Note 1 - Condensed Consolidated Financial Statements - Basis of Presentation and Business Overview Capital and Liquidity (Details) (USD $) Share data in Thousands, except Per Share data, unless otherwise specified	9 Months Ended			1 Months Ended		1 Months Ended	76 Months Ended						1 Months Ended	9 Months Ended				9 Months Ended
	Sep. 30, 2014 segment	Sep. 30, 2013	Sep. 30, 2014 Senior Notes Due 2019 [Member]	Jun. 30, 2014 Senior Notes Due 2015	Sep. 30, 2014 Mortgage Insurance Segment	Jul. 31, 2014 Radian Asset Assurance [Member]	Sep. 30, 2014 Radian Asset Assurance [Member]	Dec. 31, 2013 Radian Asset Assurance [Member]	Sep. 30, 2014 Parent Company	Sep. 30, 2014 Minimum [Member]	Sep. 30, 2014 Maximum [Member]	Sep. 30, 2014 Less Than [Member] Mortgage Insurance Segment	May 31, 2014 Common Stock	Sep. 30, 2014 Common Stock	Sep. 30, 2014 State Insurance Regulations [Member] Mortgage Insurance Segment state	Sep. 30, 2014 Non RBC States [Member] Minimum [Member]	Sep. 30, 2014 Non RBC States [Member] Maximum [Member]	Sep. 30, 2014 Primary Mortgage Product [Member] Mortgage Insurance Segment	Sep. 30, 2014 Bank of America Settlement Agreement [Member] Mortgage Insurance Segment servicers
Basis of Presentation and Business Overview [Line Items]
Equity Method Investment, Ownership Percentage										20.00%	50.00%
Business Overview [Abstract]
Number of Operating Segments	3
Mortgage Insurance [Abstract]
Private Mortgage Insurance Protects Lenders For Loans Made With This Maximum Downpayment Percentage					20.00%
Percentage Of Primary Insurance On Domestic First-Lien Mortgages To Total Risk In Force					96.50%
First Lien Primary Mortgage Insurance Risk In Force					$ 44,000,000,000
Percentage Of Pool Insurance On Domestic First-Lien Mortgages To Total Risk In Force					3.30%
NonTraditional Risk In Force					79,900,000
Percentage Of Non-Traditional RIF To Total RIF												1.00%
BAC Settlement Agreement [Abstract]
Number of Servicers With Which the Entity is in Settlement Discussions With																			1
Loss Contingency, Settlement Agreement, Percentage of Subject Loans Not Held by Insureds or Are Non-GSE Investors																			12.00%
Business Conditions [Abstract]
Percentage of Legacy Portfolio Risk in Force to Total Risk in Force					33.00%
Percentage of Portfolio Risk in Force Originated Since 2009 to Total Risk in Force					67.00%
Percentage Decrease In New Defaults																		20.00%
Maximum Loan To Value Percentage For G.S.E. Acquired Loans					80.00%
Minimum Percentage Of The Loans In Excess Of An 80% L.T.V. Which Must Be Retained By The Mortgage Originator Or Seller					10.00%
Number of Days Until Eligibility Requirements Become Effective After Final Publication	180 days
Transition Period for Compliance to New Eligibility Requirements	2 years
Number Of States That Have A Statutory Or Regulatory Risk Based Capital Requirement															16
Risk To Capital Ratio, Regulatory Maximum	25
Capital Required for Capital Adequacy																1,000,000	5,000,000
Capital and Liquidity
Percentage Reduction Of Net Par Outstanding							83.00%
Net Par Outstanding							19,400,000,000
Statutory Accounting Practices, Dividends Paid with Approval of Regulatory Agency						150,000,000
Statutory capital							1,033,100,000	1,198,000,000
Proceeds from Issuance of Debt			293,800,000
Common Stock, Shares, Issued													17,825
Shares Issued, Price Per Share													$ 14.50
Issuance of common stock	247,188,000	299,410,000												247,200,000
Extinguishment of Debt, Amount				54,500,000
Repayments of Long-term Debt	57,223,000	79,372,000		57,200,000
Gains (Losses) on Extinguishment of Debt				(2,800,000)
Unrestricted Cash And Liquid Investments Including Activity After The Balance Sheet Date									$ 762,000,000