Note 14 - Statutory Information Statutory Information (Details) (USD $)	12 Months Ended			1 Months Ended
	Dec. 31, 2013	Dec. 31, 2014 years	Dec. 31, 2012	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2012	Dec. 31, 2015
Statutory Accounting Practices [Line Items]
Restricted Cash and Cash Equivalents		2,200,000,000
Additional Risk And Capital Information
Cash Dividends Paid to Parent Company by Consolidated Subsidiaries	7,600,000
Differences Between GAAP Basis and STAT Basis [Member]
STAT Accounting Information [Abstract]
Mortgage Guaranty Insurance Companies Are Required Each Year To Establish A Contingency Reserve Equal To This Percentage Of Premiums Earned In Such Year		50.00%
Number Of Years A Fifty Percent Contingency Reserve Is Required To Be Maintained		10
Mortgage Guaranty Insurance Companies Contingency Reserve May Be Reduced With Regulatory Approval To The Extent That Losses In Any Calendar Year Exceed This Percentage Of Earned Premiums For Such Year		35.00%
PENNSYLVANIA
Additional Risk And Capital Information
Policyholder Dividends, Rate on Policy Earnings		10.00%
New York State Division of Taxation and Finance [Member]
STAT Accounting Information [Abstract]
For Financial Guaranty Policies, Each Insurer Must Establish A Contingency Reserve Equal To The Greater Of This Percentage Of Premiums Written Or A Stated Percentage Of The Principal Guaranteed		50.00%
Range Of Years The Contingency Reserve Must Be Maintained, Low End		15 years
Range Of Years The Contingency Reserve Must Be Maintained, High End		20 years
Radian Guaranty [Member]
Statutory Accounting Practices [Line Items]
Statutory Unassigned Negative Surplus	623,100,000	715,700,000
Statutory policyholders’ surplus	1,317,800,000	1,325,200,000	926,000,000
Statutory contingency reserve	23,000,000	389,400,000	0
STAT Accounting Information [Abstract]
Statutory Accounting Practices, Statutory Net Income Amount	(23,800,000)	273,700,000	(175,900,000)
Radian Guaranty [Member] | Scenario, Forecast [Member]
STAT Accounting Information [Abstract]
Statutory Accounting Practices, Statutory Amount Available for Dividend Payments							0
Radian Guaranty Reinsurance Inc [Member]
Statutory Accounting Practices [Line Items]
Income Tax Examination, Amount Indemnified Under Agreement Related to Deficiency Amounts		163,000,000
Statutory Unassigned Negative Surplus	360,700,000	341,200,000
Statutory policyholders’ surplus	59,300,000	78,800,000	42,300,000
Statutory contingency reserve	38,500,000	81,400,000	0
Additional Risk And Capital Information
Required statutory surplus		20,000,000
STAT Accounting Information [Abstract]
Statutory Accounting Practices, Statutory Net Income Amount	55,500,000	62,500,000	16,000,000
Radian Guaranty Reinsurance Inc [Member] | Scenario, Forecast [Member]
STAT Accounting Information [Abstract]
Statutory Accounting Practices, Statutory Amount Available for Dividend Payments							0
Radian Insurance [Member]
Statutory Accounting Practices [Line Items]
Statutory Unassigned Negative Surplus	305,000,000	279,500,000
Statutory policyholders’ surplus	230,800,000	256,300,000	218,600,000
Statutory contingency reserve	35,500,000	46,700,000	20,600,000
Additional Risk And Capital Information
Required statutory surplus		20,000,000
STAT Accounting Information [Abstract]
Statutory Accounting Practices, Statutory Net Income Amount	26,500,000	32,000,000	58,000,000
Radian Insurance [Member] | Scenario, Forecast [Member]
STAT Accounting Information [Abstract]
Statutory Accounting Practices, Statutory Amount Available for Dividend Payments							0
Radian Mortgage Insurance Inc [Member]
Statutory Accounting Practices [Line Items]
Statutory Unassigned Negative Surplus	69,100,000	46,000,000
Statutory policyholders’ surplus	98,000,000	121,100,000	81,800,000
Statutory contingency reserve	6,900,000	12,600,000	0
Additional Risk And Capital Information
Required statutory surplus		20,000,000
STAT Accounting Information [Abstract]
Statutory Accounting Practices, Statutory Net Income Amount	18,100,000	18,900,000	1,700,000
Radian Mortgage Insurance Inc [Member] | Scenario, Forecast [Member]
STAT Accounting Information [Abstract]
Statutory Accounting Practices, Statutory Amount Available for Dividend Payments							0
Radian Mortgage Assurance [Member]
Statutory Accounting Practices [Line Items]
Risk In Force		0
Statutory Unassigned Negative Surplus	161,000,000	161,500,000
Statutory policyholders’ surplus	18,000,000	17,500,000	18,500,000
Additional Risk And Capital Information
Required statutory surplus		1,125,000
Minimum Statutory Surplus Committed To Be Maintained Each Quarter		5,000,000
STAT Accounting Information [Abstract]
Statutory Accounting Practices, Statutory Net Income Amount	(500,000)	(500,000)	2,000,000
Radian Mortgage Assurance [Member] | Scenario, Forecast [Member]
STAT Accounting Information [Abstract]
Statutory Accounting Practices, Statutory Amount Available for Dividend Payments							0
Radian Investor Surety Inc. [Member]
Statutory Accounting Practices [Line Items]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures				20,000,000
Risk In Force		0
Statutory policyholders’ surplus		20,000,000
Radian Asset Assurance [Member]
Statutory Accounting Practices [Line Items]
Statutory policyholders’ surplus	1,198,000,000	1,138,900,000	1,144,100,000
Statutory contingency reserve	264,000,000	189,100,000	300,100,000
Additional Risk And Capital Information
Claims Paying Resources		1,400,000,000
Required statutory surplus		66,400,000
Cash Dividends Paid to Parent Company by Consolidated Subsidiaries				150,000,000	36,000,000	54,000,000
Statutory Minimum Policyholders' Surplus Required For Financial Guaranty Insurers In The State Of New York		65,000,000
Statutory Minimum Policyholders' Surplus Required For Other Lines Of Insurance By The State Of New York		1,400,000
STAT Accounting Information [Abstract]
Statutory Accounting Practices, Statutory Net Income Amount	$ 24,900,000	12,600,000	$ 103,300,000
Radian Asset Assurance [Member] | New York State Department of Financial Services [Member]
Additional Risk And Capital Information
Policyholder Dividends, Rate on Policy Earnings		10.00%
Statutory Accounting Practices, Percent of Statutory Adjusted Net Investment Income Available for Dividend Payments without Regulatory Approval		100.00%
Radian Asset Assurance [Member] | Minimum [Member] | NEW YORK
Additional Risk And Capital Information
Aggregate Risk Limit for Financial Guarantee Insurance Contracts		0.33%
Radian Asset Assurance [Member] | Maximum [Member] | NEW YORK
Additional Risk And Capital Information
Aggregate Risk Limit for Financial Guarantee Insurance Contracts		4.00%