Derivatives - Net Gains (Losses) with Respect to Derivative Instruments Not Designated as Hedging Instruments (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on derivatives instruments	$ (15,980)	$ (629)	$ (27,246)	$ (6,114)
Forward Foreign Currency Exchange Rate Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on derivatives not designated as hedging instruments	(6,630)	446	(5,158)	(6,854)
LFI and Other Similar Deferred Compensation Arrangements [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on derivatives not designated as hedging instruments	(5,753)	(312)	(13,106)	2,202
Total Return Swaps and Other [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on derivatives designated as hedging instruments	$ (3,597)	$ (763)	$ (8,982)	$ (1,462)