Note 5 - Fair Value of Financial Instruments Fair Value Assets Liabilities by Hierarchy Level (Details) - USD ($) | 12 Months Ended | |
Dec. 31, 2015 | Dec. 31, 2014 |
Fair Value by Hierarchy Level [Line Items] | | | | | |
Total liabilities | | $ 3,145,169,000 | | $ 4,670,586,000 | |
Reported Value Measurement [Member] | | | | | |
Fair Value by Hierarchy Level [Line Items] | | | | | |
Cost Method Investments | | 1,700,000 | | 14,600,000 | |
Fair Value, Measurements, Recurring | | | | | |
Fair Value by Hierarchy Level [Line Items] | | | | | |
Total Investments at Fair Value | | 4,297,000,000 | [1] | 3,614,700,000 | [2] |
Total Assets at Fair Value | | 4,297,000,000 | | 3,614,700,000 | |
Fair Value, Assets, Level 2 to Level 1 Transfers, Amount | | 0 | | | |
Fair Value, Assets, Level 1 to Level 2 Transfers, Amount | | 0 | | 0 | |
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net | | 0 | | | |
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Transfers, Net | | 0 | | | |
US government and agency securities | Fair Value, Measurements, Recurring | | | | | |
Fair Value by Hierarchy Level [Line Items] | | | | | |
Total Investments at Fair Value | | 678,300,000 | | 839,900,000 | |
Fair Value, Assets, Level 2 to Level 1 Transfers, Amount | | | | 137,300,000 | |
State and municipal obligations | Fair Value, Measurements, Recurring | | | | | |
Fair Value by Hierarchy Level [Line Items] | | | | | |
Total Investments at Fair Value | | 341,900,000 | | 362,800,000 | |
Money market instruments | Fair Value, Measurements, Recurring | | | | | |
Fair Value by Hierarchy Level [Line Items] | | | | | |
Total Investments at Fair Value | | 443,300,000 | | 600,300,000 | |
Corporate bonds and notes | Fair Value, Measurements, Recurring | | | | | |
Fair Value by Hierarchy Level [Line Items] | | | | | |
Total Investments at Fair Value | | 1,383,200,000 | | 992,800,000 | |
RMBS | Fair Value, Measurements, Recurring | | | | | |
Fair Value by Hierarchy Level [Line Items] | | | | | |
Total Investments at Fair Value | | 297,100,000 | | 132,300,000 | |
CMBS | Fair Value, Measurements, Recurring | | | | | |
Fair Value by Hierarchy Level [Line Items] | | | | | |
Total Investments at Fair Value | | 544,600,000 | | 246,800,000 | |
Other ABS | Fair Value, Measurements, Recurring | | | | | |
Fair Value by Hierarchy Level [Line Items] | | | | | |
Total Investments at Fair Value | | 371,600,000 | | 185,500,000 | |
Foreign government securities | Fair Value, Measurements, Recurring | | | | | |
Fair Value by Hierarchy Level [Line Items] | | | | | |
Total Investments at Fair Value | | 37,600,000 | | 37,700,000 | |
Equity securities | Fair Value, Measurements, Recurring | | | | | |
Fair Value by Hierarchy Level [Line Items] | | | | | |
Total Investments at Fair Value | | 100,400,000 | | 215,600,000 | [3] |
Fair Value, Assets, Level 2 to Level 1 Transfers, Amount | | | | 21,000,000 | |
Other investments | Fair Value, Measurements, Recurring | | | | | |
Fair Value by Hierarchy Level [Line Items] | | | | | |
Total Investments at Fair Value | | 99,000,000 | [4] | 1,000,000 | [5] |
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring | | | | | |
Fair Value by Hierarchy Level [Line Items] | | | | | |
Total Investments at Fair Value | | 1,188,500,000 | [1] | 1,601,200,000 | [2] |
Total Assets at Fair Value | | 1,188,500,000 | | 1,601,200,000 | |
Assets Held-for-sale, Long Lived, Fair Value Disclosure | | | | 495,100,000 | |
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 | | 670,300,000 | | 836,900,000 | |
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 | | 443,300,000 | | 600,300,000 | |
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 | Equity securities | Fair Value, Measurements, Recurring | | | | | |
Fair Value by Hierarchy Level [Line Items] | | | | | |
Total Investments at Fair Value | | 74,900,000 | | 164,000,000 | [3] |
Fair Value, Inputs, Level 1 | Other investments | Fair Value, Measurements, Recurring | | | | | |
Fair Value by Hierarchy Level [Line Items] | | | | | |
Total Investments at Fair Value | | 0 | [4] | 0 | [5] |
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | | | | | |
Fair Value by Hierarchy Level [Line Items] | | | | | |
Total Investments at Fair Value | | 3,108,000,000 | [1] | 2,013,500,000 | [2] |
Total Assets at Fair Value | | 3,108,000,000 | | 2,013,500,000 | |
Assets Held-for-sale, Long Lived, Fair Value Disclosure | | | | 839,200,000 | |
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 | | 8,000,000 | | 3,000,000 | |
