Supplemental Financial Information (Schedule of Consolidating Statements of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Schedule Of Supplemental Financial Information [Line Items]
Net Sales	$ 233,677	$ 200,615
Cost of sales	183,521	170,700
Gross profit	50,156	29,915
Selling, general, and administrative expense	36,549	20,945
Income from operations	13,607	8,970
Interest expense	3,691	3,700
Other income	(195)	(3,559)
Income before taxes	10,111	8,829
Provision for income taxes	3,618	3,292
Income from continuing operations	6,493	5,537
Loss before taxes	0	(44)
Benefit of income taxes	0	(16)
Loss from discontinued operations	0	(28)
Equity in earnings from subsidiaries	0	0
Net income	6,493	5,509
Gibraltar Industries, Inc.
Schedule Of Supplemental Financial Information [Line Items]
Net Sales	0	0
Cost of sales	0	0
Gross profit	0	0
Selling, general, and administrative expense	40	40
Income from operations	(40)	(40)
Interest expense	3,403	3,402
Other income	(46)	7
Income before taxes	(3,397)	(3,449)
Provision for income taxes	(1,207)	(1,210)
Income from continuing operations	(2,190)	(2,239)
Loss before taxes		0
Benefit of income taxes		0
Loss from discontinued operations		0
Equity in earnings from subsidiaries	8,960	7,851
Net income	6,770	5,612
Guarantor Subsidiaries
Schedule Of Supplemental Financial Information [Line Items]
Net Sales	211,219	184,350
Cost of sales	165,439	156,864
Gross profit	45,780	27,486
Selling, general, and administrative expense	32,070	19,362
Income from operations	13,710	8,124
Interest expense	310	327
Other income	56	(3,523)
Income before taxes	13,344	11,320
Provision for income taxes	4,634	4,261
Income from continuing operations	8,710	7,059
Loss before taxes		(44)
Benefit of income taxes		(16)
Loss from discontinued operations		(28)
Equity in earnings from subsidiaries	250	820
Net income	8,960	7,851
Non-Guarantor Subsidiaries
Schedule Of Supplemental Financial Information [Line Items]
Net Sales	27,293	19,748
Cost of sales	22,640	17,216
Gross profit	4,653	2,532
Selling, general, and administrative expense	4,439	1,543
Income from operations	214	989
Interest expense	(22)	(29)
Other income	(205)	(43)
Income before taxes	441	1,061
Provision for income taxes	191	241
Income from continuing operations	250	820
Loss before taxes		0
Benefit of income taxes		0
Loss from discontinued operations		0
Equity in earnings from subsidiaries	0	0
Net income	250	820
Eliminations
Schedule Of Supplemental Financial Information [Line Items]
Net Sales	(4,835)	(3,483)
Cost of sales	(4,558)	(3,380)
Gross profit	(277)	(103)
Selling, general, and administrative expense	0	0
Income from operations	(277)	(103)
Interest expense	0	0
Other income	0	0
Income before taxes	(277)	(103)
Provision for income taxes	0	0
Income from continuing operations	(277)	(103)
Loss before taxes		0
Benefit of income taxes		0
Loss from discontinued operations		0
Equity in earnings from subsidiaries	(9,210)	(8,671)
Net income	$ (9,487)	$ (8,774)