Loans and The Allowance for Loan Losses - Summary of Impaired Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Recorded Investment
Recorded Investment, without valuation allowance	$ 8,610	$ 10,823
Recorded Investment, with a valuation allowance	1,538	1,459
Recorded Investment, total	10,148	12,282
Unpaid Principal Balance
Unpaid Principal Balance, without a valuation allowance	9,301	11,880
Unpaid Principal Balance, with a valuation allowance	1,538	1,459
Unpaid Principal Balance, total	10,839	13,339
Related Allowance	52	81
1-4 Family Residential
Recorded Investment
Recorded Investment, with a valuation allowance	1,537	1,448
Unpaid Principal Balance
Unpaid Principal Balance, with a valuation allowance	1,537	1,448
Related Allowance	51	80
Consumer, Excluding Consumer Other Portfolio Segment | 1-4 Family Residential
Recorded Investment
Recorded Investment, without valuation allowance	4,490	4,501
Unpaid Principal Balance
Unpaid Principal Balance, without a valuation allowance	4,886	4,897
Consumer, Excluding Consumer Other Portfolio Segment | Home Equity
Recorded Investment
Recorded Investment, without valuation allowance	1,327	1,387
Unpaid Principal Balance
Unpaid Principal Balance, without a valuation allowance	1,469	1,523
Consumer, Excluding Consumer Other Portfolio Segment | Commercial Real Estate
Recorded Investment
Recorded Investment, without valuation allowance	2,397	4,744
Unpaid Principal Balance
Unpaid Principal Balance, without a valuation allowance	2,500	5,206
Commercial business
Recorded Investment
Recorded Investment, without valuation allowance	305	0
Unpaid Principal Balance
Unpaid Principal Balance, without a valuation allowance	341	11
Consumer
Recorded Investment
Recorded Investment, without valuation allowance	91	191
Recorded Investment, with a valuation allowance	1	11
Unpaid Principal Balance
Unpaid Principal Balance, without a valuation allowance	105	243
Unpaid Principal Balance, with a valuation allowance	1	11
Related Allowance	$ 1	$ 1