Note 5 - Fair Value of Financial Instruments Impact of Non-Performance Risk on Fair Value Disclosure (Details) (USD $)	12 Months Ended
	Dec. 31, 2013 basispoint		Dec. 31, 2012 basispoint		Dec. 31, 2011 basispoint	Dec. 31, 2010 basispoint
Five Year CDS Spread Details [Abstract]
Derivative Liability, Fair Value, Gross Liability	$ 445,100,000		$ 800,900,000
Derivative Credit Risk Valuation Adjustment, Derivative Liabilities	209,900,000		615,600,000
Derivative liabilities, net	235,200,000		185,300,000
VIE debt - at fair value	94,645,000		108,858,000		228,240,000
Fair Value Inputs [Abstract]
Number of Financial Guarantee Insurance Contracts That Require Posting of Collateral	4
Variable Interest Entity Other Assets	92,023,000		99,337,000
Variable Interest Entity Accounts Payable And Other Liabilities	254,000		366,000
Fair Value, Concentration of Risk, Market Risk Management, Additional Details [Member]
Five Year CDS Spread Details [Abstract]
Radian Group's five year CDS Spread (in basis points)	323		913		2,732	465
Number of Years for CDS Spread Related to Non Performance Risk In Fair Value Disclosure	5 years
Market View Of The Probability That Registrant Will Default In The Next Five Years	22.90%		47.70%
Number Of Years In Which The Market Believes Radian Group Will Default	5 years
Change in Impact of Non Performance Risk on Fair Value of Financial Instruments	405,700,000
Corporate Collateralized Debt Obligations [Member]
Five Year CDS Spread Details [Abstract]
Derivative Liability, Fair Value, Gross Liability	30,400,000		98,800,000
Derivative Credit Risk Valuation Adjustment, Derivative Liabilities	29,000,000		101,600,000
Derivative liabilities, net	1,400,000		(2,800,000)
Non Corporate Collateralized Debt Obligations And Other Derivative Transactions [Member]
Five Year CDS Spread Details [Abstract]
Derivative Liability, Fair Value, Gross Liability	409,700,000	[1]	689,100,000	[1]
Derivative Credit Risk Valuation Adjustment, Derivative Liabilities	178,700,000	[1]	509,300,000	[1]
Derivative liabilities, net	231,000,000	[1]	179,800,000	[1]
NIMS Related [Member]
Five Year CDS Spread Details [Abstract]
Derivative Liability, Fair Value, Gross Liability	5,000,000	[2]	13,000,000	[2]
Derivative Credit Risk Valuation Adjustment, Derivative Liabilities	2,200,000	[2]	4,700,000	[2]
Derivative liabilities, net	2,800,000	[2]	8,300,000	[2]
Consolidated Financial Guaranty Insurance Contracts [Member] | Fair Value, Inputs, Level 3
Five Year CDS Spread Details [Abstract]
VIE debt - at fair value	91,800,000
Fair Value Inputs [Abstract]
Maximum exposure (1)	109,300,000
Variable Interest Entity Other Assets	91,900,000
Variable Interest Entity Accounts Payable And Other Liabilities	$ 100,000
Collateralized Debt Obligations [Member]
Fair Value Inputs [Abstract]
Percent of Aggregate Net Par Outstanding for Corporate CDOs Whose Contractual Premiums are Subject to Change Due to Right of Termination	88.00%
Percent of Aggregate Net Par Outstanding Corporate CDOs Subject to Termination With Fair Value Cap	8.00%
Percent of Aggregate Net Par Outstanding for Non Corporate CDOs Whose Contractual Premiums are Subject to Change Due to Right of Termination	86.00%
Percent of Aggregate Net Par Outstanding Non Corporate CDOs Subject to Termination With Fair Value Cap	26.00%

[1] Includes the net fair value liability recorded within derivative assets and derivative liabilities and the net fair value liabilities included in our consolidated VIEs.

[2] Includes NIMS VIE debt and NIMS derivative assets.