Note 5 - Fair Value of Financial Instruments Rollforward of Level III Assets and Liabilities Fair Value Disclosure (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Fair Value Level III Assets and Liabilities [Roll Forward]
Total Level III Assets	4.90%
Total Level III Liabilities	100.00%
Fair Value, Measurements, Recurring
Fair Value Level III Assets and Liabilities [Roll Forward]
Fair Value, Transfers Between Level 1 And Level 2, Amount	$ 0
Derivative liabilities net [Member] | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3
Fair Value Level III Assets and Liabilities [Roll Forward]
Beginning Balance Level III Liabilities	709,100,000	214,900,000
VIE Consolidation, Liabilities		51,800,000	[1]
Realized and Unrealized Gains (Losses) Included in Earnings Level III Liabilities	(629,000,000)	551,200,000	[2]
Purchases Level III Liabilities	0	0
Sales Level III Liabilities	0	0
Issuances Level III Liabilities	0	0
Settlements Level III Liabilities	30,500,000	(5,200,000)
Transfers Into (Out of) Level III Liabilities	0	0	[3]
Ending Balance Level III Liabilities	110,600,000	709,100,000
Unrealized Gains (Losses) Recorded in Earnings on Level III Liabilities Still Held	579,100,000	(588,100,000)
VIE debt | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3
Fair Value Level III Assets and Liabilities [Roll Forward]
Beginning Balance Level III Liabilities	520,100,000	296,100,000
VIE Consolidation, Liabilities		253,500,000	[1]
Realized and Unrealized Gains (Losses) Included in Earnings Level III Liabilities	(138,500,000)	213,500,000	[2]
Purchases Level III Liabilities	0	0
Sales Level III Liabilities	0	0
Issuances Level III Liabilities	0	0
Settlements Level III Liabilities	(153,400,000)	(243,000,000)	[4]
Transfers Into (Out of) Level III Liabilities	0	0	[3]
Ending Balance Level III Liabilities	228,200,000	520,100,000
Unrealized Gains (Losses) Recorded in Earnings on Level III Liabilities Still Held	158,500,000	(165,700,000)
VIE debt | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3 | Financial Guaranty Segment
Fair Value Level III Assets and Liabilities [Roll Forward]
Settlements Level III Liabilities		36,300,000	[4]
Total Level III liabilities net [Member] | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3
Fair Value Level III Assets and Liabilities [Roll Forward]
Beginning Balance Level III Liabilities	1,229,200,000	511,000,000
VIE Consolidation, Liabilities		201,700,000	[1]
Realized and Unrealized Gains (Losses) Included in Earnings Level III Liabilities	(767,500,000)	764,700,000	[2]
Purchases Level III Liabilities	0	0
Sales Level III Liabilities	0	0
Issuances Level III Liabilities	0	0
Settlements Level III Liabilities	(122,900,000)	(248,200,000)
Transfers Into (Out of) Level III Liabilities	0	0	[3]
Ending Balance Level III Liabilities	338,800,000	1,229,200,000
Committed Preferred Securities CPS | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3
Fair Value Level III Assets and Liabilities [Roll Forward]
Settlements Level III Liabilities		31,200,000	[4]
Committed Preferred Securities CPS | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3 | Consolidated VIEs [Member]
Fair Value Level III Assets and Liabilities [Roll Forward]
Settlements Level III Liabilities		11,100,000	[4]
NIMS VIEs [Member] | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3
Fair Value Level III Assets and Liabilities [Roll Forward]
Settlements Level III Liabilities		186,600,000	[4]
State and municipal obligations | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3
Fair Value Level III Assets and Liabilities [Roll Forward]
Beginning Balance Level III Assets	23,200,000	24,400,000
VIE Consolidation, Assets		0	[1]
Realized and Unrealized Gains (Losses) Level III Assets Included in Earnings	1,200,000	100,000	[2]
Purchases Level III Assets	39,100,000	1,400,000
Sales Level III Assets	600,000	0
Issuances Level III Assets	0	0
Settlements Level III Assets	400,000	2,700,000
Transfers Into (Out of) Level III Assets	0	0	[3]
Ending Balance Level III Assets	62,500,000	23,200,000
RMBS | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3
Fair Value Level III Assets and Liabilities [Roll Forward]
