Supplemental Financial Information (Condensed Consolidating Statements of Cash Flows) (Details) - USD ($) $ in Thousands		12 Months Ended
	Apr. 15, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities of continuing operations		$ 122,738	$ 86,684	$ 32,583
Net cash used in operating activities of discontinued operations		0	0	(41)
Net cash provided by operating activities		122,738	86,684	32,542
Cash Flows from Investing Activities
Other, net		1,118	1,154	277
Purchases of property, plant, and equipment		(10,779)	(12,373)	(23,291)
Acquisitions, net of cash acquired		(23,412)	(140,621)	0
Net proceeds from sale of property and equipment		953	26,500	5,992
Net proceeds from sale of business	$ 8,300	8,250	0	0
Net cash used in investing activities		(23,870)	(125,340)	(17,022)
Cash Flows from Financing Activities
Long-term debt payments		(400)	(73,642)	(407)
Proceeds from long-term debt		0	73,242	0
Payment of debt issuance costs		(54)	(1,166)	(35)
Purchase of treasury stock at market prices		(1,539)	(956)	(575)
Intercompany financing		0	0	0
Excess tax benefit from stock compensation		1,249	537	100
Net proceeds from issuance of common stock		3,341	1,801	595
Net cash provided by (used in) financing activities		2,597	(184)	(322)
Effect of exchange rate changes on cash		(146)	(2,912)	(1,627)
Net increase (decrease) in cash and cash equivalents		101,319	(41,752)	13,571
Cash and cash equivalents at beginning of year		68,858	110,610	97,039
Cash and cash equivalents at end of year		170,177	68,858	110,610
Gibraltar Industries, Inc.
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities of continuing operations				(13,437)
Net cash used in operating activities of discontinued operations				0
Net cash provided by operating activities		(34,243)	(13,309)	(13,437)
Cash Flows from Investing Activities
Other, net		0	0	0
Purchases of property, plant, and equipment		0	0	0
Acquisitions, net of cash acquired		0	0
Net proceeds from sale of property and equipment		0	0	0
Net proceeds from sale of business		0
Net cash used in investing activities		0	0	0
Cash Flows from Financing Activities
Long-term debt payments		0	0	0
Proceeds from long-term debt			0
Payment of debt issuance costs		0	0	0
Purchase of treasury stock at market prices		(1,539)	(956)	(575)
Intercompany financing		31,192	11,927	13,317
Excess tax benefit from stock compensation		1,249	537	100
Net proceeds from issuance of common stock		3,341	1,801	595
Net cash provided by (used in) financing activities		34,243	13,309	13,437
Effect of exchange rate changes on cash		0	0	0
Net increase (decrease) in cash and cash equivalents		0	0	0
Cash and cash equivalents at beginning of year		0	0	0
Cash and cash equivalents at end of year		0	0	0
Guarantor Subsidiaries
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities of continuing operations				40,820
Net cash used in operating activities of discontinued operations				(41)
Net cash provided by operating activities		139,641	94,440	40,779
Cash Flows from Investing Activities
Other, net		1,118	1,154	277
Purchases of property, plant, and equipment		(10,321)	(11,754)	(19,286)
Acquisitions, net of cash acquired		(23,412)	(114,145)
Net proceeds from sale of property and equipment		230	26,500	5,989
Net proceeds from sale of business		0
Net cash used in investing activities		(32,385)	(98,245)	(13,020)
Cash Flows from Financing Activities
Long-term debt payments		(400)	(73,642)	(407)
Proceeds from long-term debt			73,242
Payment of debt issuance costs		(54)	(1,166)	(35)
Purchase of treasury stock at market prices		0	0	0
Intercompany financing		(2,573)	(46,498)	(11,707)
Excess tax benefit from stock compensation		0	0	0
Net proceeds from issuance of common stock		0	0	0
Net cash provided by (used in) financing activities		(3,027)	(48,064)	(12,149)
Effect of exchange rate changes on cash		0	0	0
Net increase (decrease) in cash and cash equivalents		104,229	(51,869)	15,610
Cash and cash equivalents at beginning of year		39,597	91,466	75,856
Cash and cash equivalents at end of year		143,826	39,597	91,466
Non-Guarantor Subsidiaries
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities of continuing operations				5,200
Net cash used in operating activities of discontinued operations				0
Net cash provided by operating activities		17,340	5,553	5,200
Cash Flows from Investing Activities
Other, net		0	0	0
Purchases of property, plant, and equipment		(458)	(619)	(4,005)
Acquisitions, net of cash acquired		0	(26,476)
Net proceeds from sale of property and equipment		723	0	3
Net proceeds from sale of business		8,250
Net cash used in investing activities		8,515	(27,095)	(4,002)
Cash Flows from Financing Activities
Long-term debt payments		0	0	0
Proceeds from long-term debt			0
Payment of debt issuance costs		0	0	0
Purchase of treasury stock at market prices		0	0	0
Intercompany financing		(28,619)	34,571	(1,610)
Excess tax benefit from stock compensation		0	0	0
Net proceeds from issuance of common stock		0	0	0
Net cash provided by (used in) financing activities		(28,619)	34,571	(1,610)
Effect of exchange rate changes on cash		(146)	(2,912)	(1,627)
Net increase (decrease) in cash and cash equivalents		(2,910)	10,117	(2,039)
Cash and cash equivalents at beginning of year		29,261	19,144	21,183
Cash and cash equivalents at end of year		26,351	29,261	19,144
Eliminations
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities of continuing operations				0
Net cash used in operating activities of discontinued operations				0
Net cash provided by operating activities		0	0	0
Cash Flows from Investing Activities
Other, net		0	0	0
Purchases of property, plant, and equipment		0	0	0
Acquisitions, net of cash acquired		0	0
Net proceeds from sale of property and equipment		0	0	0
Net proceeds from sale of business		0
Net cash used in investing activities		0	0	0
Cash Flows from Financing Activities
Long-term debt payments		0	0	0
Proceeds from long-term debt			0
Payment of debt issuance costs		0	0	0
Purchase of treasury stock at market prices		0	0	0
Intercompany financing		0	0	0
Excess tax benefit from stock compensation		0	0	0
Net proceeds from issuance of common stock		0	0	0
Net cash provided by (used in) financing activities		0	0	0
Effect of exchange rate changes on cash		0	0	0
Net increase (decrease) in cash and cash equivalents		0	0	0
Cash and cash equivalents at beginning of year		0	0	0
Cash and cash equivalents at end of year		$ 0	$ 0	$ 0