Financial Instruments - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2016 USD ($) Country	Jan. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Five Year Credit Facility Expiring In November 2020
Derivative [Line Items]
Line of credit facility, borrowing capacity	$ 1,000,000,000
Line of credit facility, expiration date	2020-11
Line of credit facility, term, in years	5 years
Commercial Paper
Derivative [Line Items]
Commercial paper borrowings outstanding	$ 525,600,000		$ 0
National Healthcare Systems and Private Sector Customers
Derivative [Line Items]
Accounts receivable, net	49,600,000
Accounts receivable greater than 365 days past due	$ 4,700,000
The number of countries in Europe in which certain collection risks exist | Country	4
Medicon Inc | Other Long-term Liabilities
Derivative [Line Items]
Liability for non-continent future payments for business combinations	$ 54,100,000		50,300,000
Fair Value, Inputs, Level 2
Derivative [Line Items]
Fair value of long-term debt including current maturities and the effects of the related interest rate swap contract	1,227,000,000		1,449,800,000
Fair Value, Inputs, Level 2 | Medicon Inc
Derivative [Line Items]
Liability for non-continent future payments for business combinations	70,900,000		66,000,000
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring
Derivative [Line Items]
Fair value of contingent consideration	22,800,000		11,200,000
Foreign Exchange Contract
Derivative [Line Items]
Notional value of derivative contracts	$ 205,400,000		$ 191,600,000
Interest rate swap contract
Derivative [Line Items]
Notional value of derivative contracts		$ 250,000,000
Fixed-rate notes interest percentage		2.875%
Fixed-rate notes due date	2016-01
Forward Starting Interest Rate Swaps
Derivative [Line Items]
Notional value of derivative contracts	$ 250,000,000
Derivative termination date	2016-05