Supplemental Financial Information (Schedule of Condensed Consolidating Statements of Cash Flows) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Schedule Of Supplemental Financial Information [Line Items]
Net cash used in operating activities	$ (14,752)	$ (14,626)
Purchases of property, plant, and equipment	(2,022)	(4,056)
Other investing activities	(61)	0
Net proceeds from sale of property and equipment	26,181	137
Net cash provided by (used in) investing activities	24,098	(3,919)
Long-term debt payments	0	(2)
Purchase of treasury stock at market prices	(356)	(408)
Net proceeds from issuance of common stock	9	365
Intercompany financing	0	0
Excess tax benefit from stock compensation	18	91
Net cash (used in) provided by financing activities	(329)	46
Effect of exchange rate changes on cash	(1,327)	(354)
Net increase (decrease) in cash and cash equivalents	7,690	(18,853)
Cash and cash equivalents at beginning of year	110,610	97,039
Cash and cash equivalents at end of period	118,300	78,186
Gibraltar Industries, Inc.
Schedule Of Supplemental Financial Information [Line Items]
Net cash used in operating activities	(6,609)	(6,639)
Purchases of property, plant, and equipment	0	0
Other investing activities	0
Net proceeds from sale of property and equipment	0	0
Net cash provided by (used in) investing activities	0	0
Long-term debt payments		0
Purchase of treasury stock at market prices	(356)	(408)
Net proceeds from issuance of common stock	9	365
Intercompany financing	6,938	6,591
Excess tax benefit from stock compensation	18	91
Net cash (used in) provided by financing activities	6,609	6,639
Effect of exchange rate changes on cash	0	0
Net increase (decrease) in cash and cash equivalents	0	0
Cash and cash equivalents at beginning of year	0	0
Cash and cash equivalents at end of period	0	0
Guarantor Subsidiaries
Schedule Of Supplemental Financial Information [Line Items]
Net cash used in operating activities	(8,853)	(8,985)
Purchases of property, plant, and equipment	(1,720)	(2,474)
Other investing activities	(61)
Net proceeds from sale of property and equipment	26,181	135
Net cash provided by (used in) investing activities	24,400	(2,339)
Long-term debt payments		(2)
Purchase of treasury stock at market prices	0	0
Net proceeds from issuance of common stock	0	0
Intercompany financing	(6,184)	(6,929)
Excess tax benefit from stock compensation	0	0
Net cash (used in) provided by financing activities	(6,184)	(6,931)
Effect of exchange rate changes on cash	0	0
Net increase (decrease) in cash and cash equivalents	9,363	(18,255)
Cash and cash equivalents at beginning of year	91,466	75,856
Cash and cash equivalents at end of period	100,829	57,601
Non-Guarantor Subsidiaries
Schedule Of Supplemental Financial Information [Line Items]
Net cash used in operating activities	710	998
Purchases of property, plant, and equipment	(302)	(1,582)
Other investing activities	0
Net proceeds from sale of property and equipment	0	2
Net cash provided by (used in) investing activities	(302)	(1,580)
Long-term debt payments		0
Purchase of treasury stock at market prices	0	0
Net proceeds from issuance of common stock	0	0
Intercompany financing	(754)	338
Excess tax benefit from stock compensation	0	0
Net cash (used in) provided by financing activities	(754)	338
Effect of exchange rate changes on cash	(1,327)	(354)
Net increase (decrease) in cash and cash equivalents	(1,673)	(598)
Cash and cash equivalents at beginning of year	19,144	21,183
Cash and cash equivalents at end of period	17,471	20,585
Eliminations
Schedule Of Supplemental Financial Information [Line Items]
Net cash used in operating activities	0	0
Purchases of property, plant, and equipment	0	0
Other investing activities	0
Net proceeds from sale of property and equipment	0	0
Net cash provided by (used in) investing activities	0	0
Long-term debt payments		0
Purchase of treasury stock at market prices	0	0
Net proceeds from issuance of common stock	0	0
Intercompany financing	0	0
Excess tax benefit from stock compensation	0	0
Net cash (used in) provided by financing activities	0	0
Effect of exchange rate changes on cash	0	0
Net increase (decrease) in cash and cash equivalents	0	0
Cash and cash equivalents at beginning of year	0	0
Cash and cash equivalents at end of period	$ 0	$ 0