Note 4 - Fair Value of Financial Instruments Fair Value, Measurement Inputs Disclosure (Details) (USD $)																																																									9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended				9 Months Ended	12 Months Ended													9 Months Ended					9 Months Ended
	Sep. 30, 2014 Corporate collateralized debt obligations (CDO's)[Member]	Sep. 30, 2014 Non Corporate Collateralized Debt Obligations And Other Derivative Transactions [Member]	Sep. 30, 2014 Base Correlation Model Valuation Technique [Member] Corporate collateralized debt obligations (CDO's)[Member] Fair Value, Inputs, Level 3		Dec. 31, 2013 Base Correlation Model Valuation Technique [Member] Corporate collateralized debt obligations (CDO's)[Member] Fair Value, Inputs, Level 3		Sep. 30, 2014 Base Correlation Model Valuation Technique [Member] Minimum [Member] Corporate collateralized debt obligations (CDO's)[Member] Fair Value, Inputs, Level 3		Dec. 31, 2013 Base Correlation Model Valuation Technique [Member] Minimum [Member] Corporate collateralized debt obligations (CDO's)[Member] Fair Value, Inputs, Level 3		Sep. 30, 2014 Base Correlation Model Valuation Technique [Member] Maximum [Member] Corporate collateralized debt obligations (CDO's)[Member] Fair Value, Inputs, Level 3		Dec. 31, 2013 Base Correlation Model Valuation Technique [Member] Maximum [Member] Corporate collateralized debt obligations (CDO's)[Member] Fair Value, Inputs, Level 3		Sep. 30, 2014 Base Correlation Model Valuation Technique [Member] Weighted Average [Member] Corporate collateralized debt obligations (CDO's)[Member] Fair Value, Inputs, Level 3	Dec. 31, 2013 Base Correlation Model Valuation Technique [Member] Weighted Average [Member] Corporate collateralized debt obligations (CDO's)[Member] Fair Value, Inputs, Level 3	Sep. 30, 2014 Discounted Cash Flow Valuation Technique [Member] US States and Political Subdivisions Debt Securities [Member] Fair Value, Inputs, Level 3		Dec. 31, 2013 Discounted Cash Flow Valuation Technique [Member] US States and Political Subdivisions Debt Securities [Member] Fair Value, Inputs, Level 3		Sep. 30, 2014 Discounted Cash Flow Valuation Technique [Member] Other investments Fair Value, Inputs, Level 3		Dec. 31, 2013 Discounted Cash Flow Valuation Technique [Member] Other investments Fair Value, Inputs, Level 3		Sep. 30, 2014 Discounted Cash Flow Valuation Technique [Member] Collateralized Debt Obligation of Commercial Mortgage Backed Securities [Member] Fair Value, Inputs, Level 3		Dec. 31, 2013 Discounted Cash Flow Valuation Technique [Member] Collateralized Debt Obligation of Commercial Mortgage Backed Securities [Member] Fair Value, Inputs, Level 3		Sep. 30, 2014 Discounted Cash Flow Valuation Technique [Member] TruPs Collateralized Debt Obligation [Member] Fair Value, Inputs, Level 3		Dec. 31, 2013 Discounted Cash Flow Valuation Technique [Member] TruPs Collateralized Debt Obligation [Member] Fair Value, Inputs, Level 3		Sep. 30, 2014 Discounted Cash Flow Valuation Technique [Member] TruPs-Related VIE [Member] Fair Value, Inputs, Level 3		Dec. 31, 2013 Discounted Cash Flow Valuation Technique [Member] TruPs-Related VIE [Member] Fair Value, Inputs, Level 3		Sep. 30, 2014 Discounted Cash Flow Valuation Technique [Member] NIMS VIEs [Member] Fair Value, Inputs, Level 3		Dec. 31, 2013 Discounted Cash Flow Valuation Technique [Member] NIMS VIEs [Member] Fair Value, Inputs, Level 3		Sep. 30, 2014 Discounted Cash Flow Valuation Technique [Member] Minimum [Member] Collateralized Debt Obligation of Commercial Mortgage Backed Securities [Member] Fair