v3.26.1
Cover and DEI - shares
 6 Months Ended
Jun. 30, 2026
Jul. 15, 2026
Document Information [Line Items]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Jun. 30, 2026  
Document Transition Report false  
Entity File Number 1-38494  
Entity Registrant Name Arcosa, Inc.  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 82-5339416  
Entity Address, Address Line One 500 N. Akard Street, Suite 400  
Entity Address, City or Town Dallas,  
Entity Address, State or Province TX  
Entity Address, Postal Zip Code 75201  
City Area Code 972  
Local Phone Number 942-6500  
Title of 12(b) Security Common Stock ($0.01 par value)  
Trading Symbol ACA  
Security Exchange Name NYSE  
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   49,106,809
Entity Central Index Key 0001739445  
Amendment Flag false  
Document Fiscal Year Focus 2026  
Document Fiscal Period Focus Q2  
Current Fiscal Year End Date --12-31