Note 5 - Investments Schedule of Contractual Maturities (Details) - USD ($) $ in Thousands		24 Months Ended	42 Months Ended
		Jun. 30, 2015	Jun. 30, 2015	Aug. 29, 2017	Dec. 31, 2014
Available-for-sale Securities, Amortized Cost
Available-for-sale Debt Securities, Amortized Cost Basis		$ 1,196,446	$ 1,196,446		$ 528,660
Available-for-sale Securities, Fair Value
Available-for-sale Securities, Debt Securities		1,178,842	1,178,842		536,890
Debt Securities
Available-for-sale Securities, Amortized Cost
Available-for-sale Debt Securities, Amortized Cost Basis		1,196,446	1,196,446
Available-for-sale Securities, Fair Value
Available-for-sale Securities, Debt Securities		1,178,842	1,178,842
Non Asset Backed Security Investments, Contractual Maturities
Available-for-sale Securities, Amortized Cost
Due in one year or less	[1]	7,381	7,381
Due after one year through five years	[1]	51,208	51,208
Due after five years through ten years	[1]	345,233	345,233
Due after ten years	[1]	172,863	172,863
Available-for-sale Securities, Fair Value
Due in one year or less	[1]	7,399	7,399
Due after one year through five years	[1]	51,265	51,265
Due after five years through ten years	[1]	340,126	340,126
Due after ten years	[1]	166,487	166,487
RMBS
Available-for-sale Securities, Amortized Cost
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Amortized Cost Basis	[2]	158,134	158,134
Available-for-sale Securities, Fair Value
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Fair Value	[2]	156,532	156,532
CMBS
Available-for-sale Securities, Amortized Cost
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Amortized Cost Basis	[2]	218,531	218,531
Available-for-sale Securities, Fair Value
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Fair Value	[2]	213,988	213,988
Other ABS
Available-for-sale Securities, Amortized Cost
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Amortized Cost Basis	[2]	243,096	243,096
Available-for-sale Securities, Fair Value
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Fair Value	[2]	243,045	243,045
Mortgage Insurance Segment | 2013 Freddie Mac Agreement [Member] | Minimum [Member] | Scenario, Forecast [Member]
Available-for-sale Securities, Fair Value
Restricted Investments Held as Collateral for Master Transaction Agreement, Net				$ 205,000
Radian Guaranty Inc [Member] | 2013 Freddie Mac Agreement [Member]
Available-for-sale Securities, Fair Value
Restricted Investments Held as Collateral for Master Transaction Agreement, Net		210,300	210,300		$ 209,300
Primary Mortgage Product [Member] | First Lien Position [Member] | Mortgage Insurance Segment | 2013 Freddie Mac Agreement [Member]
Available-for-sale Securities, Fair Value
Final Loss Mitigation Activity		$ 128,000
Not Final Loss Mitigation Activity			$ 13,000

[1] Actual maturities may differ as a result of calls before scheduled maturity.

[2] RMBS, CMBS, and Other ABS are shown separately, as they are not due at a single maturity date.