v3.25.1
Cover
Jun. 11, 2025
Document Information [Line Items]  
Document Type 8-K
Document Period End Date Jun. 11, 2025
Entity Registrant Name CAPITAL SOUTHWEST CORPORATION
Entity Incorporation, State or Country Code TX
Entity File Number 814-00061
Entity Tax Identification Number 75-1072796
Entity Address, Address Line One 8333 Douglas Avenue
Entity Address, Address Line Two Suite 1100
Entity Address, City or Town Dallas
Entity Address, State or Province TX
Entity Address, Postal Zip Code 75225
City Area Code 214
Local Phone Number 238-5700
Written Communications false
Soliciting Material false
Pre-commencement Tender Offer false
Pre-commencement Issuer Tender Offer false
Entity Emerging Growth Company false
Entity Central Index Key 0000017313
Amendment Flag false
Common Stock  
Document Information [Line Items]  
Title of 12(b) Security Common Stock, $0.25 par value per share
Trading Symbol CSWC
Security Exchange Name NASDAQ
Medium-term Notes  
Document Information [Line Items]  
Title of 12(b) Security 7.75% Notes due 2028
Trading Symbol CSWCZ
Security Exchange Name NASDAQ