Value, Inputs, Level 3		Dec. 31, 2013 Discounted Cash Flow Valuation Technique [Member] Minimum [Member] Collateralized Debt Obligation of Commercial Mortgage Backed Securities [Member] Fair Value, Inputs, Level 3		Sep. 30, 2014 Discounted Cash Flow Valuation Technique [Member] Minimum [Member] TruPs Collateralized Debt Obligation [Member] Fair Value, Inputs, Level 3		Dec. 31, 2013 Discounted Cash Flow Valuation Technique [Member] Minimum [Member] TruPs Collateralized Debt Obligation [Member] Fair Value, Inputs, Level 3		Sep. 30, 2014 Discounted Cash Flow Valuation Technique [Member] Maximum [Member] Collateralized Debt Obligation of Commercial Mortgage Backed Securities [Member] Fair Value, Inputs, Level 3		Dec. 31, 2013 Discounted Cash Flow Valuation Technique [Member] Maximum [Member] Collateralized Debt Obligation of Commercial Mortgage Backed Securities [Member] Fair Value, Inputs, Level 3		Sep. 30, 2014 Discounted Cash Flow Valuation Technique [Member] Maximum [Member] TruPs Collateralized Debt Obligation [Member] Fair Value, Inputs, Level 3		Dec. 31, 2013 Discounted Cash Flow Valuation Technique [Member] Maximum [Member] TruPs Collateralized Debt Obligation [Member] Fair Value, Inputs, Level 3		Sep. 30, 2014 Discounted Cash Flow Valuation Technique [Member] Weighted Average [Member] US States and Political Subdivisions Debt Securities [Member] Fair Value, Inputs, Level 3	Dec. 31, 2013 Discounted Cash Flow Valuation Technique [Member] Weighted Average [Member] US States and Political Subdivisions Debt Securities [Member] Fair Value, Inputs, Level 3	Sep. 30, 2014 Discounted Cash Flow Valuation Technique [Member] Weighted Average [Member] Other investments Fair Value, Inputs, Level 3	Dec. 31, 2013 Discounted Cash Flow Valuation Technique [Member] Weighted Average [Member] Other investments Fair Value, Inputs, Level 3	Sep. 30, 2014 Discounted Cash Flow Valuation Technique [Member] Weighted Average [Member] Collateralized Debt Obligation of Commercial Mortgage Backed Securities [Member] Fair Value, Inputs, Level 3	Sep. 30, 2014 Discounted Cash Flow Valuation Technique [Member] Weighted Average [Member] TruPs Collateralized Debt Obligation [Member] Fair Value, Inputs, Level 3	Dec. 31, 2013 Discounted Cash Flow Valuation Technique [Member] Weighted Average [Member] TruPs Collateralized Debt Obligation [Member] Fair Value, Inputs, Level 3	Sep. 30, 2014 Discounted Cash Flow Valuation Technique [Member] Weighted Average [Member] TruPs-Related VIE [Member] Fair Value, Inputs, Level 3	Dec. 31, 2013 Discounted Cash Flow Valuation Technique [Member] Weighted Average [Member] TruPs-Related VIE [Member] Fair Value, Inputs, Level 3	Sep. 30, 2014 Discounted Cash Flow Valuation Technique [Member] Weighted Average [Member] NIMS VIEs [Member] Fair Value, Inputs, Level 3		Dec. 31, 2013 Discounted Cash Flow Valuation Technique [Member] Weighted Average [Member] NIMS VIEs [Member] Fair Value, Inputs, Level 3		Sep. 30, 2014 Risk-Based Model Valuation Technique [Member] Non Corporate Collateralized Debt Obligations And Other Derivative Transactions [Member] Fair Value, Inputs, Level 3		Dec. 31, 2013 Risk-Based Model Valuation Technique [Member] Non Corporate Collateralized Debt Obligations And Other Derivative Transactions [Member] Fair Value, Inputs, Level 3		Sep. 30, 2014 Risk-Based Model Valuation Technique [Member] Minimum [Member] Non Corporate Collateralized Debt Obligations And Other Derivative Transactions [Member] Fair Value, Inputs, Level 3		Dec. 31, 2013 Risk-Based Model Valuation Technique [Member] Minimum [Member] Non Corporate Collateralized Debt Obligations