Beginning Balance Level III Assets	52,500,000	0
VIE Consolidation, Assets		44,300,000	[1]
Realized and Unrealized Gains (Losses) Level III Assets Included in Earnings	(3,100,000)	19,600,000	[2]
Purchases Level III Assets	0	0
Sales Level III Assets	0	0
Issuances Level III Assets	0	0
Settlements Level III Assets	3,900,000	11,400,000
Transfers Into (Out of) Level III Assets	0	0	[3]
Ending Balance Level III Assets	45,500,000	52,500,000
CMBS | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3
Fair Value Level III Assets and Liabilities [Roll Forward]
Beginning Balance Level III Assets	23,000,000	0
VIE Consolidation, Assets		23,800,000	[1]
Realized and Unrealized Gains (Losses) Level III Assets Included in Earnings	12,400,000	(800,000)	[2]
Purchases Level III Assets	0	0
Sales Level III Assets	0	0
Issuances Level III Assets	0	0
Settlements Level III Assets	0	0
Transfers Into (Out of) Level III Assets	0	0	[3]
Ending Balance Level III Assets	35,400,000	23,000,000
CDO | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3
Fair Value Level III Assets and Liabilities [Roll Forward]
Beginning Balance Level III Assets	2,400,000	0
VIE Consolidation, Assets		3,800,000	[1]
Realized and Unrealized Gains (Losses) Level III Assets Included in Earnings	2,700,000	(1,800,000)	[2]
Purchases Level III Assets	0	0
Sales Level III Assets	0	(400,000)
Issuances Level III Assets	0	0
Settlements Level III Assets	(400,000)	0
Transfers Into (Out of) Level III Assets	0	0	[3]
Ending Balance Level III Assets	5,500,000	2,400,000
Other ABS | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3
Fair Value Level III Assets and Liabilities [Roll Forward]
Beginning Balance Level III Assets	3,300,000	0
VIE Consolidation, Assets		3,500,000	[1]
Realized and Unrealized Gains (Losses) Level III Assets Included in Earnings	(400,000)	(200,000)	[2]
Purchases Level III Assets	0	0
Sales Level III Assets	0	0
Issuances Level III Assets	0	0
Settlements Level III Assets	0	0
Transfers Into (Out of) Level III Assets	0	0	[3]
Ending Balance Level III Assets	2,900,000	3,300,000
Hybrid securities | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3
Fair Value Level III Assets and Liabilities [Roll Forward]
Beginning Balance Level III Assets	0	600,000
VIE Consolidation, Assets		0	[1]
Realized and Unrealized Gains (Losses) Level III Assets Included in Earnings	(100,000)	0	[2]
Purchases Level III Assets	700,000	0
Sales Level III Assets	0	0
Issuances Level III Assets	0	0
Settlements Level III Assets	0	0
Transfers Into (Out of) Level III Assets	4,200,000	(600,000)	[3]
Ending Balance Level III Assets	4,800,000	0
Equity securities | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3
Fair Value Level III Assets and Liabilities [Roll Forward]
Beginning Balance Level III Assets	2,900,000	1,700,000
VIE Consolidation, Assets		0	[1]
Realized and Unrealized Gains (Losses) Level III Assets Included in Earnings	(1,200,000)	200,000	[2]
Purchases Level III Assets	3,700,000	400,000
Sales Level III Assets	1,000,000	100,000
Issuances Level III Assets	0	0
Settlements Level III Assets	0	0
Transfers Into (Out of) Level III Assets	(3,600,000)	700,000	[3]
Ending Balance Level III Assets	800,000	2,900,000
Other investments | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3
Fair Value Level III Assets and Liabilities [Roll Forward]
Beginning Balance Level III Assets	4,600,000	3,800,000
VIE Consolidation, Assets		3,700,000	[1]
Realized and Unrealized Gains (Losses) Level III Assets Included in Earnings	3,200,000	(1,600,000)	[2]
Purchases Level III Assets	0	0
Sales Level III Assets	700,000	1,000,000
Issuances Level III Assets	0	(300,000)
Settlements Level III Assets	300,000	0
Transfers Into (Out of) Level III Assets	0	0	[3]
Ending Balance Level III Assets	6,800,000	4,600,000
Investments | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3
Fair Value Level III Assets and Liabilities [Roll Forward]
Beginning Balance Level III Assets	111,900,000	30,500,000
VIE Consolidation, Assets		79,100,000	[1]
Realized and Unrealized Gains (Losses) Level III Assets Included in Earnings	14,700,000	15,500,000	[2]
