Business Combinations - Due Diligence, Merger-related and Merger Integration Costs (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Business Combinations [Abstract]
Advertising	$ 2	$ 19	$ 61	$ 19
Employee Benefits	68	5	271	5
Occupancy and bank premises	289	0	2,145	0
Furniture, fixtures, and equipment	186	6	365	6
Information technology	142	259	254	259
Professional fees	510	542	1,257	938
Salaries and wages	477	320	823	400
Other	1,378	85	2,195	120
Total due diligence, merger-related and merger integration expenses	$ 3,052	$ 1,236	$ 7,371	$ 1,747