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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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