Note 3 - Derivative Instruments Derivatives (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013 derivative		Dec. 31, 2012
Net Interest Margin Securities Related And Other [Member]
Derivative [Line Items]
Number of Credit Risk Derivatives Held	2	[1]
Derivative, Notional Amount	$ 0	[1]
Derivative Assets (Liabilities), at Fair Value, Net	13,533	[1]
Corporate collateralized debt obligations (CDO's)[Member]
Derivative [Line Items]
Number of Credit Risk Derivatives Held	23
Derivative, Notional Amount	9,103,298
Derivative Assets (Liabilities), at Fair Value, Net	2,286
Non Corporate CDOS and other derivative transactions[Member]
Derivative [Line Items]
Number of Credit Risk Derivatives Held	44
Derivative, Notional Amount	4,728,579
Derivative Assets (Liabilities), at Fair Value, Net	(259,537)
Trust Preferred Securities (TruPs) [Member]
Derivative [Line Items]
Number of Credit Risk Derivatives Held	13
Derivative, Notional Amount	1,032,996
Derivative Assets (Liabilities), at Fair Value, Net	(35,652)
CDOS of commercial mortgage backed securities (CMBS)[Member]
Derivative [Line Items]
Number of Credit Risk Derivatives Held	4
Derivative, Notional Amount	1,831,000
Derivative Assets (Liabilities), at Fair Value, Net	(99,255)
Structured finance [Member]
Derivative [Line Items]
Number of Credit Risk Derivatives Held	5
Derivative, Notional Amount	552,466
Derivative Assets (Liabilities), at Fair Value, Net	(82,133)
Public finance [Member]
Derivative [Line Items]
Number of Credit Risk Derivatives Held	22
Derivative, Notional Amount	1,312,117
Derivative Assets (Liabilities), at Fair Value, Net	(42,497)
Total Assumed [Member]
Derivative [Line Items]
Number of Credit Risk Derivatives Held	31
Derivative, Notional Amount	253,412
Derivative Assets (Liabilities), at Fair Value, Net	(12,268)
Assumed structured finance [Member]
Derivative [Line Items]
Number of Credit Risk Derivatives Held	26
Derivative, Notional Amount	159,774
Derivative Assets (Liabilities), at Fair Value, Net	(11,765)
Assumed public finance [Member]
Derivative [Line Items]
Number of Credit Risk Derivatives Held	5
Derivative, Notional Amount	93,638
Derivative Assets (Liabilities), at Fair Value, Net	(503)
Financial Guaranty VIE Derivative Liabilities [Member]
Derivative [Line Items]
Number of Credit Risk Derivatives Held	1	[2]
Derivative, Notional Amount	77,686	[2]
Derivative Assets (Liabilities), at Fair Value, Net	(68,040)	[2]
Radian Group Consolidated [Member]
Derivative [Line Items]
Number of Credit Risk Derivatives Held	101
Derivative, Notional Amount	14,162,975		19,200,000
Derivative Assets (Liabilities), at Fair Value, Net	$ (324,026)		$ (253,264)

[1] Represents NIMS derivative assets related to consolidated NIMS VIEs and other purchased derivatives for which we do not have loss exposure that exceeds our net asset amount.

[2] Represents the fair value of a CDS included in a VIE that we have consolidated. See Note 5 for more information on this transaction, the underlying reference securities and our maximum exposure to loss from this consolidated financial guaranty transaction. 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.