Note 5 - Fair Value of Financial Instruments Fair Value Assets Liabilities by Hierarchy Level (Details) (USD $)	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Fair Value by Hierarchy Level [Line Items]
Held-to-maturity Securities	$ 358,000		$ 679,000
Derivative Assets	16,642,000		13,609,000
Derivative liabilities	307,185,000		266,873,000		126,006,000
VIE debt - at fair value	94,645,000		108,858,000		228,240,000
Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	4,883,400,000	[1]	5,103,000,000	[2]
Derivative Assets	16,600,000		13,600,000
Other Assets	91,900,000	[3]	99,200,000	[3]
Total Assets at Fair Value	4,991,900,000		5,215,800,000
Derivative liabilities	307,200,000		266,900,000
VIE debt - at fair value	94,600,000	[4]	108,900,000	[5]
Total Liabilities at Fair Value	401,800,000		375,800,000
Fair Value, Measurements, Recurring | Reported Value Measurement [Member]
Fair Value by Hierarchy Level [Line Items]
Held-to-maturity Securities			700,000
Other invested assets fair value disclosure	47,400,000		48,700,000
US government and agency securities | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	1,157,900,000		571,600,000
State and municipal obligations | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	621,000,000		688,000,000
Money market instruments | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	672,600,000		638,000,000
Corporate bonds and notes | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	1,036,600,000		1,373,600,000
RMBS | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	560,400,000		663,400,000
CMBS | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	288,900,000		237,300,000
Other ABS | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	195,800,000		254,100,000
Foreign government securities | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	40,700,000		117,700,000
Hybrid securities | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value			211,900,000
Equity securities | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	225,800,000	[6]	265,900,000	[6]
Other investments | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	83,700,000	[7]	81,500,000	[8]
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	1,555,900,000	[1]	874,700,000	[2]
Derivative Assets	0		0
Other Assets	0	[3]	0	[3]
Total Assets at Fair Value	1,555,900,000		874,700,000
Derivative liabilities	0		0
VIE debt - at fair value	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 [Line Items]
Total Investments at Fair Value	755,000,000		137,800,000
Fair Value, Inputs, Level 1 | State and municipal obligations | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	0		0
Fair Value, Inputs, Level 1 | Money market instruments | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	672,600,000		638,000,000
Fair Value, Inputs, Level 1 | Corporate bonds and notes | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	0		0
Fair Value, Inputs, Level 1 | RMBS | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	0		0
Fair Value, Inputs, Level 1 | CMBS | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	0		0
Fair Value, Inputs, Level 1 | Other ABS | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	0		0
Fair Value, Inputs, Level 1 | Foreign government securities | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	0		0
Fair Value, Inputs, Level 1 | Hybrid securities | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value			0
Fair Value, Inputs, Level 1 | Equity securities | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	128,300,000	[6]	98,900,000	[6]
Fair Value, Inputs, Level 1 | Other investments | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	0	[7]	0	[8]
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	3,226,000,000	[1]	4,127,600,000	[2]
Derivative Assets	10,300,000		0
Other Assets	0	[3]	0	[3]
Total Assets at Fair Value	3,236,300,000		4,127,600,000
Derivative liabilities	0		0
VIE debt - at fair value	0	[4]	0	[5]
Total Liabilities at Fair Value	0		0
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | Reported Value Measurement [Member]
Fair Value by Hierarchy Level [Line Items]
Held-to-maturity Securities	400,000		700,000
Fair Value, Inputs, Level 2 | Trust Preferred Securities [Member] | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	600,000		900,000
Fair Value, Inputs, Level 2 | US government and agency securities | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	402,900,000		433,800,000
Fair Value, Inputs, Level 2 | State and municipal obligations | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	602,300,000		669,000,000
Fair Value, Inputs, Level 2 | Money market instruments | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
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 [Line Items]
Total Investments at Fair Value	1,036,600,000		1,373,600,000
