Income Taxes - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2016 USD ($)
Income Tax [Line Items]
Charitable contribution carryforward	$ 2,468,000
Federal income tax reserve for loan losses	$ 2,033,000
Percentage of tax reserve for loan losses used for purpose other than to absorb losses subject to taxation	150.00%
Deferred income tax liability not been provided	$ 812,000
Federal [Member]
Income Tax [Line Items]
Net operating loss carryforward	7,887,000
Operating Loss Carryforwards Expires on December 31, 2033 [Member] | Federal [Member]
Income Tax [Line Items]
Net operating loss carryforward	$ 4,745,000
Operating loss carryforward expiration date	Dec. 31, 2033
Operating Loss Carryforwards Expires on December 31, 2034 [Member] | Federal [Member]
Income Tax [Line Items]
Net operating loss carryforward	$ 406,000
Operating loss carryforward expiration date	Dec. 31, 2034
Operating Loss Carryforward Expires on December 31, 2035 [Member] | Federal [Member]
Income Tax [Line Items]
Net operating loss carryforward	$ 1,542,000
Operating loss carryforward expiration date	Dec. 31, 2035
Operating Loss Carryforward Expires on December 31, 2036 [Member] | Federal [Member]
Income Tax [Line Items]
Net operating loss carryforward	$ 1,194,000
Operating loss carryforward expiration date	Dec. 31, 2036
Deferred Tax Assets Charitable Contribution Carryforward Expires on December 31, 2021 [Member]
Income Tax [Line Items]
Charitable contribution carryforward	$ 154,000
Charitable contributions carryforward expiration years	Dec. 31, 2021