Quarterly report pursuant to Section 13 or 15(d)

Cover Page

Cover Page - shares
6 Months Ended
Jun. 30, 2021
Aug. 06, 2021
Cover [Abstract]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Jun. 30, 2021  
Document Transition Report false  
Entity File Number 0-19687  
Entity Registrant Name Synalloy Corporation  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 57-0426694  
Entity Address, Address Line One 4510 Cox Road,  
Entity Address, Address Line Two Suite 201,  
Entity Address, City or Town Richmond,  
Entity Address, State or Province VA  
Entity Address, Postal Zip Code 23060  
City Area Code (804)  
Local Phone Number 822-3260  
Title of 12(b) Security Common Stock, par value $1.00 per share  
Trading Symbol SYNL  
Security Exchange Name NASDAQ  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Non-accelerated Filer  
Smaller Reporting Company true  
Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   9,268,854
Entity Central Index Key 0000095953  
Current Fiscal Year End Date --12-31  
Document Fiscal Year Focus 2021  
Document Fiscal Period Focus Q2  
Amendment Flag false