Note 5 - Investments Schedule of Contractual Maturities (Details) - USD ($) $ in Thousands		Jun. 30, 2016	Dec. 31, 2015
Available-for-sale Securities, Amortized Cost
Available-for-sale Debt Securities, Amortized Cost Basis		$ 2,614,680	$ 1,893,356
Available-for-sale Securities, Fair Value
Available-for-sale Securities, Debt Securities		2,711,395	1,865,461
Debt Securities
Available-for-sale Securities, Amortized Cost
Available-for-sale Debt Securities, Amortized Cost Basis		2,614,680
Available-for-sale Securities, Fair Value
Available-for-sale Securities, Debt Securities		2,711,395
Non Asset Backed Security Investments, Contractual Maturities
Available-for-sale Securities, Amortized Cost
Due in one year or less	[1]	25,974
Due after one year through five years	[1]	289,287
Due after five years through ten years	[1]	670,894
Due after ten years	[1]	389,764
Available-for-sale Securities, Fair Value
Due in one year or less	[1]	25,768
Due after one year through five years	[1]	295,684
Due after five years through ten years	[1]	700,619
Due after ten years	[1]	427,840
RMBS
Available-for-sale Securities, Amortized Cost
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Amortized Cost Basis	[2]	316,533
Available-for-sale Securities, Fair Value
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Fair Value	[2]	323,980
CMBS
Available-for-sale Securities, Amortized Cost
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Amortized Cost Basis	[2]	485,693
Available-for-sale Securities, Fair Value
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Fair Value	[2]	501,811
Other ABS
Available-for-sale Securities, Amortized Cost
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Amortized Cost Basis	[2]	436,535
Available-for-sale Securities, Fair Value
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Fair Value	[2]	435,693
2013 Freddie Mac Agreement [Member] | Radian Guaranty Inc [Member]
Available-for-sale Securities, Fair Value
Restricted Investments Held as Collateral for Master Transaction Agreement, Net		$ 75,400	$ 74,700

[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.