Note 14 - Statutory Information Risk to Capital Calculation (Details) (Radian Guaranty [Member], USD $) In Millions, unless otherwise specified	Sep. 30, 2012		Dec. 31, 2011
Radian Guaranty [Member]
Statutory Accounting Practices [Line Items]
Net Risk In Force	$ 20,552.3	[1]	$ 18,095.7	[1]
Statutory surplus	$ 1,022.2		$ 843.2
Risk To Capital Ratio	0.201		0.215

[1] Risk in force, net excludes risk ceded through reinsurance contracts and risk in force on defaulted loans.