Note 5 - Fair Value of Financial Instruments Fair Value, Option, Quantitative Disclosures (Details) (USD $)	Dec. 31, 2012 contract	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Consolidated Financial Guaranty Insurance Contracts [Member]	Dec. 31, 2011 Consolidated Financial Guaranty Insurance Contracts [Member]	Dec. 31, 2012 Consolidated Financial Guaranty Insurance Contracts [Member] Fair Value, Inputs, Level 3	Dec. 31, 2012 NIMS VIEs [Member]	Dec. 31, 2011 NIMS VIEs [Member]	Dec. 31, 2012 Other investments Discounted Cash Flow Valuation Technique [Member] Fair Value, Inputs, Level 3		Dec. 31, 2012 US States and Political Subdivisions Debt Securities [Member] Discounted Cash Flow Valuation Technique [Member] Fair Value, Inputs, Level 3		Dec. 31, 2012 Collateralized Debt Obligation of Commercial Mortgage Backed Securities [Member] Discounted Cash Flow Valuation Technique [Member] Fair Value, Inputs, Level 3		Dec. 31, 2012 TruPs Collateralized Debt Obligation [Member] Discounted Cash Flow Valuation Technique [Member] Fair Value, Inputs, Level 3		Dec. 31, 2012 NIMS derivative assets Discounted Cash Flow Valuation Technique [Member] Fair Value, Inputs, Level 3		Dec. 31, 2012 TruPs Collateralized Debt Obligations and TruPs-Related VIE Liabilitie [Member] Discounted Cash Flow Valuation Technique [Member] Fair Value, Inputs, Level 3		Dec. 31, 2012 Non Corporate Collateralized Debt Obligations And Other Derivative Transactions [Member] Risk-Based Model Valuation Technique [Member] Fair Value, Inputs, Level 3		Dec. 31, 2012 NIMS VIEs [Member] Discounted Cash Flow Valuation Technique [Member] Fair Value, Inputs, Level 3		Dec. 31, 2012 Corporate collateralized debt obligations (CDO's)[Member] Base Correlation Model Valuation Technique [Member] Fair Value, Inputs, Level 3		Dec. 31, 2012 Maximum [Member] Collateralized Debt Obligation of Commercial Mortgage Backed Securities [Member] Discounted Cash Flow Valuation Technique [Member] Fair Value, Inputs, Level 3		Dec. 31, 2012 Maximum [Member] TruPs Collateralized Debt Obligation [Member] Discounted Cash Flow Valuation Technique [Member] Fair Value, Inputs, Level 3		Dec. 31, 2012 Maximum [Member] TruPs Collateralized Debt Obligations and TruPs-Related VIE Liabilitie [Member] Discounted Cash Flow Valuation Technique [Member] Fair Value, Inputs, Level 3		Dec. 31, 2012 Maximum [Member] Non Corporate Collateralized Debt Obligations And Other Derivative Transactions [Member] Risk-Based Model Valuation Technique [Member] Fair Value, Inputs, Level 3		Sep. 30, 2012 Maximum [Member] Non Corporate Collateralized Debt Obligations And Other Derivative Transactions [Member] Risk-Based Model Valuation Technique [Member] Fair Value, Inputs, Level 3	Dec. 31, 2012 Maximum [Member] NIMS VIEs [Member] Discounted Cash Flow Valuation Technique [Member] Fair Value, Inputs, Level 3		Dec. 31, 2012 Maximum [Member] Corporate collateralized debt obligations (CDO's)[Member] Base Correlation Model Valuation Technique [Member] Fair Value, Inputs, Level 3		Dec. 31, 2012 Minimum [Member] Collateralized Debt Obligation of Commercial Mortgage Backed Securities [Member] Discounted Cash Flow Valuation Technique [Member] Fair Value, Inputs, Level 3		Dec. 31, 2012 Minimum [Member] TruPs Collateralized Debt Obligation [Member] Discounted Cash Flow Valuation Technique [Member] Fair Value, Inputs, Level 3		Dec. 31, 2012 Minimum [Member] TruPs Collateralized Debt Obligations and TruPs-Related VIE Liabilitie [Member] Discounted Cash Flow Valuation Technique [Member] Fair Value, Inputs, Level 3		Dec. 31, 2012 Minimum [Member] Non Corporate Collateralized Debt Obligations And Other Derivative Transactions [Member] Risk-Based Model Valuation Technique [Member] Fair Value, Inputs, Level 3		Dec. 31, 2012 Minimum [Member] NIMS VIEs [Member] Discounted Cash Flow Valuation Technique [Member] Fair Value, Inputs, Level 3		Dec. 31, 2012 Minimum [Member] Corporate collateralized debt obligations (CDO's)[Member] Base Correlation Model Valuation Technique [Member] Fair Value, Inputs, Level 3		Dec. 31, 2012 Weighted Average [Member] Other investments Discounted Cash Flow Valuation Technique [Member] Fair Value, Inputs, Level 3	Dec. 31, 2012 Weighted Average [Member] US States and Political Subdivisions Debt Securities [Member] Discounted Cash Flow Valuation Technique [Member] Fair Value, Inputs, Level 3	Dec. 31, 2012 Weighted Average [Member] TruPs Collateralized Debt Obligation [Member] Discounted Cash Flow Valuation Technique [Member] Fair Value, Inputs, Level 3	Dec. 31, 2012 Weighted Average [Member] NIMS derivative assets Discounted Cash Flow Valuation Technique [Member] Fair Value, Inputs, Level 3	Dec. 31, 2012 Weighted Average [Member] TruPs Collateralized Debt Obligations and TruPs-Related VIE Liabilitie [Member] Discounted Cash Flow Valuation Technique [Member] Fair Value, Inputs, Level 3	Dec. 31, 2012 Weighted Average [Member] NIMS VIEs [Member] Discounted Cash Flow Valuation Technique [Member] Fair Value, Inputs, Level 3	Dec. 31, 2012 Weighted Average [Member] Corporate collateralized debt obligations (CDO's)[Member] Base