Supplemental Financial Information (Schedule of Condensed Consolidating Statements of Cash Flows) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Schedule Of Supplemental Financial Information [Line Items]
Net cash provided by (used in) operating activities	$ 11,758	$ (3,785)
Cash paid for acquisitions	(134,318)	0
Purchases of property, plant, and equipment	(4,624)	(11,498)
Other investing activities	1,154	121
Net proceeds from sale of property and equipment	26,181	5,950
Net cash used in investing activities	(111,607)	(5,427)
Long-term debt payments	(11,792)	(407)
Proceeds from long-term debt	41,392	0
Purchase of treasury stock at market prices	(387)	(408)
Net proceeds from issuance of common stock	180	404
Intercompany financing	0	0
Excess tax benefit from stock compensation	37	81
Net cash provided by (used in) financing activities	29,430	(330)
Effect of exchange rate changes on cash	(769)	260
Net decrease in cash and cash equivalents	(71,188)	(9,282)
Cash and cash equivalents at beginning of year	110,610	97,039
Cash and cash equivalents at end of period	39,422
Gibraltar Industries, Inc.
Schedule Of Supplemental Financial Information [Line Items]
Net cash provided by (used in) operating activities	(6,621)	(6,664)
Cash paid for acquisitions	0
Purchases of property, plant, and equipment	0	0
Other investing activities	0	0
Net proceeds from sale of property and equipment	0	0
Net cash used in investing activities	0	0
Long-term debt payments	0	0
Proceeds from long-term debt	0
Purchase of treasury stock at market prices	(387)	(408)
Net proceeds from issuance of common stock	180	404
Intercompany financing	6,791	6,587
Excess tax benefit from stock compensation	37	81
Net cash provided by (used in) financing activities	6,621	6,664
Effect of exchange rate changes on cash	0	0
Net 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
Guarantor Subsidiaries
Schedule Of Supplemental Financial Information [Line Items]
Net cash provided by (used in) operating activities	16,091	272
Cash paid for acquisitions	(106,055)
Purchases of property, plant, and equipment	(4,307)	(9,232)
Other investing activities	1,154	121
Net proceeds from sale of property and equipment	26,181	5,947
Net cash used in investing activities	(83,027)	(3,164)
Long-term debt payments	(11,792)	(407)
Proceeds from long-term debt	41,392
Purchase of treasury stock at market prices	0	0
Net proceeds from issuance of common stock	0	0
Intercompany financing	(36,970)	(6,028)
Excess tax benefit from stock compensation	0	0
Net cash provided by (used in) financing activities	(7,370)	(6,435)
Effect of exchange rate changes on cash	0	0
Net decrease in cash and cash equivalents	(74,306)	(9,327)
Cash and cash equivalents at beginning of year	91,466	75,856
Cash and cash equivalents at end of period	17,160
Non-Guarantor Subsidiaries
Schedule Of Supplemental Financial Information [Line Items]
Net cash provided by (used in) operating activities	2,288	2,607
Cash paid for acquisitions	(28,263)
Purchases of property, plant, and equipment	(317)	(2,266)
Other investing activities	0	0
Net proceeds from sale of property and equipment	0	3
Net cash used in investing activities	(28,580)	(2,263)
Long-term debt payments	0	0
Proceeds from long-term debt	0
Purchase of treasury stock at market prices	0	0
Net proceeds from issuance of common stock	0	0
Intercompany financing	30,179	(559)
Excess tax benefit from stock compensation	0	0
Net cash provided by (used in) financing activities	30,179	(559)
Effect of exchange rate changes on cash	(769)	260
Net decrease in cash and cash equivalents	3,118	45
Cash and cash equivalents at beginning of year	19,144	21,183
Cash and cash equivalents at end of period	22,262
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 investing activities	0	0
Net proceeds from sale of property and equipment	0	0
Net cash used in investing activities	0	0
Long-term debt payments	0	0
Proceeds from long-term debt	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 provided by (used in) financing activities	0	0
Effect of exchange rate changes on cash	0	0
Net 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