Financial Instruments (Schedule of Carrying Amount, Fair Value, and Placement in Fair Value Hierarchy of Company's Financial Instruments, Excluding Financial Instruments, which the Carrying Amount Approximates Fair Value) (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Financial Instruments - Assets
Net Loans	$ 408,793	$ 408,548
Financial Instruments - Liabilities
Time Deposits	166,967	167,355
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Net Loans	406,345	405,876
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Time Deposits	164,626	165,257
Significant Other Observable Inputs (Level 2)
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Net Loans	405,638	405,410
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Time Deposits	164,626	165,257
Significant Unobservable Inputs (Level 3)
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Net Loans	$ 707	$ 466