Financial Instruments - Derivative Instruments Notional Amount Outstanding (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Foreign currency contracts [Member]
Schedule Of Information By Major Category Of Credit Derivatives Contracts [Line Items]
Derivative instruments outstanding	$ 283,550	$ 191,150
Interest rate swaps [Member]
Schedule Of Information By Major Category Of Credit Derivatives Contracts [Line Items]
Derivative instruments outstanding	$ 775,000	$ 425,000