Quarterly report pursuant to Section 13 or 15(d)

Document and Entity Information

v3.21.1
Document and Entity Information - shares
3 Months Ended
Mar. 31, 2021
May 07, 2021
Cover [Abstract]    
Document Type 10-Q  
Document Period End Date Mar. 31, 2021  
Entity Registrant Name Williams Industrial Services Group Inc.  
Title of 12(b) Security Common Stock, par value $0.01 per share  
Trading Symbol WLMS  
Security Exchange Name NYSE  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Non-accelerated Filer  
Entity Small Business true  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   25,896,001
Entity Central Index Key 0001136294  
Current Fiscal Year End Date --12-31  
Document Fiscal Year Focus 2021  
Document Fiscal Period Focus Q1  
Amendment Flag false