Note 5 - Fair Value of Financial Instruments Fair Value Assets Liabilities by Hierarchy Level (Details) (USD $)	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Fair Value by Hierarchy Level [Line Items]
VIE Other Assets	$ 105,903,000		$ 112,426,000
Fair Value by Hierarchy Level Assets and Liabilities
Total Level III Assets	4.90%
Total Level III Liabilities	100.00%
Derivative Assets	17,212,000		26,212,000
Derivative liabilities	126,006,000		723,579,000		238,697,000
VIE debt	228,240,000		520,114,000		296,080,000
Fixed-maturities held to maturity	2,748,000		11,416,000
NIMS VIEs [Member]
Fair Value by Hierarchy Level Assets and Liabilities
Derivative Assets	1,600,000		10,900,000
VIE debt	9,400,000		141,000,000
Consolidated Financial Guaranty Insurance Contracts [Member]
Fair Value by Hierarchy Level Assets and Liabilities
Derivative Assets	0		0
Derivative liabilities	19,500,000		19,200,000
VIE debt	218,800,000		379,100,000
Number Of Consolidated Other Financial Guaranty Transactions	2
Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	5,719,900,000	[1]	6,556,900,000	[2]
Derivative Assets	17,200,000		26,200,000
Other Assets	104,000,000	[3]	109,700,000	[3]
Total Assets at Fair Value	5,841,100,000		6,692,800,000
Derivative liabilities	126,000,000		723,600,000
VIE debt	228,200,000	[4]	520,100,000	[5]
Total Liabilities at Fair Value	354,200,000		1,243,700,000
Fair Value, Measurements, Recurring | Carrying (Reported) Amount, Fair Value Disclosure [Member]
Fair Value by Hierarchy Level Assets and Liabilities
Fixed-maturities held to maturity	2,600,000		10,800,000
Short Term Investments (Carried at Cost) Fair Value Disclosure	0		1,600,000
Other invested assets fair value disclosure	61,000,000		59,600,000
US government and agency securities | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	1,110,500,000		1,806,400,000
State and municipal obligations | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	1,047,500,000		1,182,900,000
Money market instruments | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	723,200,000		310,900,000
Corporate bonds and notes | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	700,500,000		1,060,400,000
RMBS | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	930,200,000		966,000,000
CMBS | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	225,800,000		196,600,000
CDO | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	5,500,000		2,400,000
Other ABS | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	99,900,000		134,400,000
Foreign government securities | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	102,900,000		83,500,000
Hybrid securities | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	346,300,000		318,900,000
Equity securities | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	269,200,000	[6]	339,900,000	[6]
Other investments | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	158,400,000	[7]	154,600,000	[8]
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	1,226,100,000	[1]	1,554,300,000	[2]
Derivative Assets	0		0
Other Assets	0	[3]	0	[3]
Total Assets at Fair Value	1,226,100,000		1,554,300,000
Derivative liabilities	0		0
VIE debt	0	[4]	0	[5]
Total Liabilities at Fair Value	0		0
Fair Value, Inputs, Level 1 | US government and agency securities | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	386,900,000		1,075,000,000
Fair Value, Inputs, Level 1 | State and municipal obligations | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	0		0
Fair Value, Inputs, Level 1 | Money market instruments | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	723,200,000		310,900,000
Fair Value, Inputs, Level 1 | Corporate bonds and notes | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	0		0
Fair Value, Inputs, Level 1 | RMBS | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	0		0
Fair Value, Inputs, Level 1 | CMBS | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	0		0
Fair Value, Inputs, Level 1 | CDO | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	0		0
Fair Value, Inputs, Level 1 | Other ABS | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	0		0
Fair Value, Inputs, Level 1 | Foreign government securities | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	0		0
Fair Value, Inputs, Level 1 | Hybrid securities | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	0		0
Fair Value, Inputs, Level 1 | Equity securities | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	116,000,000	[6]	168,400,000	[6]
Fair Value, Inputs, Level 1 | Other investments | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	0	[7]	0	[8]
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	4,329,600,000	[1]	4,890,700,000	[2]
Derivative Assets	200,000		0
Other Assets	0	[3]	0	[3]
Total Assets at Fair Value	4,329,800,000		4,890,700,000
Derivative liabilities	0		0
VIE debt	0	[4]	0	[5]
Total Liabilities at Fair Value	0		0
Fair Value, Inputs, Level 2 | US government and agency securities | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	723,600,000		731,400,000
Fair Value, Inputs, Level 2 | State and municipal obligations | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	985,000,000		1,159,700,000
Fair Value, Inputs, Level 2 | Money market instruments | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	0		0
Fair Value, Inputs, Level 2 | Corporate bonds and notes | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	700,500,000		1,060,400,000
Fair Value, Inputs, Level 2 | RMBS | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	884,700,000		913,500,000
Fair Value, Inputs, Level 2 | CMBS | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	190,400,000		173,600,000
