Note 13 - Statutory Information Risk To Capital Calculation (Details) $ in Millions		6 Months Ended	12 Months Ended
		Jun. 30, 2015 USD ($) state	Dec. 31, 2014 USD ($)
Risk to Capital Line Items [Line Items]
Risk To Capital Ratio, Regulatory Maximum		25
Radian Guaranty [Member]
Risk to Capital Line Items [Line Items]
Percentage of New Insurance Written Attributable To States With Statutory Or Regulatory Risk Based Capital Requirements		56.00%	56.00%
Risk In Force	[1]	$ 32,290.6	$ 30,615.7
Statutory capital		1,367.0	1,325.2
Contingency reserve		592.7	389.4
Statutory Accounting Practice, Statutory Position		$ 1,959.7	$ 1,714.6
Risk-to-capital		16.5	17.9
Statutory Accounting Practices, Statutory Net Income Amount		$ 295.7
Mortgage Insurance Segment | State Insurance Regulations [Member]
Risk to Capital Line Items [Line Items]
Number Of States That Have A Statutory Or Regulatory Risk Based Capital Requirement | state		16
Minimum [Member] | Non RBC States [Member]
Risk to Capital Line Items [Line Items]
Capital Required for Capital Adequacy		$ 1.0
Maximum [Member] | Non RBC States [Member]
Risk to Capital Line Items [Line Items]
Capital Required for Capital Adequacy		$ 5.0

[1] Excludes risk ceded through reinsurance contracts (to third parties and affiliates) and RIF on defaulted loans.