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Equity-Method Eligible Investments - Carrying Values of Equity Method Eligible Investments Recorded within Other Long-Term Investments (Details) - USD ($) $ in Millions | Mar. 31, 2023 | Dec. 31, 2022
--- | --- | ---
Investments in unconsolidated affiliates |  |
Other long-term investments | $ 1,643.0 | $ 1,488.0
Kudu investments |  |
Investments in unconsolidated affiliates |  |
Other long-term investments | $ 683.2 | $ 695.9
Kudu investments | Minimum |  |
Investments in unconsolidated affiliates |  |
Ownership interest (as a percent) | 4.10% | 4.10%
Kudu investments | Maximum |  |
Investments in unconsolidated affiliates |  |
Ownership interest (as a percent) | 30.00% | 30.00%
Marketing Technology (MediaAlpha) |  |
Investments in unconsolidated affiliates |  |
Ownership interest (as a percent) | 26.80% | 27.10%
Other long-term investments | $ 253.8 | $ 168.6
PassportCard/DavidShield |  |
Investments in unconsolidated affiliates |  |
Ownership interest (as a percent) | 53.80% | 53.80%
Other long-term investments | $ 140.0 | $ 135.0
Elementum Holdings, L.P. |  |
Investments in unconsolidated affiliates |  |
Ownership interest (as a percent) | 26.60% | 29.70%
Other long-term investments | $ 30.0 | $ 30.0
Other |  |
Investments in unconsolidated affiliates |  |
Other long-term investments | 180.8 | 84.4
Equity Method Investments |  |
Investments in unconsolidated affiliates |  |
Other long-term investments | $ 10.5 | $ 0.0

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