v2.4.0.6
Document And Entity Information (USD $)
6 Months Ended
Sep. 30, 2010
Oct. 28, 2011
Entity Registrant Name CAPITAL SOUTHWEST CORP  
Entity Central Index Key 0000017313  
Current Fiscal Year End Date --03-31  
Entity Well-known Seasoned Issuer No  
Entity Voluntary Filers No  
Entity Current Reporting Status Yes  
Entity Filer Category Accelerated Filer  
Entity Public Float $ 250,728,582  
Entity Common Stock, Shares Outstanding   3,754,538
Document Fiscal Year Focus 2011  
Document Fiscal Period Focus Q2  
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Sep. 30, 2011