Capital Requirements and Restrictions on Retained Earnings - Additional Information (Detail) $ in Thousands	12 Months Ended
Dec. 31, 2019 USD ($) category event	Dec. 31, 2018	Dec. 31, 2015
Banking and Thrift [Abstract]
Capital conservation buffer phase ratio	2.50%	1.875%	0.00%
Number of capital categories provided by PCA regulation \| category	5
Number of events resulting in change in Bank's capital category \| event	0
Accumulated net earnings \| $	$ 51,612

A segregation of retained earnings which is available for dividend distribution. Earnings not paid out as dividends but instead reinvested in the core business or used to pay off debt. Unappropriated profit is part of shareholder equity. Also called cumulative distributions or earned surplus or accumulated earnings or unappropriated profit.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(23)(a)(4)(ii))
-URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(30)(a)(3)(ii))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Balance Type:	credit
Period Type:	instant