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Investment Securities - Fair Value of Hedge Funds and Private Equity Funds (Details) - USD ($) $ in Millions | Sep. 30, 2022 | Dec. 31, 2021
--- | --- | ---
Total private equity funds and hedge funds included in other long-term investments |  |
Debt and Equity Securities, FV-NI [Line Items] |  |
Fair Value | $ 239.8 | $ 153.8
Unfunded Commitments | 102.5 | 44.0
Private equity funds |  |
Debt and Equity Securities, FV-NI [Line Items] |  |
Fair Value | 185.1 | 141.8
Unfunded Commitments | 102.5 | 44.0
Private equity funds | Aerospace/Defense/Government |  |
Debt and Equity Securities, FV-NI [Line Items] |  |
Fair Value | 102.9 | 69.8
Unfunded Commitments | 45.1 | 11.8
Private equity funds | Financial services |  |
Debt and Equity Securities, FV-NI [Line Items] |  |
Fair Value | 77.9 | 67.7
Unfunded Commitments | 54.9 | 29.3
Private equity funds | Real estate |  |
Debt and Equity Securities, FV-NI [Line Items] |  |
Fair Value | 4.3 | 4.3
Unfunded Commitments | 2.5 | 2.9
Hedge funds |  |
Debt and Equity Securities, FV-NI [Line Items] |  |
Fair Value | 54.7 | 12.0
Unfunded Commitments | 0.0 | 0.0
Hedge funds | Long/short equity financials and business services |  |
Debt and Equity Securities, FV-NI [Line Items] |  |
Fair Value | 49.3 | 0.0
Unfunded Commitments | 0.0 | 0.0
Hedge funds | European small/mid cap |  |
Debt and Equity Securities, FV-NI [Line Items] |  |
Fair Value | 5.4 | 12.0
Unfunded Commitments | $ 0.0 | $ 0.0

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