Fair Value (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Assets:
Cash and cash equivalents	$ 1,305.7		$ 2,605.2
Short-term investments	231.0		14.5
Available-for-sale securities	5.1		4.8
Interest rate and foreign currency derivative instruments	46.8		32.4
Cost method investments	14.1		21.5
Liabilities:
Short-term debt	11.5		5.2
Interest rate and foreign currency derivative instruments	1.4		15.9
Contingent purchase price obligations	430.4		322.0
Long-term debt, including current portion	5,270.0		4,655.9
Carrying Amount
Assets:
Cash and cash equivalents	1,305.7		2,605.2
Short-term investments	231.0		14.5
Available-for-sale securities	5.1		4.8
Interest rate and foreign currency derivative instruments	46.8		32.4
Cost method investments	14.1		21.5
Liabilities:
Short-term debt	11.5		5.2
Interest rate and foreign currency derivative instruments	1.4		15.9
Contingent purchase price obligations	430.4		322.0
Long-term debt, including current portion	5,022.4		4,565.6
Contingent purchase price obligations
Changes in Level 3 Contingent Purchase Price Obligations [Roll Forward]
January 1	322.0	$ 300.7
Acquisitions	150.8	51.6
Revaluation and interest	13.8	3.8
Payments	(62.7)	(42.3)
Foreign currency translation	6.5	(7.8)
June 30	430.4	$ 306.0
Fair Value, Measurements, Recurring [Member]
Assets:
Cash and cash equivalents	1,305.7		2,605.2
Short-term investments	231.0		14.5
Available-for-sale securities	5.1		4.8
Interest rate and foreign currency derivative instruments	46.8		32.4
Liabilities:
Interest rate and foreign currency derivative instruments	1.4		15.9
Contingent purchase price obligations	430.4		322.0
Fair Value, Measurements, Recurring [Member] | Level 1
Assets:
Cash and cash equivalents	1,305.7		2,605.2
Short-term investments	231.0		14.5
Available-for-sale securities	5.1		4.8
Fair Value, Measurements, Recurring [Member] | Level 2
Assets:
Interest rate and foreign currency derivative instruments	46.8		32.4
Liabilities:
Interest rate and foreign currency derivative instruments	1.4		15.9
Fair Value, Measurements, Recurring [Member] | Level 3
Liabilities:
Contingent purchase price obligations	$ 430.4		$ 322.0