Selected Balance Sheet Data - Summary of Net Change in Carrying Value of MSRs (Detail) - USD ($) $ in Thousands |
9 Months Ended | 12 Months Ended |
|---|---|---|
Sep. 30, 2018 |
Dec. 31, 2017 |
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| Servicing Asset at Amortized Cost, Balance [Roll Forward] | ||
| Beginning balance | $ 0 | $ 0 |
| Additions from acquisition | 2,121 | 0 |
| Additions | 373 | 0 |
| Amortization | (165) | 0 |
| Ending balance | $ 2,329 | $ 0 |
| X | ||||||||||
- Definition Servicing asset at amortized cost, additions following acquisition. No definition available.
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| X | ||||||||||
- Definition Amortized amount of contract to service financial assets under which the benefits of servicing are expected to more than adequately compensate the servicer. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition Amount of additions from purchases, assumption or transfer to contract to service financial assets under which the benefits of servicing are expected to more than adequately compensate the servicer. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition Amount of amortization of contract to service financial assets under which the benefits of servicing are expected to more than adequately compensate the servicer. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. No definition available.
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