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Investment Securities - Other Long-Term Investments (Details) - USD ($) $ in Millions | Dec. 31, 2024 | Dec. 31, 2023
--- | --- | ---
Investment securities |  |
Other long-term investments | $ 2,150.2 | $ 1,998.2
Operating Segments | P&C Insurance and Reinsurance (Ark/WM Outrigger) |  |
Investment securities |  |
Other long-term investments | 547.8 | 440.9
Operating Segments | Asset Management (Kudu) |  |
Investment securities |  |
Other long-term investments | 1,014.0 | 896.3
Other Operations |  |
Investment securities |  |
Other long-term investments | 588.4 | 661.0
PassportCard/DavidShield |  |
Investment securities |  |
Other long-term investments | 150.0 | 150.0
PassportCard/DavidShield | Operating Segments | P&C Insurance and Reinsurance (Ark/WM Outrigger) |  |
Investment securities |  |
Other long-term investments | 0.0 | 0.0
PassportCard/DavidShield | Operating Segments | Asset Management (Kudu) |  |
Investment securities |  |
Other long-term investments | 0.0 | 0.0
PassportCard/DavidShield | Other Operations |  |
Investment securities |  |
Other long-term investments | 150.0 | 150.0
Elementum |  |
Investment securities |  |
Other long-term investments | 35.0 | 35.0
Elementum | Operating Segments | P&C Insurance and Reinsurance (Ark/WM Outrigger) |  |
Investment securities |  |
Other long-term investments | 0.0 | 0.0
Elementum | Operating Segments | Asset Management (Kudu) |  |
Investment securities |  |
Other long-term investments | 0.0 | 0.0
Elementum | Other Operations |  |
Investment securities |  |
Other long-term investments | 35.0 | 35.0
Other unconsolidated entities |  |
Investment securities |  |
Other long-term investments | 63.6 | 48.1
Other unconsolidated entities | Operating Segments | P&C Insurance and Reinsurance (Ark/WM Outrigger) |  |
Investment securities |  |
Other long-term investments | 0.0 | 0.0
Other unconsolidated entities | Operating Segments | Asset Management (Kudu) |  |
Investment securities |  |
Other long-term investments | 0.0 | 0.0
Other unconsolidated entities | Other Operations |  |
Investment securities |  |
Other long-term investments | 63.6 | 48.1
Private equity funds and hedge funds |  |
Investment securities |  |
Other long-term investments | 360.6 | 312.9
Private equity funds and hedge funds | Operating Segments | P&C Insurance and Reinsurance (Ark/WM Outrigger) |  |
Investment securities |  |
Other long-term investments | 104.1 | 55.5
Private equity funds and hedge funds | Operating Segments | Asset Management (Kudu) |  |
Investment securities |  |
Other long-term investments | 0.0 | 0.0
Private equity funds and hedge funds | Other Operations |  |
Investment securities |  |
Other long-term investments | 256.5 | 257.4
Bank loan fund |  |
Investment securities |  |
Other long-term investments | 264.7 | 194.4
Bank loan fund | Operating Segments | P&C Insurance and Reinsurance (Ark/WM Outrigger) |  |
Investment securities |  |
Other long-term investments | 264.7 | 194.4
Bank loan fund | Operating Segments | Asset Management (Kudu) |  |
Investment securities |  |
Other long-term investments | 0.0 | 0.0
Bank loan fund | Other Operations |  |
Investment securities |  |
Other long-term investments | 0.0 | 0.0
Lloyd’s trust deposits |  |
Investment securities |  |
Other long-term investments | 149.9 | 158.0
Lloyd’s trust deposits | Operating Segments | P&C Insurance and Reinsurance (Ark/WM Outrigger) |  |
Investment securities |  |
Other long-term investments | 149.9 | 158.0
Lloyd’s trust deposits | Operating Segments | Asset Management (Kudu) |  |
Investment securities |  |
Other long-term investments | 0.0 | 0.0
Lloyd’s trust deposits | Other Operations |  |
Investment securities |  |
Other long-term investments | 0.0 | 0.0
ILS funds |  |
Investment securities |  |
Other long-term investments | 74.0 | 160.5
ILS funds | Operating Segments | P&C Insurance and Reinsurance (Ark/WM Outrigger) |  |
Investment securities |  |
Other long-term investments | 0.0 | 0.0
ILS funds | Operating Segments | Asset Management (Kudu) |  |
Investment securities |  |
Other long-term investments | 0.0 | 0.0
ILS funds | Other Operations |  |
Investment securities |  |
Other long-term investments | 74.0 | 160.5
Private debt instruments |  |
Investment securities |  |
Other long-term investments | 14.9 | 15.8
Private debt instruments | Operating Segments | P&C Insurance and Reinsurance (Ark/WM Outrigger) |  |
Investment securities |  |
Other long-term investments | 0.0 | 0.0
Private debt instruments | Operating Segments | Asset Management (Kudu) |  |
Investment securities |  |
Other long-term investments | 5.6 | 5.8
Private debt instruments | Other Operations |  |
Investment securities |  |
Other long-term investments | 9.3 | 10.0
Other |  |
Investment securities |  |
Other long-term investments | 29.1 | 33.0
Other | Operating Segments | P&C Insurance and Reinsurance (Ark/WM Outrigger) |  |
Investment securities |  |
Other long-term investments | 29.1 | 33.0
Other | Operating Segments | Asset Management (Kudu) |  |
Investment securities |  |
Other long-term investments | 0.0 | 0.0
Other | Other Operations |  |
Investment securities |  |
Other long-term investments | 0.0 | 0.0
Kudu’s Participation Contracts | Kudu |  |
Investment securities |  |
Other long-term investments | 1,008.4 | 890.5
Kudu’s Participation Contracts | Kudu | Operating Segments | P&C Insurance and Reinsurance (Ark/WM Outrigger) |  |
Investment securities |  |
Other long-term investments | 0.0 | 0.0
Kudu’s Participation Contracts | Kudu | Operating Segments | Asset Management (Kudu) |  |
Investment securities |  |
Other long-term investments | 1,008.4 | 890.5
Kudu’s Participation Contracts | Kudu | Other Operations |  |
Investment securities |  |
Other long-term investments | 0.0 | 0.0
Investments, Excluding MediaAlpha | Total unconsolidated entities |  |
Investment securities |  |
Other long-term investments | 1,257.0 | 1,123.6
Investments, Excluding MediaAlpha | Total unconsolidated entities | Operating Segments | P&C Insurance and Reinsurance (Ark/WM Outrigger) |  |
Investment securities |  |
Other long-term investments | 0.0 | 0.0
Investments, Excluding MediaAlpha | Total unconsolidated entities | Operating Segments | Asset Management (Kudu) |  |
Investment securities |  |
Other long-term investments | 1,008.4 | 890.5
Investments, Excluding MediaAlpha | Total unconsolidated entities | Other Operations |  |
Investment securities |  |
Other long-term investments | $ 248.6 | $ 233.1

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