Note 16 - Statutory Information Risk To Capital Calculation (Details) $ in Millions		1 Months Ended
		Jun. 30, 2016 USD ($) state	Dec. 31, 2015 USD ($)
Risk to Capital Line Items [Line Items]
Risk To Capital Ratio, Regulatory Maximum		25
Radian Guaranty
Risk to Capital Line Items [Line Items]
RIF, net (1)	[1]	$ 34,028.0	$ 36,396.1
Common stock and paid-in capital		2,041.5	2,041.4
Surplus Notes		0.0	325.0
Unassigned earnings (deficit)		(653.6)	(679.9)
Statutory policyholders’ surplus		1,387.9	1,686.5
Contingency reserve		1,051.1	860.9
Statutory capital		$ 2,439.0	$ 2,547.4
Risk-to-capital		14.0	14.3
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
Non RBC States [Member] | Minimum [Member]
Risk to Capital Line Items [Line Items]
Capital Required for Capital Adequacy		$ 1.0
Non RBC States [Member] | Maximum [Member]
Risk to Capital Line Items [Line Items]
Capital Required for Capital Adequacy		5.0
Reportable Legal Entities [Member] | Radian Guaranty
Risk to Capital Line Items [Line Items]
Repayments of Notes Payable		$ 325.0

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