Borrowings (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Borrowings and FHLB Advances [Abstract]
Available federal funds lines	$ 55,000	$ 45,000
Available credit with FHLB	236,300	217,000
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Abstract]
Federal funds purchased	0	10,000
Overnight repurchase agreements	26,048	20,693
FHLB advances	30,000	47,500
Total short-term borrowings	56,048	78,193
Maximum month-end outstanding balance	99,898	79,819
Average outstanding balance during the period	$ 79,960	$ 53,165
Average interest rate (year-to-date)	1.13%	0.72%
Average interest rate at end of period	1.10%	1.27%
FHLB advances outstanding	$ 30,000	$ 20,000
Loan maturity date	Apr. 01, 2023
Loans outstanding	$ 2,900
Interest rate	4.48%
Minimum [Member]
Borrowings and FHLB Advances [Abstract]
Overnight repurchase agreements maturity period	1 day
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Abstract]
FHLB interest rate	1.54%
Maximum [Member]
Borrowings and FHLB Advances [Abstract]
Overnight repurchase agreements maturity period	4 days
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Abstract]
FHLB interest rate	2.77%
Advance One [Member]
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Abstract]
FHLB advance maturity date	Feb. 28, 2019
Advance Two [Member]
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Abstract]
FHLB advance maturity date	Jun. 19, 2020