Fair Value (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Carrying Amount
Assets:
Cash and cash equivalents	$ 4,388.1		$ 5,600.5
Marketable equity securities	1.3		1.6
Non-marketable equity securities	6.7		8.9
Foreign currency derivatives	0.3		0.6
Liabilities:
Short-term debt	9.3		3.9
Foreign currency derivatives	0.3		0.3
Contingent purchase price obligations	159.5		71.9
Long-term debt	5,300.7		5,807.3
Fair Value
Assets:
Cash and cash equivalents	4,388.1		5,600.5
Marketable equity securities	1.3		1.6
Non-marketable equity securities	6.7		8.9
Foreign currency derivatives	0.3		0.6
Liabilities:
Short-term debt	9.3		3.9
Foreign currency derivatives	0.3		0.3
Contingent purchase price obligations	159.5		71.9
Long-term debt	5,729.6		6,380.6
Contingent purchase price obligations
Changes in Contingent Purchase Price Obligations [Roll Forward]
January 1	71.9	$ 107.7
Acquisitions	92.2	10.0
Revaluation and interest	0.9	1.6
Payments	(5.4)	(12.8)
Foreign currency translation	(0.1)	(2.2)
June 30	159.5	$ 104.3
Fair Value, Recurring [Member]
Assets:
Cash and cash equivalents	4,388.1		5,600.5
Marketable equity securities	1.3		1.6
Foreign currency derivatives	0.3		0.6
Liabilities:
Foreign currency derivatives	0.3		0.3
Contingent purchase price obligations	159.5		71.9
Fair Value, Recurring [Member] | Level 1
Assets:
Cash and cash equivalents	4,388.1		5,600.5
Marketable equity securities	1.3		1.6
Fair Value, Recurring [Member] | Level 2
Assets:
Foreign currency derivatives	0.3		0.6
Liabilities:
Foreign currency derivatives	0.3		0.3
Fair Value, Recurring [Member] | Level 3
Liabilities:
Contingent purchase price obligations	$ 159.5		$ 71.9