Note 14 - Selected Financial Information of Registrant - Radian Group Selected Financial Information of Registrant (Details) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Condensed Financial Statements, Captions [Line Items]
Total assets	$ 6,928,796	$ 7,620,887
Long-term Debt	811,319	964,788
Total liabilities	5,799,486	6,761,107
Total stockholders’ equity	1,129,310	859,780
Total liabilities and stockholders’ equity	6,928,796	7,620,887
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Investments in and Advances to Affiliates, Amount of Equity	1,218,817	947,724
Total assets	1,994,889	1,864,896
Long-term Debt	811,319	964,788
Total liabilities	865,579	1,005,116
Total stockholders’ equity	1,129,310	859,780
Total liabilities and stockholders’ equity	$ 1,994,889	$ 1,864,896