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Fair Value Measurements - Fair Value Inputs (Details) - USD ($) | Mar. 31, 2019 | Dec. 31, 2018
--- | --- | ---
Fair Value, Inputs, Level 3 [Member] | Partnership Interest [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments | $ 138,800,000 |
Fair Value, Measurements, Recurring [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments, Fair Value Disclosure | 7,523,800,000 | $ 7,140,100,000
Fair Value, Measurements, Recurring [Member] | Investments in Fixed Maturities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 6,573,100,000 | 6,424,200,000
Fair Value, Measurements, Recurring [Member] | U.S. Government and Government Agencies and Authorities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 858,400,000 | 865,700,000
Fair Value, Measurements, Recurring [Member] | States and Political Subdivisions [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 1,681,900,000 | 1,619,100,000
Fair Value, Measurements, Recurring [Member] | Foreign Governments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 5,200,000 | 5,900,000
Fair Value, Measurements, Recurring [Member] | Corporate Bonds and Notes [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 3,480,100,000 | 3,393,800,000
Fair Value, Measurements, Recurring [Member] | Collateralized Loan Obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 531,500,000 | 524,000,000.0
Fair Value, Measurements, Recurring [Member] | Other Mortgage- and Asset-backed |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 16,000,000.0 | 15,700,000
Fair Value, Measurements, Recurring [Member] | Equity Securities [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 916,900,000 | 684,400,000
Fair Value, Measurements, Recurring [Member] | Exchange Traded Funds [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 656,000,000.0 | 427,300,000
Fair Value, Measurements, Recurring [Member] | Partnership Interest [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 192,000,000.0 | 192,000,000.0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments, Fair Value Disclosure | 823,000,000.0 | 594,200,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Investments in Fixed Maturities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 154,500,000 | 156,500,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | U.S. Government and Government Agencies and Authorities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 154,500,000 | 156,500,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | States and Political Subdivisions [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Foreign Governments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Corporate Bonds and Notes [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Collateralized Loan Obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Other Mortgage- and Asset-backed |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Equity Securities [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 668,500,000 | 437,700,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Exchange Traded Funds [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure |  | 427,300,000
Equity, Fair Value Disclosure | 656,000,000.0 |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Partnership Interest [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure |  | 0
Equity, Fair Value Disclosure | 0 |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments, Fair Value Disclosure | 5,558,100,000 | 5,456,500,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Investments in Fixed Maturities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 5,467,900,000 | 5,370,300,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. Government and Government Agencies and Authorities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 703,900,000 | 709,200,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | States and Political Subdivisions [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 1,681,900,000 | 1,619,100,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Foreign Governments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 5,200,000 | 5,900,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Corporate Bonds and Notes [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 3,068,200,000 | 3,011,200,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Collateralized Loan Obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 3,000,000.0 | 19,100,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other Mortgage- and Asset-backed |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 5,700,000 | 5,800,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Equity Securities [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 56,400,000 | 54,700,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Exchange Traded Funds [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure |  | 0
Equity, Fair Value Disclosure | 0 |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Partnership Interest [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure |  | 0
Equity, Fair Value Disclosure | 0 |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments, Fair Value Disclosure | 950,700,000 | 897,400,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Investments in Fixed Maturities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 950,700,000 | 897,400,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | U.S. Government and Government Agencies and Authorities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | States and Political Subdivisions [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Foreign Governments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Corporate Bonds and Notes [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 411,900,000 | 382,600,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Collateralized Loan Obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 528,500,000 | 504,900,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Other Mortgage- and Asset-backed |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 10,300,000 | 9,900,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Equity Securities [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Exchange Traded Funds [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure |  | 0
Equity, Fair Value Disclosure | 0 |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Partnership Interest [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure |  | 0
Equity, Fair Value Disclosure | 0 |
Finance, Insurance and Real Estate [Member] | Fair Value, Measurements, Recurring [Member] | Preferred Stock [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 42,700,000 | 41,200,000
Finance, Insurance and Real Estate [Member] | Fair Value, Measurements, Recurring [Member] | Common Stock [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 11,400,000 | 10,200,000
