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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, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |  |
Gain (loss), net on derivative contract | $ 10,871 | $ 14,629 | $ 32,287
FX/Commodities Options [Member] |  |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |  |
Gain (loss), net on derivative contract | 293 | 252 | 14,657
FX Swaps [Member] |  |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |  |
Gain (loss), net on derivative contract | 381 | 2,340 | 1,271
Equity Options [Member] |  |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |  |
Gain (loss), net on derivative contract |  | 318 | 102
Interest Rate Swaps [Member] |  |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |  |
Gain (loss), net on derivative contract |  |  | (5)
Futures [Member] |  |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |  |
Gain (loss), net on derivative contract | 10,100 | 15,316 | 16,484
Forwards [Member] |  |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |  |
Gain (loss), net on derivative contract | $ 97 | $ (3,597) | $ (222)

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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=121590274&loc=SL5618551-113959 + Details
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