Federal Home Loan Bank Advances (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
FHLB Advances:
Average balance outstanding during the year	$ 89,279	$ 71,940
Maximum amount outstanding at any month-end during the year	104,000	85,000
Balance outstanding at end of year	$ 65,000	$ 85,000
Weighted average interest rate at end of year	1.86%	1.94%
Average cost of advances during the year	1.97%	2.13%
Weighted average contractual maturity (in months)	18 months	13 months
General borrowing limit	30.00%
FHLB advances, remaining amount available to borrow	$ 42,900
Required payments over the next five years
2018	27,500
2019	8,000
2020	29,500
Total	65,000	$ 85,000
First mortgage loans
FHLB Advances:
FHLB advances, collateral real estate loans	$ 128,400	$ 161,100