Financial Instruments (Details 1) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Marketable Debt and Equity Securities
Fair Value	$ 5,912.4	$ 4,880.9
Gross Unrealized Gains	13.2	0.3
Gross Unrealized Losses	(2.1)	(10.6)
Amortized Cost	5,901.3	4,891.2
Corporate debt securities Current
Marketable Debt and Equity Securities
Fair Value	913.4	394.3
Gross Unrealized Gains	0.3	0.0
Gross Unrealized Losses	(0.2)	(0.5)
Amortized Cost	913.3	394.8
Corporate debt securities Non-current
Marketable Debt and Equity Securities
Fair Value	1,376.9	1,116.6
Gross Unrealized Gains	7.8	0.1
Gross Unrealized Losses	(0.4)	(4.1)
Amortized Cost	1,369.5	1,120.6
Government securities Current
Marketable Debt and Equity Securities
Fair Value	1,521.3	1,723.4
Gross Unrealized Gains	0.6	0.1
Gross Unrealized Losses	0.0	(1.1)
Amortized Cost	1,520.7	1,724.4
Government securities Non-current
Marketable Debt and Equity Securities
Fair Value	1,452.1	1,152.5
Gross Unrealized Gains	3.1	0.0
Gross Unrealized Losses	(0.6)	(3.1)
Amortized Cost	1,449.6	1,155.6
Mortgage and other asset backed securities Current
Marketable Debt and Equity Securities
Fair Value	0.1	2.8
Gross Unrealized Gains	0.0	0.0
Gross Unrealized Losses	0.0	0.0
Amortized Cost	0.1	2.8
Mortgage and other asset backed securities Non-current
Marketable Debt and Equity Securities
Fair Value	648.6	491.3
Gross Unrealized Gains	1.4	0.1
Gross Unrealized Losses	(0.9)	(1.8)
Amortized Cost	648.1	493.0
Marketable equity securities
Marketable Debt and Equity Securities
Fair Value	32.4	37.5
Gross Unrealized Gains	0.9	9.2
Gross Unrealized Losses	(2.1)	0.0
Amortized Cost	$ 33.6	$ 28.3

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 25
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=65884222&loc=d3e22054-111558

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
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