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Derivative Instruments (Details) $ in Millions, ₩ in Billions | 1 Months Ended | 3 Months Ended | 12 Months Ended
--- | --- | --- | ---
Nov. 30, 2018 USD ($) | Nov. 30, 2018 KRW (₩) | Mar. 31, 2020 USD ($) | Mar. 31, 2019 USD ($) | Dec. 31, 2018 USD ($) | Dec. 31, 2019 USD ($)
Derivatives [Line Items] |  |  |  |  |  |
Gain/Loss on fair value of foreign currency forward contracts |  |  | $ 34.4 |  |  | $ (0.5)
Gains (losses) on net investment hedges |  |  | 23.0 | $ 14.0 |  |
Net gains (losses) of other income (expense) related to foreign currency forward contracts |  |  | $ (2.4) | 4.8 |  |
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 |  |  | 15 months |  |  | 15 months
Not designated as hedging instrument |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |
Derivative, Notional Amount |  |  | $ 698.4 |  |  | $ 793.8
Other current assets | Designated as hedging instrument |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |
Derivative asset, fair value |  |  | 72.3 |  |  | 33.8
Other current assets | Not designated as hedging instrument |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |
Derivative asset, fair value |  |  | 5.1 |  |  | 8.0
Other noncurrent assets | Designated as hedging instrument |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |
Derivative asset, fair value |  |  | 4.0 |  |  | 0.0
Accrued expenses and other | Designated as hedging instrument |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |
Derivative liability, fair value |  |  | 0.8 |  |  | 2.0
Accrued expenses and other | Not designated as hedging instrument |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |
Derivative liability, fair value |  |  | 2.9 |  |  | 2.4
Foreign exchange contract | Designated as hedging instrument |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |
Derivative, Notional Amount |  |  | 2,559.6 |  |  | 1,892.4
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 |  |  | 1.7
Fair Value Hedging [Member] | Interest rate swap | Accrued expenses and other |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |
Derivative liability, fair value |  |  | $ 0.0 |  |  | 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 |  |  | $ 22.7 |  |  | 1.5
Derivative qualifying as net investment hedge, excluded component |  |  | 2.0 |  |  | 2.9
Gains (losses) on net investment hedges |  |  | 24.2 | 11.8 |  |
Gains (losses) on net investment hedge, excluded component |  |  | (0.3) | 4.4 |  |
Net Investment Hedging | Foreign exchange contract | Other current assets |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |
Derivative asset, fair value |  |  | 25.9 |  |  | 2.0
Revenue | Cash flows, revenue | Foreign exchange contract |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |
Gain (loss) on reclassification of cash flow hedges, effective portion |  |  | 27.0 | 14.8 |  |
Gain (loss) recognized in net income, excluded component |  |  | 9.3 | 3.7 |  |
Operating expense | Cash flows, operating expenses | Foreign exchange contract |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |
Gain (loss) on reclassification of cash flow hedges, effective portion |  |  | (0.1) | (0.5) |  |
Gain (loss) recognized in net income, excluded component |  |  | (0.9) | (0.9) |  |
Other income (expense) | Net Investment Hedging |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |
Gain (loss) recognized in net income, excluded component |  |  | 0.9 | $ 2.2 |  |
Euro | Foreign exchange contract | Designated as hedging instrument |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |
Derivative, Notional Amount |  |  | 2,116.4 |  |  | 1,892.4
British pound | Foreign exchange contract | Designated as hedging instrument |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |
Derivative, Notional Amount |  |  | 186.1 |  |  | 0.0
Swiss franc | Foreign exchange contract | Designated as hedging instrument |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |
Derivative, Notional Amount |  |  | 103.1 |  |  | 0.0
Japan, Yen | Foreign exchange contract | Designated as hedging instrument |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |
Derivative, Notional Amount |  |  | 79.5 |  |  | 0.0
Canadian dollar | Foreign exchange contract | Designated as hedging instrument |  |  |  |  |  |
Derivatives [Line Items] |  |  |  |  |  |
Derivative, Notional Amount |  |  | $ 74.5 |  |  | $ 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] |  |  |  |  |  |
Range of durations of foreign currency forward contracts |  |  | 12 months |  |  |
Gain/Loss on fair value of foreign currency forward contracts |  |  | $ 31.8 |  |  |

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