Supplemental Financial Information (Schedule of Consolidating Statements of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Schedule Of Supplemental Financial Information [Line Items]
Net Sales	$ 253,171	$ 234,960	$ 453,786	$ 425,992
Cost of sales	209,052	194,837	379,752	356,005
Gross profit	44,119	40,123	74,034	69,987
Selling, general, and administrative expense	32,918	25,393	53,863	54,924
Income from operations	11,201	14,730	20,171	15,063
Interest expense	3,811	3,691	7,511	7,331
Other expense (income)	1,101	519	(2,458)	549
Income before taxes	6,289	10,520	15,118	7,183
Provision for income taxes	2,202	4,089	5,494	2,838
Income from continuing operations	4,087	6,431	9,624	4,345
Loss before taxes	0	0	(44)	0
Benefit of income taxes	0	0	(16)	0
Loss from discontinued operations	0	0	(28)	0
Equity in earnings from subsidiaries	0	0	0	0
Net income	4,087	6,431	9,596	4,345
Gibraltar Industries, Inc.
Schedule Of Supplemental Financial Information [Line Items]
Net Sales	0	0	0	0
Cost of sales	0	0	0	0
Gross profit	0	0	0	0
Selling, general, and administrative expense	31	25	71	61
Income from operations	(31)	(25)	(71)	(61)
Interest expense	3,402	3,403	6,804	6,764
Other expense (income)	(19)	0	(12)	0
Income before taxes	(3,414)	(3,428)	(6,863)	(6,825)
Provision for income taxes	(1,197)	(1,187)	(2,407)	(2,364)
Income from continuing operations	(2,217)	(2,241)	(4,456)	(4,461)
Loss before taxes			0
Benefit of income taxes			0
Loss from discontinued operations			0
Equity in earnings from subsidiaries	6,655	9,025	14,506	9,340
Net income	4,438	6,784	10,050	4,879
Guarantor Subsidiaries
Schedule Of Supplemental Financial Information [Line Items]
Net Sales	235,468	216,885	419,818	389,666
Cost of sales	193,554	179,207	350,418	324,368
Gross profit	41,914	37,678	69,400	65,298
Selling, general, and administrative expense	30,322	23,511	49,684	51,274
Income from operations	11,592	14,167	19,716	14,024
Interest expense	433	322	760	636
Other expense (income)	1,058	519	(2,465)	549
Income before taxes	10,101	13,326	21,421	12,839
Provision for income taxes	3,174	5,095	7,435	4,861
Income from continuing operations	6,927	8,231	13,986	7,978
Loss before taxes			(44)
Benefit of income taxes			(16)
Loss from discontinued operations			(28)
Equity in earnings from subsidiaries	(272)	794	548	1,362
Net income	6,655	9,025	14,506	9,340
Non-Guarantor Subsidiaries
Schedule Of Supplemental Financial Information [Line Items]
Net Sales	22,419	22,971	42,167	45,890
Cost of sales	19,863	20,173	37,079	40,667
Gross profit	2,556	2,798	5,088	5,223
Selling, general, and administrative expense	2,565	1,857	4,108	3,589
Income from operations	(9)	941	980	1,634
Interest expense	(24)	(34)	(53)	(69)
Other expense (income)	62	0	19	0
Income before taxes	(47)	975	1,014	1,703
Provision for income taxes	225	181	466	341
Income from continuing operations	(272)	794	548	1,362
Loss before taxes			0
Benefit of income taxes			0
Loss from discontinued operations			0
Equity in earnings from subsidiaries	0	0	0	0
Net income	(272)	794	548	1,362
Eliminations
Schedule Of Supplemental Financial Information [Line Items]
Net Sales	(4,716)	(4,896)	(8,199)	(9,564)
Cost of sales	(4,365)	(4,543)	(7,745)	(9,030)
Gross profit	(351)	(353)	(454)	(534)
Selling, general, and administrative expense	0	0	0	0
Income from operations	(351)	(353)	(454)	(534)
Interest expense	0	0	0	0
Other expense (income)	0	0	0	0
Income before taxes	(351)	(353)	(454)	(534)
Provision for income taxes	0	0	0	0
Income from continuing operations	(351)	(353)	(454)	(534)
Loss before taxes			0
Benefit of income taxes			0
Loss from discontinued operations			0
Equity in earnings from subsidiaries	(6,383)	(9,819)	(15,054)	(10,702)
Net income	$ (6,734)	$ (10,172)	$ (15,508)	$ (11,236)