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Investment Securities (Significant Unobservable Inputs) (Details) - NR | 6 Months Ended | 12 Months Ended
--- | --- | ---
Jun. 30, 2019 USD ($) $ / shares | Dec. 31, 2018 USD ($)
Kudu Investments | Discounted cash flow |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Assets, fair value | $ 142,200,000 |
MediaAlpha |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Assets, fair value | 114,700,000 |
DavidShield & PassportCard | Discounted cash flow |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Assets, fair value | 75,000,000.0 | $ 75,000,000.0
Elementum Holdings, L.P. | Discounted cash flow |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Assets, fair value | 55,100,000 |
Private Debt Instrument | Discounted cash flow |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Assets, fair value | 21,700,000 | 10,000,000.0
durchblicker | Discounted cash flow |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Assets, fair value | 15,500,000 | 15,500,000
Vidado (f.k.a. Captricity, Inc.) | Discounted cash flow |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Assets, fair value | 14,500,000 |
Captricity | Discounted cash flow |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Assets, fair value |  | 14,500,000
Galvanic Applied Sciences | Multiple of EBITDA |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Assets, fair value | 2,200,000 | 3,100,000
Compare.com | Discounted cash flow |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Assets, fair value |  | $ 16,900,000
Compare.com | Estimated Net Realizable Value |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Assets, fair value | $ 1,900,000 |
Unit price | MediaAlpha |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Share Price | $ / shares | $ 208.98 |
Discount rate | DavidShield & PassportCard |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Fair value, discount rate | 18.00% | 18.00%
Discount rate | Private Debt Instrument |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Fair value, discount rate |  | 9.23%
Discount rate | durchblicker |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Fair value, discount rate | 23.00% | 23.00%
Discount rate | Vidado (f.k.a. Captricity, Inc.) |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Fair value, discount rate | 23.00% |
Discount rate | Captricity |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Fair value, discount rate |  | 23.00%
Discount rate | Compare.com |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Fair value, discount rate |  | 22.00%
Revenue exit multiple | DavidShield & PassportCard |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Measurement input | 1.00 | 1.00
Revenue exit multiple | durchblicker |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Measurement input | 2.25 | 2.25
Revenue exit multiple | Captricity |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Measurement input | 3.75 | 3.75
Revenue exit multiple | Compare.com |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Measurement input |  | 2.75
Transaction price | Elementum Holdings, L.P. |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Fair value, discount rate | 5510000000.00% |
EBITDA multiple | Galvanic Applied Sciences |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Fair value, discount rate | 600.00% | 600.00%
Discount to Book Value | Compare.com |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Fair value, discount rate | 94.00% |
Minimum | Discount rate | Kudu Investments |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Fair value, discount rate | 15.30% |
Minimum | Discount rate | Private Debt Instrument |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Fair value, discount rate | 6.56% |
Minimum | Revenue exit multiple | Kudu Investments |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Fair value, discount rate | 6.60% |
Maximum | Discount rate | Kudu Investments |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Fair value, discount rate | 19.60% |
Maximum | Discount rate | Private Debt Instrument |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Fair value, discount rate | 8.71% |
Maximum | Revenue exit multiple | Kudu Investments |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Fair value, discount rate | 12.20% |

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