Derivatives (Details) - Summary of interest rate swap designated as a cash flow hedges - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Summary of interest rate swap designated as a cash flow hedges [Abstract]
Notional amount	$ 75,000	$ 100,000	$ 75,000
Weighted average pay rates	1.80%	1.79%	1.70%
Weighted average receive rates	2.79%	1.82%	2.19%
Weighted average maturity	1 year 8 months 12 days	2 years 2 months 12 days	2 years
Fair value	$ 768	$ 1,714	$ 1,159