Supplemental Financial Information (Schedule of Consolidating Balance Sheets) (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
Schedule Of Supplemental Financial Information [Line Items]
Cash and cash equivalents	$ 118,300,000	$ 110,610,000	$ 78,186,000	$ 97,039,000
Accounts receivable, net of reserve of $4,154 and $4,280 in 2015 and 2014	115,284,000	101,141,000
Intercompany balances	0	0
Inventories	133,624,000	128,743,000
Other current assets	22,116,000	19,937,000
Total current assets	389,324,000	360,431,000
Property, plant, and equipment, net	113,769,000	129,575,000
Goodwill	235,523,000	236,044,000
Acquired intangibles	80,439,000	82,215,000
Other assets	4,702,000	5,895,000
Investment in subsidiaries	0	0
Total assets	823,757,000	814,160,000
Accounts payable	90,155,000	81,246,000
Accrued expenses	48,419,000	52,439,000
Current maturities of long-term debt	400,000	400,000
Total current liabilities	138,974,000	134,085,000
Long-term debt	213,200,000	213,200,000
Deferred income taxes	49,652,000	49,772,000
Other non-current liabilities	32,572,000	29,874,000
Total shareholders’ equity	389,359,000	387,229,000
Total liabilities and shareholders' equity	823,757,000	814,160,000
Gibraltar Industries, Inc.
Schedule Of Supplemental Financial Information [Line Items]
Cash and cash equivalents	0	0	0	0
Accounts receivable, net of reserve of $4,154 and $4,280 in 2015 and 2014	0	0
Intercompany balances	18,298,000	21,619,000
Inventories	0	0
Other current assets	1,283,000	4,484,000
Total current assets	19,581,000	26,103,000
Property, plant, and equipment, net	0	0
Goodwill	0	0
Acquired intangibles	0	0
Other assets	2,810,000	2,931,000
Investment in subsidiaries	578,899,000	573,664,000
Total assets	601,290,000	602,698,000
Accounts payable	0	0
Accrued expenses	1,931,000	5,469,000
Current maturities of long-term debt	0	0
Total current liabilities	1,931,000	5,469,000
Long-term debt	210,000,000	210,000,000
Deferred income taxes	0	0
Other non-current liabilities	0	0
Total shareholders’ equity	389,359,000	387,229,000
Total liabilities and shareholders' equity	601,290,000	602,698,000
Guarantor Subsidiaries
Schedule Of Supplemental Financial Information [Line Items]
Cash and cash equivalents	100,829,000	91,466,000	57,601,000	75,856,000
Accounts receivable, net of reserve of $4,154 and $4,280 in 2015 and 2014	104,708,000	91,713,000
Intercompany balances	(400,000)	(1,850,000)
Inventories	126,248,000	120,091,000
Other current assets	19,885,000	14,488,000
Total current assets	351,270,000	315,908,000
Property, plant, and equipment, net	101,858,000	116,628,000
Goodwill	229,558,000	229,558,000
Acquired intangibles	75,915,000	77,259,000
Other assets	1,892,000	2,964,000
Investment in subsidiaries	30,541,000	32,404,000
Total assets	791,034,000	774,721,000
Accounts payable	83,969,000	74,751,000
Accrued expenses	44,667,000	45,561,000
Current maturities of long-term debt	400,000	400,000
Total current liabilities	129,036,000	120,712,000
Long-term debt	3,200,000	3,200,000
Deferred income taxes	47,741,000	47,717,000
Other non-current liabilities	32,158,000	29,428,000
Total shareholders’ equity	578,899,000	573,664,000
Total liabilities and shareholders' equity	791,034,000	774,721,000
Non-Guarantor Subsidiaries
Schedule Of Supplemental Financial Information [Line Items]
Cash and cash equivalents	17,471,000	19,144,000	20,585,000	21,183,000
Accounts receivable, net of reserve of $4,154 and $4,280 in 2015 and 2014	10,576,000	9,428,000
Intercompany balances	(17,898,000)	(19,769,000)
Inventories	7,376,000	8,652,000
Other current assets	948,000	965,000
Total current assets	18,473,000	18,420,000
Property, plant, and equipment, net	11,911,000	12,947,000
Goodwill	5,965,000	6,486,000
Acquired intangibles	4,524,000	4,956,000
Other assets	0	0
Investment in subsidiaries	0	0
Total assets	40,873,000	42,809,000
Accounts payable	6,186,000	6,495,000
Accrued expenses	1,821,000	1,409,000
Current maturities of long-term debt	0	0
Total current liabilities	8,007,000	7,904,000
Long-term debt	0	0
Deferred income taxes	1,911,000	2,055,000
Other non-current liabilities	414,000	446,000
Total shareholders’ equity	30,541,000	32,404,000
Total liabilities and shareholders' equity	40,873,000	42,809,000
Eliminations
Schedule Of Supplemental Financial Information [Line Items]
Cash and cash equivalents	0	0	0	0
Accounts receivable, net of reserve of $4,154 and $4,280 in 2015 and 2014	0	0
Intercompany balances	0	0
Inventories	0	0
Other current assets	0	0
Total current assets	0	0
Property, plant, and equipment, net	0	0
Goodwill	0	0
Acquired intangibles	0	0
Other assets	0	0
Investment in subsidiaries	(609,440,000)	(606,068,000)
Total assets	(609,440,000)	(606,068,000)
Accounts payable	0	0
Accrued expenses	0	0
Current maturities of long-term debt	0	0
Total current liabilities	0	0
Long-term debt	0	0
Deferred income taxes	0	0
Other non-current liabilities	0	0
Total shareholders’ equity	(609,440,000)	(606,068,000)
Total liabilities and shareholders' equity	$ (609,440,000)	$ (606,068,000)