Business Combination - Pro forma (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Unaudited pro forma information
After tax merger related expenses	$ 28	$ 28
After tax merger related expenses per share (in US$ per share)	$ (0.01)	$ (0.01)
Total revenues (net interest income plus nonintererest income)	$ 30,808	$ 59,463
Net income	$ 5,969	$ 10,258
Net income per share, basic and diluted	$ 1.63	$ 2.78