Borrowings - Additional Information (Detail) In Millions, unless otherwise specified	6 Months Ended	1 Months Ended		6 Months Ended		1 Months Ended			1 Months Ended	6 Months Ended						6 Months Ended				6 Months Ended
	Jun. 30, 2012 USD ($)	Jun. 30, 2010 2.58% Senior Euro Notes USD ($)	Jun. 30, 2010 2.58% Senior Euro Notes EUR (€)	Jun. 30, 2012 2.58% Senior Euro Notes	Jun. 09, 2010 2.58% Senior Euro Notes USD ($)	Dec. 31, 2010 4.5 % Senior Notes USD ($)	Dec. 06, 2010 4.5 % Senior Notes USD ($)	Apr. 15, 2010 4.5 % Senior Notes	Dec. 31, 2011 4.2% Senior Notes USD ($)	Jun. 30, 2012 4.2% Senior Notes	Dec. 09, 2011 4.2% Senior Notes USD ($)	Jun. 30, 2012 Other Borrowings USD ($)	Jun. 30, 2012 Minimum 2.58% Senior Euro Notes	Jun. 30, 2012 Minimum Other Borrowings	Jun. 30, 2012 Maximum Other Borrowings	Jun. 30, 2012 Letters Of Credit USD ($)	Jun. 30, 2012 Swing line Loans USD ($)	Jun. 30, 2012 Revolving Credit Facility USD ($)	Jun. 30, 2012 Revolving Credit Facility Minimum	Jun. 30, 2012 Revolving Credit Facility Maximum
Line of Credit Facility [Line Items]
Replaced credit facility due to expire	$ 600.0
Revolving facility principal amount	700.0															75.0	25.0
Revolving facility expiration date	Jun. 27, 2016
Revolving facility closing date	Jun. 27, 2011
Aggregate commitments of designated borrowers under the Credit Facility	950.0
Applicable margin over LIBOR																		1.05%	0.875%	1.70%
Annual credit facility fee basis point rate spread over LIBOR	20
Leverage ratio																				3.25
Current borrowings under revolving facility																		693.0
Outstanding letters of credit																		7.0
Principal amount of private placement		96.8	81.0						350.0
Stated interest rate					2.58%		4.50%	4.50%			4.20%			0.40%	3.70%
Debt instrument maturity period		Jun. 09, 2015	Jun. 09, 2015			Dec. 15, 2020			Dec. 15, 2021
Debt instrument maximum amount outstanding					750.0
Repayment, minimum percentage outstanding				5.00%
Debt instrument face amount							300.0
Net proceeds from debt offering							295.7				346.2
Debt offering initial discount							1.6				0.9
Debt offering underwriting commission						1.9			2.3
Estimated offering expenses						0.8			0.6
Contingent percentage of principal amount plus accrued and unpaid interest						101.00%				101.00%
Outstanding repayment of indebtedness						250.0			306.0
Other borrowings												$ 10.6
Interest coverage ratio													3.0