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Derivatives - Summary of Gains and Losses on Derivative Contracts (Detail) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |  |
Gain (loss), net on derivative contract | $ 14,629 | $ 32,287 | $ 23,090
FX/Commodities Options [Member] |  |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |  |
Gain (loss), net on derivative contract | 252 | 14,657 | 12,852
FX Swaps [Member] |  |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |  |
Gain (loss), net on derivative contract | 2,340 | 1,271 | 1,332
Equity Options [Member] |  |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |  |
Gain (loss), net on derivative contract | 318 | 102 | 591
Interest Rate Swaps [Member] |  |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |  |
Gain (loss), net on derivative contract |  | (5) | 47
Futures [Member] |  |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |  |
Gain (loss), net on derivative contract | 15,316 | 16,484 | 8,306
Forwards [Member] |  |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |  |
Gain (loss), net on derivative contract | $ (3,597) | $ (222) | $ (38)

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- Definition Amount of increase (decrease) in the fair value of derivatives recognized in the income statement. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -Subparagraph (b)(1) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5618551-113959 + Details
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