Fair Value Measurements (Details) (USD $) In Millions	Sep. 30, 2011	Dec. 31, 2010
Liabilities:
Derivative contracts	$ 2.0	$ 12.2
Quoted Prices in Active Markets, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Cash Equivalents, Fair Value Disclosure	0	0
Derivative contracts	0	0
Plan assets for deferred compensation	0	0
Total	1.2	44.8
Liabilities:
Derivative contracts	0	0
Contingent consideration	0	0
Total	0	0
Quoted Prices in Active Markets, Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Corporate debt securities [Member]
Assets:
Fair Value, Measured on Recurring Basis, Investments	0	0
Quoted Prices in Active Markets, Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Government securities [Member]
Assets:
Fair Value, Measured on Recurring Basis, Investments	0	0
Quoted Prices in Active Markets, Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Mortgage and other asset backed securities [Member]
Assets:
Fair Value, Measured on Recurring Basis, Investments	0	0
Quoted Prices in Active Markets, Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Strategic investments [Member]
Assets:
Fair Value, Measured on Recurring Basis, Investments	1.2	44.8
Quoted Prices in Active Markets, Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Venture capital investments [Member]
Assets:
Fair Value, Measured on Recurring Basis, Investments	0	0
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring [Member]
Assets:
Cash Equivalents, Fair Value Disclosure	241.3	651.8
Derivative contracts	18.9	1.3
Plan assets for deferred compensation	12.6	13.0
Total	2,566.5	1,857.3
Liabilities:
Derivative contracts	2.0	12.2
Contingent consideration	0	0
Total	2.0	12.2
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring [Member] | Corporate debt securities [Member]
Assets:
Fair Value, Measured on Recurring Basis, Investments	542.6	313.0
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring [Member] | Government securities [Member]
Assets:
Fair Value, Measured on Recurring Basis, Investments	1,482.0	785.3
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring [Member] | Mortgage and other asset backed securities [Member]
Assets:
Fair Value, Measured on Recurring Basis, Investments	269.1	92.9
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring [Member] | Strategic investments [Member]
Assets:
Fair Value, Measured on Recurring Basis, Investments	0	0
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring [Member] | Venture capital investments [Member]
Assets:
Fair Value, Measured on Recurring Basis, Investments	0	0
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring [Member]
Assets:
Cash Equivalents, Fair Value Disclosure	0	0
Derivative contracts	0	0
Plan assets for deferred compensation	0	0
Total	23.1	20.8
Liabilities:
Derivative contracts	0	0
Contingent consideration	125.9	81.2
Total	125.9	81.2
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring [Member] | Corporate debt securities [Member]
Assets:
Fair Value, Measured on Recurring Basis, Investments	0	0
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring [Member] | Government securities [Member]
Assets:
Fair Value, Measured on Recurring Basis, Investments	0	0
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring [Member] | Mortgage and other asset backed securities [Member]
Assets:
Fair Value, Measured on Recurring Basis, Investments	0	0
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring [Member] | Strategic investments [Member]
Assets:
Fair Value, Measured on Recurring Basis, Investments	0	0
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring [Member] | Venture capital investments [Member]
Assets:
Fair Value, Measured on Recurring Basis, Investments	23.1	20.8
Fair Value, Measurements, Recurring [Member]
Assets:
Cash Equivalents, Fair Value Disclosure	241.3	651.8
Derivative contracts	18.9	1.3
Plan assets for deferred compensation	12.6	13.0
Total	2,590.8	1,922.9
Liabilities:
Derivative contracts	2.0	12.2
Contingent consideration	125.9	81.2
Total	127.9	93.4
Fair Value, Measurements, Recurring [Member] | Corporate debt securities [Member]
Assets:
Fair Value, Measured on Recurring Basis, Investments	542.6	313.0
Fair Value, Measurements, Recurring [Member] | Government securities [Member]
Assets:
Fair Value, Measured on Recurring Basis, Investments	1,482.0	785.3
Fair Value, Measurements, Recurring [Member] | Mortgage and other asset backed securities [Member]
Assets:
Fair Value, Measured on Recurring Basis, Investments	269.1	92.9
Fair Value, Measurements, Recurring [Member] | Strategic investments [Member]
Assets:
Fair Value, Measured on Recurring Basis, Investments	1.2	44.8
Fair Value, Measurements, Recurring [Member] | Venture capital investments [Member]
Assets:
Fair Value, Measured on Recurring Basis, Investments	$ 23.1	$ 20.8