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Investment Securities (Significant Unobservable Inputs) (Details) - Standard Poors NR Rating $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2019 USD ($) | Dec. 31, 2018 USD ($)
Measurement Input, Discount Rate | MediaAlpha |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Fair Value, Discount Rate | 15.00% |
Measurement Input, Discount Rate | DavidShield & PassportCard |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Fair Value, Discount Rate | 22.00% | 18.00%
Measurement Input, Discount Rate | Elementum Holdings, L.P. |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Fair Value, Discount Rate | 20.00% |
Terminal Revenue Growth Rate | 4.00% |
Measurement Input, Discount Rate | Private debt instrument |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Fair Value, Discount Rate |  | 9.00%
Measurement Input, Discount Rate | Other |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Fair Value, Discount Rate |  | 23.00%
Terminal Revenue Growth Rate | 4.00% |
Measurement Input, Discount Rate | Compare.com |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Fair Value, Discount Rate |  | 22.00%
Measurement Input, Revenue Multiple | DavidShield & PassportCard |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Terminal Revenue Growth Rate | 4.00% |
Equity Securities, FV-NI, Measurement Input |  | 1
Measurement Input, Revenue Multiple | Compare.com |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Equity Securities, FV-NI, Measurement Input |  | 3
Measurement Input, Long-term Revenue Growth Rate | MediaAlpha |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Terminal Revenue Growth Rate | 4.00% |
Estimated Net Realizable Value | Compare.com |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Assets, fair value | $ 2.5 |
Minimum | Measurement Input, Discount Rate | Kudu Investments |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Fair Value, Discount Rate | 15.00% |
Minimum | Measurement Input, Discount Rate | Private debt instrument |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Fair Value, Discount Rate | 4.00% |
Minimum | Measurement Input, Discount Rate | Other |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Fair Value, Discount Rate | 25.00% |
Minimum | Measurement Input, Revenue Multiple | Other |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Equity Securities, FV-NI, Measurement Input |  | 2
Maximum | Measurement Input, Discount Rate | Kudu Investments |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Fair Value, Discount Rate | 22.00% |
Maximum | Measurement Input, Discount Rate | Private debt instrument |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Fair Value, Discount Rate | 9.00% |
Maximum | Measurement Input, Discount Rate | Other |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Fair Value, Discount Rate | 32.00% |
Maximum | Measurement Input, Revenue Multiple | Other |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Equity Securities, FV-NI, Measurement Input |  | 4
Estimated Net Realizable Value | Compare.com |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Assets, fair value | $ 2.5 |
Discounted Cash Flow Valuation Technique | Kudu Investments |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Assets, fair value | 266.5 |
Discounted Cash Flow Valuation Technique | MediaAlpha |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Assets, fair value | 180.0 |
Discounted Cash Flow Valuation Technique | DavidShield & PassportCard |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Assets, fair value | 90.0 | $ 75.0
Discounted Cash Flow Valuation Technique | Elementum Holdings, L.P. |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Assets, fair value | 55.1 |
Discounted Cash Flow Valuation Technique | Private debt instrument |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Assets, fair value | 23.7 | 10.0
Discounted Cash Flow Valuation Technique | Other |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Assets, fair value | $ 23.7 | 30.0
Discounted Cash Flow Valuation Technique | Compare.com |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Assets, fair value |  | 16.9
Multiple of EBITDA | Galvanic |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Assets, fair value |  | $ 3.1
Equity Securities, FV-NI, Measurement Input |  | 6

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