Note 6 - Investments Investments Trading Securities (Details) (USD $)	3 Months Ended		9 Months Ended			9 Months Ended	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Sep. 30, 2014 Securities (Assets)	Dec. 31, 2013 Securities (Assets)	Sep. 30, 2014 US government and agency securities	Dec. 31, 2013 US government and agency securities	Sep. 30, 2014 State and municipal obligations	Dec. 31, 2013 State and municipal obligations	Sep. 30, 2014 Corporate bonds and notes	Dec. 31, 2013 Corporate bonds and notes	Sep. 30, 2014 RMBS	Dec. 31, 2013 RMBS	Sep. 30, 2014 CMBS	Dec. 31, 2013 CMBS	Sep. 30, 2014 Other ABS	Dec. 31, 2013 Other ABS	Sep. 30, 2014 Foreign government securities	Dec. 31, 2013 Foreign government securities	Sep. 30, 2014 Equity securities	Dec. 31, 2013 Equity securities	Sep. 30, 2014 Other investments	Dec. 31, 2013 Other investments	Sep. 30, 2014 Portugal, Ireland, Italy, Greece, Spain and Hungary Government Securities [Member] Foreign government securities	Dec. 31, 2013 Portugal, Ireland, Italy, Greece, Spain and Hungary Government Securities [Member] Foreign government securities	Sep. 30, 2014 Non European Countries Outside U.S. Under Economic Stress [Member] Foreign government securities	Dec. 31, 2013 Non European Countries Outside U.S. Under Economic Stress [Member] Foreign government securities	Aug. 31, 2013 2013 Freddie Mac Agreement [Member] Mortgage Insurance Segment	Sep. 30, 2014 2013 Freddie Mac Agreement [Member] Mortgage Insurance Segment Primary Mortgage Product [Member] First Lien Position [Member]	Dec. 31, 2013 2013 Freddie Mac Agreement [Member] Mortgage Insurance Segment Primary Mortgage Product [Member] First Lien Position [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Investment Portfolio	$ 4,975,401,000		$ 4,975,401,000		$ 4,931,157,000																					$ 0	$ 0	$ 0	$ 0
Trading Securities	2,479,496,000		2,479,496,000		3,117,429,000			249,102,000	393,815,000	605,255,000	595,070,000	881,362,000	1,024,574,000	221,820,000	487,239,000	272,281,000	288,895,000	136,802,000	195,816,000	23,744,000	40,657,000	88,397,000	90,604,000	733,000	759,000
Trading Securities, Unrealized Holding Gain	(7,663,000)	(12,666,000)	107,865,000	(169,107,000)		87,400,000	(140,900,000)
Restricted Investments Held as Collateral for Master Transaction Agreement, Net																														$ 205,000,000	$ 209,000,000	$ 205,000,000