Note 3 - Derivative Instruments Change in Fair Value of Derivative Instruments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Derivative Instruments, Gain (Loss) [Line Items]
Change in fair value of derivative instruments	$ 86,535	$ (33,124)	$ (81,135)	$ (105,881)
Net Premiums Earned On Derivatives [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Change in fair value of derivative instruments	4,857	7,224	9,849	15,872
Financial Guaranty Credit Derivatives [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Change in fair value of derivative instruments	80,293	(39,161)	(95,431)	(119,380)
Financial Guaranty VIE Derivative Liabilities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Change in fair value of derivative instruments	1,477	(1,136)	4,539	(2,363)
Net Interest Margin Securities Related And Other [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Change in fair value of derivative instruments	(92)	(51)	(92)	(10)
Radian Group Consolidated [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Change in fair value of derivative instruments	$ 86,535	$ (33,124)	$ (81,135)	$ (105,881)