Fair Value Measurements (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Fair Value Disclosures [Abstract]
Notional amount of interest rate swap		$ 300.0
Assets [Abstract]
Commercial paper	1,709.0	1,171.9
Foreign time deposits	341.7	189.1
Other cash equivalents	685.0	1,078.9
Foreign exchange derivative assets	10.2	26.3
Interest rate swap derivative asset	0	48.1
Deferred executive compensation investments	81.7	70.9
Assets measured at fair value on a recurring basis	2,827.6	2,585.2
Liabilities [Abstract]
Foreign exchange derivative liabilities		0.7
Interest rate swap derivative liability		48.1
Deferred executive compensation liabilities	73.5	62.3
Contingent consideration liabilities	224.3	214.6
Liabilities measured at fair value on a recurring basis	297.8	325.7
Reconciliation of the change in the contingent consideration liabilities [Roll Forward]
Balance, beginning of year	214.6	44.5
Additions during the period related to business combinations	6.9	169.2
Change in the estimated fair value of the contingent consideration liabilities	5.4	11.9
Payments made during the period	(5.1)	(3.0)
Foreign exchange translation effects	2.5	(8.0)
Balance, end of year	224.3	214.6
Probability of success in meeting development milestones, lower range (in hundredths)	40.00%
Probability of success in meeting development milestones, higher range (in hundredths)	75.00%
Level 1 [Member]
Assets [Abstract]
Commercial paper	0	0
Foreign time deposits	0	0
Other cash equivalents	0	0
Foreign exchange derivative assets	0	0
Interest rate swap derivative asset		0
Deferred executive compensation investments	66.8	58.0
Assets measured at fair value on a recurring basis	66.8	58.0
Liabilities [Abstract]
Foreign exchange derivative liabilities		0
Interest rate swap derivative liability		0
Deferred executive compensation liabilities	58.6	49.4
Contingent consideration liabilities	0	0
Liabilities measured at fair value on a recurring basis	58.6	49.4
Level 2 [Member]
Assets [Abstract]
Commercial paper	1,709.0	1,171.9
Foreign time deposits	341.7	189.1
Other cash equivalents	685.0	1,078.9
Foreign exchange derivative assets	10.2	26.3
Interest rate swap derivative asset		48.1
Deferred executive compensation investments	14.9	12.9
Assets measured at fair value on a recurring basis	2,760.8	2,527.2
Liabilities [Abstract]
Foreign exchange derivative liabilities		0.7
Interest rate swap derivative liability		48.1
Deferred executive compensation liabilities	14.9	12.9
Contingent consideration liabilities	0	0
Liabilities measured at fair value on a recurring basis	14.9	61.7
Level 3 [Member]
Assets [Abstract]
Commercial paper	0	0
Foreign time deposits	0	0
Other cash equivalents	0	0
Foreign exchange derivative assets	0	0
Interest rate swap derivative asset		0
Deferred executive compensation investments	0	0
Assets measured at fair value on a recurring basis	0	0
Liabilities [Abstract]
Foreign exchange derivative liabilities		0
Interest rate swap derivative liability		0
Deferred executive compensation liabilities	0	0
Contingent consideration liabilities	224.3	214.6
Liabilities measured at fair value on a recurring basis	$ 224.3	$ 214.6