Fair Value, Inputs, Level 2 | RMBS | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	560,400,000		663,400,000
Fair Value, Inputs, Level 2 | CMBS | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	288,900,000		237,300,000
Fair Value, Inputs, Level 2 | Other ABS | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	194,900,000		252,400,000
Fair Value, Inputs, Level 2 | Foreign government securities | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	40,700,000		117,700,000
Fair Value, Inputs, Level 2 | Hybrid securities | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value			211,900,000
Fair Value, Inputs, Level 2 | Equity securities | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	97,100,000	[6]	166,000,000	[6]
Fair Value, Inputs, Level 2 | Other investments | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	2,200,000	[7]	2,500,000	[8]
Fair Value, Inputs, Level 2 | Short Term CDs | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	1,600,000		1,600,000
Fair Value, Inputs, Level 3
Fair Value by Hierarchy Level [Line Items]
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 debt - at fair value	91,800,000
Number Of Consolidated Other Financial Guaranty Transactions	2
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	101,500,000	[1]	100,700,000	[2]
Derivative Assets	6,300,000		13,600,000
Other Assets	91,900,000	[3]	99,200,000	[3]
Total Assets at Fair Value	199,700,000		213,500,000
Derivative liabilities	307,200,000		266,900,000
VIE debt - at fair value	94,600,000	[4]	108,900,000	[5]
Total Liabilities at Fair Value	401,800,000		375,800,000
Total Level III Assets	4.00%		4.10%
Total Level III Liabilities	100.00%		100.00%
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | NIMS VIEs [Member]
Fair Value by Hierarchy Level [Line Items]
VIE debt - at fair value	2,800,000		9,900,000
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | Consolidated Financial Guaranty Insurance Contracts [Member]
Fair Value by Hierarchy Level [Line Items]
VIE debt - at fair value	91,800,000		99,000,000
Fair Value, Inputs, Level 3 | Trust Preferred Securities [Member] | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	200,000
Fair Value, Inputs, Level 3 | US government and agency securities | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
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 [Line Items]
Total Investments at Fair Value	18,700,000		19,000,000
Fair Value, Inputs, Level 3 | Money market instruments | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
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 [Line Items]
Total Investments at Fair Value	0		0
Fair Value, Inputs, Level 3 | RMBS | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	0		0
Fair Value, Inputs, Level 3 | CMBS | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	0		0
Fair Value, Inputs, Level 3 | Other ABS | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	900,000		1,700,000
Fair Value, Inputs, Level 3 | Foreign government securities | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	0		0
Fair Value, Inputs, Level 3 | Hybrid securities | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value			0
Fair Value, Inputs, Level 3 | Equity securities | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	400,000	[6]	1,000,000	[6]
Fair Value, Inputs, Level 3 | Other investments | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	81,500,000	[7]	79,000,000	[8]
Fair Value, Inputs, Level 3 | Lottery Annuities
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value			1,000,000
Fair Value, Inputs, Level 3 | Lottery Annuities | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	300,000
Fair Value, Inputs, Level 3 | Guaranteed Investment Contract Held by a Consolidated VIE [Member] | Fair Value, Measurements, Recurring
Fair Value by Hierarchy Level [Line Items]
Total Investments at Fair Value	$ 81,000,000		$ 78,000,000

[1] Does not include fixed-maturities held to maturity ($0.4 million) and certain other invested assets ($47.4 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 ($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] Primarily comprising manufactured housing loan collateral related to two consolidated financial guaranty VIEs.

[4] Comprising consolidated debt related to NIMS VIEs ($2.8 million) and amounts related to financial guaranty VIEs ($91.8 million).

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

[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 TruPs ($0.6 million) and short-term CDs ($1.6 million) included within Level II and lottery annuities ($0.3 million), TruPs ($0.2 million), and a guaranteed investment contract held by a consolidated VIE ($81.0 million) within Level III.

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