Financial Instruments - Additional Information (Detail) (USD $)	1 Months Ended					6 Months Ended
	Mar. 31, 2012	Jun. 30, 2012 Year	Dec. 31, 2011	Jun. 30, 2012 Fair Value, Inputs, Level 3	Dec. 31, 2011 Fair Value, Inputs, Level 3	Jun. 30, 2012 Line of Credit Facility	Jun. 30, 2012 Interest Rate Swap Contract	Dec. 31, 2011 Interest Rate Swap Contract
Derivative [Line Items]
Notional value of forward currency and option contracts		$ 82,900,000	$ 205,200,000
Fixed-rate notes interest percentage							2.875%
Fixed-rate notes due date							2016
Notional value of interest rate swap contract							250,000,000
Fair value of contingent consideration				72,600,000	77,100,000
Fair value of commercial paper borrowings		303,500,000	304,500,000
Line of credit facility, borrowing capacity		600,000,000
Line of credit facility, years		5
Line of credit facility, expiration date						2016-10
Fair value of long-term debt							$ 1,000,000,000	$ 1,000,000,000
Interest bearing bonds, maturity in years	Thirty