Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Deferred tax adjustment related to reduction in U.S. federal statutory income tax rate, value		$ 3,009,000	$ 0	$ 0
U.S. statutory federal income tax rate		35.00%	35.00%	35.00%
Unrecognized tax benefit		$ 0	$ 0
Income tax matters accrued interest or penalties		0	0
Expense relate to interest and penalties		$ 0	$ 0	$ 0
Income tax examination, open tax year description		Tax years 2014 through 2016 remain open to federal examination.
Net operating loss carryforward, amount		$ 338,000
Annual limit on utilization of operating loss carryforward		1,455,000
Scenario, Forecast [Member]
Business Acquisition [Line Items]
U.S. statutory federal income tax rate	21.00%
Farmers Citizens Bank [Member]
Business Acquisition [Line Items]
Net operating loss carryforward, amount		$ 6,367,000
Net operating loss carryforward, expiration year		2033