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Derivative Instruments (Details) $ in Millions, ₩ in Billions | 1 Months Ended | 3 Months Ended | 6 Months Ended | 9 Months Ended |
--- | --- | --- | --- | --- | ---
Nov. 30, 2018 USD ($) | Nov. 30, 2018 KRW (₩) | Mar. 31, 2021 USD ($) | Mar. 31, 2020 USD ($) | Sep. 30, 2019 USD ($) | Jun. 30, 2020 | Sep. 30, 2020 USD ($) | Dec. 31, 2020 USD ($)
Derivatives [Line Items] |  |  |  |  |  |  |  |
Gain/Loss on fair value of foreign currency forward contracts |  |  | $ 41.5 |  |  |  |  | $ (212.5)
Net gains (losses) of other income (expense) related to foreign currency forward contracts |  |  | (17.4) | $ (2.4) |  |  |  |
Unrealized Gross Losses on Foreign Currency Derivatives, Net, before Tax |  |  | 73.5 |  |  |  |  |
Unrealized Gross Gains on Foreign Currency Derivatives, Net, before Tax |  |  | 32.0 |  |  |  |  |
Gains (losses) on net investment hedges |  |  | $ 22.4 | 23.0 |  |  |  |
Minimum |  |  |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |  |  |
Range of durations of foreign currency forward contracts |  |  | 1 month |  |  | 1 month |  |
Maximum |  |  |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |  |  |
Range of durations of foreign currency forward contracts |  |  | 21 months |  |  | 24 months |  |
Not designated as hedging instrument |  |  |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |  |  |
Derivative, Notional Amount |  |  | $ 1,358.8 |  |  |  |  | 1,158.0
Other current assets | Designated as hedging instrument |  |  |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |  |  |
Derivative asset, fair value |  |  | 20.6 |  |  |  |  | 0.0
Other current assets | Not designated as hedging instrument |  |  |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |  |  |
Derivative asset, fair value |  |  | 12.7 |  |  |  |  | 20.5
Other noncurrent assets | Designated as hedging instrument |  |  |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |  |  |
Derivative asset, fair value |  |  | 15.2 |  |  |  |  | 0.0
Accrued expenses and other | Designated as hedging instrument |  |  |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |  |  |
Derivative liability, fair value |  |  | 60.8 |  |  |  |  | 157.1
Accrued expenses and other | Not designated as hedging instrument |  |  |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |  |  |
Derivative liability, fair value |  |  | 27.8 |  |  |  |  | 4.7
Foreign exchange contract | Designated as hedging instrument |  |  |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |  |  |
Derivative, Notional Amount |  |  | 3,186.4 |  |  |  |  | 3,229.7
Interest rate swap | Designated as hedging instrument |  |  |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |  |  |
Derivative, Notional Amount |  |  | 675.0 |  |  |  |  |
Cash Flow Hedging [Member] | Foreign exchange contract | Other long-term liabilities |  |  |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |  |  |
Derivative liability, fair value |  |  | $ 0.0 |  |  |  |  | 35.7
Fair Value Hedging [Member] | Interest rate swap | Accrued expenses and other |  |  |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |  |  |
Derivative liability, fair value |  |  |  |  |  |  |  | 2.3
Net Investment Hedging |  |  |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |  |  |
Remaining duration of Net Investment Hedges |  |  | 7 months |  |  |  |  |
Unrealized gain (loss) on net investment hedges in AOCI |  |  | $ 2.7 |  |  |  | $ 21.2 |
Derivative qualifying as net investment hedge, excluded component |  |  | 0.1 |  |  |  |  | 0.2
Gains (losses) on net investment hedges |  |  | 23.8 | 24.2 |  |  |  |
Gains (losses) on net investment hedge, excluded component |  |  | (1.4) | (0.3) |  |  |  |
Net Investment Hedging | Foreign exchange contract | Other current assets |  |  |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |  |  |
Derivative asset, fair value |  |  | 2.7 |  |  |  |  | 0.0
Net Investment Hedging | Foreign exchange contract | Accrued expenses and other |  |  |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |  |  |
Derivative liability, fair value |  |  | 0.0 |  |  |  |  | 19.7
Interest Expense | Interest rate swap |  |  |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |  |  |
Gain on interest rate swap |  |  | 3.3 |  |  |  |  |
Revenue | Foreign exchange contract |  |  |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |  |  |
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax |  |  | (23.1) | 27.0 |  |  |  |
Revenue | Cash flows, revenue | Foreign exchange contract |  |  |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |  |  |
Gain on interest rate swap |  |  | (3.0) | 9.3 |  |  |  |
Operating expense | Foreign exchange contract |  |  |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |  |  |
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax |  |  | (0.4) | (0.1) |  |  |  |
Operating expense | Cash flows, operating expenses | Foreign exchange contract |  |  |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |  |  |
Gain on interest rate swap |  |  | (0.1) | (0.9) |  |  |  |
Other income (expense) | Net Investment Hedging |  |  |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |  |  |
Other Comprehensive Income (Loss), Derivative, Excluded Component, Increase (Decrease), before Adjustments and Tax |  |  | 0.1 | $ 0.9 |  |  |  |
Euro | Foreign exchange contract | Designated as hedging instrument |  |  |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |  |  |
Derivative, Notional Amount |  |  | 2,657.6 |  |  |  |  | 2,979.1
British pound | Foreign exchange contract | Designated as hedging instrument |  |  |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |  |  |
Derivative, Notional Amount |  |  | 98.5 |  |  |  |  | 0.0
Swiss franc | Foreign exchange contract | Designated as hedging instrument |  |  |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |  |  |
Derivative, Notional Amount |  |  | 190.4 |  |  |  |  | 250.6
Japan, Yen | Foreign exchange contract | Designated as hedging instrument |  |  |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |  |  |
Derivative, Notional Amount |  |  | 80.5 |  |  |  |  | 0.0
Canadian dollar | Foreign exchange contract | Designated as hedging instrument |  |  |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |  |  |
Derivative, Notional Amount |  |  | $ 159.4 |  |  |  |  | $ 0.0
2.900% Senior Notes due 2020 |  |  |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |  |  |
Senior notes interest rate |  |  | 2.90% |  |  |  |  |
Samsung Bioepis |  |  |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |  |  |
Percentage of stake in entity |  |  |  | 5.00% |  |  |  |
Equity Method Investment, Ownership Percentage |  |  | 49.90% |  |  |  |  |
Payments to acquire additional investment in equity method investment | $ 676.6 | ₩ 759.5 |  |  | $ 676.6 |  |  |
Short-term derivative |  |  |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |  |  |
Gain/Loss on fair value of foreign currency forward contracts |  |  | $ 54.3 |  |  |  |  |
Range of durations of foreign currency forward contracts |  |  | 12 months |  |  |  |  |

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