Note 13 - Statutory Information Statutory Information (Details) (USD $)		6 Months Ended		12 Months Ended			1 Months Ended	6 Months Ended		1 Months Ended	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2013 Radian Guaranty [Member]		Dec. 31, 2012 Radian Guaranty [Member]		Jun. 30, 2013 Radian Asset Assurance [Member]	Jul. 31, 2014 Radian Asset Assurance [Member] Scenario, Forecast [Member]	Jun. 30, 2013 Parent Company	Jun. 30, 2013 State Insurance Regulations [Member] Mortgage Insurance Segment state	Jul. 31, 2013 Subsequent Event [Member] Radian Asset Assurance [Member]	Jun. 30, 2013 Corporate Expenses and Interest Payments Due in Current Year [Member] Parent Company	Jun. 30, 2013 Primary Mortgage Product [Member] Mortgage Insurance Segment Radian Guaranty [Member]
Statutory Accounting Practices [Line Items]
Number Of States That Have A Statutory Or Regulatory Risk Based Capital Requirement									16
Risk To Capital Ratio, Regulatory Maximum									0.25
Percentage of New Insurance Written Attributable To States With Statutory Or Regulatory Risk Based Capital Requirements												55.20%
Unrestricted Cash and Liquid Investments								$ 918,600,000
Statutory net income (loss)		900,000		(175,900,000)
Statutory Accounting Practices, Statutory Capital and Surplus, Balance		1,135,900,000		926,000,000		1,200,000,000
Contingency Reserve		19,700,000		0
Statutory Accounting Practices, Statutory Policyholders' Surplus Plus Contingency Reserves		1,155,600,000		926,000,000
Net Risk In Force		22,741,900,000	[1]	19,226,700,000	[1]
Risk To Capital Ratio		0.197		0.208
Risk to Capital, Entity's Intended Maximum		0.20
Capital Contributions		115,000,000
Claims Paying Resources						1,600,000,000
Payment of Dividend by Subsidiary to Parent							40,000,000			36,000,000
Restricted Cash and Cash Equivalents	1,100,000,000
Proceeds from Contributions from Affiliates								102,600,000			14,300,000
Unrestricted Cash and Liquid Investments Net of Subsidiaries Prepaid Corporate Expenses								$ 816,000,000

[1] RIF, net excludes risk ceded through reinsurance contracts and RIF on defaulted loans.