Supplemental Financial Information (Schedule of Consolidating Statements of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Schedule Of Supplemental Financial Information [Line Items]
Net Sales	$ 206,605	$ 237,671
Cost of sales	157,350	183,521
Gross profit	49,255	54,150
Selling, general, and administrative expense	39,576	36,389
Income from operations	9,679	17,761
Interest expense	3,576	3,691
Other expense (income)	54	(35)
Income before taxes	6,049	14,105
Provision for income taxes	2,053	5,076
Equity in earnings from subsidiaries	0	0
Net income	3,996	9,029
Reportable Legal Entities | 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	43	40
Income from operations	(43)	(40)
Interest expense	3,402	3,403
Other expense (income)	0	(46)
Income before taxes	(3,445)	(3,397)
Provision for income taxes	(1,344)	(1,207)
Equity in earnings from subsidiaries	6,343	11,496
Net income	4,242	9,306
Reportable Legal Entities | Guarantor Subsidiaries
Schedule Of Supplemental Financial Information [Line Items]
Net Sales	197,748	215,213
Cost of sales	150,507	165,439
Gross profit	47,241	49,774
Selling, general, and administrative expense	36,506	31,911
Income from operations	10,735	17,863
Interest expense	192	310
Other expense (income)	130	216
Income before taxes	10,413	17,337
Provision for income taxes	3,378	6,092
Equity in earnings from subsidiaries	(692)	251
Net income	6,343	11,496
Reportable Legal Entities | Non-Guarantor Subsidiaries
Schedule Of Supplemental Financial Information [Line Items]
Net Sales	11,242	27,293
Cost of sales	8,982	22,640
Gross profit	2,260	4,653
Selling, general, and administrative expense	3,027	4,438
Income from operations	(767)	215
Interest expense	(18)	(22)
Other expense (income)	(76)	(205)
Income before taxes	(673)	442
Provision for income taxes	19	191
Equity in earnings from subsidiaries	0	0
Net income	(692)	251
Eliminations
Schedule Of Supplemental Financial Information [Line Items]
Net Sales	(2,385)	(4,835)
Cost of sales	(2,139)	(4,558)
Gross profit	(246)	(277)
Selling, general, and administrative expense	0	0
Income from operations	(246)	(277)
Interest expense	0	0
Other expense (income)	0	0
Income before taxes	(246)	(277)
Provision for income taxes	0	0
Equity in earnings from subsidiaries	(5,651)	(11,747)
Net income	$ (5,897)	$ (12,024)