Supplemental Financial Information (Schedule Of Consolidating Balance Sheets) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012	Dec. 31, 2011
Schedule Of Supplemental Financial Information [Line Items]
Cash and cash equivalents	$ 30,288	$ 48,028	$ 35,327	$ 54,117
Accounts receivable, net	111,532	89,473
Inventories	125,439	116,357
Other current assets	13,625	13,380
Total current assets	280,884	267,238
Property, plant, and equipment, net	147,628	151,613
Goodwill	358,934	359,863
Acquired intangibles	96,709	98,759
Other assets	7,376	6,201
Total assets	891,531	883,674
Accounts payable	81,934	69,060
Accrued expenses	36,561	47,432
Current maturities of long-term debt	417	1,093
Total current liabilities	118,912	117,585
Long-term debt	214,006	206,710
Deferred income taxes	56,960	57,068
Other non-current liabilities	30,788	25,489
Shareholders' equity	470,865	476,822
Total liabilities and shareholders' equity	891,531	883,674
Gibraltar Industries, Inc. [Member]
Schedule Of Supplemental Financial Information [Line Items]
Intercompany balances	23,964	(16,349)
Other current assets	4,260	6,524
Total current assets	28,224	(9,825)
Other assets	3,630	2,259
Investment in subsidiaries	650,917	688,450
Total assets	682,771	680,884
Accrued expenses	1,906	1,360
Total current liabilities	1,906	1,360
Long-term debt	210,000	202,702
Shareholders' equity	470,865	476,822
Total liabilities and shareholders' equity	682,771	680,884
Guarantor Subsidiaries [Member]
Schedule Of Supplemental Financial Information [Line Items]
Cash and cash equivalents	9,375	26,163	18,491	34,691
Accounts receivable, net	98,306	78,565
Intercompany balances	(3,816)	37,397
Inventories	116,494	107,137
Other current assets	8,296	5,815
Total current assets	228,655	255,077
Property, plant, and equipment, net	137,047	140,394
Goodwill	331,634	331,404
Acquired intangibles	88,895	90,311
Other assets	3,739	3,941
Investment in subsidiaries	55,104	56,716
Total assets	845,074	877,843
Accounts payable	73,526	61,841
Accrued expenses	32,301	43,843
Current maturities of long-term debt	417	1,093
Total current liabilities	106,244	106,777
Long-term debt	4,006	4,008
Deferred income taxes	53,665	53,639
Other non-current liabilities	30,242	24,969
Shareholders' equity	650,917	688,450
Total liabilities and shareholders' equity	845,074	877,843
Non-Guarantor Subsidiaries [Member]
Schedule Of Supplemental Financial Information [Line Items]
Cash and cash equivalents	20,913	21,865	16,836	19,426
Accounts receivable, net	13,226	10,908
Intercompany balances	(20,148)	(21,048)
Inventories	8,945	9,220
Other current assets	1,069	1,041
Total current assets	24,005	21,986
Property, plant, and equipment, net	10,581	11,219
Goodwill	27,300	28,459
Acquired intangibles	7,814	8,448
Other assets	7	1
Total assets	69,707	70,113
Accounts payable	8,408	7,219
Accrued expenses	2,354	2,229
Total current liabilities	10,762	9,448
Deferred income taxes	3,295	3,429
Other non-current liabilities	546	520
Shareholders' equity	55,104	56,716
Total liabilities and shareholders' equity	69,707	70,113
Eliminations [Member]
Schedule Of Supplemental Financial Information [Line Items]
Cash and cash equivalents
Investment in subsidiaries	(706,021)	(745,166)
Total assets	(706,021)	(745,166)
Shareholders' equity	(706,021)	(745,166)
Total liabilities and shareholders' equity	$ (706,021)	$ (745,166)