Correlation Model Valuation Technique [Member] Fair Value, Inputs, Level 3	Sep. 30, 2012 Less Than [Member] Minimum [Member] Non Corporate Collateralized Debt Obligations And Other Derivative Transactions [Member] Risk-Based Model Valuation Technique [Member] Fair Value, Inputs, Level 3	Sep. 30, 2012 Less Than [Member] Minimum [Member] Corporate collateralized debt obligations (CDO's)[Member] Base Correlation Model Valuation Technique [Member] Fair Value, Inputs, Level 3	Dec. 31, 2012 Fair Value, Measurements, Recurring		Dec. 31, 2011 Fair Value, Measurements, Recurring		Dec. 31, 2012 Fair Value, Measurements, Recurring Fair Value, Inputs, Level 3		Dec. 31, 2011 Fair Value, Measurements, Recurring Fair Value, Inputs, Level 3		Dec. 31, 2012 Fair Value, Measurements, Recurring Consolidated Financial Guaranty Insurance Contracts [Member] Fair Value, Inputs, Level 3	Dec. 31, 2011 Fair Value, Measurements, Recurring Consolidated Financial Guaranty Insurance Contracts [Member] Fair Value, Inputs, Level 3	Dec. 31, 2012 Fair Value, Measurements, Recurring NIMS VIEs [Member] Fair Value, Inputs, Level 3	Dec. 31, 2011 Fair Value, Measurements, Recurring NIMS VIEs [Member] Fair Value, Inputs, Level 3	Dec. 31, 2012 Fair Value, Measurements, Recurring Other investments		Dec. 31, 2011 Fair Value, Measurements, Recurring Other investments		Dec. 31, 2012 Fair Value, Measurements, Recurring Other investments Fair Value, Inputs, Level 3		Dec. 31, 2011 Fair Value, Measurements, Recurring Other investments Fair Value, Inputs, Level 3		Dec. 31, 2012 Fair Value, Measurements, Recurring US States and Political Subdivisions Debt Securities [Member]	Dec. 31, 2011 Fair Value, Measurements, Recurring US States and Political Subdivisions Debt Securities [Member]	Dec. 31, 2012 Fair Value, Measurements, Recurring US States and Political Subdivisions Debt Securities [Member] Fair Value, Inputs, Level 3	Dec. 31, 2011 Fair Value, Measurements, Recurring US States and Political Subdivisions Debt Securities [Member] Fair Value, Inputs, Level 3
Fair Value, Option, Quantitative Disclosures [Line Items]
Number of Financial Guarantee Insurance Contracts That Require Posting of Collateral	0
Investments, Fair Value Disclosure									$ 78,000,000	[1]	$ 19,000,000	[1]																																																	$ 5,103,000,000	[2]	$ 5,719,900,000	[3]	$ 100,700,000	[2]	$ 164,200,000	[3]					$ 81,500,000	[4]	$ 158,400,000	[5]	$ 79,000,000	[4]	$ 6,800,000	[5]	$ 688,000,000	$ 1,047,500,000	$ 19,000,000	$ 62,500,000
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, Discount Rate																																																				1.90%	8.80%
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, Expected Loss Rate																																																					19.00%
Derivative Assets	13,609,000	17,212,000		0	0		1,585,000	1,602,000					1,600,000	[1]	1,600,000	[1]	1,600,000	[1]							8,800,000	[1]																																			13,600,000		17,200,000		13,600,000		17,000,000
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, Correlation Factor																																																										85.00%
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, CDS Spread Percent																											9.10%	[6]	9.10%	[6]	9.10%	[6]	9.10%	[6]		10.90%	[6]	9.10%	[6]	8.00%	[6]	8.00%	[6]	8.00%	[6]	8.00%	[6]	8.50%	[6]	8.00%	[6]				8.50%
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, Average Credit Spread																																						2.70%																						0.10%
Derivative, Expected Remaining Life																																			20 years																								1 year
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, Correlation Factor Related to Vintage and Credit Rating																											85.00%													72.00%
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, Principal Recovery Rate																																																						65.00%		65.00%
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, Principal Recovery Rate Using Distressed Pricing Scenario																																																						60.00%		60.00%
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, Probability of Paying a Conditional Liquidity Claim																													36.70%		36.70%											0.80%		0.80%
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, NIMS Spread																																																							44.00%		43.70%
Derivative liabilities	266,873,000	126,006,000	723,579,000	70,467,000	19,501,000								76,300,000	[1]							171,800,000	[1]			6,000,000	[1]																																			266,900,000		126,000,000		266,900,000		126,000,000
Derivative Liabilities and Variable Interest Entity, Consolidated, Carrrying Amount, Liabilities																			12,700,000	[1]
VIE debt - at fair value	$ 108,858,000	$ 228,240,000	$ 520,114,000	$ 98,983,000	$ 218,790,000	$ 99,000,000	$ 9,875,000	$ 9,450,000															$ 9,900,000	[1]																																					$ 108,900,000	[7]	$ 228,200,000	[8]	$ 108,900,000	[7]	$ 228,200,000	[8]	$ 99,000,000	$ 218,800,000	$ 9,900,000	$ 9,400,000

