Summary of Notional Amounts of Outstanding Foreign Exchange Forwards, Cash Flow Hedging (Detail) (Cash Flow Hedging [Member], Forward Contracts [Member]) In Millions, unless otherwise specified	Sep. 30, 2014 Foreign Currency Forward Contracts to Purchase US Dollars with Euros [Member] USD ($)	Dec. 31, 2013 Foreign Currency Forward Contracts to Purchase US Dollars with Euros [Member] USD ($)	Sep. 30, 2014 Foreign Currency Forward Contracts To Sell US Dollars For Euros [Member] USD ($)	Dec. 31, 2013 Foreign Currency Forward Contracts To Sell US Dollars For Euros [Member] USD ($)	Sep. 30, 2014 Foreign Currency Forward Contracts to Purchase US Dollars With GBP [Member] USD ($)	Dec. 31, 2013 Foreign Currency Forward Contracts to Purchase US Dollars With GBP [Member] USD ($)	Sep. 30, 2014 Foreign Currency Forward Contracts To Purchase US Dollars With Other Foreign Currencies [Member] USD ($)	Dec. 31, 2013 Foreign Currency Forward Contracts To Purchase US Dollars With Other Foreign Currencies [Member] USD ($)	Sep. 30, 2014 Foreign Currency Forward Contracts to Sell US Dollars for Other Foreign Currencies [Member] USD ($)	Dec. 31, 2013 Foreign Currency Forward Contracts to Sell US Dollars for Other Foreign Currencies [Member] USD ($)	Sep. 30, 2014 Foreign Currency Forward Contracts To Purchase Euros With Other Foreign Currencies [Member] EUR (€)	Dec. 31, 2013 Foreign Currency Forward Contracts To Purchase Euros With Other Foreign Currencies [Member] EUR (€)	Sep. 30, 2014 Foreign Currency Forward Contracts To Purchase Euros With GBP [Member] EUR (€)	Dec. 31, 2013 Foreign Currency Forward Contracts To Purchase Euros With GBP [Member] EUR (€)	Sep. 30, 2014 Foreign Currency Forward Contracts to Sell Euros for GBP [Member] EUR (€)	Dec. 31, 2013 Foreign Currency Forward Contracts to Sell Euros for GBP [Member] EUR (€)
Derivative [Line Items]
Derivative Notional Amount	$ 38.5	$ 14.2	$ 53.7	$ 53.2	$ 0.2	$ 0	$ 1.0	$ 0	$ 0	$ 0	€ 55.3	€ 13.1	€ 24.5	€ 22.1	€ 35.4	€ 0