v3.26.1
Cover - shares
3 Months Ended
Jun. 30, 2026
Jul. 24, 2026
Cover [Abstract]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Jun. 30, 2026  
Document Transition Report false  
Entity File Number 001-37454  
Entity Registrant Name CSW INDUSTRIALS, INC.  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 47-2266942  
Entity Address, Address Line One 5420 Lyndon B. Johnson Freeway, Suite 500  
Entity Address, City or Town Dallas  
Entity Address, State or Province TX  
Entity Address, Postal Zip Code 75240  
City Area Code 214  
Local Phone Number 884-3777  
Title of 12(b) Security Common Stock, par value $0.01 per share  
Trading Symbol CSW  
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   16,293,487
Amendment Flag false  
Document Fiscal Year Focus 2027  
Document Fiscal Period Focus Q1  
Entity Central Index Key 0001624794  
Current Fiscal Year End Date --03-31