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Derivatives - Summary of Gains and Losses on Derivative Contracts (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain on derivative contract	$ 19,261	$ 15,481	$ 55,885	$ 26,808
Rate Lock Commitments and Forwards [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain on derivative contract	7,257	10,236	20,885	10,236
Futures [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain on derivative contract	3,230	2,091	14,878	5,790
Foreign Exchange/Commodities Options [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain on derivative contract	8,491	3,004	19,152	9,632
Foreign Exchange Swaps [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain on derivative contract	$ 283	142	873	1,111
Equity Options [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain on derivative contract			102
Interest Rate Swaps [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain on derivative contract		$ 8	$ (5)	$ 39

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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

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