And Other Derivative Transactions [Member] Fair Value, Inputs, Level 3		Sep. 30, 2014 Risk-Based Model Valuation Technique [Member] Maximum [Member] Non Corporate Collateralized Debt Obligations And Other Derivative Transactions [Member] Fair Value, Inputs, Level 3		Sep. 30, 2013 Risk-Based Model Valuation Technique [Member] Maximum [Member] Non Corporate Collateralized Debt Obligations And Other Derivative Transactions [Member] Fair Value, Inputs, Level 3	Dec. 31, 2013 Risk-Based Model Valuation Technique [Member] Maximum [Member] Non Corporate Collateralized Debt Obligations And Other Derivative Transactions [Member] Fair Value, Inputs, Level 3		Sep. 30, 2014 Risk-Based Model Valuation Technique [Member] Less Than [Member] Minimum [Member] Non Corporate Collateralized Debt Obligations And Other Derivative Transactions [Member] Fair Value, Inputs, Level 3	Sep. 30, 2013 Risk-Based Model Valuation Technique [Member] Less Than [Member] Minimum [Member] Non Corporate Collateralized Debt Obligations And Other Derivative Transactions [Member] Fair Value, Inputs, Level 3
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investments, Fair Value Disclosure																	$ 18,600,000	[1]	$ 18,700,000	[1]	$ 82,500,000	[1]	$ 81,000,000	[1]
Fair Value Inputs, Discount Rate																																																									11.80%	12.30%	0.80%	1.20%				7.80%	13.10%
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, Expected Loss Rate																																																									11.00%	11.10%
Derivative Assets (Liabilities), at Fair Value, Net	(423,000)	(122,591,000)	(400,000)	[1]	(1,400,000)	[1]																			(39,300,000)	[1]	(67,800,000)	[1]	(18,400,000)	[1]	(43,900,000)	[1]																																						(74,400,000)	[1]	(119,400,000)	[1]
Variable Interest Entity, Consolidated, Fair Value, Net Asset (Liability)																																	$ (46,700,000)	[1]	$ (68,400,000)	[1]	$ (3,200,000)	[1]	$ (2,800,000)	[1]
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, Correlation Factor															85.00%	85.00%
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, Average Credit Spread							0.10%		0.10%		0.60%		0.90%
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, CDS Spread Percent							1.10%	[2]	0.80%	[2]	4.10%	[2]	4.30%	[2]																											1.10%	[2]	0.80%	[2]	1.10%	[2]	0.80%	[2]	4.10%	[2]	4.30%	[2]	4.10%	[2]	4.30%	[2]										7.20%	[2]	7.90%	[2]					1.10%	[2]	0.80%	[2]	4.10%	[2]		4.30%	[2]
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, Correlation Factor Related to Vintage and Credit Rating																																											72.00%								85.00%										80.00%
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, Principal Recovery Rate																																																														75.00%	75.00%
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, Principal Recovery Rate Using Distressed Pricing Scenario																																																														65.00%	65.00%
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, Probability of Paying a Conditional Liquidity Claim																																													0.20%		1.10%						10.00%		12.40%
Fair Value Assumptions, Expected Term																																																																														16 years		20 years			1 year	1 year
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, NIMS Spread																																																																		40.10%		43.80%

[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] 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.