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v3.20.2

Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Millions | Oct. 30, 2020 | Oct. 26, 2020 | Oct. 01, 2020 | Oct. 31, 2020 | Sep. 30, 2020 | Dec. 31, 2019 | Feb. 26, 2019 | Dec. 31, 2018
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Subsequent Event [Line Items] |  |  |  |  |  |  |  |
Other long-term investments |  |  |  |  | $ 1,171.2 | $ 856.3 |  |
MediaAlpha |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |
Fully diluted ownership interest (as a percent) |  |  |  |  |  |  | 42.00% | 58.90%
Subsequent Event | Ark Insurance Holdings Limited |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |
Merger agreement, equity capital contributed |  |  | $ 605.4 |  |  |  |  |
Equity capital, pre money valuation amount |  |  | 300.0 |  |  |  |  |
Additional equity purchase from shareholders |  |  | 40.9 |  |  |  |  |
Investment, potential additional contribution of equity capital |  |  | $ 200.0 |  |  |  |  |
Ownership interest after all transactions |  |  | 72.00% |  |  |  |  |
Business combination, consideration transferred |  |  | $ 800.0 |  |  |  |  |
Investment owned, after additional equity contributions |  |  | $ 1,000.0 |  |  |  |  |
Fully diluted ownership interest after additional funding |  |  | 63.00% |  |  |  |  |
Equity incentives, rate of return threshold |  |  | 8.00% |  |  |  |  |
Percent of shares outstanding |  |  | 12.50% |  |  |  |  |
Amount of equity contribution pre-funded |  | $ 400.0 |  |  |  |  |  |
Subsequent Event | Ark Insurance Holdings Limited | Tranche One |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |
Invested capital return threshold, multiples |  |  | 2.0 |  |  |  |  |
Subsequent Event | Ark Insurance Holdings Limited | Tranche Two |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |
Invested capital return threshold, multiples |  |  | 2.5 |  |  |  |  |
Subsequent Event | Ark Insurance Holdings Limited | Tranche Three |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |
Invested capital return threshold, multiples |  |  | 3.0 |  |  |  |  |
Subsequent Event | Ark Insurance Holdings Limited | Forecast |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |
Ownership interest after additional funding |  |  | 77.10% |  |  |  |  |
Fully diluted ownership interest after additional funding |  |  | 67.50% |  |  |  |  |
Subsequent Event | MediaAlpha |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |
Share price (in USD per share) | $ 33.83 |  |  |  |  |  |  |
Subsequent Event | Ark Insurance Holdings Limited |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |
Letters of credit outstanding |  | $ 150.0 | $ 150.0 |  |  |  |  |
Subsequent Event | IPO | MediaAlpha |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |
Sale of stock, price per share (in USD per share) | $ 19.00 |  |  |  |  |  |  |
Equity market capitalization | $ 1,200.0 |  |  |  |  |  |  |
Equity enterprise valuation | 1,400.0 |  |  |  |  |  |  |
MediaAlpha | Subsequent Event |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |
Other long-term investments | $ 390.1 |  |  | $ 694.6 |  |  |  |
Investment owned (in shares) | 20,532,202 |  |  |  |  |  |  |
Fully diluted ownership interest (as a percent) | 32.30% |  |  |  |  |  |  |
MediaAlpha | Subsequent Event | IPO |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |
Sale of stock, number of shares issued in transaction (in shares) | 3,609,894 |  |  |  |  |  |  |
Sale of stock, consideration received in transaction | $ 63.8 |  |  |  |  |  |  |

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