Supplemental Financial Information (Schedule of Consolidating Balance Sheets) (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
Schedule Of Supplemental Financial Information [Line Items]
Cash and cash equivalents	$ 39,422	$ 110,610	$ 87,757	$ 97,039
Accounts receivable, net of reserve of $4,657 and $4,280 in 2015 and 2014	180,382	101,141
Intercompany balances	0	0
Inventories	134,751	128,743
Other current assets	23,339	19,937
Total current assets	377,894	360,431
Property, plant, and equipment, net	124,995	129,575
Goodwill	292,918	236,044
Acquired intangibles	136,731	82,215
Other assets	7,461	5,895
Investment in subsidiaries	0	0
Total assets	939,999	814,160
Accounts payable	114,731	81,246
Accrued expenses	92,383	52,439
Current maturities of long-term debt	400	400
Total current liabilities	207,514	134,085
Long-term debt	242,800	213,200
Deferred income taxes	54,731	49,772
Other non-current liabilities	38,334	29,874
Total shareholders’ equity	396,620	387,229
Total liabilities and shareholders' equity	939,999	814,160
Gibraltar Industries, Inc.
Schedule Of Supplemental Financial Information [Line Items]
Cash and cash equivalents	0	0	0	0
Accounts receivable, net of reserve of $4,657 and $4,280 in 2015 and 2014	0	0
Intercompany balances	(114,041)	21,619
Inventories	0	0
Other current assets	2,448	4,484
Total current assets	(111,593)	26,103
Property, plant, and equipment, net	0	0
Goodwill	0	0
Acquired intangibles	0	0
Other assets	2,689	2,931
Investment in subsidiaries	720,452	573,664
Total assets	611,548	602,698
Accounts payable	0	0
Accrued expenses	4,928	5,469
Current maturities of long-term debt	0	0
Total current liabilities	4,928	5,469
Long-term debt	210,000	210,000
Deferred income taxes	0	0
Other non-current liabilities	0	0
Total shareholders’ equity	396,620	387,229
Total liabilities and shareholders' equity	611,548	602,698
Guarantor Subsidiaries
Schedule Of Supplemental Financial Information [Line Items]
Cash and cash equivalents	17,160	91,466	66,529	75,856
Accounts receivable, net of reserve of $4,657 and $4,280 in 2015 and 2014	160,282	91,713
Intercompany balances	137,658	(1,850)
Inventories	124,810	120,091
Other current assets	17,840	14,488
Total current assets	457,750	315,908
Property, plant, and equipment, net	110,822	116,628
Goodwill	271,343	229,558
Acquired intangibles	120,151	77,259
Other assets	4,772	2,964
Investment in subsidiaries	57,621	32,404
Total assets	1,022,459	774,721
Accounts payable	106,333	74,751
Accrued expenses	75,842	45,561
Current maturities of long-term debt	400	400
Total current liabilities	182,575	120,712
Long-term debt	32,800	3,200
Deferred income taxes	48,744	47,717
Other non-current liabilities	37,888	29,428
Total shareholders’ equity	720,452	573,664
Total liabilities and shareholders' equity	1,022,459	774,721
Non-Guarantor Subsidiaries
Schedule Of Supplemental Financial Information [Line Items]
Cash and cash equivalents	22,262	19,144	21,228	21,183
Accounts receivable, net of reserve of $4,657 and $4,280 in 2015 and 2014	20,100	9,428
Intercompany balances	(23,617)	(19,769)
Inventories	9,941	8,652
Other current assets	3,051	965
Total current assets	31,737	18,420
Property, plant, and equipment, net	14,173	12,947
Goodwill	21,575	6,486
Acquired intangibles	16,580	4,956
Other assets	0	0
Investment in subsidiaries	0	0
Total assets	84,065	42,809
Accounts payable	8,398	6,495
Accrued expenses	11,613	1,409
Current maturities of long-term debt	0	0
Total current liabilities	20,011	7,904
Long-term debt	0	0
Deferred income taxes	5,987	2,055
Other non-current liabilities	446	446
Total shareholders’ equity	57,621	32,404
Total liabilities and shareholders' equity	84,065	42,809
Eliminations
Schedule Of Supplemental Financial Information [Line Items]
Cash and cash equivalents	0	0	$ 0	$ 0
Accounts receivable, net of reserve of $4,657 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	(778,073)	(606,068)
Total assets	(778,073)	(606,068)
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	(778,073)	(606,068)
Total liabilities and shareholders' equity	$ (778,073)	$ (606,068)