Supplemental Financial Information (Consolidating Statements of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Condensed Income Statements, Captions [Line Items]
Net sales	$ 231,838	$ 272,734	$ 265,738	$ 237,671	$ 282,093	$ 304,994	$ 253,171	$ 200,615	$ 1,007,981	$ 1,040,873	$ 862,087
Cost of sales									763,219	853,897	722,042
Gross profit	53,882	67,887	68,843	54,150	51,546	61,396	44,119	29,915	244,762	186,976	140,045
Selling, general, and administrative expense									161,623	134,028	102,492
Intangible asset impairment									10,175	4,863	107,970
Income (loss) from operations	584	26,363	28,416	17,601	4,520	23,394	11,201	8,970	72,964	48,085	(70,417)
Interest expense	3,595	3,625	3,666	3,691	3,614	3,878	3,811	3,700	14,577	15,003	14,421
Other expense (income)									8,404	(4,018)	(88)
Income (loss) before taxes									49,983	37,100	(84,750)
Provision for (benefit of) income taxes									16,264	13,624	(2,958)
Income (loss) from continuing operations	(7,708)	13,786	18,612	9,029	220	13,632	4,087	5,537	33,719	23,476	(81,792)
Loss before taxes									(70)	(44)	(51)
Benefit of income taxes									(26)	(16)	(19)
Loss from discontinued operations	(44)	0	0	0	0	0	0	(28)	(44)	(28)	(32)
Equity in earnings from subsidiaries									0	0	0
Net income (loss)	$ (7,752)	$ 13,786	$ 18,612	$ 9,029	$ 220	$ 13,632	$ 4,087	$ 5,509	33,675	23,448	(81,824)
Gibraltar Industries, Inc.
Condensed Income Statements, Captions [Line Items]
Net sales									0	0	0
Cost of sales									0	0	0
Gross profit									0	0	0
Selling, general, and administrative expense									14,302	133	128
Intangible asset impairment									0	0	0
Income (loss) from operations									(14,302)	(133)	(128)
Interest expense									13,609	13,609	13,568
Other expense (income)									8,716	50	144
Income (loss) before taxes									(36,627)	(13,792)	(13,840)
Provision for (benefit of) income taxes									(11,768)	(4,427)	(4,381)
Income (loss) from continuing operations									(24,859)	(9,365)	(9,459)
Loss before taxes									0	0	0
Benefit of income taxes									0	0	0
Loss from discontinued operations									0	0	0
Equity in earnings from subsidiaries									57,857	36,401	(71,191)
Net income (loss)									32,998	27,036	(80,650)
Guarantor Subsidiaries
Condensed Income Statements, Captions [Line Items]
Net sales									950,945	960,614	792,078
Cost of sales									722,315	785,085	661,041
Gross profit									228,630	175,529	131,037
Selling, general, and administrative expense									137,867	116,529	95,735
Intangible asset impairment									7,980	4,863	107,970
Income (loss) from operations									82,783	54,137	(72,668)
Interest expense									1,042	1,469	995
Other expense (income)									(12)	(3,801)	(328)
Income (loss) before taxes									81,753	56,469	(73,335)
Provision for (benefit of) income taxes									27,551	18,827	753
Income (loss) from continuing operations									54,202	37,642	(74,088)
Loss before taxes									(70)	(44)	(51)
Benefit of income taxes									(26)	(16)	(19)
Loss from discontinued operations									(44)	(28)	(32)
Equity in earnings from subsidiaries									3,699	(1,213)	2,929
Net income (loss)									57,857	36,401	(71,191)
Non-Guarantor Subsidiaries
Condensed Income Statements, Captions [Line Items]
Net sales									78,184	109,984	88,096
Cost of sales									62,729	94,949	77,914
Gross profit									15,455	15,035	10,182
Selling, general, and administrative expense									9,454	17,366	6,629
Intangible asset impairment									2,195	0	0
Income (loss) from operations									3,806	(2,331)	3,553
Interest expense									(74)	(75)	(142)
Other expense (income)									(300)	(267)	96
Income (loss) before taxes									4,180	(1,989)	3,599
Provision for (benefit of) income taxes									481	(776)	670
Income (loss) from continuing operations									3,699	(1,213)	2,929
Loss before taxes									0	0	0
Benefit of income taxes									0	0	0
Loss from discontinued operations									0	0	0
Equity in earnings from subsidiaries									0	0	0
Net income (loss)									3,699	(1,213)	2,929
Eliminations
Condensed Income Statements, Captions [Line Items]
Net sales									(21,148)	(29,725)	(18,087)
Cost of sales									(21,825)	(26,137)	(16,913)
Gross profit									677	(3,588)	(1,174)
Selling, general, and administrative expense									0	0	0
Intangible asset impairment									0	0	0
Income (loss) from operations									677	(3,588)	(1,174)
Interest expense									0	0	0
Other expense (income)									0	0	0
Income (loss) before taxes									677	(3,588)	(1,174)
Provision for (benefit of) income taxes									0	0	0
Income (loss) from continuing operations									677	(3,588)	(1,174)
Loss before taxes									0	0	0
Benefit of income taxes									0	0	0
Loss from discontinued operations									0	0	0
Equity in earnings from subsidiaries									(61,556)	(35,188)	68,262
Net income (loss)									$ (60,879)	$ (38,776)	$ 67,088