Loans and the Allowance for Loan Losses - Additional Information (Details)	3 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2019 USD ($) Loan	Jun. 30, 2019 USD ($) Loan	Dec. 31, 2018 USD ($) Loan
Receivables [Abstract]
Loans outstanding to directors and officers	$ 36,000	$ 36,000	$ 488,000
Loans to directors and officers, additions		67,000	139,000
Loans to directors and officers, repayments		519,000	167,000
Commitments to lend additional funds to borrowers whose loans were on non-accrual status	$ 0	$ 0	$ 0
Number of TDRs defaulted during the period | Loan	0	0	0
Number of loans determined to be troubled debt restructurings | Loan		2	3
Troubled debt restructuring carrying value	$ 105,000	$ 105,000	$ 117,000
Number of loans modified as troubled debt restructuring | Loan	0	0	0
Specific allowances for troubled debt restructurings	$ 0	$ 0	$ 0
Other real estate owned	185,000	185,000
Loans secured by one- to-four family residential properties in process of foreclosure	$ 0	$ 0	$ 351,000