Financial Instruments - Derivative Instruments Notional Amount Outstanding (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Foreign currency contracts [Member]
Schedule Of Information By Major Category Of Credit Derivatives Contracts [Line Items]
Derivative instruments outstanding	$ 881,600	$ 573,200
Interest rate swaps [Member]
Schedule Of Information By Major Category Of Credit Derivatives Contracts [Line Items]
Derivative instruments outstanding	$ 350,000	$ 475,000