Note 14 - Selected Financial Information of Registrant - Radian Group Selected Financial Information of Registrant (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Condensed Financial Statements, Captions [Line Items]
Total assets	$ 5,758,573	$ 5,903,200
Long-term debt	921,927	663,571
Total liabilities	4,864,053	5,166,875
Total stockholders’ equity	894,520	736,325
Total liabilities and stockholders’ equity	5,758,573	5,903,200
Parent Company
Condensed Financial Statements, Captions [Line Items]
Investments in subsidiaries, at equity in net assets	1,356,140	1,234,229
Total assets	2,051,620	1,550,619
Long-term debt	921,927	663,571
Total liabilities	1,157,100	814,294
Total stockholders’ equity	894,520	736,325
Total liabilities and stockholders’ equity	$ 2,051,620	$ 1,550,619