Supplemental Financial Information (Schedule of Consolidating Statements of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Schedule Of Supplemental Financial Information [Line Items]
Net Sales	$ 263,099	$ 253,171	$ 496,776	$ 453,786
Cost of sales	196,895	209,052	380,416	379,752
Gross profit	66,204	44,119	116,360	74,034
Selling, general, and administrative expense	40,427	32,918	76,976	53,863
Income from operations	25,777	11,201	39,384	20,171
Interest expense	3,666	3,811	7,357	7,511
Other expense (income)	8,035	1,101	7,840	(2,458)
Income before taxes	14,076	6,289	24,187	15,118
(Benefit of) provision for income taxes	(2,913)	2,202	705	5,494
Income from continuing operations	16,989	4,087	23,482	9,624
Loss before taxes	0	0	0	(44)
Benefit of income taxes	0	0	0	(16)
Loss from discontinued operations	0	0	0	(28)
Equity in earnings from subsidiaries	0	0	0	0
Net income	16,989	4,087	23,482	9,596
Reportable Legal Entities | 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	14,134	31	14,174	71
Income from operations	(14,134)	(31)	(14,174)	(71)
Interest expense	3,401	3,402	6,804	6,804
Other expense (income)	8,533	(19)	8,487	(12)
Income before taxes	(26,068)	(3,414)	(29,465)	(6,863)
(Benefit of) provision for income taxes	(8,275)	(1,197)	(9,482)	(2,407)
Income from continuing operations	(17,793)	(2,217)	(19,983)	(4,456)
Loss before taxes				0
Benefit of income taxes				0
Loss from discontinued operations				0
Equity in earnings from subsidiaries	35,141	6,655	44,101	14,506
Net income	17,348	4,438	24,118	10,050
Reportable Legal Entities | Guarantor Subsidiaries
Schedule Of Supplemental Financial Information [Line Items]
Net Sales	245,273	235,468	456,492	419,818
Cost of sales	183,557	193,554	348,996	350,418
Gross profit	61,716	41,914	107,496	69,400
Selling, general, and administrative expense	29,367	30,322	61,437	49,684
Income from operations	32,349	11,592	46,059	19,716
Interest expense	285	433	595	760
Other expense (income)	65	1,058	121	(2,465)
Income before taxes	31,999	10,101	45,343	21,421
(Benefit of) provision for income taxes	4,277	3,174	8,911	7,435
Income from continuing operations	27,722	6,927	36,432	13,986
Loss before taxes				(44)
Benefit of income taxes				(16)
Loss from discontinued operations				(28)
Equity in earnings from subsidiaries	7,419	(272)	7,669	548
Net income	35,141	6,655	44,101	14,506
Reportable Legal Entities | Non-Guarantor Subsidiaries
Schedule Of Supplemental Financial Information [Line Items]
Net Sales	19,922	22,419	47,215	42,167
Cost of sales	15,075	19,863	37,715	37,079
Gross profit	4,847	2,556	9,500	5,088
Selling, general, and administrative expense	(3,074)	2,565	1,365	4,108
Income from operations	7,921	(9)	8,135	980
Interest expense	(20)	(24)	(42)	(53)
Other expense (income)	(563)	62	(768)	19
Income before taxes	8,504	(47)	8,945	1,014
(Benefit of) provision for income taxes	1,085	225	1,276	466
Income from continuing operations	7,419	(272)	7,669	548
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	7,419	(272)	7,669	548
Eliminations
Schedule Of Supplemental Financial Information [Line Items]
Net Sales	(2,096)	(4,716)	(6,931)	(8,199)
Cost of sales	(1,737)	(4,365)	(6,295)	(7,745)
Gross profit	(359)	(351)	(636)	(454)
Selling, general, and administrative expense	0	0	0	0
Income from operations	(359)	(351)	(636)	(454)
Interest expense	0	0	0	0
Other expense (income)	0	0	0	0
Income before taxes	(359)	(351)	(636)	(454)
(Benefit of) provision for income taxes	0	0	0	0
Income from continuing operations	(359)	(351)	(636)	(454)
Loss before taxes				0
Benefit of income taxes				0
Loss from discontinued operations				0
Equity in earnings from subsidiaries	(42,560)	(6,383)	(51,770)	(15,054)
Net income	$ (42,919)	$ (6,734)	$ (52,406)	$ (15,508)