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v3.20.2

Investment Securities - Rollforward of Fair Value Measurements by Level (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended |  |
--- | --- | --- | --- | ---
Mar. 31, 2019 | Sep. 30, 2020 | Sep. 30, 2019 | Dec. 31, 2019 | Dec. 31, 2018
Debt and Equity Securities, FV-NI [Line Items] |  |  |  |  |
Beginning balance | $ 2,328.7 | $ 2,746.0 | $ 2,328.7 |  |
Net realized and unrealized gains (losses) |  | 302.4 | 347.5 |  |
Amortization/Accretion |  | (3.0) | (1.0) |  |
Purchases |  | 563.6 | 750.4 |  |
Sales |  | (1,075.6) | (856.2) |  |
Transfers in |  | 0.0 | 82.6 |  |
Transfers out |  | 0.0 | (82.6) |  |
Ending balance |  | 2,533.4 | 2,569.4 |  |
Level 1 Investments |  |  |  |  |
Debt and Equity Securities, FV-NI [Line Items] |  |  |  |  |
Beginning balance | 842.6 | 780.0 | 842.6 |  |
Net realized and unrealized gains (losses) |  | 29.2 | 121.8 |  |
Amortization/Accretion |  | 0.0 | 0.2 |  |
Purchases |  | 128.8 | 101.4 |  |
Sales |  | (642.7) | (362.3) |  |
Transfers in |  | 0.0 | 0.0 |  |
Transfers out |  | 0.0 | 0.0 |  |
Ending balance |  | 295.3 | 703.7 |  |
Level 2 Investments |  |  |  |  |
Debt and Equity Securities, FV-NI [Line Items] |  |  |  |  |
Beginning balance | 1,160.5 | 1,109.6 | 1,160.5 |  |
Net realized and unrealized gains (losses) |  | 12.5 | 66.6 |  |
Amortization/Accretion |  | (3.0) | (1.2) |  |
Purchases |  | 316.2 | 331.3 |  |
Sales |  | (368.5) | (465.2) |  |
Transfers in |  | 0.0 | 0.0 |  |
Transfers out |  | 0.0 | 0.0 |  |
Ending balance |  | 1,066.8 | 1,092.0 |  |
Common equity securities | Level 3 Investments |  |  |  |  |
Debt and Equity Securities, FV-NI [Line Items] |  |  |  |  |
Beginning balance |  | 0.1 |  |  |
Net realized and unrealized gains (losses) |  | 0.0 |  |  |
Amortization/Accretion |  | 0.0 |  |  |
Purchases |  | 0.0 |  |  |
Sales |  | 0.0 |  |  |
Transfers in |  | 0.0 |  |  |
Transfers out |  | 0.0 |  |  |
Ending balance |  | 0.1 |  |  |
Other long-term investments | Level 3 Investments |  |  |  |  |
Debt and Equity Securities, FV-NI [Line Items] |  |  |  |  |
Beginning balance | 138.7 | 654.0 | 138.7 |  |
Net realized and unrealized gains (losses) |  | 275.6 | 154.2 |  |
Amortization/Accretion |  | 0.0 | 0.0 |  |
Purchases |  | 78.8 | 211.3 |  |
Sales |  | (8.1) |  |  |
Transfers in |  | 0.0 | 82.6 |  |
Transfers out |  | 0.0 | 0.0 |  |
Ending balance |  | 1,000.3 | 586.8 |  |
Hedge and private equity funds included in other long-term investments | NAV |  |  |  |  |
Debt and Equity Securities, FV-NI [Line Items] |  |  |  |  |
Beginning balance | 186.9 | 202.3 | 186.9 |  |
Net realized and unrealized gains (losses) |  | (14.9) | 4.9 |  |
Amortization/Accretion |  | 0.0 | 0.0 |  |
Purchases |  | 39.8 | 106.4 |  |
Sales |  | (56.3) | (28.7) |  |
Transfers in |  | 0.0 | 0.0 |  |
Transfers out |  | 0.0 | (82.6) |  |
Ending balance |  | 170.9 | 186.9 |  |
Short-term investments |  |  |  |  |
Debt and Equity Securities, FV-NI [Line Items] |  |  |  |  |
Short-term investments, at fair value |  | 571.8 | 272.5 | $ 201.2 | $ 214.2
Realized and unrealized losses |  | $ 0.4 | 0.3 |  |
Asset Management (Kudu) | NAV |  |  |  |  |
Debt and Equity Securities, FV-NI [Line Items] |  |  |  |  |
Purchases |  |  | 70.1 |  |
Transfers out |  |  | $ (71.7) |  |
Marketing Technology (MediaAlpha) |  |  |  |  |
Debt and Equity Securities, FV-NI [Line Items] |  |  |  |  |
Unrealized investment gain | $ 114.7 |  |  |  |

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- Definition The sum of the periodic adjustments of the differences between securities' face values and purchase prices that are charged against earnings. This is called accretion if the security was purchased at a discount and amortization if it was purchased at premium. As a noncash item, this element is an adjustment to net income when calculating cash provided by or used in operations using the indirect method. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585 + Details
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