Note 20 - Quarterly Financial Data (Details) (USD $) Share data in Thousands, except Per Share data, unless otherwise specified	12 Months Ended			3 Months Ended																12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Quarterly Financial Data (Unaudited) [Member]		Sep. 30, 2012 Quarterly Financial Data (Unaudited) [Member]		Jun. 30, 2012 Quarterly Financial Data (Unaudited) [Member]		Mar. 31, 2012 Quarterly Financial Data (Unaudited) [Member]		Dec. 31, 2011 Quarterly Financial Data (Unaudited) [Member]		Sep. 30, 2011 Quarterly Financial Data (Unaudited) [Member]		Jun. 30, 2011 Quarterly Financial Data (Unaudited) [Member]		Mar. 31, 2011 Quarterly Financial Data (Unaudited) [Member]		Dec. 31, 2012 Quarterly Financial Data (Unaudited) [Member]		Dec. 31, 2011 Quarterly Financial Data (Unaudited) [Member]
Net premiums earned-insurance	$ 738,982,000	$ 756,025,000	$ 825,733,000	$ 193,875,000		$ 190,963,000		$ 186,779,000		$ 167,365,000		$ 184,413,000		$ 179,655,000		$ 188,934,000		$ 203,023,000		$ 738,982,000		$ 756,025,000
Net investment income	114,337,000	163,520,000	178,760,000	23,112,000		25,635,000		30,877,000		34,713,000		38,694,000		38,763,000		43,823,000		42,240,000		114,337,000		163,520,000
(Loss) Gain on Investments	184,888,000	202,177,000	139,944,000	6,351,000	[1]	84,659,000	[1]	26,419,000	[1]	67,459,000	[1]	38,866,000	[1]	81,640,000	[1]	44,236,000	[1]	37,435,000	[1]	184,888,000	[1]	202,177,000	[1]
Net impairment losses recognized in earnings	(3,000)	(1,202,000)	(90,000)
Change in fair value of derivative instruments	(144,025,000)	628,395,000	(558,712,000)	2,912,000	[2]	(41,056,000)	[2]	(33,124,000)	[2]	(72,757,000)	[2]	69,769,000	[2]	126,008,000	[2]	188,726,000	[2]	243,892,000	[2]	(144,025,000)	[2]	628,395,000	[2]
Net (losses) gains on other financial instruments	(82,269,000)	193,329,000	(211,681,000)	(1,815,000)	[3]	(740,000)	[3]	(61,862,000)	[3]	(17,852,000)	[3]	32,429,000	[3]	80,602,000	[3]	5,047,000	[3]	75,251,000	[3]	(82,269,000)	[3]	193,329,000	[3]
Gain on sale of affiliate	7,708,000	0	34,815,000
Provision for losses	959,171,000	1,296,521,000	1,739,244,000	305,797,000	[4]	176,352,000	[4]	210,868,000	[4]	266,154,000	[4]	355,984,000	[4]	249,598,000	[4]	263,566,000	[4]	427,373,000	[4]	959,171,000	[4]	1,296,521,000	[4]
Change in reserve for premium deficiency	41,000	(7,092,000)	(14,621,000)									(665,000)		(1,942,000)		(3,102,000)		(1,383,000)				(7,092,000)
Policy Acquisition Amortization Expense And Other Operating Expenses				65,994,000		63,356,000		50,998,000		78,200,000		51,193,000		56,689,000		60,341,000		60,350,000		258,548,000		228,573,000
Equity in net (loss) income of affiliates	(13,000)	65,000	14,668,000
Net (loss) income	(451,468,000)	302,150,000	(1,805,867,000)	(177,302,000)	[5]	14,325,000	[5]	(119,259,000)	[5]	(169,232,000)	[5]	(121,539,000)	[5]	183,568,000	[5]	137,115,000	[5]	103,006,000	[5]	(451,468,000)	[5]	302,150,000	[5]
Diluted net (loss) income per share	$ (3.41)	$ 2.26	$ (15.74)	$ (1.34)	[6],[7]	$ 0.11	[6],[7]	$ (0.90)	[6],[7]	$ (1.28)	[6],[7]	$ (0.92)	[6],[7]	$ 1.37	[6],[7]	$ 1.03	[6],[7]	$ 0.77	[6],[7]	$ (3.41)	[6],[7]	$ 2.26	[6],[7]
Weighted-average number of common and common equivalent shares outstanding—diluted	132,533	133,863	114,697	132,525	[7]	134,033	[7]	132,346	[7]	132,465	[7]	133,463	[7]	133,513	[7]	133,614	[7]	133,703	[7]	132,533	[7]	133,863	[7]
Valuation Allowance, Deferred Tax Asset, Change in Amount	$ 192,000,000

[1] The 2012 and 2011 periods reflect realized gains and losses on investments in connection with the continued reallocation of our investment portfolio and unrealized gains and losses on our trading securities.

[2] The change in fair value of derivative instruments for 2012 and 2011 reflects the volatility in the cumulative unrealized (loss) gain attributable to the market’s perception of our non-performance risk as a result of the changes in our CDS spread during both years. There was minimal spread tightening in the fourth quarter of 2012.

[3] The 2012 and 2011 periods primarily reflect fair value gains and losses on our VIE debt.

[4] The results for the fourth quarter of 2012 include the effects of an increase in our IBNR reserve estimate. The provision for losses in the fourth quarter of 2011 was primarily driven by reserves established on new default notices, which increased consistent with seasonal trends.

[5] Net income in the third quarter of 2012 reflects increased gains on investments and a decline in the provision for losses in our mortgage insurance segment. The net loss for the fourth quarter of 2011 was primarily due to an increase in both the mortgage insurance and financial guaranty provision for losses.

[6] Net (loss) income per share is computed independently for each period presented. Consequently, the sum of the quarters may not equal the total net (loss) income per share for the year.

[7] Diluted net (loss) income per share and average shares outstanding per the accounting standard regarding earnings per share.