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 | | 341,900,000 | | 362,800,000 | |
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 | | 1,383,200,000 | | 992,800,000 | |
Fair Value, Inputs, Level 2 | RMBS | Fair Value, Measurements, Recurring | | | | | |
Fair Value by Hierarchy Level [Line Items] | | | | | |
Total Investments at Fair Value | | 297,100,000 | | 132,300,000 | |
Fair Value, Inputs, Level 2 | CMBS | Fair Value, Measurements, Recurring | | | | | |
Fair Value by Hierarchy Level [Line Items] | | | | | |
Total Investments at Fair Value | | 544,600,000 | | 246,800,000 | |
Fair Value, Inputs, Level 2 | Other ABS | Fair Value, Measurements, Recurring | | | | | |
Fair Value by Hierarchy Level [Line Items] | | | | | |
Total Investments at Fair Value | | 371,600,000 | | 185,500,000 | |
Fair Value, Inputs, Level 2 | Foreign government securities | Fair Value, Measurements, Recurring | | | | | |
Fair Value by Hierarchy Level [Line Items] | | | | | |
Total Investments at Fair Value | | 37,600,000 | | 37,700,000 | |
Fair Value, Inputs, Level 2 | Equity securities | Fair Value, Measurements, Recurring | | | | | |
Fair Value by Hierarchy Level [Line Items] | | | | | |
Total Investments at Fair Value | | 25,000,000 | | 51,600,000 | [3] |
Fair Value, Inputs, Level 2 | Other investments | Fair Value, Measurements, Recurring | | | | | |
Fair Value by Hierarchy Level [Line Items] | | | | | |
Total Investments at Fair Value | | 99,000,000 | [4] | 1,000,000 | [5] |
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | | | | | |
Fair Value by Hierarchy Level [Line Items] | | | | | |
Total Investments at Fair Value | [1] | 500,000 | | | |
Total Assets at Fair Value | | 500,000 | | | |
Total liabilities | | 0 | | | |
Assets Held-for-sale, Long Lived, Fair Value Disclosure | | | | 102,600,000 | |
VIE debt - at fair value | | | | $ 3,800,000 | |
Total Level III Liabilities as a Percentage of Total Liabilities Measured at Fair Value | | | | 100.00% | |
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 | | | |
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 | | 0 | | | |
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 | | | |
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 | | | |
Fair Value, Inputs, Level 3 | RMBS | Fair Value, Measurements, Recurring | | | | | |
Fair Value by Hierarchy Level [Line Items] | | | | | |
Total Investments at Fair Value | | 0 | | | |
Fair Value, Inputs, Level 3 | CMBS | Fair Value, Measurements, Recurring | | | | | |
Fair Value by Hierarchy Level [Line Items] | | | | | |
Total Investments at Fair Value | | 0 | | | |
Fair Value, Inputs, Level 3 | Other ABS | Fair Value, Measurements, Recurring | | | | | |
Fair Value by Hierarchy Level [Line Items] | | | | | |
Total Investments at Fair Value | | 0 | | | |
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 | | | |
Fair Value, Inputs, Level 3 | Equity securities | Fair Value, Measurements, Recurring | | | | | |
Fair Value by Hierarchy Level [Line Items] | | | | | |
Total Investments at Fair Value | | 500,000 | | | |
Total Assets at Fair Value | | 500,000 | | $ 0 | |
Net gains (losses) on investments and other financial instruments | | 0 | | | |
Fair Value, Inputs, Level 3 | Other investments | Fair Value, Measurements, Recurring | | | | | |
Fair Value by Hierarchy Level [Line Items] | | | | | |
Total Investments at Fair Value | [4] | $ 0 | | | |
Fair Value, Inputs, Level 3 | Maximum [Member] | Fair Value, Measurements, Recurring | | | | | |
Fair Value by Hierarchy Level [Line Items] | | | | | |
Total Level III Assets as a Percentage of Total Assets Measured at Fair Value | | 0.10% | | | |
| |
[1] | Does not include certain other invested assets ($1.7 million), primarily invested in limited partnerships, accounted for as cost-method investments and not measured at fair value. | |
[2] | Does not include certain other invested assets ($14.6 million), primarily invested in limited partnerships, accounted for as cost-method investments and not measured at fair value. Also excludes investments classified as assets held for sale of $495.1 million, $839.2 million and $102.6 million, with fair values categorized in Level I, Level II and Level III, respectively. | |
[3] | Comprising broadly diversified domestic equity mutual funds and certain common stocks included within Level I and various preferred stocks invested across numerous companies and industries included within Level II. | |
[4] | Comprising short-term certificates of deposit and commercial paper. | |
[5] | Comprising short-term certificates of deposit. | |