Note 7 - Reinsurance Reinsurance Premiums Written and Earned (Details) (USD $)	3 Months Ended
	Mar. 31, 2014 transaction	Mar. 31, 2013
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Number of Quota Share Reinsurance Agreements	2
Premiums Written, Net [Abstract]
Direct Premiums Written	$ 229,322,000	$ 245,467,000
Assumed Premiums Written	473,000	(10,397,000)
Ceded Premiums Written	(16,089,000)	(27,885,000)
Net premiums written—insurance	213,706,000	207,185,000
Premiums Earned, Net [Abstract]
Net premiums earned-insurance	205,665,000	192,588,000
Mortgage Insurance and Financial Guarantee Contracts [Member]
Premiums Written, Net [Abstract]
Direct Premiums Written	229,322,000	245,467,000
Assumed Premiums Written	473,000	(10,397,000)
Ceded Premiums Written	(16,089,000)	(27,885,000)
Net premiums written—insurance	213,706,000	207,185,000
Premiums Earned, Net [Abstract]
Direct Premiums Earned	221,959,000	207,940,000
Assumed Premiums Earned	2,147,000	2,211,000
Ceded Premiums Earned	(18,441,000)	(17,563,000)
Net premiums earned-insurance	205,665,000	192,588,000
Initial Quota Share Reinsurance Transaction [Member] | Radian Guaranty [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
First Lien Primary Mortgage Insurance Risk In Force Ceded	1,300,000,000
Premiums Written, Net [Abstract]
Ceded Premiums Written	(5,304,000)	(6,122,000)
Premiums Earned, Net [Abstract]
Ceded Premiums Earned	(6,807,000)	(7,833,000)
Initial Quota Share Reinsurance Transaction [Member] | Radian Guaranty [Member] | Maximum [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
First Lien Primary Mortgage Insurance Risk In Force Ceded	1,600,000,000
Second Quota Share Reinsurance Transaction [Member] | Radian Guaranty [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
First Lien Primary Mortgage Insurance Risk In Force Ceded	1,400,000,000
Premiums Written, Net [Abstract]
Ceded Premiums Written	(7,293,000)	(16,440,000)
Premiums Earned, Net [Abstract]
Ceded Premiums Earned	$ (6,585,000)	$ (2,838,000)