Note 4 - Fair Value of Financial Instruments Fair Value Measurement Inputs for Level III Assets and Liabilities (Details) (USD $)	Sep. 30, 2012		Dec. 31, 2011
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Derivative Assets	$ 14,857,000		$ 17,212,000
Derivative liabilities	267,323,000		126,006,000
VIE debt	109,651,000		228,240,000
Fair Value, Inputs, Level 3 | Discounted Cash Flow Valuation Technique [Member] | Collateralized Debt Obligation of Commercial Mortgage Backed Securities [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Derivative Assets	1,600,000	[1]
Derivative liabilities	81,500,000	[1]
Fair Value, Inputs, Level 3 | Discounted Cash Flow Valuation Technique [Member] | Collateralized Debt Obligation of Commercial Mortgage Backed Securities [Member] | Minimum [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, CDS Spread Percent	8.50%	[2]
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, Correlation Factor Related to Vintage and Credit Rating	72.00%
Fair Value, Inputs, Level 3 | Discounted Cash Flow Valuation Technique [Member] | Collateralized Debt Obligation of Commercial Mortgage Backed Securities [Member] | Maximum [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, CDS Spread Percent	11.50%	[2]
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, Correlation Factor Related to Vintage and Credit Rating	85.00%
Fair Value, Inputs, Level 3 | Discounted Cash Flow Valuation Technique [Member] | TruPs Collateralized Debt Obligation [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Derivative Assets	1,600,000	[1]
Fair Value, Inputs, Level 3 | Discounted Cash Flow Valuation Technique [Member] | TruPs Collateralized Debt Obligation [Member] | Minimum [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, CDS Spread Percent	8.50%	[2]
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, Probability of Paying a Conditional Liquidity Claim	0.80%
Fair Value, Inputs, Level 3 | Discounted Cash Flow Valuation Technique [Member] | TruPs Collateralized Debt Obligation [Member] | Maximum [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, CDS Spread Percent	11.50%	[2]
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, Probability of Paying a Conditional Liquidity Claim	32.00%
Fair Value, Inputs, Level 3 | Discounted Cash Flow Valuation Technique [Member] | TruPs Collateralized Debt Obligation [Member] | Weighted Average [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, Principal Recovery Percent	60.00%
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, Principal Recovery Rate Using Distressed Pricing Scenario	55.00%
Fair Value, Inputs, Level 3 | Discounted Cash Flow Valuation Technique [Member] | TruPs Collateralized Debt Obligations and TruPs-Related VIE Liabilitie [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Derivative liabilities	12,900,000	[1]
Fair Value, Inputs, Level 3 | Discounted Cash Flow Valuation Technique [Member] | TruPs Collateralized Debt Obligations and TruPs-Related VIE Liabilitie [Member] | Minimum [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, CDS Spread Percent	8.50%	[2]
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, Probability of Paying a Conditional Liquidity Claim	0.80%
Fair Value, Inputs, Level 3 | Discounted Cash Flow Valuation Technique [Member] | TruPs Collateralized Debt Obligations and TruPs-Related VIE Liabilitie [Member] | Maximum [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, CDS Spread Percent	11.50%	[2]
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, Probability of Paying a Conditional Liquidity Claim	32.00%
Fair Value, Inputs, Level 3 | Discounted Cash Flow Valuation Technique [Member] | TruPs Collateralized Debt Obligations and TruPs-Related VIE Liabilitie [Member] | Weighted Average [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, Principal Recovery Percent	60.00%
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, Principal Recovery Rate Using Distressed Pricing Scenario	55.00%
Fair Value, Inputs, Level 3 | Discounted Cash Flow Valuation Technique [Member] | NIMS derivative assets
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Derivative Assets	1,800,000	[1]
Fair Value, Inputs, Level 3 | Discounted Cash Flow Valuation Technique [Member] | NIMS derivative assets | Weighted Average [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, CDS Spread Percent	10.90%
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, NIMS Spread	43.60%
Fair Value, Inputs, Level 3 | Discounted Cash Flow Valuation Technique [Member] | NIMS VIEs [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
VIE debt	9,500,000	[1]
Fair Value, Inputs, Level 3 | Discounted Cash Flow Valuation Technique [Member] | NIMS VIEs [Member] | Minimum [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, CDS Spread Percent	11.00%	[2]
Fair Value, Inputs, Level 3 | Discounted Cash Flow Valuation Technique [Member] | NIMS VIEs [Member] | Maximum [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, CDS Spread Percent	11.30%	[2]
Fair Value, Inputs, Level 3 | Discounted Cash Flow Valuation Technique [Member] | NIMS VIEs [Member] | Weighted Average [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, CDS Spread Percent	43.60%
Fair Value, Inputs, Level 3 | Discounted Cash Flow Valuation Technique [Member] | State and municipal obligations
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total Investments at Fair Value	18,800,000	[1]
Fair Value, Inputs, Level 3 | Discounted Cash Flow Valuation Technique [Member] | State and municipal obligations | Weighted Average [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, Discount Rate	8.50%
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, Expected Loss Rate	19.00%
Fair Value, Inputs, Level 3 | Discounted Cash Flow Valuation Technique [Member] | Other investments
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total Investments at Fair Value	75,600,000	[1]
Fair Value, Inputs, Level 3 | Discounted Cash Flow Valuation Technique [Member] | Other investments | Weighted Average [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, Discount Rate	2.60%
Fair Value, Inputs, Level 3 | Base Correlation Model Valuation Technique [Member] | Corporate collateralized debt obligations (CDO's)[Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Derivative Assets	9,700,000	[1]
Derivative liabilities	8,600,000	[1]
Fair Value, Inputs, Level 3 | Base Correlation Model Valuation Technique [Member] | Corporate collateralized debt obligations (CDO's)[Member] | Minimum [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, CDS Spread Percent	8.50%	[2]
Fair Value, Inputs, Level 3 | Base Correlation Model Valuation Technique [Member] | Corporate collateralized debt obligations (CDO's)[Member] | Minimum [Member] | Less Than [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, Average Credit Spread	0.10%
Fair Value, Inputs, Level 3 | Base Correlation Model Valuation Technique [Member] | Corporate collateralized debt obligations (CDO's)[Member] | Maximum [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, Average Credit Spread	2.90%
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, CDS Spread Percent	11.50%	[2]
Fair Value, Inputs, Level 3 | Base Correlation Model Valuation Technique [Member] | Corporate collateralized debt obligations (CDO's)[Member] | Weighted Average [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, Correlation Factor	85.00%
Fair Value, Inputs, Level 3 | Risk-Based Model Valuation Technique [Member] | Non Corporate CDOS and other derivative transactions[Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Derivative liabilities	$ 164,200,000	[1]
Fair Value, Inputs, Level 3 | Risk-Based Model Valuation Technique [Member] | Non Corporate CDOS and other derivative transactions[Member] | Minimum [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, CDS Spread Percent	8.50%	[2]
Fair Value, Inputs, Level 3 | Risk-Based Model Valuation Technique [Member] | Non Corporate CDOS and other derivative transactions[Member] | Minimum [Member] | Less Than [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Derivative, Expected Remaining Life	1 year
Fair Value, Inputs, Level 3 | Risk-Based Model Valuation Technique [Member] | Non Corporate CDOS and other derivative transactions[Member] | Maximum [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value, Measurement with Unobservable Inputs, Additional Disclosure, CDS Spread Percent	11.50%	[2]
Derivative, Expected Remaining Life	20 years

[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.