Acquisitions - Operating Cost Savings and Other Business Synergies as Result of Acquisition (Details) - HomeTown Bankshares Corporation Merger - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Total revenues	$ 95,178	$ 98,232
Net income	$ 29,841	$ 27,974
Earnings per share (in dollars per share)	$ 2.70	$ 2.52