Derivatives (Details) - Summary of interest rate swap designated as a cash flow hedges - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Summary of interest rate swap designated as a cash flow hedges [Abstract]
Notional amount	$ 100,000	$ 100,000	$ 100,000
Weighted average pay rates	1.68%	1.52%	1.66%
Weighted average receive rates	2.12%	1.07%	1.23%
Weighted average maturity	1 year 8 months 12 days	2 years 8 months 12 days	2 years 4 months 24 days
Fair value	$ 1,906	$ 164	$ 798