Derivatives - Fair Value of Derivative Contracts (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative contracts, Assets	$ 1,868	$ 1,979
Derivative contracts, Liabilities	4,153	91,129
Notional Amounts	11,776,260	18,374,656	[1]
FX/Commodities Options [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative contracts, Assets	26	39
Derivative contracts, Liabilities		88,016
Notional Amounts	4,487	4,745,428	[1]
FX Swaps [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative contracts, Assets	1,278	1,611
Derivative contracts, Liabilities	2,244	2,072
Notional Amounts	555,519	482,295	[1]
Forwards [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative contracts, Assets	564	236
Derivative contracts, Liabilities	1,285	639
Notional Amounts	110,051	79,008	[1]
Futures [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative contracts, Assets		93
Derivative contracts, Liabilities	624	402
Notional Amounts	$ 11,106,203	$ 13,067,925	[1]

[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.