Income Taxes - Net Deferred Tax Asset and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets:
Allowance for loan losses	$ 884	$ 848
Deferred compensation	658	615
Accrued employee benefits	229	227
Loss carryforwards	4,080	4,105
Unrealized loss on available for sale securities	586	292
Premises and equipment	262	274
Other	91	436
Total deferred tax assets	6,790	6,797
Deferred tax liabilities:
Loan fees	136	161
Premises and equipment
Mortgage servicing rights	570	623
FHLB stock dividends	38	42
Total deferred tax liabilities	744	826
Net deferred tax asset	$ 6,046	$ 5,971