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Commitments and Contingencies (Details) - USD ($) $ in Millions | 9 Months Ended |
--- | --- | ---
Sep. 30, 2020 | Sep. 30, 2019 | Dec. 31, 2019
Debt Instrument [Line Items] |  |  |
Investment commitments | $ 1,910.0 |  | $ 1,690.0
Interest expense on senior notes and other borrowings | 60.6 | $ 68.6 |
Senior notes | 3.535% Senior Notes due 2050 |  |  |
Debt Instrument [Line Items] |  |  |
Senior notes, face amount | $ 1,000.0 |  |
Senior notes, stated percentage | 3.635% |  |
Description of interest rate terms | Interest will be calculated on the basis of a 360-day year of twelve 30-day months |  |
Maturity date of senior notes | Jun. 30, 2050 |  |

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