v3.19.1
Document and Entity Information Document - shares
3 Months Ended
Mar. 31, 2019
May 06, 2019
Document Information [Line Items]    
Entity Registrant Name Radian Group Inc.  
Entity Central Index Key 0000890926  
Current Fiscal Year End Date --12-31  
Entity Filer Category Large Accelerated Filer  
Document Type 10-Q  
Document Period End Date Mar. 31, 2019  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q1  
Amendment Flag false  
Entity Common Stock, Shares Outstanding   208,020,528
Entity Current Reporting Status Yes  
Entity Emerging Growth Company false  
Entity Small Business false