Fair Value (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Assets:
Cash and cash equivalents	$ 1,936.6		$ 2,605.2
Short-term investments	32.6		14.5
Available-for-sale securities	5.3		4.8
Interest rate and foreign currency derivative instruments	36.1		32.4
Cost method investments	14.4		21.5
Liabilities:
Short-term debt	25.0		5.2
Interest rate and foreign currency derivative instruments	0.7		15.9
Contingent purchase price obligations	404.5		322.0
Long-term debt, including current portion	5,303.3		4,655.9
Carrying Amount
Assets:
Cash and cash equivalents	1,936.6		2,605.2
Short-term investments	32.6		14.5
Available-for-sale securities	5.3		4.8
Interest rate and foreign currency derivative instruments	36.1		32.4
Cost method investments	14.4		21.5
Liabilities:
Short-term debt	25.0		5.2
Interest rate and foreign currency derivative instruments	0.7		15.9
Contingent purchase price obligations	404.5		322.0
Long-term debt, including current portion	5,007.5		4,565.6
Contingent purchase price obligations
Changes in Level 3 Contingent Purchase Price Obligations [Roll Forward]
January 1	322.0	$ 300.7
Acquisitions	156.0	68.2
Revaluation and interest	16.7	26.3
Payments	(86.8)	(55.6)
Foreign currency translation	(3.4)	(11.9)
September 30	404.5	$ 327.7
Fair Value, Measurements, Recurring [Member]
Assets:
Cash and cash equivalents	1,936.6		2,605.2
Short-term investments	32.6		14.5
Available-for-sale securities	5.3		4.8
Interest rate and foreign currency derivative instruments	36.1		32.4
Liabilities:
Interest rate and foreign currency derivative instruments	0.7		15.9
Contingent purchase price obligations	404.5		322.0
Fair Value, Measurements, Recurring [Member] | Level 1
Assets:
Cash and cash equivalents	1,936.6		2,605.2
Short-term investments	32.6		14.5
Available-for-sale securities	5.3		4.8
Fair Value, Measurements, Recurring [Member] | Level 2
Assets:
Interest rate and foreign currency derivative instruments	36.1		32.4
Liabilities:
Interest rate and foreign currency derivative instruments	0.7		15.9
Fair Value, Measurements, Recurring [Member] | Level 3
Liabilities:
Contingent purchase price obligations	$ 404.5		$ 322.0