v3.25.2
Document and Entity Information - shares
 6 Months Ended
Jun. 30, 2025
Jul. 25, 2025
Document and Entity Information [Abstract]    
Document Type 10-Q  
Document Quarterly Report true  
Document Transition Report false  
Document Period End Date Jun. 30, 2025  
Securities Act File Number 1-33891  
Entity Registrant Name ORION GROUP HOLDINGS, INC.  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 26-0097459  
Entity Address, Address Line One 2940 Riverby Road  
Entity Address, Address Line Two Suite 400  
Entity Address, City or Town Houston  
Entity Address, State or Province TX  
Entity Address, Postal Zip Code 77020  
City Area Code 713  
Local Phone Number 852-6500  
Title of 12(b) Security Common stock, $0.01 par value per share  
Trading Symbol ORN  
Security Exchange Name NYSE  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   39,735,245
Current Fiscal Year End Date --12-31  
Document Fiscal Year Focus 2025  
Document Fiscal Period Focus Q2  
Entity Central Index Key 0001402829  
Amendment Flag false