Fair Value (Details) (USD $) In Millions, unless otherwise specified			9 Months Ended
	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2014 Contingent purchase price obligations	Sep. 30, 2013 Contingent purchase price obligations	Sep. 30, 2014 Contingent purchase price obligations Interest Expense [Member]	Sep. 30, 2013 Contingent purchase price obligations Interest Expense [Member]	Sep. 30, 2014 Carrying Amount	Dec. 31, 2013 Carrying Amount	Sep. 30, 2014 Fair Value, Measurements, Recurring [Member] Level 1	Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Level 1	Sep. 30, 2014 Fair Value, Measurements, Recurring [Member] Level 2	Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Level 2	Sep. 30, 2014 Fair Value, Measurements, Recurring [Member] Level 3	Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Level 3	Sep. 30, 2014 Fair Value, Measurements, Recurring [Member] Total	Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Total
Assets:
Cash and cash equivalents	$ 837.7	$ 2,710.5					$ 837.7	$ 2,710.5	$ 837.7	$ 2,710.5					$ 837.7	$ 2,710.5
Short-term investments	12.6	18.2					12.6	18.2	12.6	18.2					12.6	18.2
Available-for-sale securities	5.2	4.9					5.2	4.9	5.2	4.9					5.2	4.9
Foreign currency and interest rate derivative instruments	5.4	2.2					5.4	2.2			5.4				5.4
Foreign currency derivative instruments												2.2				2.2
Cost method investments	23.2	22.2					23.2	22.2
Liabilities:
Short-term borrowings	31.3	5.9					31.3	5.9
Foreign currency derivative instruments	2.1	0.1					2.1	0.1			2.1	0.1			2.1	0.1
Contingent interest derivative	0	2.1					0	2.1				2.1				2.1
Contingent purchase price obligations	241.0	220.2					241.0	220.2					241.0	220.2	241.0	220.2
Debt	3,982.6	4,302.7					3,779.2	4,033.8
Changes in Level 3 Contingent Purchase Price Obligations [Roll Forward]
January 1			220.2	266.2
Acquisitions			103.1	34.8
Revaluation and interest					0.1	(9.5)
Payments			(74.5)	(68.9)
Foreign currency translation			(7.9)	(9.3)
September 30			$ 241.0	$ 213.3