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v3.22.2.2

Fair Value Measurements - Narrative (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2022 | Sep. 30, 2021 | Sep. 30, 2022 | Sep. 30, 2021 | Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Transfers out of Level 3 | $ 0.0 | $ 211.7 | $ 5.7 | $ 212.3 |
Debt Securities, Available-for-Sale | 6,577.1 |  | 6,577.1 |  | $ 7,986.9
Equity Securities, FV-NI, Current | 322.7 |  | 322.7 |  | 830.6
Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Total | 7,044.4 |  | 7,044.4 |  | 8,863.9
Convertible debt at fair value | 42.6 |  | 42.6 |  | 46.4
Fair Value, Measurements, Recurring | Measured at Net Asset Value |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Total | 208.5 |  | 208.5 |  | 325.0
Convertible debt at fair value | 0.0 |  | 0.0 |  | 0.0
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Total | 233.2 |  | 233.2 |  | 251.4
Convertible debt at fair value | 0.0 |  | 0.0 |  | 0.0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Total | 183.8 |  | 183.8 |  | 586.6
Convertible debt at fair value | 0.0 |  | 0.0 |  | 0.0
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Total | 6,418.9 |  | 6,418.9 |  | 7,700.9
Convertible debt at fair value | 42.6 |  | 42.6 |  | 46.4
Limited Liability Companies and Limited Partnerships | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Equity Securities, FV-NI, Current | 208.5 |  | 208.5 |  | 325.0
Limited Liability Companies and Limited Partnerships | Fair Value, Measurements, Recurring | Measured at Net Asset Value |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Equity Securities, FV-NI, Current | 208.5 |  | 208.5 |  | 325.0
Limited Liability Companies and Limited Partnerships | Significant Unobservable Inputs (Level 3) |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Unfunded commitments | 92.5 |  | 92.5 |  |
Limited Liability Companies and Limited Partnerships | Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Equity Securities, FV-NI, Current | 0.0 |  | 0.0 |  | 0.0
Limited Liability Companies and Limited Partnerships | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Equity Securities, FV-NI, Current | 0.0 |  | 0.0 |  | 0.0
Limited Liability Companies and Limited Partnerships | Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Equity Securities, FV-NI, Current | 0.0 |  | 0.0 |  | 0.0
U.S. Government and Government Agencies and Authorities | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 526.8 |  | 526.8 |  | 637.4
U.S. Government and Government Agencies and Authorities | Fair Value, Measurements, Recurring | Measured at Net Asset Value |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 0.0 |  | 0.0 |  | 0.0
U.S. Government and Government Agencies and Authorities | Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 0.0 |  | 0.0 |  | 0.0
U.S. Government and Government Agencies and Authorities | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 112.0 |  | 112.0 |  | 132.8
U.S. Government and Government Agencies and Authorities | Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 414.8 |  | 414.8 |  | 504.6
States and Political Subdivisions | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 1,552.1 |  | 1,552.1 |  | 1,890.1
States and Political Subdivisions | Fair Value, Measurements, Recurring | Measured at Net Asset Value |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 0.0 |  | 0.0 |  | 0.0
States and Political Subdivisions | Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 0.0 |  | 0.0 |  | 0.0
States and Political Subdivisions | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 0.0 |  | 0.0 |  | 0.0
States and Political Subdivisions | Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 1,552.1 |  | 1,552.1 |  | 1,890.1
Foreign Governments | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 3.7 |  | 3.7 |  | 5.5
Foreign Governments | Fair Value, Measurements, Recurring | Measured at Net Asset Value |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 0.0 |  | 0.0 |  | 0.0
Foreign Governments | Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 0.0 |  | 0.0 |  | 0.0
Foreign Governments | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 0.0 |  | 0.0 |  | 0.0
Foreign Governments | Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 3.7 |  | 3.7 |  | 5.5
Corporate Debt Securities [Member] | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 3,341.5 |  | 3,341.5 |  | 4,386.9
Corporate Debt Securities [Member] | Fair Value, Measurements, Recurring | Measured at Net Asset Value |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 0.0 |  | 0.0 |  | 0.0
Corporate Debt Securities [Member] | Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 218.7 |  | 218.7 |  | 236.8
Corporate Debt Securities [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 0.0 |  | 0.0 |  | 0.0
Corporate Debt Securities [Member] | Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 3,122.8 |  | 3,122.8 |  | 4,150.1
Redeemable Preferred Stocks | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 8.0 |  | 8.0 |  | 7.4
Redeemable Preferred Stocks | Fair Value, Measurements, Recurring | Measured at Net Asset Value |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 0.0 |  | 0.0 |  |
Redeemable Preferred Stocks | Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 6.8 |  | 6.8 |  |
Redeemable Preferred Stocks | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 0.0 |  | 0.0 |  |
Redeemable Preferred Stocks | Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 1.2 |  | 1.2 |  |
Collateralized Loan Obligations | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 952.6 |  | 952.6 |  | 752.1
Collateralized Loan Obligations | Fair Value, Measurements, Recurring | Measured at Net Asset Value |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 0.0 |  | 0.0 |  | 0.0
Collateralized Loan Obligations | Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 0.0 |  | 0.0 |  | 0.0
Collateralized Loan Obligations | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 0.0 |  | 0.0 |  | 0.0
Collateralized Loan Obligations | Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 952.6 |  | 952.6 |  | 752.1
Other Mortgage- and Asset-backed | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 294.4 |  | 294.4 |  | 307.5
Other Mortgage- and Asset-backed | Fair Value, Measurements, Recurring | Measured at Net Asset Value |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 0.0 |  | 0.0 |  | 0.0
Other Mortgage- and Asset-backed | Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 5.2 |  | 5.2 |  | 7.0
