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Indebtedness (Details) - USD ($) | 1 Months Ended | 3 Months Ended | 9 Months Ended |  |
--- | --- | --- | --- | --- | ---
Feb. 28, 2021 | Sep. 30, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020 | Apr. 30, 2020 | Sep. 15, 2015
Debt Instrument [Line Items] |  |  |  |  |  |  |
Payments of financing costs |  |  |  | $ 24,400,000 |  |  |
Repayments of Senior Debt | $ 151,800,000 |  |  |  |  |  |
Repayments of borrowings and premiums paid on debt exchange |  |  |  | 170,000,000.0 | $ 0 |  |
Interest Expense |  | $ 66,300,000 | $ 56,300,000 | $ 187,300,000 | $ 166,500,000 |  |
2.250% Senior Notes due May 1, 2030 |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Senior notes interest rate |  | 2.25% |  | 2.25% |  |  |
3.150% Senior Notes due May 1, 2050 |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Senior notes interest rate |  | 3.15% |  | 3.15% |  |  |
5.200% Senior Notes due 2045 |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Senior notes interest rate |  | 5.20% |  | 5.20% |  |  |
Repayments of Senior Debt | 12,100,000 |  |  |  |  |  |
Debt Instrument, Redemption, Amount | 8,900,000 |  |  |  |  |  |
Long Term Debt, Exchanged, Amount | 624,600,000 |  |  |  |  |  |
Gain (Loss) on Extinguishment of Debt |  | $ 3,200,000 |  |  |  |  |
Repayments of borrowings and premiums paid on debt exchange |  | 13,800,000 |  |  |  |  |
Interest Expense |  | $ 6,100,000 |  |  |  |  |
3.250% Senior Notes, Due February 15, 2051 |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Senior notes interest rate |  | 3.25% |  | 3.25% |  |  |
Long Term Debt, Exchanged, Amount | $ 700,700,000 |  |  |  |  |  |
Senior Notes |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Face amount |  |  |  |  |  | $ 3,000,000,000 |
Senior Notes | 2.250% Senior Notes due May 1, 2030 |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Face amount |  |  |  |  |  | $ 1,500,000,000 |
Senior notes interest rate |  |  |  |  |  | 2.25% |
Percentage par value of senior notes |  |  |  |  |  | 99.973% |
Senior Notes | 3.150% Senior Notes due May 1, 2050 |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Face amount |  |  |  |  |  | $ 1,500,000,000 |
Senior notes interest rate |  |  |  |  |  | 3.15% |
Percentage par value of senior notes |  |  |  |  |  | 99.174% |
Senior Notes | 2.90% Senior Notes Due Sept 15, 2020 |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Face amount |  |  |  |  |  |  | $ 1,500,000,000
Senior notes interest rate |  |  |  |  |  |  | 2.90%
Percentage par value of senior notes |  |  |  |  |  |  | 99.792%
Payment of early call premium and write off of remaining unamortized debt issuance costs |  |  |  | $ 12,700,000 |  |  |
Interest Expense | Senior Notes | 2.90% Senior Notes Due Sept 15, 2020 |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Pre-tax charge, payment of early call premium and write off of remaining unamortized debt issuance costs, net of derivative gain |  |  |  | 9,400,000 |  |  |
Interest Expense | Interest rate swap |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Derivative, gain on derivative |  |  |  | $ 3,300,000 |  |  |

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