Note 14 - Selected Financial Information of Registrant - Radian Group Selected Financial Information of Registrant (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Condensed Financial Statements, Captions [Line Items]
Total assets	$ 6,054,000	$ 5,903,200
Long-term debt	913,952	663,571
Total liabilities	5,151,134	5,166,875
Total stockholders’ equity	902,866	736,325
Total liabilities and stockholders’ equity	6,054,000	5,903,200
Parent Company
Condensed Financial Statements, Captions [Line Items]
Investments in subsidiaries, at equity in net assets	1,161,878	1,234,229
Total assets	2,017,981	1,550,619
Long-term debt	913,952	663,571
Total liabilities	1,115,115	814,294
Total stockholders’ equity	902,866	736,325
Total liabilities and stockholders’ equity	$ 2,017,981	$ 1,550,619