Document and Entity Information Document - shares	6 Months Ended
	Jun. 30, 2020	Aug. 06, 2020
Document Information [Line Items]
Document Transition Report	false
Document Quarterly Report	true
Title of 12(b) Security	Common Stock, $0.001 par value per share
Entity Incorporation, State or Country Code	DE
Entity Registrant Name	Radian Group Inc
City Area Code	215
Local Phone Number	231-1000
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	Jun. 30, 2020
Entity File Number	1-11356
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Common Stock, Shares Outstanding		191,553,680
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Shell Company	false
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Tax Identification Number	23-2691170
Entity Address, Address Line One	1500 Market Street
Entity Address, City or Town	Philadelphia
Entity Address, State or Province	PA
Entity Address, Postal Zip Code	19102
Trading Symbol	RDN
Security Exchange Name	NYSE