Mortgage Servicing Rights - Fair Value of Mortgage Servicing Rights (Detail) $ in Thousands	12 Months Ended
Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Servicing Assets at Fair Value [Line Items]
Balance at beginning of period	$ 7,098
Balance at end of period	6,200	$ 7,098
Contractually specified servicing fees, late fees and ancillary fees earned	1,917	2,038	$ 2,076
Mortgage servicing rights
Servicing Assets at Fair Value [Line Items]
Balance at beginning of period	7,098	6,687	6,595
Additions	913	557	810
Change in fair value	(1,811)	(146)	(718)
Balance at end of period	$ 6,200	$ 7,098	$ 6,687
Constant prepayment rate
Servicing Assets at Fair Value [Line Items]
Fair Value Of Mortgage Servicing Rights Weighted Average	0.062	0.076	0.089
Discount rate
Servicing Assets at Fair Value [Line Items]
Fair Value Of Mortgage Servicing Rights Weighted Average	0.120	0.120	0.130
Loans
Servicing Assets at Fair Value [Line Items]
Balance at beginning of period	$ 785,138	$ 811,065	$ 816,623
Balance at end of period	$ 767,662	$ 785,138	$ 811,065

Amount of contractually specified servicing fee, late fee, and ancillary fee recognized as income for servicing asset and servicing liability.

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The value of new servicing assets, subsequently measured at fair value, acquired or created during the current period through purchases or from transfers of financial assets.

+ References

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Fair value of an asset representing net future revenue from contractually specified servicing fees, late charges, and other ancillary revenues, in excess of future costs related to servicing arrangements.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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The increase (decrease) in the fair value of servicing assets that are subsequently measured at fair value.

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Value of input used to measure servicing asset.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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