Supplemental Financial Information (Schedule Of Consolidating Balance Sheets) (Details) (USD $) In Thousands	Sep. 30, 2011	Dec. 31, 2010	Sep. 30, 2010	May 24, 2010	Dec. 31, 2009
Cash and cash equivalents	$ 33,055	$ 60,866	$ 48,315		$ 23,596
Accounts receivable, net	118,325	70,371
Intercompany balances
Inventories	110,967	77,848
Other current assets	24,352	20,229
Assets of discontinued operations		13,063
Total current assets	286,699	242,377
Property, plant, and equipment, net	154,483	145,783
Goodwill	348,551	298,346
Acquired intangibles	96,991	66,301
Other assets	6,915	16,766
Equity method investments		1,345		1,500
Assets of discontinued operations		39,972
Investment in subsidiaries
Total assets	893,639	810,890
Accounts payable	80,533	56,775
Accrued expenses	66,774	36,785
Current maturities of long-term debt	408	408
Liabilities of discontinued operations		6,150
Total current liabilities	147,715	100,118
Long-term debt	206,667	206,789
Deferred income taxes	51,370	37,119
Other non-current liabilities	22,314	23,221
Liabilities of discontinued operations		2,790
Shareholders' equity	465,573	440,853
Total liabilities and shareholders' equity	893,639	810,890
Gibraltar Industries, Inc. [Member]
Cash and cash equivalents
Accounts receivable, net
Intercompany balances	(86,808)	17,194
Inventories
Other current assets	5,087	6,592
Assets of discontinued operations
Total current assets	(81,721)	23,786
Property, plant, and equipment, net
Goodwill
Acquired intangibles
Other assets	3,071	3,613
Equity method investments
Assets of discontinued operations
Investment in subsidiaries	751,896	616,787
Total assets	673,246	644,186
Accounts payable
Accrued expenses	5,440	1,360
Current maturities of long-term debt
Liabilities of discontinued operations
Total current liabilities	5,440	1,360
Long-term debt	202,233	201,973
Deferred income taxes
Other non-current liabilities
Liabilities of discontinued operations
Shareholders' equity	465,573	440,853
Total liabilities and shareholders' equity	673,246	644,186
Guarantor Subsidiaries [Member]
Cash and cash equivalents	13,655	46,349	31,770		10,105
Accounts receivable, net	102,720	57,268
Intercompany balances	109,400	5,657
Inventories	103,033	71,355
Other current assets	18,553	12,750
Assets of discontinued operations		10,501
Total current assets	347,361	203,880
Property, plant, and equipment, net	142,570	132,355
Goodwill	320,843	270,245
Acquired intangibles	87,587	55,827
Other assets	3,811	13,152
Equity method investments		1,345
Assets of discontinued operations		34,503
Investment in subsidiaries	53,095	55,172
Total assets	955,267	766,479
Accounts payable	72,323	48,739
Accrued expenses	57,522	33,053
Current maturities of long-term debt	408	408
Liabilities of discontinued operations		4,576
Total current liabilities	130,253	86,776
Long-term debt	4,434	4,816
Deferred income taxes	46,992	35,176
Other non-current liabilities	21,692	22,763
Liabilities of discontinued operations		161
Shareholders' equity	751,896	616,787
Total liabilities and shareholders' equity	955,267	766,479
Non-Guarantor Subsidiaries [Member]
Cash and cash equivalents	19,400	14,517	16,545		13,491
Accounts receivable, net	15,605	13,103
Intercompany balances	(22,592)	(22,851)
Inventories	7,934	6,493
Other current assets	712	887
Assets of discontinued operations		2,562
Total current assets	21,059	14,711
Property, plant, and equipment, net	11,913	13,428
Goodwill	27,708	28,101
Acquired intangibles	9,404	10,474
Other assets	33	1
Equity method investments
Assets of discontinued operations		5,469
Investment in subsidiaries
Total assets	70,117	72,184
Accounts payable	8,210	8,036
Accrued expenses	3,812	2,372
Current maturities of long-term debt
Liabilities of discontinued operations		1,574
Total current liabilities	12,022	11,982
Long-term debt
Deferred income taxes	4,378	1,943
Other non-current liabilities	622	458
Liabilities of discontinued operations		2,629
Shareholders' equity	53,095	55,172
Total liabilities and shareholders' equity	70,117	72,184
Eliminations [Member]
Cash and cash equivalents
Accounts receivable, net
Intercompany balances
Inventories
Other current assets
Assets of discontinued operations
Total current assets
Property, plant, and equipment, net
Goodwill
Acquired intangibles
Other assets
Equity method investments
Assets of discontinued operations
Investment in subsidiaries	(804,991)	(671,959)
Total assets	(804,991)	(671,959)
Accounts payable
Accrued expenses
Current maturities of long-term debt
Liabilities of discontinued operations
Total current liabilities
Long-term debt
Deferred income taxes
Other non-current liabilities
Liabilities of discontinued operations
Shareholders' equity	(804,991)	(671,959)
Total liabilities and shareholders' equity	$ (804,991)	$ (671,959)