Borrowings - Additional Information (Detail)	12 Months Ended	1 Months Ended				1 Months Ended			1 Months Ended	12 Months Ended						12 Months Ended					12 Months Ended
	Dec. 31, 2014 USD ($)	Jun. 30, 2010 2.58% Senior Euro Notes EUR (€)	Dec. 31, 2014 2.58% Senior Euro Notes USD ($)	Jun. 09, 2010 2.58% Senior Euro Notes USD ($)	Dec. 31, 2014 2.58% Senior Euro Notes Minimum	Dec. 31, 2010 4.5 % Senior Notes USD ($)	Dec. 06, 2010 4.5 % Senior Notes USD ($)	Apr. 15, 2010 4.5 % Senior Notes	Dec. 31, 2011 4.2% Senior Notes USD ($)	Dec. 31, 2014 4.2% Senior Notes	Dec. 09, 2011 4.2% Senior Notes USD ($)	Dec. 31, 2014 Other Borrowings USD ($)	Dec. 31, 2013 Other Borrowings USD ($)	Dec. 31, 2014 Other Borrowings Minimum	Dec. 31, 2014 Other Borrowings Maximum	Dec. 31, 2014 Letters Of Credit USD ($)	Dec. 31, 2014 Swing line Loans USD ($)	Dec. 31, 2014 Revolving Credit Facility USD ($)	Dec. 31, 2013 Revolving Credit Facility USD ($)	Dec. 31, 2014 Revolving Credit Facility Minimum	Dec. 31, 2014 Revolving Credit Facility Maximum
Line of Credit Facility [Line Items]
Replaced credit facility due to expire	$ 600,000,000
Revolving facility principal amount	700,000,000															75,000,000	25,000,000
Revolving facility expiration date	Jun. 27, 2016
Aggregate commitments of designated borrowers under the Credit Facility	950,000,000
Applicable margin over LIBOR																		1.05%		0.875%	1.70%
Basis spread on variable rate																		0.20%
Leverage ratio																					3.25
Outstanding letters of credit																		7,400,000
Current borrowings under revolving facility																		115,000,000	10,000,000
Revolving Facility, amount available to borrow																		577,600,000
Principal amount of private placement		81,000,000							350,000,000
Stated interest rate				2.58%			4.50%	4.50%			4.20%			0.20%	1.30%
Debt instrument maturity period		Jun. 09, 2015				Dec. 15, 2020			Dec. 15, 2021
Debt instrument maximum amount outstanding				750,000,000
Long-term debt			98,500,000
Repayment, minimum percentage outstanding		5.00%
Debt instrument face amount							300,000,000
Net proceeds from debt offering							295,700,000				346,200,000
Debt offering initial discount							1,600,000				900,000
Debt offering underwriting commission						1,900,000			2,300,000
Estimated offering expenses						800,000			600,000
Contingent percentage of principal amount plus accrued and unpaid interest						101.00%				101.00%
Outstanding repayment of indebtedness						250,000,000			306,000,000
Other borrowings												$ 2,170,000	$ 4,271,000
Interest coverage ratio					3.0