Fair Values of Financial Instruments - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Related allowance	$ 120	$ 110
Provision for loan losses	$ 464	381
Foreclosed and repossessed assets		13
Real estate, gross		22
Write-downs		9
Discount rate	10.00%
Loans classified as TDRs	$ 239	835
Commitment period to extend credit (or less)	30 days
Standby letters of credit	$ 76	146
Impaired Residential Mortgage Loan Two
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans classified as TDRs	58
Market and Income Approach Valuation Technique
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired financing receivable, recorded investment	1,200	643
Related allowance	120	47
Market and Income Approach Valuation Technique | Impaired Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Provision for loan losses	$ 95	$ 47