	1,619	843	2,620	1,916
Eliminations [Member]
Net sales	(4,972)	(4,709)	(11,406)	(9,177)
Cost of sales	(4,478)	(4,056)	(10,294)	(8,255)
Gross profit	(494)	(653)	(1,112)	(922)
(Loss) income from operations	(494)	(653)	(1,112)	(922)
Other income
(Loss) income before taxes	(494)	(653)	(1,112)	(922)
(Loss) income from continuing operations	(494)	(653)	(1,112)	(922)
(Benefit of) provision for income taxes
Equity in earnings from subsidiaries	(12,538)	(7,750)	(25,137)	9,353
Net (loss) income	$ (13,032)	$ (8,403)	$ (26,249)	$ 8,431