Finance, Insurance and Real Estate [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Preferred Stock [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure |  | 0
Equity Securities at Fair Value | 0 |
Finance, Insurance and Real Estate [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Common Stock [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure |  | 10,200,000
Equity, Fair Value Disclosure | 11,400,000 |
Finance, Insurance and Real Estate [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Preferred Stock [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure |  | 41,200,000
Equity, Fair Value Disclosure | 42,700,000 |
Finance, Insurance and Real Estate [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Common Stock [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure |  | 0
Equity, Fair Value Disclosure | 0 |
Finance, Insurance and Real Estate [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Preferred Stock [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure |  | 0
Equity, Fair Value Disclosure | 0 |
Finance, Insurance and Real Estate [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Common Stock [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure |  | 0
Equity, Fair Value Disclosure | 0 |
All Industries Other than Finance, Insurance and Real Estate [Member] | Fair Value, Measurements, Recurring [Member] | Preferred Stock [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 14,100,000 | 13,000,000.0
All Industries Other than Finance, Insurance and Real Estate [Member] | Fair Value, Measurements, Recurring [Member] | Common Stock [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 700,000 | 700,000
All Industries Other than Finance, Insurance and Real Estate [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Preferred Stock [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure |  | 0
Equity, Fair Value Disclosure | 800,000 |
All Industries Other than Finance, Insurance and Real Estate [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Common Stock [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure |  | 200,000
Equity, Fair Value Disclosure | 300,000 |
All Industries Other than Finance, Insurance and Real Estate [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Preferred Stock [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure |  | 13,000,000.0
Equity, Fair Value Disclosure | 13,300,000 |
All Industries Other than Finance, Insurance and Real Estate [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Common Stock [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure |  | 500,000
Equity, Fair Value Disclosure | 400,000 |
All Industries Other than Finance, Insurance and Real Estate [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Preferred Stock [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure |  | 0
Equity, Fair Value Disclosure | 0 |
All Industries Other than Finance, Insurance and Real Estate [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Common Stock [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure |  | 0
Equity, Fair Value Disclosure | 0 |
Fair Value, Inputs, Net Asset Value [Member] | Fair Value, Measurements, Recurring [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Investments, Fair Value Disclosure | 192,000,000.0 | 192,000,000.0
Fair Value, Inputs, Net Asset Value [Member] | Fair Value, Measurements, Recurring [Member] | Investments in Fixed Maturities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 0 | 0
Fair Value, Inputs, Net Asset Value [Member] | Fair Value, Measurements, Recurring [Member] | U.S. Government and Government Agencies and Authorities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 0 | 0
Fair Value, Inputs, Net Asset Value [Member] | Fair Value, Measurements, Recurring [Member] | States and Political Subdivisions [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 0 | 0
Fair Value, Inputs, Net Asset Value [Member] | Fair Value, Measurements, Recurring [Member] | Foreign Governments |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 0 | 0
Fair Value, Inputs, Net Asset Value [Member] | Fair Value, Measurements, Recurring [Member] | Corporate Bonds and Notes [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 0 | 0
Fair Value, Inputs, Net Asset Value [Member] | Fair Value, Measurements, Recurring [Member] | Collateralized Loan Obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 0 | 0
Fair Value, Inputs, Net Asset Value [Member] | Fair Value, Measurements, Recurring [Member] | Other Mortgage- and Asset-backed |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 0 | 0
Fair Value, Inputs, Net Asset Value [Member] | Fair Value, Measurements, Recurring [Member] | Equity Securities [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure | 192,000,000.0 | 192,000,000.0
Fair Value, Inputs, Net Asset Value [Member] | Fair Value, Measurements, Recurring [Member] | Exchange Traded Funds [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure |  | 0
Equity, Fair Value Disclosure | 0 |
Fair Value, Inputs, Net Asset Value [Member] | Fair Value, Measurements, Recurring [Member] | Partnership Interest [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure |  | 192,000,000.0
Equity, Fair Value Disclosure | 192,000,000.0 |
Fair Value, Inputs, Net Asset Value [Member] | Finance, Insurance and Real Estate [Member] | Fair Value, Measurements, Recurring [Member] | Preferred Stock [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure |  | 0
Equity, Fair Value Disclosure | 0 |
Fair Value, Inputs, Net Asset Value [Member] | Finance, Insurance and Real Estate [Member] | Fair Value, Measurements, Recurring [Member] | Common Stock [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure |  | 0
Equity, Fair Value Disclosure | 0 |
Fair Value, Inputs, Net Asset Value [Member] | All Industries Other than Finance, Insurance and Real Estate [Member] | Fair Value, Measurements, Recurring [Member] | Preferred Stock [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure |  | 0
Equity, Fair Value Disclosure | 0 |
Fair Value, Inputs, Net Asset Value [Member] | All Industries Other than Finance, Insurance and Real Estate [Member] | Fair Value, Measurements, Recurring [Member] | Common Stock [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale Securities, Fair Value Disclosure |  | $ 0
Equity, Fair Value Disclosure | $ 0 |

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- Definition The amount of unfunded commitments for which the entity is obligated, to those certain investments for which net asset value per share is calculated (including by unit, membership interest, or other equity (ownership interest) unit measure) (alternative investments). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 6A -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=99377789&loc=SL6742756-110258 + Details
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