Parent Company Only Financial Statements - Statements of Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income
Interest income	$ 24,291	$ 21,147	$ 19,949
Total interest income	26,698	23,320	21,574
Expenses
Interest expense	3,233	2,049	1,843
Directors’ fees	329	322	240
Miscellaneous	3,398	3,169	3,098
Total noninterest expenses	22,151	20,844	20,925
Income before income taxes	6,881	5,375	4,611
Income tax benefit	746	2,879	937
Net Income	6,135	2,496	3,674
Fauquier Bankshares, Inc [Member]
Income
Interest income	4	4	8
Dividends from subsidiaries	1,813	1,808	901
Total interest income	1,817	1,812	909
Expenses
Interest expense	199	199	200
Legal and professional fees	149	105	112
Directors’ fees	218	212	164
Miscellaneous	288	145	141
Total noninterest expenses	854	661	617
Income before income taxes	963	1,151	292
Income tax benefit	(289)	(229)	(207)
Income before equity in undistributed net income of subsidiaries	1,252	1,380	499
Equity in undistributed net income of subsidiaries	4,883	1,116	3,175
Net Income	$ 6,135	$ 2,496	$ 3,674