Supplemental Financial Information (Schedule Of Consolidating Statements Of Comprehensive Income) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Schedule Of Supplemental Financial Information [Line Items]
Net (loss) income	$ (3,647)	$ 1,362
Other comprehensive (loss) income:
Foreign currency translation adjustment	(3,097)	1,935
Adjustment to retirement benefit liability, net of tax	2	2
Adjustment to post-retirement health care liability, net of tax	38	16
Other comprehensive income (loss)	(3,057)	1,953
Total comprehensive (loss) income	(6,704)	3,315
Gibraltar Industries, Inc. [Member]
Schedule Of Supplemental Financial Information [Line Items]
Net (loss) income	(3,437)	1,720
Other comprehensive (loss) income:
Total comprehensive (loss) income	(3,437)	1,720
Guarantor Subsidiaries [Member]
Schedule Of Supplemental Financial Information [Line Items]
Net (loss) income	3,407	4,350
Other comprehensive (loss) income:
Adjustment to retirement benefit liability, net of tax	2	2
Adjustment to post-retirement health care liability, net of tax	38	16
Other comprehensive income (loss)	40	18
Total comprehensive (loss) income	3,447	4,368
Non-Guarantor Subsidiaries [Member]
Schedule Of Supplemental Financial Information [Line Items]
Net (loss) income	638	1,095
Other comprehensive (loss) income:
Foreign currency translation adjustment	(3,097)	1,935
Other comprehensive income (loss)	(3,097)	1,935
Total comprehensive (loss) income	(2,459)	3,030
Eliminations [Member]
Schedule Of Supplemental Financial Information [Line Items]
Net (loss) income	(4,255)	(5,803)
Other comprehensive (loss) income:
Total comprehensive (loss) income	$ (4,255)	$ (5,803)