Cover Page - shares	9 Months Ended
	Sep. 30, 2020	Oct. 26, 2020
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2020
Document Transition Report	false
Entity File Number	0-22462
Entity Registrant Name	GIBRALTAR INDUSTRIES, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	16-1445150
Entity Address, Address Line One	3556 Lake Shore Road
Entity Address, Address Line Two	P.O. Box 2028
Entity Address, City or Town	Buffalo
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	14219-0228
City Area Code	716
Local Phone Number	826-6500
Title of 12(b) Security	Common Stock, $0.01 par value per share
Trading Symbol	ROCK
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		32,522,138
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3
Entity Central Index Key	0000912562
Current Fiscal Year End Date	--12-31