Note 16 - Statutory Information Risk To Capital Calculation (Details) (Radian Guaranty [Member], USD $) In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Radian Guaranty [Member]
Statutory Accounting Practices [Line Items]
Risk In Force	$ 19,226.7	[1]	$ 18,095.7	[1]
Statutory policyholers' surplus	926.0		843.2		1,295.7
Contingency Reserve	0		0		19.6
Statutory policyholders' position	$ 926.0		$ 843.2
Risk To Capital Ratio	20.8		21.5

[1] RIF, net excludes risk ceded through reinsurance contracts (to both external parties as well as subsidiaries and affiliates) and RIF on defaulted loans.