Fair Value, Inputs, Level 2 | CDO | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	0		0
Fair Value, Inputs, Level 2 | Other ABS | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	97,000,000		131,100,000
Fair Value, Inputs, Level 2 | Foreign government securities | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	102,900,000		83,500,000
Fair Value, Inputs, Level 2 | Hybrid securities | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	341,500,000		318,900,000
Fair Value, Inputs, Level 2 | Equity securities | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	152,400,000	[6]	168,600,000	[6]
Fair Value, Inputs, Level 2 | Other investments | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	151,600,000	[7]	150,000,000	[8]
Fair Value, Inputs, Level 2 | Committed Preferred Securities CPS | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	150,000,000
Fair Value, Inputs, Level 2 | Short Term CDs | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	1,600,000
Fair Value, Inputs, Level 2 | Lottery Annuities
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value			2,600,000
Fair Value, Inputs, Level 3
Fair Value by Hierarchy Level Assets and Liabilities
Number Of Consolidated Other Financial Guaranty Transactions	2		2
Fair Value, Inputs, Level 3 | Consolidated Financial Guaranty Insurance Contracts [Member]
Fair Value by Hierarchy Level [Line Items]
VIE Other Assets	104,000,000
Fair Value by Hierarchy Level Assets and Liabilities
VIE debt	103,700,000
Number Of Consolidated Other Financial Guaranty Transactions	2
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	164,200,000	[1]	111,900,000	[2]
Derivative Assets	17,000,000		26,200,000
Other Assets	104,000,000	[3]	109,700,000	[3]
Total Assets at Fair Value	285,200,000		247,800,000
Derivative liabilities	228,200,000		723,600,000
VIE debt	126,000,000		520,100,000
Total Liabilities at Fair Value	354,200,000		1,243,700,000
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | NIMS VIEs [Member]
Fair Value by Hierarchy Level Assets and Liabilities
VIE debt	9,400,000		141,000,000
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | Consolidated Financial Guaranty Insurance Contracts [Member]
Fair Value by Hierarchy Level Assets and Liabilities
VIE debt	218,800,000		379,100,000
Fair Value, Inputs, Level 3 | US government and agency securities | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	0		0
Fair Value, Inputs, Level 3 | State and municipal obligations | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	62,500,000		23,200,000
Fair Value, Inputs, Level 3 | Money market instruments | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	0		0
Fair Value, Inputs, Level 3 | Corporate bonds and notes | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	0		0
Fair Value, Inputs, Level 3 | RMBS | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	45,500,000		52,500,000
Fair Value, Inputs, Level 3 | CMBS | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	35,400,000		23,000,000
Fair Value, Inputs, Level 3 | CDO | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	5,500,000		2,400,000
Fair Value, Inputs, Level 3 | Other ABS | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	2,900,000		3,300,000
Fair Value, Inputs, Level 3 | Foreign government securities | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	0		0
Fair Value, Inputs, Level 3 | Hybrid securities | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	4,800,000		0
Fair Value, Inputs, Level 3 | Equity securities | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	800,000	[6]	2,900,000	[6]
Fair Value, Inputs, Level 3 | Other investments | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	6,800,000	[7]	4,600,000	[8]
Fair Value, Inputs, Level 3 | Lottery Annuities | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	1,600,000
Fair Value, Inputs, Level 3 | Consolidated Committed Preferred Custodial Trust Securities [Member] | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Investments at Fair Value	$ 5,200,000		$ 2,000,000
Fair Value, Inputs, Level 3 | Assets, Total [Member] | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level Assets and Liabilities
Total Level III Assets	4.90%		3.70%
Total Level III Liabilities	100.00%		100.00%

[1] 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.

[2] Does not include fixed-maturities held to maturity ($10.8 million), certain short-term investments ($1.6 million), primarily invested in CDs and time deposits, and other invested assets ($59.6 million), primarily invested in limited partnerships, accounted for as cost-method investments and not measured at fair value.

[3] Comprising manufactured housing loan collateral related to two consolidated financial guaranty VIEs.

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

[5] Comprising consolidated debt related to NIMS VIEs ($141.0 million) and amounts related to financial guaranty VIEs ($379.1 million) that required consolidation as of January 1, 2010, under the accounting standard update regarding improvements to financial reporting by enterprises involved with VIEs.

[6] Comprising broadly diversified domestic equity mutual funds included within Level I and various preferred and common stocks invested across numerous companies and industries included within Levels II and III.

[7] 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.

[8] Comprising short-term commercial paper within CPS trusts included within Level II, and lottery annuities ($2.6 million) and TruPs held by consolidated VIEs ($2.0 million) included within Level III.