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Debt - Junior Convertible Securities (Details) - USD ($) | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2021 | Sep. 30, 2021 | Sep. 30, 2020 | Dec. 31, 2020
Debt Instrument [Line Items] |  |  |  |
Debt | $ 2,491,800,000 | $ 2,491,800,000 |  | $ 2,312,100,000
Repayments of long-term debt |  | 26,100,000 | $ 350,000,000.0 |
Repurchase of junior convertible securities, equity impact | 1,300,000 | 6,100,000 |  |
Additional Paid-In Capital |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Repurchase of junior convertible securities, equity impact | 1,300,000 | 6,100,000 |  |
Junior convertible securities |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Debt | $ 297,500,000 | $ 297,500,000 |  | $ 314,000,000.0
Junior Convertible Trust Preferred Securities | Junior convertible securities |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Debt interest rate | 5.15% | 5.15% |  |
Debt | $ 301,400,000 | $ 301,400,000 |  |
Face amount | $ 404,700,000 | $ 404,700,000 |  |
Debt instrument, term |  | 16 years |  |
Repayments of long-term debt |  | $ 28,700,000 |  |
Repurchase of junior convertible securities, debt impact |  | 26,100,000 |  |
Deferred tax liabilities, net, decrease resulting from repurchase of junior convertible securities |  | 6,200,000 |  |
Junior Convertible Trust Preferred Securities | Junior convertible securities | Additional Paid-In Capital |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Repurchase of junior convertible securities, equity impact |  | $ 6,100,000 |  |

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- Definition Adjustment to additional paid in capital resulting from the recognition of convertible debt instruments as two separate components - a debt component and an equity component. This bifurcation may result in a basis difference associated with the liability component that represents a temporary difference for purposes of applying accounting for income taxes. The initial recognition of deferred taxes for the tax effect of that temporary difference is as an adjustment to additional paid in capital. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 25 -Paragraph 22 -URI http://asc.fasb.org/extlink&oid=123466103&loc=SL6014347-161799 + Details
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