Other Mortgage- and Asset-backed | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 0.0 |  | 0.0 |  | 0.0
Other Mortgage- and Asset-backed | Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 289.2 |  | 289.2 |  | 300.5
Investments in Fixed Maturities | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 6,679.1 |  | 6,679.1 |  | 7,986.9
Investments in Fixed Maturities | Fair Value, Measurements, Recurring | Measured at Net Asset Value |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 0.0 |  | 0.0 |  | 0.0
Investments in Fixed Maturities | Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 230.7 |  | 230.7 |  | 249.9
Investments in Fixed Maturities | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 112.0 |  | 112.0 |  | 132.8
Investments in Fixed Maturities | Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Debt Securities, Available-for-Sale | 6,336.4 |  | 6,336.4 |  | 7,604.2
Preferred Stocks | Fair Value, Measurements, Recurring | Finance, Insurance and Real Estate |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Equity Securities, FV-NI, Current | 29.8 |  | 29.8 |  | 34.2
Preferred Stocks | Fair Value, Measurements, Recurring | Finance, Insurance and Real Estate | Measured at Net Asset Value |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Equity Securities, FV-NI, Current | 0.0 |  | 0.0 |  | 0.0
Preferred Stocks | Fair Value, Measurements, Recurring | Other Industries |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Equity Securities, FV-NI, Current | 11.7 |  | 11.7 |  | 17.6
Preferred Stocks | Fair Value, Measurements, Recurring | Other Industries | Measured at Net Asset Value |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Equity Securities, FV-NI, Current | 0.0 |  | 0.0 |  | 0.0
Preferred Stocks | Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring | Finance, Insurance and Real Estate |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Equity Securities, FV-NI, Current | 0.0 |  | 0.0 |  | 0.0
Preferred Stocks | Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring | Other Industries |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Equity Securities, FV-NI, Current | 2.0 |  | 2.0 |  | 1.5
Preferred Stocks | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring | Finance, Insurance and Real Estate |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Equity Securities, FV-NI, Current | 0.0 |  | 0.0 |  | 0.0
Preferred Stocks | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring | Other Industries |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Equity Securities, FV-NI, Current | 0.0 |  | 0.0 |  | 0.0
Preferred Stocks | Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Finance, Insurance and Real Estate |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Equity Securities, FV-NI, Current | 29.8 |  | 29.8 |  | 34.2
Preferred Stocks | Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Other Industries |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Equity Securities, FV-NI, Current | 9.7 |  | 9.7 |  | 16.1
Common Stock | Fair Value, Measurements, Recurring | Finance, Insurance and Real Estate |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Equity Securities, FV-NI, Current | 0.9 |  | 0.9 |  | 18.9
Common Stock | Fair Value, Measurements, Recurring | Finance, Insurance and Real Estate | Measured at Net Asset Value |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Equity Securities, FV-NI, Current | 0.0 |  | 0.0 |  | 0.0
Common Stock | Fair Value, Measurements, Recurring | Other Industries |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Equity Securities, FV-NI, Current | 1.1 |  | 1.1 |  | 2.9
Common Stock | Fair Value, Measurements, Recurring | Other Industries | Measured at Net Asset Value |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Equity Securities, FV-NI, Current | 0.0 |  | 0.0 |  | 0.0
Common Stock | Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring | Finance, Insurance and Real Estate |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Equity Securities, FV-NI, Current | 0.0 |  | 0.0 |  | 0.0
Common Stock | Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring | Other Industries |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Equity Securities, FV-NI, Current | 0.5 |  | 0.5 |  | 0.0
Common Stock | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring | Finance, Insurance and Real Estate |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Equity Securities, FV-NI, Current | 0.9 |  | 0.9 |  | 18.9
Common Stock | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring | Other Industries |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Equity Securities, FV-NI, Current | 0.2 |  | 0.2 |  | 2.9
Common Stock | Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Finance, Insurance and Real Estate |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Equity Securities, FV-NI, Current | 0.0 |  | 0.0 |  | 0.0
Common Stock | Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Other Industries |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Equity Securities, FV-NI, Current | 0.4 |  | 0.4 |  | 0.0
Exchange Traded Funds | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Equity Securities, FV-NI, Current | 70.7 |  | 70.7 |  | 432.0
Exchange Traded Funds | Fair Value, Measurements, Recurring | Measured at Net Asset Value |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Equity Securities, FV-NI, Current | 0.0 |  | 0.0 |  | 0.0
Exchange Traded Funds | Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Equity Securities, FV-NI, Current | 0.0 |  | 0.0 |  | 0.0
Exchange Traded Funds | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Equity Securities, FV-NI, Current | 70.7 |  | 70.7 |  | 432.0
Exchange Traded Funds | Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Equity Securities, FV-NI, Current | 0.0 |  | 0.0 |  | 0.0
Equity Securities | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Equity Securities, FV-NI, Current | 322.7 |  | 322.7 |  | 830.6
Equity Securities | Fair Value, Measurements, Recurring | Measured at Net Asset Value |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Equity Securities, FV-NI, Current | 208.5 |  | 208.5 |  | 325.0
Equity Securities | Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Equity Securities, FV-NI, Current | 2.5 |  | 2.5 |  | 1.5
Equity Securities | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Equity Securities, FV-NI, Current | 71.8 |  | 71.8 |  | 453.8
Equity Securities | Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Equity Securities, FV-NI, Current | $ 39.9 |  | $ 39.9 |  | $ 50.3

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