Derivatives - Fair Value of Derivative Contracts (Detail) - USD ($) $ in Thousands		Sep. 30, 2019	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative contracts, Assets		$ 3,815	$ 1,979
Derivative contracts, Liabilities		5,361	91,129
Notional Amounts	[1]	10,408,008	18,374,656
Foreign Exchange/Commodities Options [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative contracts, Assets		2	39
Derivative contracts, Liabilities		71	88,016
Notional Amounts	[1]	36,647	4,745,428
Foreign Exchange Swaps [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative contracts, Assets		3,348	1,611
Derivative contracts, Liabilities		2,282	2,072
Notional Amounts	[1]	487,643	482,295
Forwards [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative contracts, Assets		338	236
Derivative contracts, Liabilities		2,604	639
Notional Amounts	[1]	189,935	79,008
Futures [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative contracts, Assets		127	93
Derivative contracts, Liabilities		404	402
Notional Amounts	[1]	$ 9,693,783	$ 13,067,925

[1] Notional amounts represent the sum of gross long and short derivative contracts, an indication of the volume of the Company’s derivative activity and does not represent anticipated losses.