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Financial Instruments (Details 1) - USD ($) $ in Millions | Dec. 31, 2017 | Dec. 31, 2016
--- | --- | ---
Marketable Debt and Equity Securities |  |
Fair Value | $ 5,172.5 | $ 5,398.0
Gross Unrealized Gains | 2.3 | 2.9
Gross Unrealized Losses | (2.8) | (11.2)
Amortized Cost | 5,173.0 | 5,406.3
Corporate debt securities Current |  |
Marketable Debt and Equity Securities |  |
Fair Value | 1,039.3 | 1,408.6
Gross Unrealized Gains | 0.0 | 0.2
Gross Unrealized Losses | (0.2) | (0.6)
Amortized Cost | 1,039.5 | 1,409.0
Corporate debt securities Non-current |  |
Marketable Debt and Equity Securities |  |
Fair Value | 1,570.5 | 1,255.2
Gross Unrealized Gains | 0.9 | 1.2
Gross Unrealized Losses | 0.0 | (4.7)
Amortized Cost | 1,569.6 | 1,258.7
Government securities Current |  |
Marketable Debt and Equity Securities |  |
Fair Value | 1,075.1 | 1,156.0
Gross Unrealized Gains | 0.1 | 0.2
Gross Unrealized Losses | (0.7) | (0.3)
Amortized Cost | 1,075.7 | 1,156.1
Government securities Non-current |  |
Marketable Debt and Equity Securities |  |
Fair Value | 844.2 | 1,016.5
Gross Unrealized Gains | 0.2 | 0.5
Gross Unrealized Losses | (1.1) | (3.4)
Amortized Cost | 845.1 | 1,019.4
Mortgage and other asset backed securities Current |  |
Marketable Debt and Equity Securities |  |
Fair Value | 0.8 | 4.0
Gross Unrealized Gains | 0.0 | 0.0
Gross Unrealized Losses | 0.0 | 0.0
Amortized Cost | 0.8 | 4.0
Mortgage and other asset backed securities Non-current |  |
Marketable Debt and Equity Securities |  |
Fair Value | 642.6 | 557.7
Gross Unrealized Gains | 1.1 | 0.8
Gross Unrealized Losses | (0.8) | (2.2)
Amortized Cost | 642.3 | 559.1
Marketable equity securities |  |
Marketable Debt and Equity Securities |  |
Fair Value | 11.8 | 24.9
Gross Unrealized Gains | 1.8 | 0.7
Gross Unrealized Losses | (4.4) | (9.3)
Amortized Cost | $ 14.4 | $ 33.5

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