Summary of Notional Amounts of Outstanding Foreign Exchange Forwards, Net Investment Hedging (Detail) (Net Investment Hedging [Member], Forward Contracts [Member]) In Millions, unless otherwise specified	Sep. 30, 2014 Foreign Currency Forward Contracts To Sell Euros for U S Dollars [Member] EUR (€)	Dec. 31, 2013 Foreign Currency Forward Contracts To Sell Euros for U S Dollars [Member] EUR (€)	Sep. 30, 2014 Foreign Currency Forward Contracts To Sell Japanese Yen For US Dollars [Member] JPY (¥)	Dec. 31, 2013 Foreign Currency Forward Contracts To Sell Japanese Yen For US Dollars [Member] JPY (¥)
Derivative [Line Items]
Derivative Notional Amount	€ 50.0	€ 50.0	¥ 19,700.0	¥ 19,700.0