Parent Company Only Financial Statements - Statements of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash Flows from Operating Activities
Net income	$ 6,135	$ 2,496	$ 3,674
Adjustments to reconcile net income to net cash provided by operating activities:
Issuance of vested restricted stock	90	90	68
Amortization of unearned compensation, net of forfeiture	214	126	207
Increase in other assets	(1,065)	189	2,131
Increase in other liabilities	812	(122)	(405)
Net cash provided by operating activities	7,330	5,833	6,574
Cash Flows from Financing Activities
Repurchase of common stock	(8)	(7)	(55)
Cash dividends paid on common stock	(1,813)	(1,808)	(1,803)
Net cash provided by financing activities	79,714	16,975	19,934
Decrease in cash and cash equivalents	37,810	(38,546)	14,631
Cash and Cash Equivalents
Beginning	29,300	67,846	53,215
Ending	67,110	29,300	67,846
Fauquier Bankshares, Inc [Member]
Cash Flows from Operating Activities
Net income	6,135	2,496	3,674
Adjustments to reconcile net income to net cash provided by operating activities:
Undistributed earnings of subsidiaries	(4,883)	(1,116)	(3,175)
Tax effect of restricted stock awards			42
Issuance of vested restricted stock	90	90	68
Amortization of unearned compensation, net of forfeiture	133	79	170
Increase in other assets	(33)	(8)
Increase in other liabilities	18	6	2
Net cash provided by operating activities	1,460	1,547	781
Cash Flows from Financing Activities
Repurchase of common stock	(8)	(7)	(55)
Cash dividends paid on common stock	(1,813)	(1,808)	(1,803)
Net cash provided by financing activities	(1,821)	(1,815)	(1,858)
Decrease in cash and cash equivalents	(361)	(268)	(1,077)
Cash and Cash Equivalents
Beginning	823	1,091	2,168
Ending	$ 462	$ 823	$ 1,091