Purchases Level III Assets	43,500,000	1,800,000
Sales Level III Assets	2,300,000	700,000
Issuances Level III Assets	0	(300,000)
Settlements Level III Assets	4,200,000	14,100,000
Transfers Into (Out of) Level III Assets	600,000	100,000	[3]
Ending Balance Level III Assets	164,200,000	111,900,000
Unrealized Gains (Losses) Recorded in Earnings on Level III Assets Still Held	12,000,000	12,600,000
NIMS and CPS Derivative Assets [Member] | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3
Fair Value Level III Assets and Liabilities [Roll Forward]
Beginning Balance Level III Assets		44,700,000
VIE Consolidation, Assets		0	[1]
Realized and Unrealized Gains (Losses) Level III Assets Included in Earnings		(7,700,000)	[2]
Purchases Level III Assets		1,300,000
Sales Level III Assets		100,000
Issuances Level III Assets		(100,000)
Settlements Level III Assets		26,400,000	[5]
Transfers Into (Out of) Level III Assets		0	[3]
Ending Balance Level III Assets		11,700,000
NIMS derivative assets | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3
Fair Value Level III Assets and Liabilities [Roll Forward]
Beginning Balance Level III Assets	11,700,000
Realized and Unrealized Gains (Losses) Level III Assets Included in Earnings	(2,200,000)
Purchases Level III Assets	300,000
Sales Level III Assets	0
Issuances Level III Assets	0
Settlements Level III Assets	7,700,000
Transfers Into (Out of) Level III Assets	(500,000)
Ending Balance Level III Assets	1,600,000	11,700,000
Unrealized Gains (Losses) Recorded in Earnings on Level III Assets Still Held		(1,400,000)
NIMS and CPS Derivative Assets | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3
Fair Value Level III Assets and Liabilities [Roll Forward]
Settlements Level III Assets		27,100,000	[5]
Other assets | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3
Fair Value Level III Assets and Liabilities [Roll Forward]
Beginning Balance Level III Assets	109,700,000	0
VIE Consolidation, Assets		119,700,000	[1]
Realized and Unrealized Gains (Losses) Level III Assets Included in Earnings	21,500,000	18,300,000	[2]
Purchases Level III Assets	0	0
Sales Level III Assets	0	0
Issuances Level III Assets	0	0
Settlements Level III Assets	27,200,000	28,300,000
Transfers Into (Out of) Level III Assets	0	0	[3]
Ending Balance Level III Assets	104,000,000	109,700,000
Unrealized Gains (Losses) Recorded in Earnings on Level III Assets Still Held	9,400,000	4,000,000
Total Level III Assets | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3
Fair Value Level III Assets and Liabilities [Roll Forward]
Beginning Balance Level III Assets	233,300,000	75,200,000
VIE Consolidation, Assets		198,800,000	[1]
Realized and Unrealized Gains (Losses) Level III Assets Included in Earnings	34,000,000	26,100,000	[2]
Purchases Level III Assets	43,800,000	3,100,000
Sales Level III Assets	2,300,000	800,000
Issuances Level III Assets	0	(400,000)
Settlements Level III Assets	39,100,000	68,800,000
Transfers Into (Out of) Level III Assets	100,000	100,000	[3]
Ending Balance Level III Assets	$ 269,800,000	$ 233,300,000
Total Level III Assets	4.90%	3.70%
Total Level III Liabilities	100.00%	100.00%

[1] Represents the impact of our adoption of the accounting standard update regarding improvements to financial reporting by enterprises involved with VIEs.

[2] Includes unrealized gains (losses) relating to assets and liabilities still held as of December 31, 2010, as follows: $12.6 million for investments, $(1.4) million for NIMS derivative assets, $4.0 million for other assets, $(588.1) million for derivative liabilities, and $(165.7) million for VIE debt.

[3] Transfers are recognized at the end of the period as the availability of market observed inputs change from period to period.

[4] Includes impact of consolidation of VIE from CPS Trust I in the amount of $11.1 million. Offsetting this increase was $186.6 million related to NIMS purchases, $36.3 million related to financial guaranty VIE debt paydowns, and $31.2 million for CPS VIE debt purchases.

[5] Includes impact of consolidation of VIE from CPS Trust I as of June 30, 2010, in the amount of $27.1 million.