Fair Value (Details) (USD $) In Millions, unless otherwise specified			6 Months Ended
	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2014 Contingent purchase price obligations	Jun. 30, 2013 Contingent purchase price obligations	Jun. 30, 2014 Contingent purchase price obligations Interest Expense [Member]	Jun. 30, 2013 Contingent purchase price obligations Interest Expense [Member]	Jun. 30, 2014 Carrying Amount	Dec. 31, 2013 Carrying Amount	Jun. 30, 2014 Fair Value, Measurements, Recurring [Member] Level 1	Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Level 1	Jun. 30, 2014 Fair Value, Measurements, Recurring [Member] Level 2	Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Level 2	Jun. 30, 2014 Fair Value, Measurements, Recurring [Member] Level 3	Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Level 3	Jun. 30, 2014 Fair Value, Measurements, Recurring [Member] Total	Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Total
Assets:
Cash and cash equivalents	$ 1,534.7	$ 2,710.5					$ 1,534.7	$ 2,710.5	$ 1,534.7	$ 2,710.5					$ 1,534.7	$ 2,710.5
Short-term investments	9.9	18.2					9.9	18.2	9.9	18.2					9.9	18.2
Available-for-sale securities	5.3	4.9					5.3	4.9	5.3	4.9					5.3	4.9
Foreign currency and interest rate derivative instruments	9.8	2.2					9.8	2.2			9.8				9.8
Foreign currency derivative instruments												2.2				2.2
Cost method investments	23.5	22.2					23.5	22.2
Liabilities:
Short-term borrowings	24.7	5.9					24.7	5.9
Foreign currency derivative instruments	0.3	0.1					0.3	0.1			0.3	0.1			0.3	0.1
Contingent interest derivative	0.7	2.1					0.7	2.1			0.7	2.1			0.7	2.1
Contingent purchase price obligations	271.7	220.2					271.7	220.2					271.7	220.2	271.7	220.2
Debt	4,398.3	4,302.7					4,038.3	4,033.8
Changes in Level 3 Contingent Purchase Price Obligations [Roll Forward]
January 1			220.2	266.2
Acquisitions			90.8	19.2
Revaluation and interest					0.1	(5.7)
Payments			(43.7)	(31.8)
Foreign currency translation			4.3	(15.7)
June 30			$ 271.7	$ 232.2