Supplemental Financial Information (Schedule of Condensed Consolidating Statements of Cash Flows) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Schedule Of Supplemental Financial Information [Line Items]
Net cash provided by (used in) operating activities	$ 49,149	$ 11,758
Cash Flows from Investing Activities
Cash paid for acquisitions	(2,314)	(134,318)
Net proceeds from sale of property and equipment	162	26,181
Purchases of property, plant, and equipment	(4,035)	(4,624)
Net proceeds from sale of business	8,479	0
Other, net	1,118	1,154
Net cash provided by (used in) investing activities	3,410	(111,607)
Cash Flows from Financing Activities
Purchase of treasury stock at market prices	(462)	(387)
Long-term debt payments	400	11,792
Proceeds from long-term debt	0	41,392
Net proceeds from issuance of common stock	2,057	180
Payment of debt issuance costs	(54)	0
Inter Company Financing	0	0
Excess tax benefit from stock compensation	292	37
Net cash used in financing activities	1,433	29,430
Effect of exchange rate changes on cash	1,264	(769)
Net increase (decrease) in cash and cash equivalents	55,256	(71,188)
Cash and cash equivalents at beginning of year	68,858	110,610
Cash and cash equivalents at end of period	124,114	39,422
Reportable Legal Entities | Gibraltar Industries, Inc.
Schedule Of Supplemental Financial Information [Line Items]
Net cash provided by (used in) operating activities	(27,297)	(6,621)
Cash Flows from Investing Activities
Cash paid for acquisitions	0	0
Net proceeds from sale of property and equipment	0	0
Purchases of property, plant, and equipment	0	0
Net proceeds from sale of business	0
Other, net	0	0
Net cash provided by (used in) investing activities	0	0
Cash Flows from Financing Activities
Purchase of treasury stock at market prices	(462)	(387)
Long-term debt payments	0	0
Proceeds from long-term debt		0
Net proceeds from issuance of common stock	2,057	180
Payment of debt issuance costs	0
Inter Company Financing	25,410	6,791
Excess tax benefit from stock compensation	292	37
Net cash used in financing activities	27,297	6,621
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
Reportable Legal Entities | Guarantor Subsidiaries
Schedule Of Supplemental Financial Information [Line Items]
Net cash provided by (used in) operating activities	62,183	16,091
Cash Flows from Investing Activities
Cash paid for acquisitions	(2,314)	(106,055)
Net proceeds from sale of property and equipment	133	26,181
Purchases of property, plant, and equipment	(3,852)	(4,307)
Net proceeds from sale of business	0
Other, net	1,118	1,154
Net cash provided by (used in) investing activities	(4,915)	(83,027)
Cash Flows from Financing Activities
Purchase of treasury stock at market prices	0	0
Long-term debt payments	400	11,792
Proceeds from long-term debt		41,392
Net proceeds from issuance of common stock	0	0
Payment of debt issuance costs	(54)
Inter Company Financing	4,351	(36,970)
Excess tax benefit from stock compensation	0	0
Net cash used in financing activities	3,897	(7,370)
Effect of exchange rate changes on cash	0	0
Net increase (decrease) in cash and cash equivalents	61,165	(74,306)
Cash and cash equivalents at beginning of year	39,597	91,466
Cash and cash equivalents at end of period	100,762	17,160
Reportable Legal Entities | Non-Guarantor Subsidiaries
Schedule Of Supplemental Financial Information [Line Items]
Net cash provided by (used in) operating activities	14,263	2,288
Cash Flows from Investing Activities
Cash paid for acquisitions	0	(28,263)
Net proceeds from sale of property and equipment	29	0
Purchases of property, plant, and equipment	(183)	(317)
Net proceeds from sale of business	8,479
Other, net	0	0
Net cash provided by (used in) investing activities	8,325	(28,580)
Cash Flows from Financing Activities
Purchase of treasury stock at market prices	0	0
Long-term debt payments	0	0
Proceeds from long-term debt		0
Net proceeds from issuance of common stock	0	0
Payment of debt issuance costs	0
Inter Company Financing	(29,761)	30,179
Excess tax benefit from stock compensation	0	0
Net cash used in financing activities	(29,761)	30,179
Effect of exchange rate changes on cash	1,264	(769)
Net increase (decrease) in cash and cash equivalents	(5,909)	3,118
Cash and cash equivalents at beginning of year	29,261	19,144
Cash and cash equivalents at end of period	23,352	22,262
Eliminations
Schedule Of Supplemental Financial Information [Line Items]
Net cash provided by (used in) operating activities	0	0
Cash Flows from Investing Activities
Cash paid for acquisitions	0	0
Net proceeds from sale of property and equipment	0	0
Purchases of property, plant, and equipment	0	0
Net proceeds from sale of business	0
Other, net	0	0
Net cash provided by (used in) investing activities	0	0
Cash Flows from Financing Activities
Purchase of treasury stock at market prices	0	0
Long-term debt payments	0	0
Proceeds from long-term debt		0
Net proceeds from issuance of common stock	0	0
Payment of debt issuance costs	0
Inter Company 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 (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