Supplemental Financial Information (Schedule of Condensed Consolidating Statements of Cash Flows) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Schedule Of Supplemental Financial Information [Line Items]
Net cash provided by (used in) operating activities	$ 15,354	$ (14,752)
Cash paid for acquisitions	(2,314)	0
Purchases of property, plant, and equipment	(1,501)	(2,022)
Other, net	1,118	(61)
Net proceeds from sale of property and equipment	57	26,181
Net cash (used in) provided by investing activities	(2,640)	24,098
Purchase of treasury stock at market prices	(414)	(356)
Net proceeds from issuance of common stock	133	9
Payments of Debt Issuance Costs	(54)
Intercompany financing	0	0
Excess tax benefit from stock compensation	187	18
Net cash used in financing activities	(148)	(329)
Effect of exchange rate changes on cash	1,203	(1,327)
Net increase in cash and cash equivalents	13,769	7,690
Cash and cash equivalents at beginning of year	68,858
Cash and cash equivalents at end of period	82,627
Gibraltar Industries, Inc.
Schedule Of Supplemental Financial Information [Line Items]
Net cash provided by (used in) operating activities	(6,557)	(6,609)
Cash paid for acquisitions	0
Purchases of property, plant, and equipment	0	0
Other, net	0	0
Net proceeds from sale of property and equipment	0	0
Net cash (used in) provided by investing activities	0	0
Purchase of treasury stock at market prices	(414)	(356)
Net proceeds from issuance of common stock	133	9
Payments of Debt Issuance Costs	0
Intercompany financing	6,651	6,938
Excess tax benefit from stock compensation	187	18
Net cash used in financing activities	6,557	6,609
Effect of exchange rate changes on cash	0	0
Net increase in cash and cash equivalents	0	0
Cash and cash equivalents at beginning of year	0
Cash and cash equivalents at end of period	0
Guarantor Subsidiaries
Schedule Of Supplemental Financial Information [Line Items]
Net cash provided by (used in) operating activities	23,250	(8,853)
Purchases of property, plant, and equipment	(1,356)	(1,720)
Other, net	1,118	(61)
Net proceeds from sale of property and equipment	57	26,181
Net cash (used in) provided by investing activities	(2,495)	24,400
Purchase of treasury stock at market prices	0	0
Net proceeds from issuance of common stock	0	0
Payments of Debt Issuance Costs	(54)
Intercompany financing	(7,143)	(6,184)
Excess tax benefit from stock compensation	0	0
Net cash used in financing activities	(7,197)	(6,184)
Effect of exchange rate changes on cash	0	0
Net increase in cash and cash equivalents	13,558	9,363
Cash and cash equivalents at beginning of year	39,597
Cash and cash equivalents at end of period	53,155
Non-Guarantor Subsidiaries
Schedule Of Supplemental Financial Information [Line Items]
Net cash provided by (used in) operating activities	(1,339)	710
Cash paid for acquisitions	0
Purchases of property, plant, and equipment	(145)	(302)
Other, net	0	0
Net proceeds from sale of property and equipment	0	0
Net cash (used in) provided by investing activities	(145)	(302)
Purchase of treasury stock at market prices	0	0
Net proceeds from issuance of common stock	0	0
Payments of Debt Issuance Costs	0
Intercompany financing	492	(754)
Excess tax benefit from stock compensation	0	0
Net cash used in financing activities	492	(754)
Effect of exchange rate changes on cash	1,203	(1,327)
Net increase in cash and cash equivalents	211	(1,673)
Cash and cash equivalents at beginning of year	29,261
Cash and cash equivalents at end of period	29,472
Eliminations
Schedule Of Supplemental Financial Information [Line Items]
Net cash provided by (used in) operating activities	0	0
Cash paid for acquisitions	0
Purchases of property, plant, and equipment	0	0
Other, net	0	0
Net proceeds from sale of property and equipment	0	0
Net cash (used in) provided by investing activities	0	0
Purchase of treasury stock at market prices	0	0
Net proceeds from issuance of common stock	0	0
Payments of Debt Issuance Costs	0
Intercompany financing	0	0
Excess tax benefit from stock compensation	0	0
Net cash used in financing activities	0	0
Effect of exchange rate changes on cash	0	0
Net increase in cash and cash equivalents	0	$ 0
Cash and cash equivalents at beginning of year	0
Cash and cash equivalents at end of period	$ 0