Financial Instruments - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2015 USD ($) Country	Dec. 31, 2014 USD ($)
Commercial Paper
Derivative [Line Items]
Commercial paper borrowings outstanding	$ 0	$ 78,000,000
Five Year Credit Facility Expiring In November 2019
Derivative [Line Items]
Line of credit facility, borrowing capacity	$ 750,000,000
Line of credit facility, expiration date	2019-11
Line of credit facility, term, in years	5 years
National Healthcare Systems and Private Sector Customers
Derivative [Line Items]
Accounts receivable, net	$ 54,000,000
Accounts receivable greater than 365 days past due	$ 7,900,000
The number of countries in Europe in which certain collection risks exist | Country	4
National Healthcare Systems and Private Sector Customers | Greece
Derivative [Line Items]
Accounts receivable, net	$ 13,000,000
Accounts receivable greater than 365 days past due	6,500,000
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring
Derivative [Line Items]
Fair value of contingent consideration	11,200,000	23,100,000
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	1,465,700,000	1,481,700,000
Interest rate swap contract
Derivative [Line Items]
Notional value of derivative contracts	$ 250,000,000
Fixed-rate notes due date	2016
Fixed-rate notes interest percentage	2.875%
Forward Starting Interest Rate Swaps
Derivative [Line Items]
Notional value of derivative contracts	$ 250,000,000
Derivative termination date	2016-05
Foreign Exchange Contract
Derivative [Line Items]
Notional value of derivative contracts	$ 232,200,000	$ 191,100,000