Note 8 - Reinsurance Reinsurance Text (Details) (USD $)	12 Months Ended						1 Months Ended		3 Months Ended	1 Months Ended	3 Months Ended	1 Months Ended	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Mortgage Insurance and Financial Guarantee Contracts [Member]	Dec. 31, 2012 Mortgage Insurance and Financial Guarantee Contracts [Member]	Dec. 31, 2011 Mortgage Insurance and Financial Guarantee Contracts [Member]	Jan. 31, 2012 January 2012 Assured Guaranty Ceded Public Finance Transaction [Member] Radian Asset Assurance [Member]	Dec. 31, 2013 January 2012 Assured Guaranty Ceded Public Finance Transaction [Member] Radian Asset Assurance [Member]	Mar. 31, 2012 January 2012 Assured Guaranty Transaction [Member] Radian Asset Assurance [Member]	Jan. 31, 2013 Reinsurance [Member] 2012 FGIC Commutation [Member] Radian Asset Assurance [Member]	Mar. 31, 2013 Reinsurance [Member] 2012 FGIC Commutation [Member] Radian Asset Assurance [Member]	Jan. 31, 2012 Reinsurance [Member] January 2012 Assured Guaranty Reinsurance Commutation [Member] Radian Asset Assurance [Member]	Dec. 31, 2013 Mortgage Insurance Segment	Dec. 31, 2012 Mortgage Insurance Segment	Dec. 31, 2011 Mortgage Insurance Segment	Dec. 31, 2013 Mortgage Insurance Segment Radian Guaranty [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Risk To Capital Ratio, Regulatory Maximum																25.00%
Reduction In Net Par Outstanding							$ 1,800,000,000			$ 822,200,000		$ 13,800,000,000
Ceded Net Par Outstanding								1,100,000,000
Prepaid Reinsurance Premiums				74,700,000	64,500,000
Premiums Written, Net [Abstract]
Direct Premiums Written	1,033,421,000	892,983,000	755,758,000	1,033,421,000	892,983,000	755,758,000
Assumed Premiums Written	(11,183,000)	(88,991,000)	(11,162,000)	(11,183,000)	(88,991,000)	(11,162,000)					(12,600,000)
Ceded Premiums Written	(81,421,000)	(117,362,000)	(37,349,000)	(81,421,000)	(117,362,000)	(37,349,000)
Net premiums written—insurance	940,817,000	686,630,000	707,247,000	940,817,000	686,630,000	707,247,000			(119,800,000)				950,998,000	806,305,000	717,264,000
Premiums Earned, Net [Abstract]
Direct Premiums Earned	890,487,000	796,253,000	762,428,000	890,487,000	796,253,000	762,428,000
Assumed Premiums Earned	12,508,000	(3,571,000)	32,337,000	12,508,000	(3,571,000)	32,337,000					(2,500,000)
Ceded Premiums Earned	(72,101,000)	(53,700,000)	(38,740,000)	(72,101,000)	(53,700,000)	(38,740,000)
Net premiums earned-insurance	$ 830,894,000	$ 738,982,000	$ 756,025,000	$ 830,894,000	$ 738,982,000	$ 756,025,000			$ (22,200,000)				$ 781,420,000	$ 702,385,000	$ 680,895,000