Note 12 - Statutory Information Risk to Capital Calculation (Details) (Radian Guaranty [Member], USD $) In Millions, unless otherwise specified	Mar. 31, 2012		Dec. 31, 2011
Radian Guaranty [Member]
Statutory Accounting Practices [Line Items]
Risk In Force	$ 18,979.2	[1]	$ 18,095.7	[1]
Statutory surplus	$ 919.9		$ 843.2
Risk To Capital Ratio	0.206		0.215

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