[1] Excludes certain assets and liabilities for which we do not develop quantitative unobservable inputs. The fair value estimates for these assets and liabilities are developed using third-party pricing information, generally without adjustment.

[2] Does not include fixed-maturities held to maturity ($0.7 million) and certain other invested assets ($48.7 million), primarily invested in limited partnerships, accounted for as cost-method investments and not measured at fair value.

[3] Does not include fixed-maturities held to maturity ($2.6 million) and other invested assets ($61.0 million), primarily invested in limited partnerships, accounted for as cost-method investments and not measured at fair value.

[4] Comprising TruPs ($0.9 million) and short-term CDs ($1.6 million) included within Level II and lottery annuities ($1.0 million) and a guaranteed investment contract held by a consolidated VIE ($78.0 million) within Level III.

[5] Comprising short-term commercial paper within CPS trusts ($150.0 million) and short-term CDs ($1.6 million ) included within Level II and lottery annuities ($1.6 million) and TruPs held by consolidated VIEs ($5.2 million) included within Level III.

[6] Represents the range of our CDS spread that a typical market participant might use in the valuation analysis based on the remaining term of the investment.

[7] Comprising consolidated debt related to NIMS VIEs ($9.9 million) and amounts related to financial guaranty VIEs ($99.0 million).

[8] Comprising consolidated debt related to NIMS VIEs ($9.4 million) and amounts related to financial guaranty VIEs ($218.8 million).