Capital Requirements and Restrictions on Retained Earnings - Additional Information (Detail) $ in Thousands	12 Months Ended
Dec. 31, 2015 CapitalCategory Event	Dec. 31, 2016 USD ($)
Securities Financing Transaction [Line Items]
Number of capital categories provided by PCA regulation \| CapitalCategory	5
Number of events resulting in change in Bank's capital category \| Event	0
Scenario, Forecast [Member]
Securities Financing Transaction [Line Items]
Accumulated net earnings \| $		$ 24,216

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://www.xbrl.org/2003/role/presentationRef
-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

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.23(4))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 31
-Article 5

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 24
-Subparagraph a(4)
-Article 7

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant