Note 4 - Derivative Instruments Derivative Contract (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012 contract		Dec. 31, 2011
NIMS related and other [Member]
Derivatives, Fair Value [Line Items]
Number of Credit Risk Derivatives Held	0	[1]
Derivative, Notional Amount	$ 0	[1]
Derivative assets (liabilities), at fair value, net	1,585	[1]
Corporate collateralized debt obligations (CDO's)[Member]
Derivatives, Fair Value [Line Items]
Number of Credit Risk Derivatives Held	35
Derivative, Notional Amount	13,770,790
Derivative assets (liabilities), at fair value, net	2,817
Non Corporate CDOS and other derivative transactions[Member]
Derivatives, Fair Value [Line Items]
Number of Credit Risk Derivatives Held	46
Derivative, Notional Amount	5,015,051
Derivative assets (liabilities), at fair value, net	(173,163)
Trust Preferred Securities (TruPs) [Member]
Derivatives, Fair Value [Line Items]
Number of Credit Risk Derivatives Held	13
Derivative, Notional Amount	1,086,583
Derivative assets (liabilities), at fair value, net	(11,112)
CDOS of commercial mortgage backed securities (CMBS)[Member]
Derivatives, Fair Value [Line Items]
Number of Credit Risk Derivatives Held	4
Derivative, Notional Amount	1,831,000
Derivative assets (liabilities), at fair value, net	(74,651)
Structured finance [Member]
Derivatives, Fair Value [Line Items]
Number of Credit Risk Derivatives Held	6
Derivative, Notional Amount	643,638
Derivative assets (liabilities), at fair value, net	(42,983)
Public finance [Member]
Derivatives, Fair Value [Line Items]
Number of Credit Risk Derivatives Held	23
Derivative, Notional Amount	1,453,830
Derivative assets (liabilities), at fair value, net	(44,417)
Total Assumed [Member]
Derivatives, Fair Value [Line Items]
Number of Credit Risk Derivatives Held	42
Derivative, Notional Amount	381,210
Derivative assets (liabilities), at fair value, net	(14,036)
Assumed structured finance [Member]
Derivatives, Fair Value [Line Items]
Number of Credit Risk Derivatives Held	34
Derivative, Notional Amount	247,891
Derivative assets (liabilities), at fair value, net	(13,364)
Assumed public finance [Member]
Derivatives, Fair Value [Line Items]
Number of Credit Risk Derivatives Held	8
Derivative, Notional Amount	133,319
Derivative assets (liabilities), at fair value, net	(672)
Financial Guaranty VIE derivative liabilities [Member]
Derivatives, Fair Value [Line Items]
Number of Credit Risk Derivatives Held	1	[2]
Derivative, Notional Amount	76,349	[2]
Derivative assets (liabilities), at fair value, net	(70,467)	[2]
Radian Group Consolidated [Member]
Derivatives, Fair Value [Line Items]
Number of Credit Risk Derivatives Held	124
Derivative, Notional Amount	19,243,400		36,500,000
Derivative assets (liabilities), at fair value, net	$ (253,264)		$ (108,794)

[1] Represents NIMS derivative assets related to consolidated NIMS VIEs. Also includes common stock warrants. Because none of these investments represent financial guaranty contracts that we issued, they cannot become liabilities, and therefore, do not represent additional par exposure.

[2] Represents the fair value of a CDS included in a VIE, which we consolidate, relating to the Terminated TruPs CDOs. The assets in the VIE represent the only funds available to pay the CDS Counterparty for amounts due under the contract; therefore, the notional exposure presented for the CDS is limited to the current trust assets. See Notes 1 and 6 for information on the underlying reference securities and on our maximum exposure to loss from this consolidated financial guaranty transaction.