Document and Entity Information - shares
9 Months Ended
Sep. 30, 2019
Oct. 31, 2019
Cover [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Sep. 30, 2019  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q3  
Trading Symbol GLDD  
Entity Registrant Name Great Lakes Dredge & Dock CORP  
Entity Central Index Key 0001372020  
Current Fiscal Year End Date --12-31  
Entity Filer Category Accelerated Filer  
Entity Shell Company false  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Address, Address Line One 2122 York Road  
Entity Address, City or Town Oak Brook  
Entity Address, State or Province IL  
Entity Common Stock, Shares Outstanding   63,919,970
Entity Current Reporting Status Yes  
Entity File Number 001-33225  
Entity Tax Identification Number 20-5336063  
City Area Code 630  
Local Phone Number 574-3000  
Entity Address, Postal Zip Code 60523  
Entity Interactive Data Current Yes  
Title of 12(b) Security Common Stock (Par Value $0.0001)  
Security Exchange Name NASDAQ  
Entity Incorporation, State or Country Code DE  
Document Quarterly Report true  
Document Transition Report false