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Rollforward of Financial Instruments Classified in Level Three of Valuation Hierarchy (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Interest rate lock commitments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Beginning Balance		$ 982
Total Realized/Unrealized (Losses)/Gains Recorded in (Loss)/ Income		(982)
Mortgage servicing rights
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Beginning Balance	$ 2,729	228,099
Total Realized/Unrealized (Losses)/Gains Recorded in (Loss)/ Income	(224)	(20,076)
Total Realized/Unrealized (Losses)/Gain Recorded in Comprehensive (Loss) Income	0
Issuances		18,054
Settlements	(2,505)	(223,348)
Transfers to/(from) level 3	$ 0
Fair Value, Ending Balance		2,729
Change in Unrealized (Losses)/Gains Related to Instruments Held		$ (222)

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Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Change in Unrealized Gains (Losses) Related to Instruments Held

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Amount of gain (loss) recognized in the income statement for financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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