Other Real Estate Owned, net - Components of Other Real Estate Owned (OREO) Valuation Allowance (Detail) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Real Estate Owned And Other Repossessed Assets [Line Items]
Valuation adjustments	$ (21)	$ (245)
Valuation Allowance, Other Real Estate Owned
Real Estate Owned And Other Repossessed Assets [Line Items]
Balance, beginning of year	461	473
Valuation adjustments	21	245
Charge-offs	(67)	(257)
Balance, end of year	$ 415	$ 461

Real Estate Owned And Other Repossessed Assets [Line Items]

No definition available.

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- Definition

Amount of increase (decrease) in valuation and qualifying accounts and reserves from adjustment.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SX 210.12-09)
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24092-122690

+ Details

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- Definition

Amount of valuation and qualifying accounts and reserves.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SX 210.12-09)
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24092-122690

+ Details

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- Definition

Amount of decrease in valuation and qualifying accounts and reserves.

+ References

+ Details

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- Details

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